Sample records for dual task conditions

  1. Performance Enhancements Under Dual-task Conditions

    NASA Technical Reports Server (NTRS)

    Kramer, A. F.; Wickens, C. D.; Donchin, E.

    1984-01-01

    Research on dual-task performance has been concerned with delineating the antecedent conditions which lead to dual-task decrements. Capacity models of attention, which propose that a hypothetical resource structure underlies performance, have been employed as predictive devices. These models predict that tasks which require different processing resources can be more successfully time shared than tasks which require common resources. The conditions under which such dual-task integrality can be fostered were assessed in a study in which three factors likely to influence the integrality between tasks were manipulated: inter-task redundancy, the physical proximity of tasks and the task relevant objects. Twelve subjects participated in three experimental sessions in which they performed both single and dual-tasks. The primary task was a pursuit step tracking task. The secondary tasks required the discrimination between different intensities or different spatial positions of a stimulus. The results are discussed in terms of a model of dual-task integrality.

  2. Mind wandering in text comprehension under dual-task conditions.

    PubMed

    Dixon, Peter; Li, Henry

    2013-01-01

    In two experiments, subjects responded to on-task probes while reading under dual-task conditions. The secondary task was to monitor the text for occurrences of the letter e. In Experiment 1, reading comprehension was assessed with a multiple-choice recognition test; in Experiment 2, subjects recalled the text. In both experiments, the secondary task replicated the well-known "missing-letter effect" in which detection of e's was less effective for function words and the word "the." Letter detection was also more effective when subjects were on task, but this effect did not interact with the missing-letter effect. Comprehension was assessed in both the dual-task conditions and in control single-task conditions. In the single-task conditions, both recognition (Experiment 1) and recall (Experiment 2) was better when subjects were on task, replicating previous research on mind wandering. Surprisingly, though, comprehension under dual-task conditions only showed an effect of being on task when measured with recall; there was no effect on recognition performance. Our interpretation of this pattern of results is that subjects generate responses to on-task probes on the basis of a retrospective assessment of the contents of working memory. Further, we argue that under dual-task conditions, the contents of working memory is not closely related to the reading processes required for accurate recognition performance. These conclusions have implications for models of text comprehension and for the interpretation of on-task probe responses.

  3. Mind wandering in text comprehension under dual-task conditions

    PubMed Central

    Dixon, Peter; Li, Henry

    2013-01-01

    In two experiments, subjects responded to on-task probes while reading under dual-task conditions. The secondary task was to monitor the text for occurrences of the letter e. In Experiment 1, reading comprehension was assessed with a multiple-choice recognition test; in Experiment 2, subjects recalled the text. In both experiments, the secondary task replicated the well-known “missing-letter effect” in which detection of e's was less effective for function words and the word “the.” Letter detection was also more effective when subjects were on task, but this effect did not interact with the missing-letter effect. Comprehension was assessed in both the dual-task conditions and in control single-task conditions. In the single-task conditions, both recognition (Experiment 1) and recall (Experiment 2) was better when subjects were on task, replicating previous research on mind wandering. Surprisingly, though, comprehension under dual-task conditions only showed an effect of being on task when measured with recall; there was no effect on recognition performance. Our interpretation of this pattern of results is that subjects generate responses to on-task probes on the basis of a retrospective assessment of the contents of working memory. Further, we argue that under dual-task conditions, the contents of working memory is not closely related to the reading processes required for accurate recognition performance. These conclusions have implications for models of text comprehension and for the interpretation of on-task probe responses. PMID:24101909

  4. Discrimination of face gender and expression under dual-task conditions.

    PubMed

    García-Gutiérrez, Ana; Aguado, Luis; Romero-Ferreiro, Verónica; Pérez-Moreno, Elisa

    2017-02-01

    In order to test whether expression and gender can be attended to simultaneously without a cost in accuracy four experiments were carried out using a dual gender-expression task with male and female faces showing different emotional expressions that were backward masked by emotionally neutral faces. In the dual-facial condition the participants had to report both the gender and the expression of the targets. In two control conditions the participant reported either the gender or the expression of the face and indicated whether a surrounding frame was continuous or discontinuous. In Experiments 1-3, with angry and happy targets, asymmetric interference was observed. Gender discrimination, but no expression discrimination, was impaired in the dual-facial condition compared to the corresponding control. This effect was obtained with a between-subjects design in Experiment 1, with a within-subjects design in Experiment 2, and with androgynous face masks in Experiment 3. In Experiments 4a and 4b different target combinations were tested. No decrement of performance in the dual-facial task was observed for either gender or expression discrimination with fearful-disgusted (Experiment 4a) or fearful-happy faces (Experiment 4b). We conclude that the ability to attend simultaneously to gender and expression cues without a decrement in performance depends on the specific combination of expressions to be differentiated between. Happy and angry expressions are usually directed at the perceiver and command preferential attention. Under conditions of restricted viewing such as those of the present study, discrimination of these expressions is prioritized leading to impaired discrimination of other facial properties such as gender.

  5. Transferability of Dual-Task Coordination Skills after Practice with Changing Component Tasks

    PubMed Central

    Schubert, Torsten; Liepelt, Roman; Kübler, Sebastian; Strobach, Tilo

    2017-01-01

    Recent research has demonstrated that dual-task performance with two simultaneously presented tasks can be substantially improved as a result of practice. Among other mechanisms, theories of dual-task practice-relate this improvement to the acquisition of task coordination skills. These skills are assumed (1) to result from dual-task practice, but not from single-task practice, and (2) to be independent from the specific stimulus and response mappings during the practice situation and, therefore, transferable to new dual task situations. The present study is the first that provides an elaborated test of these assumptions in a context with well-controllable practice and transfer situations. To this end, we compared the effects of dual-task and single-task practice with a visual and an auditory sensory-motor component task on the dual-task performance in a subsequent transfer session. Importantly, stimulus and stimulus-response mapping conditions in the two component tasks changed repeatedly during practice sessions, which prevents that automatized stimulus-response associations may be transferred from practice to transfer. Dual-task performance was found to be improved after practice with the dual tasks in contrast to the single-task practice. These findings are consistent with the assumption that coordination skills had been acquired, which can be transferred to other dual-task situations independently on the specific stimulus and response mapping conditions of the practiced component tasks. PMID:28659844

  6. Are factors related to dual-task performance in people with Parkinson's disease dependent on the type of dual task?

    PubMed

    Strouwen, Carolien; Molenaar, Esther A L M; Keus, Samyra H J; Münks, Liesbeth; Heremans, Elke; Vandenberghe, Wim; Bloem, Bastiaan R; Nieuwboer, Alice

    2016-02-01

    Impaired dual-task performance significantly impacts upon functional mobility in people with Parkinson's disease (PD). The aim of this study was to identify determinants of dual-task performance in people with PD in three different dual tasks to assess their possible task-dependency. We recruited 121 home-dwelling patients with PD (mean age 65.93 years; mean disease duration 8.67 years) whom we subjected to regular walking (control condition) and to three dual-task conditions: walking combined with a backwards Digit Span task, an auditory Stroop task and a Mobile Phone task. We measured dual-task gait velocity using the GAITRite mat and dual-task reaction times and errors on the concurrent tasks as outcomes. Motor, cognitive and descriptive variables which correlated to dual-task performance (p < 0.20) were entered into a stepwise forward multiple linear regression model. Single-task gait velocity and executive function, tested by the alternating intake test, was significantly associated with gait velocity during the Digit Span (R(2) = 0.65; p < 0.001), the Stroop (R(2) = 0.73; p < 0.001) and the Mobile Phone task (R(2) = 0.62; p < 0.001). In addition, disease severity proved correlated to gait velocity during the Stroop task. Age was a surplus determinant of gait velocity while using a mobile phone. Single-task gait velocity and executive function as measured by a verbal fluency switching task were independent determinants of dual-task gait performance in people with PD. In contrast to expectation, these factors were the same across different tasks, supporting the robustness of the findings. Future study needs to determine whether these factors predict dual-task abnormalities prospectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Orienting attention in visual working memory requires central capacity: decreased retro-cue effects under dual-task conditions.

    PubMed

    Janczyk, Markus; Berryhill, Marian E

    2014-04-01

    The retro-cue effect (RCE) describes superior working memory performance for validly cued stimulus locations long after encoding has ended. Importantly, this happens with delays beyond the range of iconic memory. In general, the RCE is a stable phenomenon that emerges under varied stimulus configurations and timing parameters. We investigated its susceptibility to dual-task interference to determine the attentional requirements at the time point of cue onset and encoding. In Experiment 1, we compared single- with dual-task conditions. In Experiment 2, we borrowed from the psychological refractory period paradigm and compared conditions with high and low (dual-) task overlap. The secondary task was always binary tone discrimination requiring a manual response. Across both experiments, an RCE was found, but it was diminished in magnitude in the critical dual-task conditions. A previous study did not find evidence that sustained attention is required in the interval between cue offset and test. Our results apparently contradict these findings and point to a critical time period around cue onset and briefly thereafter during which attention is required.

  8. Orienting attention in visual working memory requires central capacity: Decreased retro-cue effects under dual-task conditions

    PubMed Central

    Berryhill, Marian E.

    2014-01-01

    The retro-cue effect (RCE) describes superior working memory performance for validly cued stimulus locations long after encoding has ended. Importantly, this happens with delays beyond the range of iconic memory. In general, the RCE is a stable phenomenon that emerges under varied stimulus configurations and timing parameters. We investigated its susceptibility to dual-task interference to determine the attentional requirements at the time point of cue onset and encoding. In Experiment 1, we compared single- with dual-task conditions. In Experiment 2, we borrowed from the psychological refractory period paradigm and compared conditions with high and low (dual-) task overlap. The secondary task was always binary tone discrimination requiring amanual response. Across both experiments, an RCE was found, but it was diminished in magnitude in the critical dual-task conditions. A previous study did not find evidence that sustained attention is required in the interval between cue offset and test. Our results apparently contradict these findings and point to a critical time period around cue onset and briefly thereafter during which attention is required. PMID:24452383

  9. Biomechanical balance response during induced falls under dual task conditions in people with knee osteoarthritis.

    PubMed

    Levinger, Pazit; Nagano, Hanatsu; Downie, Calum; Hayes, Alan; Sanders, Kerrie M; Cicuttini, Flavia; Begg, Rezaul

    2016-07-01

    People with knee osteoarthritis (OA) are at twice the risk of falling compared to older people without knee OA, however the mechanism for this is poorly understood. This study investigated the biomechanical response of the trunk and lower limb joints during a forward induced fall under different task conditions in people with and without knee OA. Twenty-four participants with OA (68.6±6.2 years) and 15 asymptomatic controls (72.4±4.8 years) participated in the study. Forward fall was induced by releasing participants from a static forward leaning position. Participants were required to recover balance during three conditions: normal, physical (obstacle clearance) and cognitive dual tasks (counting backwards). Spatiotemporal parameters, lower limb joint kinematics and kinetics of the recovery limb were compared between the two groups and across the three task conditions. The OA group demonstrated slower spatio-temporal characteristics and reduced hip and knee flexion angles, joint moments/powers and reduced muscle negative work at the knee and ankle (p<0.05). Cognitive dual task resulted in reduced centre of mass velocity and step length (p=0.03) compared to the physical dual task condition. Reduced knee (p=0.02) and hip joint powers (p=0.03) were demonstrated in the OA group in the physical task condition. When simulating a forward fall, participants with OA demonstrated difficulty in absorbing the impact and slowing down the forward momentum of the body during a recovery step. Moreover, poor dynamic postural control was demonstrated as task complexity increased. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Changes in Standing and Walking Performance Under Dual-Task Conditions Across the Lifespan.

    PubMed

    Ruffieux, Jan; Keller, Martin; Lauber, Benedikt; Taube, Wolfgang

    2015-12-01

    Simultaneous performance of a postural and a concurrent task is rather unproblematic as long as the postural task is executed in an automatic way. However, in situations where postural control requires more central processing, cognitive resources may be exceeded by the addition of an attentionally demanding task. This may lead to interference between the two tasks, manifested in a decreased performance in one or both tasks (dual-task costs). Owing to changes in attentional demands of postural tasks as well as processing capacities across the lifespan, it might be assumed that dual-task costs are particularly pronounced in children and older adults probably leading to a U-shaped pattern for dual-task costs as a function of age. However, these changes in the ability of dual-tasking posture from childhood to old age have not yet been systematically reviewed. Therefore, Web of Science and PubMed databases were searched for studies comparing dual-task performance with one task being standing or walking in healthy groups of young adults and either children or older adults. Seventy-nine studies met inclusion criteria. For older adults, the expected increase in dual-task costs could be confirmed. In contrast, in children there was only feeble evidence for a trend towards enlarged dual-task costs. More good-quality studies comparing dual-task ability in children, young, and, ideally, also older adults within the same paradigm are needed to draw unambiguous conclusions about lifespan development of dual-task performance in postural tasks. There is evidence that, in older adults, dual-task performance can be improved by training. For the other age groups, these effects have yet to be investigated.

  11. Standing balance in individuals with Parkinson's disease during single and dual-task conditions.

    PubMed

    Fernandes, Ângela; Coelho, Tiago; Vitória, Ana; Ferreira, Augusto; Santos, Rubim; Rocha, Nuno; Fernandes, Lia; Tavares, João Manuel R S

    2015-09-01

    This study aimed to examine the differences in standing balance between individuals with Parkinson's disease (PD) and subjects without PD (control group), under single and dual-task conditions. A cross-sectional study was designed using a non-probabilistic sample of 110 individuals (50 participants with PD and 60 controls) aged 50 years old and over. The individuals with PD were in the early or middle stages of the disease (characterized by Hoehn and Yahr as stages 1-3). The standing balance was assessed by measuring the centre of pressure (CoP) displacement in single-task (eyes-open/eyes-closed) and dual-task (while performing two different verbal fluency tasks). No significant differences were found between the groups regarding sociodemographic variables. In general, the standing balance of the individuals with PD was worse than the controls, as the CoP displacement across tasks was significantly higher for the individuals with PD (p<0.01), both in anteroposterior and mediolateral directions. Moreover, there were significant differences in the CoP displacement based parameters between the conditions, mainly between the eyes-open condition and the remaining conditions. However, there was no significant interaction found between group and condition, which suggests that changes in the CoP displacement between tasks were not influenced by having PD. In conclusion, this study shows that, although individuals with PD had a worse overall standing balance than individuals without the disease, the impact of performing an additional task on the CoP displacement is similar for both groups. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Does the walking task matter? Influence of different walking conditions on dual-task performances in young and older persons.

    PubMed

    Beurskens, Rainer; Bock, Otmar

    2013-12-01

    Previous literature suggests that age-related deficits of dual-task walking are particularly pronounced with second tasks that require continuous visual processing. Here we evaluate whether the difficulty of the walking task matters as well. To this end, participants were asked to walk along a straight pathway of 20m length in four different walking conditions: (a) wide path and preferred pace; (b) narrow path and preferred pace, (c) wide path and fast pace, (d) obstacled wide path and preferred pace. Each condition was performed concurrently with a task requiring visual processing or fine motor control, and all tasks were also performed alone which allowed us to calculate the dual-task costs (DTC). Results showed that the age-related increase of DTC is substantially larger with the visually demanding than with the motor-demanding task, more so when walking on a narrow or obstacled path. We attribute these observations to the fact that visual scanning of the environment becomes more crucial when walking in difficult terrains: the higher visual demand of those conditions accentuates the age-related deficits in coordinating them with a visual non-walking task. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

    PubMed

    Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau

    2017-06-22

    This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.

  14. Balancing the Demands of Two Tasks: An Investigation of Cognitive-Motor Dual-Tasking in Relapsing Remitting Multiple Sclerosis.

    PubMed

    Butchard-MacDonald, Emma; Paul, Lorna; Evans, Jonathan J

    2018-03-01

    People with relapsing remitting multiple sclerosis (PwRRMS) suffer disproportionate decrements in gait under dual-task conditions, when walking and a cognitive task are combined. There has been much less investigation of the impact of cognitive demands on balance. This study investigated whether: (1) PwRRMS show disproportionate decrements in postural stability under dual-task conditions compared to healthy controls, and (2) dual-task decrements are associated with everyday dual-tasking difficulties. The impact of mood, fatigue, and disease severity on dual-tasking was also examined. A total of 34 PwRRMS and 34 matched controls completed cognitive (digit span) and balance (movement of center of pressure on Biosway on stable and unstable surfaces) tasks under single- and dual-task conditions. Everyday dual-tasking was measured using the Dual-Tasking Questionnaire. Mood was measured by the Hospital Anxiety & Depression Scale. Fatigue was measured via the Modified Fatigue Index Scale. No differences in age, gender, years of education, estimated pre-morbid IQ, or baseline digit span between groups. Compared with controls, PwRRMS showed significantly greater decrement in postural stability under dual-task conditions on an unstable surface (p=.007), but not a stable surface (p=.679). Balance decrement scores were not correlated with everyday dual-tasking difficulties or fatigue. Stable surface balance decrement scores were significantly associated with levels of anxiety (rho=0.527; p=.001) and depression (rho=0.451; p=.007). RRMS causes dual-tasking difficulties, impacting balance under challenging conditions, which may contribute to increased risk of gait difficulties and falls. The relationship between anxiety/depression and dual-task decrement suggests that emotional factors may be contributing to dual-task difficulties. (JINS, 2018, 24, 247-258).

  15. Aging and the Vulnerability of Speech to Dual Task Demands

    PubMed Central

    Kemper, Susan; Schmalzried, RaLynn; Hoffman, Lesa; Herman, Ruth

    2010-01-01

    Tracking a digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. Tracking performance by both groups was affected by dual task demands: time on target declined and tracking error increased as dual task demands increased from the baseline condition to a moderately demanding dual task condition to a more demanding dual task condition. When dual task demands were moderate, older adults’ speech rate declined but their fluency, grammatical complexity, and content were unaffected. When the dual task was more demanding, older adults’ speech, like young adults’ speech, became highly fragmented, ungrammatical, and incoherent. Vocabulary, working memory, processing speed, and inhibition affected vulnerability to dual task costs: vocabulary provided some protection for sentence length and grammaticality, working memory conferred some protection for grammatical complexity, and processing speed provided some protection for speech rate, propositional density, coherence, and lexical diversity. Further, vocabulary and working memory capacity provided more protection for older adults than for young adults although the protective effect of processing speed was somewhat reduced for older adults as compared to the young adults. PMID:21186917

  16. Task Prioritization in Dual-Tasking: Instructions versus Preferences

    PubMed Central

    Jansen, Reinier J.; van Egmond, René; de Ridder, Huib

    2016-01-01

    The role of task prioritization in performance tradeoffs during multi-tasking has received widespread attention. However, little is known on whether people have preferences regarding tasks, and if so, whether these preferences conflict with priority instructions. Three experiments were conducted with a high-speed driving game and an auditory memory task. In Experiment 1, participants did not receive priority instructions. Participants performed different sequences of single-task and dual-task conditions. Task performance was evaluated according to participants’ retrospective accounts on preferences. These preferences were reformulated as priority instructions in Experiments 2 and 3. The results showed that people differ in their preferences regarding task prioritization in an experimental setting, which can be overruled by priority instructions, but only after increased dual-task exposure. Additional measures of mental effort showed that performance tradeoffs had an impact on mental effort. The interpretation of these findings was used to explore an extension of Threaded Cognition Theory with Hockey’s Compensatory Control Model. PMID:27391779

  17. Fear of falling is associated with prolonged anticipatory postural adjustment during gait initiation under dual-task conditions in older adults.

    PubMed

    Uemura, Kazuki; Yamada, Minoru; Nagai, Koutatsu; Tanaka, Buichi; Mori, Shuhei; Ichihashi, Noriaki

    2012-02-01

    Little is known about dynamic balance control under dual-task conditions in older adults with fear of falling (FoF). The purpose of this study was to examine the effect of FoF on anticipatory postural adjustment (APA) during gait initiation under dual-task conditions in older adults. Fifty-seven elderly volunteers (age, 79.2 [6.8] years) from the community participated in this study. Each participant was categorised into either the Fear (n=24) or No-fear (n=33) group on the basis of the presence or absence of FoF. Under single- and dual-task conditions, centre of pressure (COP) data were collected while the participants performed gait initiation trials from a starting position on a force platform. We also performed a 10-m walking test (WT), a timed up & go test (TUG), and a functional reach test (FR). The reaction and APA phases were measured from the COP data. The results showed that under the dual-task condition, the Fear group had significantly longer APA phases than the No-fear group, although no significant differences were observed between the 2 groups in the reaction and APA phases under the single-task condition and in any clinical measurements (WT, TUG, and FR). Our findings suggest that specific deficits in balance control occur in subjects with FoF during gait initiation while dual tasking, even if their physical functions are comparable to subjects without FoF. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Motor-cognitive dual-task performance: effects of a concurrent motor task on distinct components of visual processing capacity.

    PubMed

    Künstler, E C S; Finke, K; Günther, A; Klingner, C; Witte, O; Bublak, P

    2018-01-01

    Dual tasking, or the simultaneous execution of two continuous tasks, is frequently associated with a performance decline that can be explained within a capacity sharing framework. In this study, we assessed the effects of a concurrent motor task on the efficiency of visual information uptake based on the 'theory of visual attention' (TVA). TVA provides parameter estimates reflecting distinct components of visual processing capacity: perceptual threshold, visual processing speed, and visual short-term memory (VSTM) storage capacity. Moreover, goodness-of-fit values and bootstrapping estimates were derived to test whether the TVA-model is validly applicable also under dual task conditions, and whether the robustness of parameter estimates is comparable in single- and dual-task conditions. 24 subjects of middle to higher age performed a continuous tapping task, and a visual processing task (whole report of briefly presented letter arrays) under both single- and dual-task conditions. Results suggest a decline of both visual processing capacity and VSTM storage capacity under dual-task conditions, while the perceptual threshold remained unaffected by a concurrent motor task. In addition, goodness-of-fit values and bootstrapping estimates support the notion that participants processed the visual task in a qualitatively comparable, although quantitatively less efficient way under dual-task conditions. The results support a capacity sharing account of motor-cognitive dual tasking and suggest that even performing a relatively simple motor task relies on central attentional capacity that is necessary for efficient visual information uptake.

  19. Age-related decrements in dual-task performance: Comparison of different mobility and cognitive tasks. A cross sectional study.

    PubMed

    Brustio, Paolo Riccardo; Magistro, Daniele; Zecca, Massimiliano; Rabaglietti, Emanuela; Liubicich, Monica Emma

    2017-01-01

    This cross-sectional study investigated the age-related differences in dual-task performance both in mobility and cognitive tasks and the additive dual-task costs in a sample of older, middle-aged and young adults. 74 older adults (M = 72.63±5.57 years), 58 middle-aged adults (M = 46.69±4.68 years) and 63 young adults (M = 25.34±3.00 years) participated in the study. Participants performed different mobility and subtraction tasks under both single- and dual-task conditions. Linear regressions, repeated-measures and one-way analyses of covariance were used, The results showed: significant effects of the age on the dual and mobility tasks (p<0.05) and differences among the age-groups in the combined dual-task costs (p<0.05); significant decreases in mobility performance under dual-task conditions in all groups (p<0.05) and a decrease in cognitive performance in the older group (p<0.05). Dual-task activity affected mobility and cognitive performance, especially in older adults who showed a higher dual-task cost, suggesting that dual-tasks activities are affected by the age and consequently also mobility and cognitive tasks are negatively influenced.

  20. Age-related decrements in dual-task performance: Comparison of different mobility and cognitive tasks. A cross sectional study

    PubMed Central

    Brustio, Paolo Riccardo; Zecca, Massimiliano; Rabaglietti, Emanuela; Liubicich, Monica Emma

    2017-01-01

    This cross-sectional study investigated the age-related differences in dual-task performance both in mobility and cognitive tasks and the additive dual-task costs in a sample of older, middle-aged and young adults. 74 older adults (M = 72.63±5.57 years), 58 middle-aged adults (M = 46.69±4.68 years) and 63 young adults (M = 25.34±3.00 years) participated in the study. Participants performed different mobility and subtraction tasks under both single- and dual-task conditions. Linear regressions, repeated-measures and one-way analyses of covariance were used, The results showed: significant effects of the age on the dual and mobility tasks (p<0.05) and differences among the age-groups in the combined dual-task costs (p<0.05); significant decreases in mobility performance under dual-task conditions in all groups (p<0.05) and a decrease in cognitive performance in the older group (p<0.05). Dual-task activity affected mobility and cognitive performance, especially in older adults who showed a higher dual-task cost, suggesting that dual-tasks activities are affected by the age and consequently also mobility and cognitive tasks are negatively influenced. PMID:28732080

  1. Testing the Limits of Optimizing Dual-Task Performance in Younger and Older Adults

    PubMed Central

    Strobach, Tilo; Frensch, Peter; Müller, Herrmann Josef; Schubert, Torsten

    2012-01-01

    Impaired dual-task performance in younger and older adults can be improved with practice. Optimal conditions even allow for a (near) elimination of this impairment in younger adults. However, it is unknown whether such (near) elimination is the limit of performance improvements in older adults. The present study tests this limit in older adults under conditions of (a) a high amount of dual-task training and (b) training with simplified component tasks in dual-task situations. The data showed that a high amount of dual-task training in older adults provided no evidence for an improvement of dual-task performance to the optimal dual-task performance level achieved by younger adults. However, training with simplified component tasks in dual-task situations exclusively in older adults provided a similar level of optimal dual-task performance in both age groups. Therefore through applying a testing the limits approach, we demonstrated that older adults improved dual-task performance to the same level as younger adults at the end of training under very specific conditions. PMID:22408613

  2. Implicit and Explicit Knowledge Both Improve Dual Task Performance in a Continuous Pursuit Tracking Task.

    PubMed

    Ewolds, Harald E; Bröker, Laura; de Oliveira, Rita F; Raab, Markus; Künzell, Stefan

    2017-01-01

    The goal of this study was to investigate the effect of predictability on dual-task performance in a continuous tracking task. Participants practiced either informed (explicit group) or uninformed (implicit group) about a repeated segment in the curves they had to track. In Experiment 1 participants practices the tracking task only, dual-task performance was assessed after by combining the tracking task with an auditory reaction time task. Results showed both groups learned equally well and tracking performance on a predictable segment in the dual-task condition was better than on random segments. However, reaction times did not benefit from a predictable tracking segment. To investigate the effect of learning under dual-task situation participants in Experiment 2 practiced the tracking task while simultaneously performing the auditory reaction time task. No learning of the repeated segment could be demonstrated for either group during the training blocks, in contrast to the test-block and retention test, where participants performed better on the repeated segment in both dual-task and single-task conditions. Only the explicit group improved from test-block to retention test. As in Experiment 1, reaction times while tracking a predictable segment were no better than reaction times while tracking a random segment. We concluded that predictability has a positive effect only on the predictable task itself possibly because of a task-shielding mechanism. For dual-task training there seems to be an initial negative effect of explicit instructions, possibly because of fatigue, but the advantage of explicit instructions was demonstrated in a retention test. This might be due to the explicit memory system informing or aiding the implicit memory system.

  3. Implicit and Explicit Knowledge Both Improve Dual Task Performance in a Continuous Pursuit Tracking Task

    PubMed Central

    Ewolds, Harald E.; Bröker, Laura; de Oliveira, Rita F.; Raab, Markus; Künzell, Stefan

    2017-01-01

    The goal of this study was to investigate the effect of predictability on dual-task performance in a continuous tracking task. Participants practiced either informed (explicit group) or uninformed (implicit group) about a repeated segment in the curves they had to track. In Experiment 1 participants practices the tracking task only, dual-task performance was assessed after by combining the tracking task with an auditory reaction time task. Results showed both groups learned equally well and tracking performance on a predictable segment in the dual-task condition was better than on random segments. However, reaction times did not benefit from a predictable tracking segment. To investigate the effect of learning under dual-task situation participants in Experiment 2 practiced the tracking task while simultaneously performing the auditory reaction time task. No learning of the repeated segment could be demonstrated for either group during the training blocks, in contrast to the test-block and retention test, where participants performed better on the repeated segment in both dual-task and single-task conditions. Only the explicit group improved from test-block to retention test. As in Experiment 1, reaction times while tracking a predictable segment were no better than reaction times while tracking a random segment. We concluded that predictability has a positive effect only on the predictable task itself possibly because of a task-shielding mechanism. For dual-task training there seems to be an initial negative effect of explicit instructions, possibly because of fatigue, but the advantage of explicit instructions was demonstrated in a retention test. This might be due to the explicit memory system informing or aiding the implicit memory system. PMID:29312083

  4. The Applicability of Rhythm-Motor Tasks to a New Dual Task Paradigm for Older Adults

    PubMed Central

    Kim, Soo Ji; Cho, Sung-Rae; Yoo, Ga Eul

    2017-01-01

    Given the interplay between cognitive and motor functions during walking, cognitive demands required during gait have been investigated with regard to dual task performance. Along with the needs to understand how the type of concurrent task while walking affects gait performance, there are calls for diversified dual tasks that can be applied to older adults with varying levels of cognitive decline. Therefore, this study aimed to examine how rhythm-motor tasks affect dual task performance and gait control, compared to a traditional cognitive-motor task. Also, it examined whether rhythm-motor tasks are correlated with traditional cognitive-motor task performance and cognitive measures. Eighteen older adults without cognitive impairment participated in this study. Each participant was instructed to walk at self-paced tempo without performing a concurrent task (single walking task) and walk while separately performing two types of concurrent tasks: rhythm-motor and cognitive-motor tasks. Rhythm-motor tasks included instrument playing (WalkIP), matching to rhythmic cueing (WalkRC), and instrument playing while matching to rhythmic cueing (WalkIP+RC). The cognitive-motor task involved counting forward by 3s (WalkCount.f3). In each condition, dual task costs (DTC), a measure for how dual tasks affect gait parameters, were measured in terms of walking speed and stride length. The ratio of stride length to walking speed, a measure for dynamic control of gait, was also examined. The results of this study demonstrated that the task type was found to significantly influence these measures. Rhythm-motor tasks were found to interfere with gait parameters to a lesser extent than the cognitive-motor task (WalkCount.f3). In terms of ratio measures, stride length remained at a similar level, walking speed greatly decreased in the WalkCount.f3 condition. Significant correlations between dual task-related measures during rhythm-motor and cognitive-motor tasks support the potential of

  5. A new semantic vigilance task: vigilance decrement, workload, and sensitivity to dual-task costs.

    PubMed

    Epling, Samantha L; Russell, Paul N; Helton, William S

    2016-01-01

    Cognitive resource theory is a common explanation for both the performance decline in vigilance tasks, known as the vigilance decrement, and the limited ability to perform multiple tasks simultaneously. The limited supply of cognitive resources may be utilized faster than they are replenished resulting in a performance decrement, or may need to be allocated among multiple tasks with some performance cost. Researchers have proposed both domain-specific, for example spatial versus verbal processing resources, and domain general cognitive resources. One challenge in testing the domain specificity of cognitive resources in vigilance is the current lack of difficult semantic vigilance tasks which reliably produce a decrement. In the present research, we investigated whether the vigilance decrement was found in a new abbreviated semantic discrimination vigilance task, and whether there was a performance decrement in said vigilance task when paired with a word recall task, as opposed to performed individually. As hypothesized, a vigilance decrement in the semantic vigilance task was found in both the single-task and dual-task conditions, along with reduced vigilance performance in the dual-task condition and reduced word recall in the dual-task condition. This is consistent with cognitive resource theory. The abbreviated semantic vigilance task will be a useful tool for researchers interested in determining the specificity of cognitive resources utilized in vigilance tasks.

  6. Dual task cost of walking is related to fall risk in persons with multiple sclerosis.

    PubMed

    Wajda, Douglas A; Motl, Robert W; Sosnoff, Jacob J

    2013-12-15

    Persons with multiple sclerosis (MS) commonly have walking and cognitive impairments. While walking with a simultaneous cognitive task, persons with MS experience a greater decline in walking performance than healthy controls. This change in performance is termed dual task cost or dual task interference and has been associated with fall risk in older adults. We examined whether dual task cost during walking was related to fall risk in persons with MS. Thirty-three ambulatory persons with MS performed walking tasks with and without a concurrent cognitive task (dual task condition) as well as underwent a fall risk assessment. Dual task cost was operationalized as the percent change in velocity from normal walking conditions to dual task walking conditions. Fall risk was quantified using the Physiological Profile Assessment. A Spearman correlation analysis revealed a significant positive correlation between dual task cost of walking velocity and fall risk as well as dual task cost of stride length and fall risk. Overall, the findings indicate that dual task cost is associated with fall risk and may be an important target for falls prevention strategies. © 2013.

  7. Measuring listening effort: driving simulator vs. simple dual-task paradigm

    PubMed Central

    Wu, Yu-Hsiang; Aksan, Nazan; Rizzo, Matthew; Stangl, Elizabeth; Zhang, Xuyang; Bentler, Ruth

    2014-01-01

    Objectives The dual-task paradigm has been widely used to measure listening effort. The primary objectives of the study were to (1) investigate the effect of hearing aid amplification and a hearing aid directional technology on listening effort measured by a complicated, more real world dual-task paradigm, and (2) compare the results obtained with this paradigm to a simpler laboratory-style dual-task paradigm. Design The listening effort of adults with hearing impairment was measured using two dual-task paradigms, wherein participants performed a speech recognition task simultaneously with either a driving task in a simulator or a visual reaction-time task in a sound-treated booth. The speech materials and road noises for the speech recognition task were recorded in a van traveling on the highway in three hearing aid conditions: unaided, aided with omni directional processing (OMNI), and aided with directional processing (DIR). The change in the driving task or the visual reaction-time task performance across the conditions quantified the change in listening effort. Results Compared to the driving-only condition, driving performance declined significantly with the addition of the speech recognition task. Although the speech recognition score was higher in the OMNI and DIR conditions than in the unaided condition, driving performance was similar across these three conditions, suggesting that listening effort was not affected by amplification and directional processing. Results from the simple dual-task paradigm showed a similar trend: hearing aid technologies improved speech recognition performance, but did not affect performance in the visual reaction-time task (i.e., reduce listening effort). The correlation between listening effort measured using the driving paradigm and the visual reaction-time task paradigm was significant. The finding showing that our older (56 to 85 years old) participants’ better speech recognition performance did not result in reduced

  8. The functional neuroanatomy of multitasking: combining dual tasking with a short term memory task.

    PubMed

    Deprez, Sabine; Vandenbulcke, Mathieu; Peeters, Ron; Emsell, Louise; Amant, Frederic; Sunaert, Stefan

    2013-09-01

    Insight into the neural architecture of multitasking is crucial when investigating the pathophysiology of multitasking deficits in clinical populations. Presently, little is known about how the brain combines dual-tasking with a concurrent short-term memory task, despite the relevance of this mental operation in daily life and the frequency of complaints related to this process, in disease. In this study we aimed to examine how the brain responds when a memory task is added to dual-tasking. Thirty-three right-handed healthy volunteers (20 females, mean age 39.9 ± 5.8) were examined with functional brain imaging (fMRI). The paradigm consisted of two cross-modal single tasks (a visual and auditory temporal same-different task with short delay), a dual-task combining both single tasks simultaneously and a multi-task condition, combining the dual-task with an additional short-term memory task (temporal same-different visual task with long delay). Dual-tasking compared to both individual visual and auditory single tasks activated a predominantly right-sided fronto-parietal network and the cerebellum. When adding the additional short-term memory task, a larger and more bilateral frontoparietal network was recruited. We found enhanced activity during multitasking in components of the network that were already involved in dual-tasking, suggesting increased working memory demands, as well as recruitment of multitask-specific components including areas that are likely to be involved in online holding of visual stimuli in short-term memory such as occipito-temporal cortex. These results confirm concurrent neural processing of a visual short-term memory task during dual-tasking and provide evidence for an effective fMRI multitasking paradigm. © 2013 Elsevier Ltd. All rights reserved.

  9. Working Memory Training Improves Dual-Task Performance on Motor Tasks.

    PubMed

    Kimura, Takehide; Kaneko, Fuminari; Nagahata, Keita; Shibata, Eriko; Aoki, Nobuhiro

    2017-01-01

    The authors investigated whether working memory training improves motor-motor dual-task performance consisted of upper and lower limb tasks. The upper limb task was a simple reaction task and the lower limb task was an isometric knee extension task. 45 participants (age = 21.8 ± 1.6 years) were classified into a working memory training group (WM-TRG), dual-task training group, or control group. The training duration was 2 weeks (15 min, 4 times/week). Our results indicated that working memory capacity increased significantly only in the WM-TRG. Dual-task performance improved in the WM-TRG and dual-task training group. Our study provides the novel insight that working memory training improves dual-task performance without specific training on the target motor task.

  10. The effects of dual tasking on handwriting in patients with Parkinson's disease.

    PubMed

    Broeder, S; Nackaerts, E; Nieuwboer, A; Smits-Engelsman, B C M; Swinnen, S P; Heremans, E

    2014-03-28

    Previous studies have shown that patients with Parkinson's disease (PD) experience extensive problems during dual tasking. Up to now, dual-task interference in PD has mainly been investigated in the context of gait research. However, the simultaneous performance of two different tasks is also a prerequisite to efficiently perform many other tasks in daily life, including upper limb tasks. To address this issue, this study investigated the effect of a secondary cognitive task on the performance of handwriting in patients with PD. Eighteen PD patients and 11 age-matched controls performed a writing task involving the production of repetitive loops under single- and dual-task conditions. The secondary task consisted of counting high and low tones during writing. The writing tests were performed with two amplitudes (0.6 and 1.0cm) using a writing tablet. Results showed that dual-task performance was affected in PD patients versus controls. Dual tasking reduced writing amplitude in PD patients, but not in healthy controls (p=0.046). Patients' writing size was mainly reduced during the small-amplitude condition (small amplitude p=0.017; large amplitude p=0.310). This suggests that the control of writing at small amplitudes requires more compensational brain-processing recourses in PD and is as such less automatic than writing at large amplitudes. In addition, there was a larger dual-task effect on the secondary task in PD patients than controls (p=0.025). The writing tests on the writing tablet proved highly correlated to daily life writing as measured by the 'Systematic Screening of Handwriting Difficulties' test (SOS-test) and other manual dexterity tasks, particularly during dual-task conditions. Taken together, these results provide additional insights into the motor control of handwriting and the effects of dual tasking during upper limb movements in patients with PD. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Different motor tasks impact differently on cognitive performance of older persons during dual task tests.

    PubMed

    Simoni, David; Rubbieri, Gaia; Baccini, Marco; Rinaldi, Lucio; Becheri, Dimitri; Forconi, Tatiana; Mossello, Enrico; Zanieri, Samanta; Marchionni, Niccolò; Di Bari, Mauro

    2013-07-01

    Dual task paradigm states that the introduction of a second task during a cognitive or motor performance results in a decreased performance in either task. Treadmill walk, often used in clinical applications of dual task testing, has never been compared to overground walk, to ascertain its susceptibility to interference from a second task. We compared the effects of overground and treadmill gait on dual task performance. Gait kinematic parameters and cognitive performance were obtained in 29 healthy older adults (mean age 75 years, 14 females) when they were walking freely on a sensorized carpet or during treadmill walking with an optoelectronic system, in single task or dual task conditions, using alternate repetition of letters as a cognitive verbal task. During overground walking, speed, cadence, step length stride length, and double support time (all with P value<0.001) and cognitive performance (number of correct words, P<0.001) decreased substantially from single to dual task testing. When subjects walked at a fixed speed on the treadmill, cadence decreased significantly (P=0.005), whereas cognitive performance remained unaffected. Both motor and cognitive performances decline during dual task testing with overground walking. Conversely, cognitive performance remains unaffected in dual task testing on the treadmill. In the light of current dual task paradigm, these findings may have relevant implication for our understanding of motor control, as they suggest that treadmill walk does not involve brain areas susceptible to interference from the introduction of a cognitive task. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Mechanisms of Practice-Related Reductions of Dual-Task Interference with Simple Tasks: Data and Theory

    PubMed Central

    Strobach, Tilo; Torsten, Schubert

    2017-01-01

    In dual-task situations, interference between two simultaneous tasks impairs performance. With practice, however, this impairment can be reduced. To identify mechanisms leading to a practice-related improvement in sensorimotor dual tasks, the present review applied the following general hypothesis: Sources that impair dual-task performance at the beginning of practice are associated with mechanisms for the reduction of dual-task impairment at the end of practice. The following types of processes provide sources for the occurrence of this impairment: (a) capacity-limited processes within the component tasks, such as response-selection or motor response stages, and (b) cognitive control processes independent of these tasks and thus operating outside of component-task performance. Dual-task practice studies show that, under very specific conditions, capacity-limited processes within the component tasks are automatized with practice, reducing the interference between two simultaneous tasks. Further, there is evidence that response-selection stages are shortened with practice. Thus, capacity limitations at these stages are sources for dual-task costs at the beginning of practice and are overcome with practice. However, there is no evidence demonstrating the existence of practice-related mechanisms associated with capacity-limited motor-response stages. Further, during practice, there is an acquisition of executive control skills for an improved allocation of limited attention resources to two tasks as well as some evidence supporting the assumption of improved task coordination. These latter mechanisms are associated with sources of dual-task interference operating outside of component task performance at the beginning of practice and also contribute to the reduction of dual-task interference at its end. PMID:28439319

  13. Persistency and flexibility of complex brain networks underlie dual-task interference.

    PubMed

    Alavash, Mohsen; Hilgetag, Claus C; Thiel, Christiane M; Gießing, Carsten

    2015-09-01

    Previous studies on multitasking suggest that performance decline during concurrent task processing arises from interfering brain modules. Here, we used graph-theoretical network analysis to define functional brain modules and relate the modular organization of complex brain networks to behavioral dual-task costs. Based on resting-state and task fMRI we explored two organizational aspects potentially associated with behavioral interference when human subjects performed a visuospatial and speech task simultaneously: the topological overlap between persistent single-task modules, and the flexibility of single-task modules in adaptation to the dual-task condition. Participants showed a significant decline in visuospatial accuracy in the dual-task compared with single visuospatial task. Global analysis of topological similarity between modules revealed that the overlap between single-task modules significantly correlated with the decline in visuospatial accuracy. Subjects with larger overlap between single-task modules showed higher behavioral interference. Furthermore, lower flexible reconfiguration of single-task modules in adaptation to the dual-task condition significantly correlated with larger decline in visuospatial accuracy. Subjects with lower modular flexibility showed higher behavioral interference. At the regional level, higher overlap between single-task modules and less modular flexibility in the somatomotor cortex positively correlated with the decline in visuospatial accuracy. Additionally, higher modular flexibility in cingulate and frontal control areas and lower flexibility in right-lateralized nodes comprising the middle occipital and superior temporal gyri supported dual-tasking. Our results suggest that persistency and flexibility of brain modules are important determinants of dual-task costs. We conclude that efficient dual-tasking benefits from a specific balance between flexibility and rigidity of functional brain modules. © 2015 Wiley

  14. Longitudinal effects of bilingualism on dual-tasking

    PubMed Central

    Josefsson, Maria; Marsh, John E.; Hansson, Patrik; Ljungberg, Jessica K.

    2017-01-01

    An ongoing debate surrounds whether bilinguals outperform monolinguals in tests of executive processing. The aim of this study was to investigate if there are long-term (10 year) bilingual advantages in executive processing, as indexed by dual-task performance, in a sample that were 40–65 years at baseline. The bilingual (n = 24) and monolingual (n = 24) participants were matched on age, sex, education, fluid intelligence, and study sample. Participants performed free-recall for a 12-item list in three dual-task settings wherein they sorted cards either during encoding, retrieval, or during both encoding and retrieval of the word-list. Free recall without card sorting was used as a reference to compute dual-task costs. The results showed that bilinguals significantly outperformed monolinguals when they performed card-sorting during both encoding and retrieval of the word-list, the condition that presumably placed the highest demands on executive functioning. However, dual-task costs increased over time for bilinguals relative to monolinguals, a finding that is possibly influenced by retirement age and limited use of second language in the bilingual group. PMID:29281654

  15. The neural architecture of age-related dual-task interferences.

    PubMed

    Chmielewski, Witold X; Yildiz, Ali; Beste, Christian

    2014-01-01

    In daily life elderly adults exhibit deficits when dual-tasking is involved. So far these deficits have been verified on a behavioral level in dual-tasking. Yet, the neuronal architecture of these deficits in aging still remains to be explored especially when late-middle aged individuals around 60 years of age are concerned. Neuroimaging studies in young participants concerning dual-tasking were, among others, related to activity in middle frontal (MFG) and superior frontal gyrus (SFG) and the anterior insula (AI). According to the frontal lobe hypothesis of aging, alterations in these frontal regions (i.e., SFG and MFG) might be responsible for cognitive deficits. We measured brain activity using fMRI, while examining age-dependent variations in dual-tasking by utilizing the PRP (psychological refractory period) test. Behavioral data showed an increasing PRP effect in late-middle aged adults. The results suggest the age-related deteriorated performance in dual-tasking, especially in conditions of risen complexity. These effects are related to changes in networks involving the AI, the SFG and the MFG. The results suggest that different cognitive subprocesses are affected that mediate the observed dual-tasking problems in late-middle aged individuals.

  16. Dual-task performance involving hand dexterity and cognitive tasks and daily functioning in people with schizophrenia: a pilot study.

    PubMed

    Lin, Keh-chung; Wu, Yi-fang; Chen, I-chen; Tsai, Pei-luen; Wu, Ching-yi; Chen, Chia-ling

    2015-01-01

    This study investigated separate and concurrent performance on cognitive and hand dexterity tasks and the relationship to daily functioning in 16 people with schizophrenia and 16 healthy control participants. Participants performed the Purdue Pegboard Test and the Serial Seven Subtraction Test under single- and dual-task conditions and completed two daily functioning evaluations. The hand dexterity of all participants declined in the dual-task condition, but the discrepancy between single-task and dual-task hand dexterity was greater in the schizophrenia group than in the control group (p<.03, d>.70, for all). The extent of discrepancy in hand dexterity was negatively correlated with daily functioning in the schizophrenia group (rs=-.3 to -.5, ps=.04-.26). Ability to perform dual tasks may be an indicator of daily functioning in people with schizophrenia. Use of dual-task training may be considered as a therapeutic activity with these clients. Copyright © 2015 by the American Occupational Therapy Association, Inc.

  17. Speech Motor Sequence Learning: Effect of Parkinson Disease and Normal Aging on Dual-Task Performance.

    PubMed

    Whitfield, Jason A; Goberman, Alexander M

    2017-06-22

    Everyday communication is carried out concurrently with other tasks. Therefore, determining how dual tasks interfere with newly learned speech motor skills can offer insight into the cognitive mechanisms underlying speech motor learning in Parkinson disease (PD). The current investigation examines a recently learned speech motor sequence under dual-task conditions. A previously learned sequence of 6 monosyllabic nonwords was examined using a dual-task paradigm. Participants repeated the sequence while concurrently performing a visuomotor task, and performance on both tasks was measured in single- and dual-task conditions. The younger adult group exhibited little to no dual-task interference on the accuracy and duration of the sequence. The older adult group exhibited variability in dual-task costs, with the group as a whole exhibiting an intermediate, though significant, amount of dual-task interference. The PD group exhibited the largest degree of bidirectional dual-task interference among all the groups. These data suggest that PD affects the later stages of speech motor learning, as the dual-task condition interfered with production of the recently learned sequence beyond the effect of normal aging. Because the basal ganglia is critical for the later stages of motor sequence learning, the observed deficits may result from the underlying neural dysfunction associated with PD.

  18. Walking Stroop carpet: an innovative dual-task concept for detecting cognitive impairment.

    PubMed

    Perrochon, A; Kemoun, G; Watelain, E; Berthoz, A

    2013-01-01

    Several studies have reported the potential value of the dual-task concept during locomotion in clinical evaluation because cognitive decline is strongly associated with gait abnormalities. However, current dual-task tests appear to be insufficient for early diagnosis of cognitive impairment. Forty-nine subjects (young, old, with or without mild cognitive impairment) underwent cognitive evaluation (Mini-Mental State Examination, Frontal Assessment Battery, five-word test, Stroop, clock-drawing) and single-task locomotor evaluation on an electronic walkway. They were then dual-task-tested on the Walking Stroop carpet, which is an adaptation of the Stroop color-word task for locomotion. A cluster analysis, followed by an analysis of variance, was performed to assess gait parameters. Cluster analysis of gait parameters on the Walking Stroop carpet revealed an interaction between cognitive and functional abilities because it made it possible to distinguish dysexecutive cognitive fragility or decline with a sensitivity of 89% and a specificity of 94%. Locomotor abilities differed according to the group and dual-task conditions. Healthy subjects performed less well on dual-tasking under reading conditions than when they were asked to distinguish colors, whereas dysexecutive subjects had worse motor performances when they were required to dual task. The Walking Stroop carpet is a dual-task test that enables early detection of cognitive fragility that has not been revealed by traditional neuropsychological tests or single-task walking analysis.

  19. Effect of Water Immersion on Dual-task Performance: Implications for Aquatic Therapy.

    PubMed

    Schaefer, Sydney Y; Louder, Talin J; Foster, Shayla; Bressel, Eadric

    2016-09-01

    Much is known about cardiovascular and biomechanical responses to exercise during water immersion, yet an understanding of the higher-order neural responses to water immersion is unclear. The purpose of this study was to compare cognitive and motor performance between land and water environments using a dual-task paradigm, which served as an indirect measure of cortical processing. A quasi-experimental crossover research design is used. Twenty-two healthy participants (age = 24.3 ± 5.24 years) and a single-case patient (age = 73) with mild cognitive impairment performed a cognitive (auditory vigilance) and motor (standing balance) task separately (single-task condition) and simultaneously (dual-task condition) on land and in chest-deep water. Listening errors from the auditory vigilance task and centre of pressure (CoP) area for the balance task measured cognitive and motor performance, respectively. Listening errors for the single-task and dual-task conditions were 42% and 45% lower for the water than land condition, respectively (effect size [ES] = 0.38 and 0.55). CoP area for the single-task and dual-task conditions, however, were 115% and 164% lower on land than in water, respectively, and were lower (≈8-33%) when balancing concurrently with the auditory vigilance task compared with balancing alone, regardless of environment (ES = 0.23-1.7). This trend was consistent for the single-case patient. Participants tended to make fewer 'cognitive' errors while immersed chest-deep in water than on land. These same participants also tended to display less postural sway under dual-task conditions, but more in water than on land. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis

    PubMed Central

    Ghai, Shashank; Ghai, Ishan; Effenberg, Alfred O

    2017-01-01

    The use of dual-task training paradigm to enhance postural stability in patients with balance impairments is an emerging area of interest. The differential effects of dual tasks and dual-task training on postural stability still remain unclear. A systematic review and meta-analysis were conducted to analyze the effects of dual task and training application on static and dynamic postural stability among various population groups. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, from inception until June 2016, on the online databases Scopus, PEDro, MEDLINE, EMBASE, and SportDiscus. Experimental studies analyzing the effects of dual task and dual-task training on postural stability were extracted, critically appraised using PEDro scale, and then summarized according to modified PEDro level of evidence. Of 1,284 records, 42 studies involving 1,480 participants met the review’s inclusion criteria. Of the studies evaluating the effects of dual-task training on postural stability, 87.5% of the studies reported significant enhancements, whereas 30% of the studies evaluating acute effects of dual tasks on posture reported significant enhancements, 50% reported significant decrements, and 20% reported no effects. Meta-analysis of the pooled studies revealed moderate but significant enhancements of dual-task training in elderly participants (95% CI: 1.16–2.10) and in patients suffering from chronic stroke (−0.22 to 0.86). The adverse effects of complexity of dual tasks on postural stability were also revealed among patients with multiple sclerosis (−0.74 to 0.05). The review also discusses the significance of verbalization in a dual-task setting for increasing cognitive–motor interference. Clinical implications are discussed with respect to practical applications in rehabilitation settings. PMID:28356727

  1. Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis.

    PubMed

    Ghai, Shashank; Ghai, Ishan; Effenberg, Alfred O

    2017-01-01

    The use of dual-task training paradigm to enhance postural stability in patients with balance impairments is an emerging area of interest. The differential effects of dual tasks and dual-task training on postural stability still remain unclear. A systematic review and meta-analysis were conducted to analyze the effects of dual task and training application on static and dynamic postural stability among various population groups. Systematic identification of published literature was performed adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, from inception until June 2016, on the online databases Scopus, PEDro, MEDLINE, EMBASE, and SportDiscus. Experimental studies analyzing the effects of dual task and dual-task training on postural stability were extracted, critically appraised using PEDro scale, and then summarized according to modified PEDro level of evidence. Of 1,284 records, 42 studies involving 1,480 participants met the review's inclusion criteria. Of the studies evaluating the effects of dual-task training on postural stability, 87.5% of the studies reported significant enhancements, whereas 30% of the studies evaluating acute effects of dual tasks on posture reported significant enhancements, 50% reported significant decrements, and 20% reported no effects. Meta-analysis of the pooled studies revealed moderate but significant enhancements of dual-task training in elderly participants (95% CI: 1.16-2.10) and in patients suffering from chronic stroke (-0.22 to 0.86). The adverse effects of complexity of dual tasks on postural stability were also revealed among patients with multiple sclerosis (-0.74 to 0.05). The review also discusses the significance of verbalization in a dual-task setting for increasing cognitive-motor interference. Clinical implications are discussed with respect to practical applications in rehabilitation settings.

  2. Effects of age and auditory and visual dual tasks on closed-road driving performance.

    PubMed

    Chaparro, Alex; Wood, Joanne M; Carberry, Trent

    2005-08-01

    This study investigated how driving performance of young and old participants is affected by visual and auditory secondary tasks on a closed driving course. Twenty-eight participants comprising two age groups (younger, mean age = 27.3 years; older, mean age = 69.2 years) drove around a 5.1-km closed-road circuit under both single and dual task conditions. Measures of driving performance included detection and identification of road signs, detection and avoidance of large low-contrast road hazards, gap judgment, lane keeping, and time to complete the course. The dual task required participants to verbally report the sums of pairs of single-digit numbers presented through either a computer speaker (auditorily) or a dashboard-mounted monitor (visually) while driving. Participants also completed a vision and cognitive screening battery, including LogMAR visual acuity, Pelli-Robson letter contrast sensitivity, the Trails test, and the Digit Symbol Substitution (DSS) test. Drivers reported significantly fewer signs, hit more road hazards, misjudged more gaps, and increased their time to complete the course under the dual task (visual and auditory) conditions compared with the single task condition. The older participants also reported significantly fewer road signs and drove significantly more slowly than the younger participants, and this was exacerbated for the visual dual task condition. The results of the regression analysis revealed that cognitive aging (measured by the DSS and Trails test) rather than chronologic age was a better predictor of the declines seen in driving performance under dual task conditions. An overall z score was calculated, which took into account both driving and the secondary task (summing) performance under the two dual task conditions. Performance was significantly worse for the auditory dual task compared with the visual dual task, and the older participants performed significantly worse than the young subjects. These findings demonstrate

  3. Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm.

    PubMed

    Gagné, Jean-Pierre; Besser, Jana; Lemke, Ulrike

    2017-01-01

    Published investigations ( n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants' age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified.

  4. Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm

    PubMed Central

    Besser, Jana; Lemke, Ulrike

    2017-01-01

    Published investigations (n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants’ age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified. PMID:28091178

  5. Walking Stroop carpet: an innovative dual-task concept for detecting cognitive impairment

    PubMed Central

    Perrochon, A; Kemoun, G; Watelain, E; Berthoz, A

    2013-01-01

    Background Several studies have reported the potential value of the dual-task concept during locomotion in clinical evaluation because cognitive decline is strongly associated with gait abnormalities. However, current dual-task tests appear to be insufficient for early diagnosis of cognitive impairment. Methods Forty-nine subjects (young, old, with or without mild cognitive impairment) underwent cognitive evaluation (Mini-Mental State Examination, Frontal Assessment Battery, five-word test, Stroop, clock-drawing) and single-task locomotor evaluation on an electronic walkway. They were then dual-task-tested on the Walking Stroop carpet, which is an adaptation of the Stroop color–word task for locomotion. A cluster analysis, followed by an analysis of variance, was performed to assess gait parameters. Results Cluster analysis of gait parameters on the Walking Stroop carpet revealed an interaction between cognitive and functional abilities because it made it possible to distinguish dysexecutive cognitive fragility or decline with a sensitivity of 89% and a specificity of 94%. Locomotor abilities differed according to the group and dual-task conditions. Healthy subjects performed less well on dual-tasking under reading conditions than when they were asked to distinguish colors, whereas dysexecutive subjects had worse motor performances when they were required to dual task. Conclusion The Walking Stroop carpet is a dual-task test that enables early detection of cognitive fragility that has not been revealed by traditional neuropsychological tests or single-task walking analysis. PMID:23682211

  6. The effect of methylphenidate on postural stability under single and dual task conditions in children with attention deficit hyperactivity disorder - a double blind randomized control trial.

    PubMed

    Jacobi-Polishook, Talia; Shorer, Zamir; Melzer, Itshak

    2009-05-15

    To investigate the effects of Methylphenidate (MPH) on postural stability in attention deficit hyperactivity disorder (ADHD) children in single and dual task conditions. A randomized controlled double-blind study analyzing postural stability in 24 ADHD children before and after MPH vs. placebo treatments, in three task conditions: (1) Single task, standing still; (2) dual task, standing still performing a memory-attention demanding task; (3) standing still listening to music. MPH resulted in a significant improvement in postural stability during the dual task condition and while listening to music, with no equivalent improvement in placebo controls. MPH improves postural stability in ADHD, especially when an additional task is performed. This is probably due to enhanced attention abilities, thus contributing to improved balance control during performance of tasks that require attention. MPH remains to be studied as a potential drug treatment to improve balance control and physical functioning in other clinical populations.

  7. Voluntary stepping behavior under single- and dual-task conditions in chronic stroke survivors: A comparison between the involved and uninvolved legs.

    PubMed

    Melzer, Itshak; Goldring, Melissa; Melzer, Yehudit; Green, Elad; Tzedek, Irit

    2010-12-01

    If balance is lost, quick step execution can prevent falls. Research has shown that speed of voluntary stepping was able to predict future falls in old adults. The aim of the study was to investigate voluntary stepping behavior, as well as to compare timing and leg push-off force-time relation parameters of involved and uninvolved legs in stroke survivors during single- and dual-task conditions. We also aimed to compare timing and leg push-off force-time relation parameters between stroke survivors and healthy individuals in both task conditions. Ten stroke survivors performed a voluntary step execution test with their involved and uninvolved legs under two conditions: while focusing only on the stepping task and while a separate attention-demanding task was performed simultaneously. Temporal parameters related to the step time were measured including the duration of the step initiation phase, the preparatory phase, the swing phase, and the total step time. In addition, force-time parameters representing the push-off power during stepping were calculated from ground reaction data and compared with 10 healthy controls. The involved legs of stroke survivors had a significantly slower stepping time than uninvolved legs due to increased swing phase duration during both single- and dual-task conditions. For dual compared to single task, the stepping time increased significantly due to a significant increase in the duration of step initiation. In general, the force time parameters were significantly different in both legs of stroke survivors as compared to healthy controls, with no significant effect of dual compared with single-task conditions in both groups. The inability of stroke survivors to swing the involved leg quickly may be the most significant factor contributing to the large number of falls to the paretic side. The results suggest that stroke survivors were unable to rapidly produce muscle force in fast actions. This may be the mechanism of delayed execution

  8. Upper-Extremity Dual-Task Function: An Innovative Method to Assess Cognitive Impairment in Older Adults.

    PubMed

    Toosizadeh, Nima; Najafi, Bijan; Reiman, Eric M; Mager, Reine M; Veldhuizen, Jaimeson K; O'Connor, Kathy; Zamrini, Edward; Mohler, Jane

    2016-01-01

    Difficulties in orchestrating simultaneous tasks (i.e., dual-tasking) have been associated with cognitive impairments in older adults. Gait tests have been commonly used as the motor task component for dual-task assessments; however, many older adults have mobility impairments or there is a lack of space in busy clinical settings. We assessed an upper-extremity function (UEF) test as an alternative motor task to study the dual-task motor performance in older adults. Older adults (≥65 years) were recruited, and cognitive ability was measured using the Montreal cognitive assessment (MoCA). Participants performed repetitive elbow flexion with their maximum pace, once single-task, and once while counting backward by one (dual-task). Single- and dual-task gait tests were also performed with normal speed. Three-dimensional kinematics was measured both from upper-extremity and lower-extremity using wearable sensors to determine UEF and gait parameters. Parameters were compared between the cognitively impaired and healthy groups using analysis of variance tests, while controlling for age, gender, and body mass index (BMI). Correlations between UEF and gait parameters for dual-task and dual-task cost were assessed using linear regression models. Sixty-seven older adults were recruited (age = 83 ± 10 years). Based on MoCA, 10 (15%) were cognitively impaired. While no significant differences were observed in the single-task condition, within the dual-task condition, the cognitively impaired group showed significantly less arm flexion speed (62%, d = 1.51, p = 0.02) and range of motion (27%, d = 0.93, p = 0.04), and higher speed variability (88%, d = 1.82, p < 0.0001) compared to the cognitively intact group, when adjusted with age, gender, and BMI. Significant correlations were observed between UEF speed parameters and gait stride velocity for dual-task condition (r = 0.55, p < 0.0001) and dual-task cost (r = 0.28, p = 0.03). We introduced a novel test for assessing dual-task

  9. Upper-Extremity Dual-Task Function: An Innovative Method to Assess Cognitive Impairment in Older Adults

    PubMed Central

    Toosizadeh, Nima; Najafi, Bijan; Reiman, Eric M.; Mager, Reine M.; Veldhuizen, Jaimeson K.; O’Connor, Kathy; Zamrini, Edward; Mohler, Jane

    2016-01-01

    Background: Difficulties in orchestrating simultaneous tasks (i.e., dual-tasking) have been associated with cognitive impairments in older adults. Gait tests have been commonly used as the motor task component for dual-task assessments; however, many older adults have mobility impairments or there is a lack of space in busy clinical settings. We assessed an upper-extremity function (UEF) test as an alternative motor task to study the dual-task motor performance in older adults. Methods: Older adults (≥65 years) were recruited, and cognitive ability was measured using the Montreal cognitive assessment (MoCA). Participants performed repetitive elbow flexion with their maximum pace, once single-task, and once while counting backward by one (dual-task). Single- and dual-task gait tests were also performed with normal speed. Three-dimensional kinematics was measured both from upper-extremity and lower-extremity using wearable sensors to determine UEF and gait parameters. Parameters were compared between the cognitively impaired and healthy groups using analysis of variance tests, while controlling for age, gender, and body mass index (BMI). Correlations between UEF and gait parameters for dual-task and dual-task cost were assessed using linear regression models. Results: Sixty-seven older adults were recruited (age = 83 ± 10 years). Based on MoCA, 10 (15%) were cognitively impaired. While no significant differences were observed in the single-task condition, within the dual-task condition, the cognitively impaired group showed significantly less arm flexion speed (62%, d = 1.51, p = 0.02) and range of motion (27%, d = 0.93, p = 0.04), and higher speed variability (88%, d = 1.82, p < 0.0001) compared to the cognitively intact group, when adjusted with age, gender, and BMI. Significant correlations were observed between UEF speed parameters and gait stride velocity for dual-task condition (r = 0.55, p < 0.0001) and dual-task cost (r = 0.28, p = 0.03). Conclusion: We

  10. Volitional control of attention and brain activation in dual task performance.

    PubMed

    Newman, Sharlene D; Keller, Timothy A; Just, Marcel Adam

    2007-02-01

    This study used functional MRI (fMRI) to examine the neural effects of willfully allocating one's attention to one of two ongoing tasks. In a dual task paradigm, participants were instructed to focus either on auditory sentence comprehension, mental rotation, or both. One of the major findings is that the distribution of brain activation was amenable to strategic control, such that the amount of activation per task was systematically related to the attention-dividing instructions. The activation in language processing regions was lower when attending to mental rotation than when attending to the sentences, and the activation in visuospatial processing regions was lower when attending to sentences than when attending to mental rotations. Additionally, the activation was found to be underadditive, with the dual-task condition eliciting less activation than the sum of the attend sentence and attend rotation conditions. We also observed a laterality shift across conditions within language-processing regions, with the attend sentence condition showing bilateral activation, while the dual task condition showed a left hemispheric dominance. This shift suggests multiple language-processing modes and may explain the underadditivity in activation observed in the current and previous studies.

  11. The effect of single-task and dual-task balance exercise programs on balance performance in adults with osteoporosis: a randomized controlled preliminary trial.

    PubMed

    Konak, H E; Kibar, S; Ergin, E S

    2016-11-01

    Osteoporosis is a serious disease characterized by muscle weakness in the lower extremities, shortened length of trunk, and increased dorsal kyphosis leading to poor balance performance. Although balance impairment increases in adults with osteoporosis, falls and fall-related injuries have been shown to occur mainly during the dual-task performance. Several studies have shown that dual-task performance was improved with specific repetitive dual-task exercises. The aims of this study were to compare the effect of single- and dual-task balance exercise programs on static balance, dynamic balance, and activity-specific balance confidence in adults with osteoporosis and to assess the effectiveness of dual-task balance training on gait speed under dual-task conditions. Older adults (N = 42) (age range, 45-88 years) with osteoporosis were randomly assigned into two groups. Single-task balance training group was given single-task balance exercises for 4 weeks, whereas dual-task balance training group received dual-task balance exercises. Participants received 45-min individualized training session, three times a week. Static balance was evaluated by one-leg stance (OLS) and a kinesthetic ability trainer (KAT) device. Dynamic balance was measured by the Berg Balance Scale (BBS), Time Up and Go (TUG) test, and gait speed. Self-confidence was assessed with the Activities-specific Balance Confidence (ABC-6) scale. Assessments were performed at baseline and after the 4-week program. At the end of the treatment periods, KAT score, BBS score, time in OLS and TUG, gait speeds under single- and dual-task conditions, and ABC-6 scale scores improved significantly in all patients (p < 0.05). However, BBS and gait speeds under single- and dual-task conditions showed significantly greater improvement in the dual-task balance training group than in the single-task balance training group (p < 0.05). ABC-6 scale scores improved more in the single-task balance training group than

  12. Walking and talking: an investigation of cognitive-motor dual tasking in multiple sclerosis.

    PubMed

    Hamilton, F; Rochester, L; Paul, L; Rafferty, D; O'Leary, C P; Evans, J J

    2009-10-01

    Deficits in motor functioning, including walking, and in cognitive functions, including attention, are known to be prevalent in multiple sclerosis (MS), though little attention has been paid to how impairments in these areas of functioning interact. This study investigated the effects of performing a concurrent cognitive task when walking in people with MS. Level of task demand was manipulated to investigate whether this affected level of dual-task decrement. Eighteen participants with MS and 18 healthy controls took part. Participants completed walking and cognitive tasks under single- and dual-task conditions. Compared to healthy controls, MS participants showed greater decrements in performance under dual-task conditions in cognitive task performance, walking speed and swing time variability. In the MS group, the degree of decrement under dual-task conditions was related to levels of fatigue, a measure of general cognitive functioning and self-reported everyday cognitive errors, but not to measures of disease severity or duration. Difficulty with walking and talking in MS may be a result of a divided attention deficit or of overloading of the working memory system, and further investigation is needed. We suggest that difficulty with walking and talking in MS may lead to practical problems in everyday life, including potentially increasing the risk of falls. Clinical tools to assess cognitive-motor dual-tasking ability are needed.

  13. Deep white matter hyperintensities, microstructural integrity and dual task walking in older people.

    PubMed

    Ghanavati, Tabassom; Smitt, Myriam Sillevis; Lord, Stephen R; Sachdev, Perminder; Wen, Wei; Kochan, Nicole A; Brodaty, Henry; Delbaere, Kim

    2018-01-03

    To examine neural, physiological and cognitive influences on gait speed under single and dual-task conditions. Sixty-two community-dwelling older people (aged 80.0 ± 4.2 years) participated in our study. Gait speed was assessed with a timed 20-meter walk under single and dual-task (reciting alternate letters of the alphabet) conditions. Participants also underwent tests to estimate physiological fall risk based on five measures of sensorimotor function, cognitive function across five domains, brain white matter (WM) hyperintensities and WM microstructural integrity by measuring fractional anisotropy (FA). Univariate linear regression analyses showed that global physiological and cognitive measures were associated with single (β = 0.594 and β=-0.297, respectively) and dual-task gait speed (β = 0.306 and β=-0.362, respectively). Deep WMHs were associated with dual-task gait speed only (β = 0.257). Multivariate mediational analyses showed that global and executive cognition reduced the strength of the association between deep WMHs and dual-task gait speed by 27% (β = 0.188) and 44% (β = 0.145) respectively. There was a significant linear association between single-task gait speed and mean FA values of the genu (β=-0.295) and splenium (β=-0.326) of the corpus callosum, and between dual-task gait speed and mean FA values of Superior Cerebellar Peduncle (β=-0.284), splenium of the Corpus Callosum (β=-0.286) and Cingulum (β=-0.351). Greater deep WMH volumes are associated with slower walking speed under dual-task conditions, and this relationship is mediated in part by global cognition and executive abilities specifically. Furthermore, both cerebellum and cingulum are related to dual-task walking due to their role in motor skill performance and attention, respectively.

  14. Dual tasking negatively impacts obstacle avoidance abilities in post-stroke individuals with visuospatial neglect: Task complexity matters!

    PubMed

    Aravind, Gayatri; Lamontagne, Anouk

    2017-01-01

    Persons with perceptual-attentional deficits due to visuospatial neglect (VSN) after a stroke are at a risk of collisions while walking in the presence of moving obstacles. The attentional burden of performing a dual-task may further compromise their obstacle avoidance performance, putting them at a greater risk of collisions. The objective of this study was to compare the ability of persons with (VSN+) and without VSN (VSN-) to dual task while negotiating moving obstacles. Twenty-six stroke survivors (13 VSN+, 13 VSN-) were assessed on their ability to (a) negotiate moving obstacles while walking (locomotor single task); (b) perform a pitch-discrimination task (cognitive single task) and (c) simultaneously perform the walking and cognitive tasks (dual task). We compared the groups on locomotor (collision rates, minimum distance from obstacle and onset of strategies) and cognitive (error rates) outcomes. For both single and dual task walking, VSN+ individuals showed higher collision rates compared to VSN- individuals. Dual tasking caused deterioration of locomotor (more collisions, delayed onset and smaller minimum distances) and cognitive performances (higher error rate) in VSN+ individuals. Contrastingly, VSN- individuals maintained collision rates, increased minimum distance, but showed more cognitive errors, prioritizing their locomotor performance. Individuals with VSN demonstrate cognitive-locomotor interference under dual task conditions, which could severely compromise safety when ambulating in community environments and may explain the poor recovery of independent community ambulation in these individuals.

  15. Effects of Tai Chi intervention on dual-task ability in older adults: a pilot study.

    PubMed

    Hall, Courtney D; Miszko, Tanya; Wolf, Steven L

    2009-03-01

    To determine if a 12-week program of Tai Chi that has been shown to reduce falls incidence in older adults would improve the ability to allocate attention to balance under dual-task conditions. Pre-/posttest experimental research design. Movement studies research laboratory. Community dwelling older adults (N=15; range, 62-85y) participated in either Tai Chi training or health education classes (controls) for 12 weeks. Participants in the Tai Chi group attended a twice-weekly, 1.5-hour class taught by an experienced instructor. The control group attended a biweekly, 1-hour class for lectures on health-related topics. Two cognitive tasks (responding to auditory or visual stimulus as quickly as possible) were performed concurrently while maintaining static balance during the Sensory Organization Test (SOT) and while avoiding obstacles while walking. The percent change in performance relative to the single-task condition was calculated and defined as the dual-task cost. The dual-task cost was calculated for both the postural and cognitive measures. There was no improvement in the performance of postural stability or cognitive task under dual-task conditions for the SOT for Tai Chi versus controls. There was no improvement in avoiding obstacles under dual-task conditions for Tai Chi versus controls. Contrary to our hypothesis, the findings of this study did not support a benefit of Tai Chi on the ability to allocate attention to balance under dual-task conditions.

  16. Gray matter volume and dual-task gait performance in mild cognitive impairment

    PubMed Central

    Blumen, Helena M.; Verghese, Joe; Shimada, Hiroyuki; Makizako, Hyuma; Tsutsumimoto, Kota; Hotta, Ryo; Nakakubo, Sho; Suzuki, Takao

    2017-01-01

    Dual-task gait performance is impaired in older adults with mild cognitive impairment, but the brain substrates associated with dual-task gait performance are not well-established. The relationship between gray matter and gait speed under single-task and dual-task conditions (walking while counting backward) was examined in 560 seniors with mild cognitive impairment (non-amnestic mild cognitive impairment: n = 270; mean age = 72.4 yrs., 63.6 % women; amnestic mild cognitive impairment: n = 290; mean age = 73.4 yrs., 45.4 % women). Multivariate covariance-based analyses of magnetic resonance imaging data, adjusted for potential confounders including single-task gait speed, were performed to identify gray matter patterns associated with dual-task gait speed. There were no differences in gait speed or cognitive performance during dual-task gait between individuals with non-amnestic mild cognitive impairment and amnestic mild cognitive impairment. Overall, increased dual-task gait speed was associated with a gray matter pattern of increased volume in medial frontal gyrus, superior frontal gyrus, anterior cingulate, cingulate, precuneus, fusiform gyrus, middle occipital gyrus, inferior temporal gyrus and middle temporal gyrus. The relationship between dual-task gait speed and brain substrates also differed by mild cognitive impairment subtype. Our study revealed a pattern of gray matter regions associated with dual-task performance. Although dual-task gait performance was similar in amnestic and non-amnestic mild cognitive impairment, the gray matter patterns associated with dual-task gait performance differed by mild cognitive impairment subtype. These findings suggest that the brain substrates supporting dual-task gait performance in amnestic and non-amnestic subtypes are different, and consequently may respond differently to interventions, or require different interventions. PMID:27392792

  17. Neural correlates of motor-cognitive dual-tasking in young and old adults

    PubMed Central

    Papegaaij, Selma; Hortobágyi, Tibor; Godde, Ben; Kaan, Wim A.; Erhard, Peter; Voelcker-Rehage, Claudia

    2017-01-01

    When two tasks are performed simultaneously, performance often declines in one or both tasks. These so-called dual-task costs are more pronounced in old than in young adults. One proposed neurological mechanism of the dual-task costs is that old compared with young adults tend to execute single-tasks with higher brain activation. In the brain regions that are needed for both tasks, the reduced residual capacity may interfere with performance of the dual-task. This competition for shared brain regions has been called structural interference. The purpose of the study was to determine whether structural interference indeed plays a role in the age-related decrease in dual-task performance. Functional magnetic resonance imaging (fMRI) was used to investigate 23 young adults (20–29 years) and 32 old adults (66–89 years) performing a calculation (serial subtraction by seven) and balance-simulation (plantar flexion force control) task separately or simultaneously. Behavioral performance decreased during the dual-task compared with the single-tasks in both age groups, with greater dual-task costs in old compared with young adults. Brain activation was significantly higher in old than young adults during all conditions. Region of interest analyses were performed on brain regions that were active in both tasks. Structural interference was apparent in the right insula, as quantified by an age-related reduction in upregulation of brain activity from single- to dual-task. However, the magnitude of upregulation did not correlate with dual-task costs. Therefore, we conclude that the greater dual-task costs in old adults were probably not due to increased structural interference. PMID:29220349

  18. Changes in step-width during dual-task walking predicts falls.

    PubMed

    Nordin, E; Moe-Nilssen, R; Ramnemark, A; Lundin-Olsson, L

    2010-05-01

    The aim was to evaluate whether gait pattern changes between single- and dual-task conditions were associated with risk of falling in older people. Dual-task cost (DTC) of 230 community living, physically independent people, 75 years or older, was determined with an electronic walkway. Participants were followed up each month for 1 year to record falls. Mean and variability measures of gait characteristics for 5 dual-task conditions were compared to single-task walking for each participant. Almost half (48%) of the participants fell at least once during follow-up. Risk of falling increased in individuals where DTC for performing a subtraction task demonstrated change in mean step-width compared to single-task walking. Risk of falling decreased in individuals where DTC for carrying a cup and saucer demonstrated change compared to single-task walking in mean step-width, mean step-time, and step-length variability. Degree of change in gait characteristics related to a change in risk of falling differed between measures. Prognostic guidance for fall risk was found for the above DTCs in mean step-width with a negative likelihood ratio of 0.5 and a positive likelihood ratio of 2.3, respectively. Findings suggest that changes in step-width, step-time, and step-length with dual tasking may be related to future risk of falling. Depending on the nature of the second task, DTC may indicate either an increased risk of falling, or a protective strategy to avoid falling. Copyright 2010. Published by Elsevier B.V.

  19. An investigation of response and stimulus modality transfer effects after dual-task training in younger and older.

    PubMed

    Lussier, Maxime; Gagnon, Christine; Bherer, Louis

    2012-01-01

    It has been shown that dual-task training leads to significant improvement in dual-task performance in younger and older adults. However, the extent to which training benefits to untrained tasks requires further investigation. The present study assessed (a) whether dual-task training leads to cross-modality transfer in untrained tasks using new stimuli and/or motor responses modalities, (b) whether transfer effects are related to improved ability to prepare and maintain multiple task-set and/or enhanced response coordination, (c) whether there are age-related differences in transfer effects. Twenty-three younger and 23 older adults were randomly assigned to dual-task training or control conditions. All participants were assessed before and after training on three dual-task transfer conditions; (1) stimulus modality transfer (2) response modality transfer (3) stimulus and response modalities transfer task. Training group showed larger improvement than the control group in the three transfer dual-task conditions, which suggests that training leads to more than specific learning of stimuli/response associations. Attentional costs analyses showed that training led to improved dual-task cost, only in conditions that involved new stimuli or response modalities, but not both. Moreover, training did not lead to a reduced task-set cost in the transfer conditions, which suggests some limitations in transfer effects that can be expected. Overall, the present study supports the notion that cognitive plasticity for attentional control is preserved in late adulthood.

  20. Dual tasking and stuttering: from the laboratory to the clinic.

    PubMed

    Metten, Christine; Bosshardt, Hans-Georg; Jones, Mark; Eisenhuth, John; Block, Susan; Carey, Brenda; O'Brian, Sue; Packman, Ann; Onslow, Mark; Menzies, Ross

    2011-01-01

    The aim of the three studies in this article was to develop a way to include dual tasking in speech restructuring treatment for persons who stutter (PWS). It is thought that this may help clients maintain the benefits of treatment in the real world, where attentional resources are frequently diverted away from controlling fluency by the demands of other tasks. In Part 1, 17 PWS performed a story-telling task and a computer semantic task simultaneously. Part 2 reports the incorporation of the Part 1 protocol into a handy device for use in a clinical setting (the Dual Task and Stuttering Device, DAS-D). Part 3 is a proof of concept study in which three PWS reported on their experiences of using the device during treatment. In Part 1, stuttering frequency and errors on the computer task both increased under dual task conditions, indicating that the protocol would be appropriate for use in a clinical setting. All three participants in Part 3 reported positively on their experiences using the DAS-D. Dual tasking during treatment using the DAS-D appears to be a viable clinical procedure. Further research is required to establish effectiveness.

  1. The effect of changing the secondary task in dual-task paradigms for measuring listening effort.

    PubMed

    Picou, Erin M; Ricketts, Todd A

    2014-01-01

    The purpose of this study was to evaluate the effect of changing the secondary task in dual-task paradigms that measure listening effort. Specifically, the effects of increasing the secondary task complexity or the depth of processing on a paradigm's sensitivity to changes in listening effort were quantified in a series of two experiments. Specific factors investigated within each experiment were background noise and visual cues. Participants in Experiment 1 were adults with normal hearing (mean age 23 years) and participants in Experiment 2 were adults with mild sloping to moderately severe sensorineural hearing loss (mean age 60.1 years). In both experiments, participants were tested using three dual-task paradigms. These paradigms had identical primary tasks, which were always monosyllable word recognition. The secondary tasks were all physical reaction time measures. The stimulus for the secondary task varied by paradigm and was a (1) simple visual probe, (2) a complex visual probe, or (3) the category of word presented. In this way, the secondary tasks mainly varied from the simple paradigm by either complexity or depth of speech processing. Using all three paradigms, participants were tested in four conditions, (1) auditory-only stimuli in quiet, (2) auditory-only stimuli in noise, (3) auditory-visual stimuli in quiet, and (4) auditory-visual stimuli in noise. During auditory-visual conditions, the talker's face was visible. Signal-to-noise ratios used during conditions with background noise were set individually so word recognition performance was matched in auditory-only and auditory-visual conditions. In noise, word recognition performance was approximately 80% and 65% for Experiments 1 and 2, respectively. For both experiments, word recognition performance was stable across the three paradigms, confirming that none of the secondary tasks interfered with the primary task. In Experiment 1 (listeners with normal hearing), analysis of median reaction times

  2. Gray matter volume and dual-task gait performance in mild cognitive impairment.

    PubMed

    Doi, Takehiko; Blumen, Helena M; Verghese, Joe; Shimada, Hiroyuki; Makizako, Hyuma; Tsutsumimoto, Kota; Hotta, Ryo; Nakakubo, Sho; Suzuki, Takao

    2017-06-01

    Dual-task gait performance is impaired in older adults with mild cognitive impairment, but the brain substrates associated with dual-task gait performance are not well-established. The relationship between gray matter and gait speed under single-task and dual-task conditions (walking while counting backward) was examined in 560 seniors with mild cognitive impairment (non-amnestic mild cognitive impairment: n = 270; mean age = 72.4 yrs., 63.6 % women; amnestic mild cognitive impairment: n = 290; mean age = 73.4 yrs., 45.4 % women). Multivariate covariance-based analyses of magnetic resonance imaging data, adjusted for potential confounders including single-task gait speed, were performed to identify gray matter patterns associated with dual-task gait speed. There were no differences in gait speed or cognitive performance during dual-task gait between individuals with non-amnestic mild cognitive impairment and amnestic mild cognitive impairment. Overall, increased dual-task gait speed was associated with a gray matter pattern of increased volume in medial frontal gyrus, superior frontal gyrus, anterior cingulate, cingulate, precuneus, fusiform gyrus, middle occipital gyrus, inferior temporal gyrus and middle temporal gyrus. The relationship between dual-task gait speed and brain substrates also differed by mild cognitive impairment subtype. Our study revealed a pattern of gray matter regions associated with dual-task performance. Although dual-task gait performance was similar in amnestic and non-amnestic mild cognitive impairment, the gray matter patterns associated with dual-task gait performance differed by mild cognitive impairment subtype. These findings suggest that the brain substrates supporting dual-task gait performance in amnestic and non-amnestic subtypes are different, and consequently may respond differently to interventions, or require different interventions.

  3. Empirical Support for 'Hastening-Through-Re-Automatization' by Contrasting Two Motor-Cognitive Dual Tasks.

    PubMed

    Langhanns, Christine; Müller, Hermann

    2018-01-01

    Motor-cognitive dual tasks have been intensely studied and it has been demonstrated that even well practiced movements like walking show signs of interference when performed concurrently with a challenging cognitive task. Typically walking speed is reduced, at least in elderly persons. In contrast to these findings, some authors report an increased movement frequency under dual-task conditions, which they call hastening . A tentative explanation has been proposed, assuming that the respective movements are governed by an automatic control regime. Though, under single-task conditions, these automatic processes are supervised by "higher-order" cognitive control processes. However, when a concurrent cognitive task binds all cognitive resources, the automatic process is freed from the detrimental effect of cognitive surveillance, allowing higher movement frequencies. Fast rhythmic movements (>1 Hz) should more likely be governed by such an automatic process than low frequency discrete repetitive movements. Fifteen subjects performed two repetitive movements under single and dual-task condition, that is, in combination with a mental calculation task. According to the expectations derived from the explanatory concept, we found an increased movement frequency under dual-task conditions only for the fast rhythmic movement (paddleball task) but not for the slower discrete repetitive task (pegboard task). fNIRS measurements of prefrontal cortical load confirmed the idea of an automatic processing in the paddleball task, whereas the pegboard task seems to be more controlled by processes interfering with the calculation related processing.

  4. Dual Task of Fine Motor Skill and Problem Solving in Individuals With Multiple Sclerosis: A Pilot Study.

    PubMed

    Goverover, Y; Sandroff, B M; DeLuca, J

    2018-04-01

    To (1) examine and compare dual-task performance in patients with multiple sclerosis (MS) and healthy controls (HCs) using mathematical problem-solving questions that included an everyday competence component while performing an upper extremity fine motor task; and (2) examine whether difficulties in dual-task performance are associated with problems in performing an everyday internet task. Pilot study, mixed-design with both a within and between subjects' factor. A nonprofit rehabilitation research institution and the community. Participants (N=38) included persons with MS (n=19) and HCs (n=19) who were recruited from a nonprofit rehabilitation research institution and from the community. Not applicable. Participant were presented with 2 testing conditions: (1) solving mathematical everyday problems or placing bolts into divots (single-task condition); and (2) solving problems while putting bolts into divots (dual-task condition). Additionally, participants were required to perform a test of everyday internet competence. As expected, dual-task performance was significantly worse than either of the single-task tasks (ie, number of bolts into divots or correct answers, and time to answer the questions). Cognitive but not motor dual-task cost was associated with worse performance in activities of everyday internet tasks. Cognitive dual-task cost is significantly associated with worse performance of everyday technology. This was not observed in the motor dual-task cost. The implications of dual-task costs on everyday activity are discussed. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  5. Brain activations during bimodal dual tasks depend on the nature and combination of component tasks

    PubMed Central

    Salo, Emma; Rinne, Teemu; Salonen, Oili; Alho, Kimmo

    2015-01-01

    We used functional magnetic resonance imaging to investigate brain activations during nine different dual tasks in which the participants were required to simultaneously attend to concurrent streams of spoken syllables and written letters. They performed a phonological, spatial or “simple” (speaker-gender or font-shade) discrimination task within each modality. We expected to find activations associated specifically with dual tasking especially in the frontal and parietal cortices. However, no brain areas showed systematic dual task enhancements common for all dual tasks. Further analysis revealed that dual tasks including component tasks that were according to Baddeley's model “modality atypical,” that is, the auditory spatial task or the visual phonological task, were not associated with enhanced frontal activity. In contrast, for other dual tasks, activity specifically associated with dual tasking was found in the left or bilateral frontal cortices. Enhanced activation in parietal areas, however, appeared not to be specifically associated with dual tasking per se, but rather with intermodal attention switching. We also expected effects of dual tasking in left frontal supramodal phonological processing areas when both component tasks required phonological processing and in right parietal supramodal spatial processing areas when both tasks required spatial processing. However, no such effects were found during these dual tasks compared with their component tasks performed separately. Taken together, the current results indicate that activations during dual tasks depend in a complex manner on specific demands of component tasks. PMID:25767443

  6. Improving Dual-Task Control With a Posture-Second Strategy in Early-Stage Parkinson Disease.

    PubMed

    Huang, Cheng-Ya; Chen, Yu-An; Hwang, Ing-Shiou; Wu, Ruey-Meei

    2018-03-31

    To examine the task prioritization effects on postural-suprapostural dual-task performance in patients with early-stage Parkinson disease (PD) without clinically observed postural symptoms. Cross-sectional study. Participants performed a force-matching task while standing on a mobile platform, and were instructed to focus their attention on either the postural task (posture-first strategy) or the force-matching task (posture-second strategy). University research laboratory. Individuals (N=16) with early-stage PD who had no clinically observed postural symptoms. Not applicable. Dual-task change (DTC; percent change between single-task and dual-task performance) of posture error, posture approximate entropy (ApEn), force error, and reaction time (RT). Positive DTC values indicate higher postural error, posture ApEn, force error, and force RT during dual-task conditions compared with single-task conditions. Compared with the posture-first strategy, the posture-second strategy was associated with smaller DTC of posture error and force error, and greater DTC of posture ApEn. In contrast, greater DTC of force RT was observed under the posture-second strategy. Contrary to typical recommendations, our results suggest that the posture-second strategy may be an effective dual-task strategy in patients with early-stage PD who have no clinically observed postural symptoms in order to reduce the negative effect of dual tasking on performance and facilitate postural automaticity. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  7. Task-set inertia and memory-consolidation bottleneck in dual tasks.

    PubMed

    Koch, Iring; Rumiati, Raffaella I

    2006-11-01

    Three dual-task experiments examined the influence of processing a briefly presented visual object for deferred verbal report on performance in an unrelated auditory-manual reaction time (RT) task. RT was increased at short stimulus-onset asynchronies (SOAs) relative to long SOAs, showing that memory consolidation processes can produce a functional processing bottleneck in dual-task performance. In addition, the experiments manipulated the spatial compatibility of the orientation of the visual object and the side of the speeded manual response. This cross-task compatibility produced relative RT benefits only when the instruction for the visual task emphasized overlap at the level of response codes across the task sets (Experiment 1). However, once the effective task set was in place, it continued to produce cross-task compatibility effects even in single-task situations ("ignore" trials in Experiment 2) and when instructions for the visual task did not explicitly require spatial coding of object orientation (Experiment 3). Taken together, the data suggest a considerable degree of task-set inertia in dual-task performance, which is also reinforced by finding costs of switching task sequences (e.g., AC --> BC vs. BC --> BC) in Experiment 3.

  8. Age differences between children and young adults in the dynamics of dual-task prioritization: body (balance) versus mind (memory).

    PubMed

    Schaefer, Sabine; Krampe, Ralf Th; Lindenberger, Ulman; Baltes, Paul B

    2008-05-01

    Task prioritization can lead to trade-off patterns in dual-task situations. The authors compared dual-task performances in 9- and 11-year-old children and young adults performing a cognitive task and a motor task concurrently. The motor task required balancing on an ankle-disc board. Two cognitive tasks measured working memory and episodic memory at difficulty levels individually adjusted during the course of extensive training. Adults showed performance decrements in both task domains under dual-task conditions. In contrast, children showed decrements only in the cognitive tasks but actually swayed less under dual-task than under single-task conditions and continued to reduce their body sway even when instructed to focus on the cognitive task. The authors argue that children perform closer to their stability boundaries in the balance task and therefore prioritize protection of their balance under dual-task conditions. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

  9. A cognitive dual task affects gait variability in patients suffering from chronic low back pain.

    PubMed

    Hamacher, Dennis; Hamacher, Daniel; Schega, Lutz

    2014-11-01

    Chronic pain and gait variability in a dual-task situation are both associated with higher risk of falling. Executive functions regulate (dual-task) gait variability. A possible cause explaining why chronic pain increases risk of falling in an everyday dual-task situation might be that pain interferes with executive functions and results in a diminished dual-task capability with performance decrements on the secondary task. The main goal of this experiment was to evaluate the specific effects of a cognitive dual task on gait variability in chronic low back pain (CLBP) patients. Twelve healthy participants and twelve patients suffering from CLBP were included. The subjects were asked to perform a cognitive single task, a walking single task and a motor-cognitive dual task. Stride variability of trunk movements was calculated. A two-way ANOVA was performed to compare single-task walking with dual-task walking and the single cognitive task performance with the motor-cognitive dual-task performance. We did not find any differences in both of the single-task performances between groups. However, regarding single-task walking and dual-task walking, we observed an interaction effect indicating that low back pain patients show significantly higher gait variability in the dual-task condition as compared to controls. Our data suggest that chronic pain reduces motor-cognitive dual-task performance capability. We postulate that the detrimental effects are caused by central mechanisms where pain interferes with executive functions which, in turn, might contribute to increased risk of falling.

  10. Musical expertise has minimal impact on dual task performance.

    PubMed

    Cocchini, Gianna; Filardi, Maria Serena; Crhonkova, Marcela; Halpern, Andrea R

    2017-05-01

    Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organisation of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. Our study compared performance during dual task execution in expert musicians compared to controls with little if any musical experience. Participants performed a music recognition task and a visuo-spatial task separately (single task) or simultaneously (dual task). Both groups showed a significant but similar performance decline during dual tasks. In addition, the two groups showed a similar decline of dual task performance during encoding and retrieval of the musical information, mainly attributed to a decline in sensitivity. Our results suggest that attention during dual tasks is similarly distributed by expert and non-experts. These findings are in line with previous studies showing a lack of sensitivity to difficulty and lack of practice effect during dual tasks, supporting the idea that different tasks may rely on different and not-sharable attentional resources.

  11. Biomechanical Analyses of Stair-climbing while Dual-tasking

    PubMed Central

    Vallabhajosula, Srikant; Tan, Chi Wei; Mukherjee, Mukul; Davidson, Austin J.; Stergiou, Nicholas

    2015-01-01

    Stair-climbing while doing a concurrent task like talking or holding an object is a common activity of daily living which poses high risk for falls. While biomechanical analyses of overground walking during dual-tasking have been studied extensively, little is known on the biomechanics of stair-climbing while dual-tasking. We sought to determine the impact of performing a concurrent cognitive or motor task during stair-climbing. We hypothesized that a concurrent cognitive task will have a greater impact on stair climbing performance compared to a concurrent motor task and that this impact will be greater on a higher-level step. Ten healthy young adults performed 10 trials of stair-climbing each under four conditions: stair ascending only, stair ascending and performing subtraction of serial sevens from a three-digit number, stair ascending and carrying an empty opaque box and stair ascending, performing subtraction of serial sevens from a random three-digit number and carrying an empty opaque box. Kinematics (lower extremity joint angles and minimum toe clearance) and kinetics (ground reaction forces and joint moments and powers) data were collected. We found that a concurrent cognitive task impacted kinetics but not kinematics of stair-climbing. The effect of dual-tasking during stair ascent also seemed to vary based on the different phases of stair ascent stance and seem to have greater impact as one climbs higher. Overall, the results of the current study suggest that the association between the executive functioning and motor task (like gait) becomes stronger as the level of complexity of the motor task increases. PMID:25773590

  12. Gait parameter risk factors for falls under simple and dual task conditions in cognitively impaired older people.

    PubMed

    Taylor, Morag E; Delbaere, Kim; Mikolaizak, A Stefanie; Lord, Stephen R; Close, Jacqueline C T

    2013-01-01

    Impaired gait may contribute to the increased rate of falls in cognitively impaired older people. We investigated whether gait under simple and dual task conditions could predict falls in this group. The study sample consisted of 64 community dwelling older people with mild to moderate cognitive impairment. Participants walked at their preferred speed under three conditions: (a) simple walking, (b) walking while carrying a glass of water and (c) walking while counting backwards from 30. Spatiotemporal gait parameters were measured using the GAITRite(®) mat. Falls were recorded prospectively for 12months with the assistance of carers. Twenty-two (35%) people fell two or more times in the 12month follow-up period. There was a significant main effect of gait condition and a significant main effect of faller status for mean value measures (velocity, stride length, double support time and stride width) and for variability measures (swing time variability and stride length variability). Examination of individual gait parameters indicated that the multiple fallers walked more slowly, had shorter stride length, spent longer time in double support, had a wider support width and showed more variability in stride length and swing time (p<0.05). There was no significant interaction between gait condition and faller status for any of the gait variables. In conclusion, dual task activities adversely affect gait in cognitively impaired older people. Multiple fallers performed worse in each gait condition but the addition of a functional or cognitive secondary task provided no added benefit in discriminating fallers from non-fallers with cognitive impairment. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Empirical Support for ‘Hastening-Through-Re-Automatization’ by Contrasting Two Motor-Cognitive Dual Tasks

    PubMed Central

    Langhanns, Christine; Müller, Hermann

    2018-01-01

    Motor-cognitive dual tasks have been intensely studied and it has been demonstrated that even well practiced movements like walking show signs of interference when performed concurrently with a challenging cognitive task. Typically walking speed is reduced, at least in elderly persons. In contrast to these findings, some authors report an increased movement frequency under dual-task conditions, which they call hastening. A tentative explanation has been proposed, assuming that the respective movements are governed by an automatic control regime. Though, under single-task conditions, these automatic processes are supervised by “higher-order” cognitive control processes. However, when a concurrent cognitive task binds all cognitive resources, the automatic process is freed from the detrimental effect of cognitive surveillance, allowing higher movement frequencies. Fast rhythmic movements (>1 Hz) should more likely be governed by such an automatic process than low frequency discrete repetitive movements. Fifteen subjects performed two repetitive movements under single and dual-task condition, that is, in combination with a mental calculation task. According to the expectations derived from the explanatory concept, we found an increased movement frequency under dual-task conditions only for the fast rhythmic movement (paddleball task) but not for the slower discrete repetitive task (pegboard task). fNIRS measurements of prefrontal cortical load confirmed the idea of an automatic processing in the paddleball task, whereas the pegboard task seems to be more controlled by processes interfering with the calculation related processing. PMID:29887815

  14. Effects of transcranial direct current stimulation (tDCS) on multiscale complexity of dual-task postural control in older adults.

    PubMed

    Zhou, Diange; Zhou, Junhong; Chen, Hu; Manor, Brad; Lin, Jianhao; Zhang, Jue

    2015-08-01

    Transcranial direct current stimulation (tDCS) targeting the prefrontal cortex reduces the size and speed of standing postural sway in younger adults, particularly when performing a cognitive dual task. Here, we hypothesized that tDCS would alter the complex dynamics of postural sway as quantified by multiscale entropy (MSE). Twenty healthy older adults completed two study visits. Center-of-pressure (COP) fluctuations were recorded during single-task (i.e., quiet standing) and dual-task (i.e., standing while performing serial subtractions) conditions, both before and after a 20-min session of real or sham tDCS. MSE was used to estimate COP complexity within each condition. The percentage change in complexity from single- to dual-task conditions (i.e., dual-task cost) was also calculated. Before tDCS, COP complexity was lower (p = 0.04) in the dual-task condition as compared to the single-task condition. Neither real nor sham tDCS altered complexity in the single-task condition. As compared to sham tDCS, real tDCS increased complexity in the dual-task condition (p = 0.02) and induced a trend toward improved serial subtraction performance (p = 0.09). Moreover, those subjects with lower dual-task COP complexity at baseline exhibited greater percentage increases in complexity following real tDCS (R = -0.39, p = 0.05). Real tDCS also reduced the dual-task cost to complexity (p = 0.02), while sham stimulation had no effect. A single session of tDCS targeting the prefrontal cortex increased standing postural sway complexity with concurrent non-postural cognitive task. This form of noninvasive brain stimulation may be a safe strategy to acutely improve postural control by enhancing the system's capacity to adapt to stressors.

  15. Dual Motor-Cognitive Virtual Reality Training Impacts Dual-Task Performance in Freezing of Gait.

    PubMed

    Killane, Isabelle; Fearon, Conor; Newman, Louise; McDonnell, Conor; Waechter, Saskia M; Sons, Kristian; Lynch, Timothy; Reilly, Richard B

    2015-11-01

    Freezing of gait (FOG), an episodic gait disturbance characterized by the inability to generate effective stepping, occurs in more than half of Parkinson's disease patients. It is associated with both executive dysfunction and attention and becomes most evident during dual tasking (performing two tasks simultaneously). This study examined the effect of dual motor-cognitive virtual reality training on dual-task performance in FOG. Twenty community dwelling participants with Parkinson's disease (13 with FOG, 7 without FOG) participated in a pre-assessment, eight 20-minute intervention sessions, and a post-assessment. The intervention consisted of a virtual reality maze (DFKI, Germany) through which participants navigated by stepping-in-place on a balance board (Nintendo, Japan) under time pressure. This was combined with a cognitive task (Stroop test), which repeatedly divided participants' attention. The primary outcome measures were pre- and post-intervention differences in motor (stepping time, symmetry, rhythmicity) and cognitive (accuracy, reaction time) performance during single- and dual-tasks. Both assessments consisted of 1) a single cognitive task 2) a single motor task, and 3) a dual motor-cognitive task. Following the intervention, there was significant improvement in dual-task cognitive and motor parameters (stepping time and rhythmicity), dual-task effect for those with FOG and a noteworthy improvement in FOG episodes. These improvements were less significant for those without FOG. This is the first study to show benefit of a dual motor-cognitive approach on dual-task performance in FOG. Advances in such virtual reality interventions for home use could substantially improve the quality of life for patients who experience FOG.

  16. Dual-task testing to predict falls in community-dwelling older adults: a systematic review.

    PubMed

    Muir-Hunter, S W; Wittwer, J E

    2016-03-01

    Cognitive impairment increases fall risk in older adults. Dual-task testing is an accepted way to assess the interaction between cognition and mobility; however, there is a lack of evidence-based recommendations for dual-task testing to evaluate fall risk in clinical practice. To evaluate the association between dual-task testing protocols and future fall risk, and to identify the specific dual-task test protocols associated with elevated risk. MEDLINE, Pubmed and EMBASE electronic databases were searched from January 1988 to September 2013. Two independent raters identified prospective cohort studies (duration of at least 1 year) of dual-task assessment in community-dwelling participants aged ≥60 years, with 'falls' as the primary outcome. Methodological quality was scored independently by two raters using a published checklist of criteria for evaluating threats to the validity of observational studies. Deterioration in gait during dual-task testing compared with single-task performance was associated with increased fall risk. Shortcomings within the literature significantly limit knowledge translation of dual-task gait protocols into clinical practice. There is a paucity of prospective studies on the association of dual-task gait assessment with fall risk. Changes in gait under dual-task testing are associated with future fall risk, and this association is stronger than that for single-task conditions. Limitations in the available literature preclude development of detailed recommendations for dual-task gait testing procedures in clinical practice to identify and stratify fall risk in older adults. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  17. Age-related differences in dual task performance: A cross-sectional study on women.

    PubMed

    Brustio, Paolo R; Magistro, Daniele; Rabaglietti, Emanuela; Liubicich, Monica E

    2017-02-01

    Simultaneous performances of motor and attention-demanding tasks are common in activities of everyday life. The present cross-sectional study examined the changes and age-related differences on mobility performance with an additional cognitive or motor task, and evaluated the relative dual-task cost (DTC) on the motor performance in young, middle-aged and older women. A total of 30 young (mean age 25.12 ± 3.00 years), 30 middle-aged (mean age 47.82 ± 5.06 years) and 30 older women (mean age 72.74 ± 5.95 years) were recruited. Participants carried out: (i) single task: Timed Up & Go Test; (ii) cognitive dual-task: Timed Up & Go Test while counting backwards by three; (iii) manual dual-task: Timed Up & Go Test while carrying a glass of water. A repeated measures anova with between-factor as age groups and within-factor as tasks was carried out to assess the effect of aging on the performance of mobility tasks. DTC was calculated as ([performance in single-task - performance in dual-task] / performance in single task) × 100%. One-way ancova were carried out to compare the DTC among the three age groups. A significant interaction between age groups and task (F 4,172  = 6.716, P < 0.001, partial η 2  = 0.135) was observed. Specifically, older women showed a worse mobility performance under dual-task condition compared with young and middle-aged groups. Furthermore, DTC differences in cognitive task were observed in older women compared with younger and middle-aged women (F 2,86  = 7.649, P < 0.001, partial η 2  = 0.151), but not in manual task. Dual-task conditions might affect mobility performance differently across the lifespan, and could be particularly challenging in older women. Geriatr Gerontol Int 2017; 17: 315-321. © 2015 Japan Geriatrics Society.

  18. Development and Pilot Testing of the Dual Task Screen in Healthy Adolescents.

    PubMed

    Stephens, Jaclyn; Nicholson, Rachel; Slomine, Beth; Suskauer, Stacy

    Athletes with mild traumatic brain injury (mTBI) should refrain from high-risk activities until recovered (symptom free and cognitive and physical exam findings normalize). Studies have suggested that this examination may not be sufficiently sensitive because dual-task paradigms, which typically assess motor performance while a person simultaneously completes a distractor task, can detect residual deficits in athletes who otherwise appear recovered from mTBI. Paradigms used to date are time-intensive procedures conducted in laboratory settings. Here, we report findings from a pilot study of the Dual Task Screen (DTS), which is a brief evaluation with two dual-task paradigms. In 32 healthy female adolescents, the DTS was administered in a mean of 5.63 min in the community, and every participant had poorer dual-condition performance on at least one of the motor tasks. The DTS is a clinically feasible measure and merits additional study regarding utility in adolescents with mTBIs. Copyright © 2018 by the American Occupational Therapy Association, Inc.

  19. Dual-Task Assessment Protocols in Concussion Assessment: A Systematic Literature Review.

    PubMed

    Kleiner, Michelle; Wong, Lynne; Dubé, Alexandra; Wnuk, Katie; Hunter, Susan W; Graham, Laura J

    2018-02-01

    Study Design Systematic review. Background When assessed in isolation, balance and neurocognitive testing may not be sufficiently responsive to capture changes that occur with concussion. Normal daily activities require simultaneous cognitive and physical demands. Therefore, a dual-task assessment paradigm should be considered to identify performance deficits. Objectives To evaluate the literature and to identify dual-task testing protocols associated with changes in gait after concussion. Methods A systematic review of articles of individuals with concussion who underwent dual-task testing with a combination of motor and cognitive tasks was conducted. The AMED, CINAHL, Embase, PsycINFO, PubMed, Scopus, SPORTDiscus, and Web of Science databases and gray literature were searched from inception to January 29, 2017. Title and abstract, full-text, and quality review and data abstraction were performed by 2 independent reviewers. Results Twenty-four articles met the inclusion criteria. Eleven articles reported decreased gait velocity and increased medial-lateral displacement for individuals with concussion during dual-task conditions. Overall, included articles were of poor to moderate methodological quality. Fifteen articles used the same participants and data sets, creating a threat to validity and limiting the ability to make conclusions. Conclusion A deterioration in gait performance during dual-task testing is present among people with concussion. Specific recommendations for the use of a dual-task protocol to assess individuals with suspected concussion injury in a clinical setting have yet to be determined. J Orthop Sports Phys Ther 2018;48(2):87-103. Epub 7 Nov 2017. doi:10.2519/jospt.2018.7432.

  20. Investigating Perfect Timesharing: The Relationship between IM-Compatible Tasks and Dual-Task Performance

    ERIC Educational Resources Information Center

    Halvorson, Kimberly M.; Ebner, Herschel; Hazeltine, Eliot

    2013-01-01

    Why are dual-task costs reduced with ideomotor (IM) compatible tasks (Greenwald & Shulman, 1973; Lien, Proctor & Allen, 2002)? In the present experiments, we first examine three different measures of single-task performance (pure single-task blocks, mixed blocks, and long stimulus onset asynchrony [SOA] trials in dual-task blocks) and two…

  1. Characterization of cognitive and motor performance during dual-tasking in healthy older adults and patients with Parkinson's disease.

    PubMed

    Wild, Lucia Bartmann; de Lima, Daiane Borba; Balardin, Joana Bisol; Rizzi, Luana; Giacobbo, Bruno Lima; Oliveira, Henrique Bianchi; de Lima Argimon, Irani Iracema; Peyré-Tartaruga, Leonardo Alexandre; Rieder, Carlos R M; Bromberg, Elke

    2013-02-01

    The primary purpose of this study was to investigate the effect of dual-tasking on cognitive performance and gait parameters in patients with idiopathic Parkinson's disease (PD) without dementia. The impact of cognitive task complexity on cognition and walking was also examined. Eighteen patients with PD (ages 53-88, 10 women; Hoehn and Yahr stage I-II) and 18 older adults (ages 61-84; 10 women) completed two neuropsychological measures of executive function/attention (the Stroop Test and Wisconsin Card Sorting Test). Cognitive performance and gait parameters related to functional mobility of stride were measured under single (cognitive task only) and dual-task (cognitive task during walking) conditions with different levels of difficulty and different types of stimuli. In addition, dual-task cognitive costs were calculated. Although cognitive performance showed no significant difference between controls and PD patients during single or dual-tasking conditions, only the patients had a decrease in cognitive performance during walking. Gait parameters of patients differed significantly from controls at single and dual-task conditions, indicating that patients gave priority to gait while cognitive performance suffered. Dual-task cognitive costs of patients increased with task complexity, reaching significantly higher values then controls in the arithmetic task, which was correlated with scores on executive function/attention (Stroop Color-Word Page). Baseline motor functioning and task executive/attentional load affect the performance of cognitive tasks of PD patients while walking. These findings provide insight into the functional strategies used by PD patients in the initial phases of the disease to manage dual-task interference.

  2. The effect of dual tasking on foot kinematics in people with functional ankle instability.

    PubMed

    Tavakoli, Sanam; Forghany, Saeed; Nester, Christopher

    2016-09-01

    Some cases of repeated inversion ankle sprains are thought to have a neurological basis and are termed functional ankle instability (FAI). In addition to factors local to the ankle, such as loss of proprioception, cognitive demands have the ability to influence motor control and may increase the risk of repetitive lateral sprains. The purpose of this study was to investigate the effect of cognitive demand on foot kinematics in physically active people with functional ankle instability. 21 physically active participants with FAI and 19 matched healthy controls completed trials of normal walking (single task) and normal walking while performing a cognitive task (dual task). Foot motion relative to the shank was recorded. Cognitive performance, ankle kinematics and movement variability in single and dual task conditions was characterized. During normal walking, the ankle joint was significantly more inverted in FAI compared to the control group pre and post initial contact. Under dual task conditions, there was a statistically significant increase in frontal plane foot movement variability during the period 200ms pre and post initial contact in people with FAI compared to the control group (p<0.05). Dual task also significantly increased plantar flexion and inversion during the period 200ms pre and post initial contact in the FAI group (p<0.05). participants with FAI demonstrated different ankle movement patterns and increased movement variability during a dual task condition. Cognitive load may increase risk of ankle instability in these people. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Unexpected Dual Task Benefits on Cycling in Parkinson Disease and Healthy Adults: A Neuro-Behavioral Model

    PubMed Central

    Altmann, Lori J. P.; Stegemöller, Elizabeth; Hazamy, Audrey A.; Wilson, Jonathan P.; Okun, Michael S.; McFarland, Nikolaus R.; Shukla, Aparna Wagle; Hass, Chris J.

    2015-01-01

    Background When performing two tasks at once, a dual task, performance on one or both tasks typically suffers. People with Parkinson’s disease (PD) usually experience larger dual task decrements on motor tasks than healthy older adults (HOA). Our objective was to investigate the decrements in cycling caused by performing cognitive tasks with a range of difficulty in people with PD and HOAs. Methods Twenty-eight participants with Parkinson’s disease and 20 healthy older adults completed a baseline cycling task with no secondary tasks and then completed dual task cycling while performing 12 tasks from six cognitive domains representing a wide range of difficulty. Results Cycling was faster during dual task conditions than at baseline, and was significantly faster for six tasks (all p<.02) across both groups. Cycling speed improved the most during the easiest cognitive tasks, and cognitive performance was largely unaffected. Cycling improvement was predicted by task difficulty (p<.001). People with Parkinson’s disease cycled slower (p<.03) and showed reduced dual task benefits (p<.01) than healthy older adults. Conclusions Unexpectedly, participants’ motor performance improved during cognitive dual tasks, which cannot be explained in current models of dual task performance. To account for these findings, we propose a model integrating dual task and acute exercise approaches which posits that cognitive arousal during dual tasks increases resources to facilitate motor and cognitive performance, which is subsequently modulated by motor and cognitive task difficulty. This model can explain both the improvement observed on dual tasks in the current study and more typical dual task findings in other studies. PMID:25970607

  4. Home-based interventions improve trained, but not novel, dual-task balance performance in older adults: A randomized controlled trial.

    PubMed

    Wongcharoen, Suleeporn; Sungkarat, Somporn; Munkhetvit, Peeraya; Lugade, Vipul; Silsupadol, Patima

    2017-02-01

    The purpose of this study was to compare the efficacy of four different home-based interventions on dual-task balance performance and to determine the generalizability of the four trainings to untrained tasks. Sixty older adults, aged 65 and older, were randomly assigned to one of four home-based interventions: single-task motor training, single-task cognitive training, dual-task motor-cognitive training, and dual-task cognitive-cognitive training. Participants received 60-min individualized training sessions, 3 times a week for 4 weeks. Prior to and following the training program, participants were asked to walk under two single-task conditions (i.e. narrow walking and obstacle crossing) and two dual-task conditions (i.e. a trained narrow walking while performing verbal fluency task and an untrained obstacle crossing while counting backward by 3s task). A nine-camera motion capture system was used to collect the trajectories of 32 reflective markers placed on bony landmarks of participants. Three-dimensional kinematics of the whole body center of mass and base of support were computed. Results from the extrapolated center of mass displacement indicated that motor-cognitive training was more effective than the single-task motor training to improve dual-task balance performance (p=0.04, ES=0.11). Interestingly, balance performance under both single-task and dual-task conditions can also be improved through a non-motor, single-task cognitive training program (p=0.01, ES=0.13, and p=0.01, ES=0.11, respectively). However, improved dual-task processing skills during training were not transferred to the novel dual task (p=0.15, ES=0.09). This is the first study demonstrating that home-based dual-task training can be effectively implemented to improve balance performance during gait in older adults. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Cerebellum and Integration of Neural Networks in Dual-Task Processing

    PubMed Central

    Wu, Tao; Liu, Jun; Hallett, Mark; Zheng, Zheng; Chan, Piu

    2014-01-01

    Performing two tasks simultaneously (dual-task) is common in human daily life. The neural correlates of dual-task processing remain unclear. In the current study, we used a dual motor and counting task with functional MRI (fMRI) to determine whether there are any areas additionally activated for dual-task performance. Moreover, we investigated the functional connectivity of these added activated areas, as well as the training effect on brain activity and connectivity. We found that the right cerebellar vermis, left lobule V of the cerebellar anterior lobe and precuneus are additionally activated for this type of dual-tasking. These cerebellar regions had functional connectivity with extensive motor- and cognitive-related regions. Dual-task training induced less activation in several areas, but increased the functional connectivity between these cerebellar regions and numbers of motor- and cognitive-related areas. Our findings demonstrate that some regions within the cerebellum can be additionally activated with dual-task performance. Their role in dual motor and cognitive task processes is likely to integrate motor and cognitive networks, and may be involved in adjusting these networks to be more efficient in order to perform dual-tasking properly. The connectivity of the precuneus differs from the cerebellar regions. A possible role of the precuneus in dual-task may be monitoring the operation of active brain networks. PMID:23063842

  6. Fine and gross motor skills: The effects on skill-focused dual-tasks.

    PubMed

    Raisbeck, Louisa D; Diekfuss, Jed A

    2015-10-01

    Dual-task methodology often directs participants' attention towards a gross motor skill involved in the execution of a skill, but researchers have not investigated the comparative effects of attention on fine motor skill tasks. Furthermore, there is limited information about participants' subjective perception of workload with respect to task performance. To examine this, the current study administered the NASA-Task Load Index following a simulated shooting dual-task. The task required participants to stand 15 feet from a projector screen which depicted virtual targets and fire a modified Glock 17 handgun equipped with an infrared laser. Participants performed the primary shooting task alone (control), or were also instructed to focus their attention on a gross motor skill relevant to task execution (gross skill-focused) and a fine motor skill relevant to task execution (fine skill-focused). Results revealed that workload was significantly greater during the fine skill-focused task for both skill levels, but performance was only affected for the lesser-skilled participants. Shooting performance for the lesser-skilled participants was greater during the gross skill-focused condition compared to the fine skill-focused condition. Correlational analyses also demonstrated a significant negative relationship between shooting performance and workload during the gross skill-focused task for the higher-skilled participants. A discussion of the relationship between skill type, workload, skill level, and performance in dual-task paradigms is presented. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Using dual tasks to test immediate transfer of training between naturalistic movements: a proof-of-principle study.

    PubMed

    Schaefer, Sydney Y; Lang, Catherine E

    2012-01-01

    Theories of motor learning predict that training a movement reduces the amount of attention needed for its performance (i.e., more automatic). If training one movement transfers, then the amount of attention needed for performing a second movement should also be reduced, as measured under dual task conditions. The authors' purpose was to test whether dual task paradigms are feasible for detecting transfer of training between two naturalistic movements. Immediately following motor training, subjects improved performance of a second untrained movement under single and dual task conditions. Subjects with no training did not. Improved performance in the untrained movement was likely due to transfer, and suggests that dual tasks may be feasible for detecting transfer between naturalistic actions.

  8. Dual-task gait differences in female and male adolescents following sport-related concussion.

    PubMed

    Howell, David R; Stracciolini, Andrea; Geminiani, Ellen; Meehan, William P

    2017-05-01

    Concussion may affect females and males differentially. Identification of gender-related differences after concussion, therefore, may help clinicians with individualized evaluations. We examined potential differences in dual-task gait between females and males after concussion. Thirty-five participants diagnosed with a concussion (49% female, mean age=15.0±2.1 years, 7.5±3.0 days post-injury) and 51 controls (51% female, mean age=14.4±2.1 years) completed a symptom inventory and single/dual-task gait assessment. The primary outcome variable, the dual-task cost, was calculated as the percent change between single-task and dual-task conditions to account for individual differences in spatio-temporal gait variables. No significant differences in symptom severity measured by the post-concussion symptom scale were observed between females (32.0±18.0) and males (27.8±18.2). Compared with males, adolescent females walked with significantly decreased cadence dual-task costs after concussion (-19.7%±10.0% vs. -11.3%±9.2%, p=0.007) when adjusted for age, height, and prior concussion history. No significant differences were found between female and male control groups on other dual-task cost gait measures. Females and males with concussion also walked with significantly shorter stride lengths than controls during single-task (females: 1.13±0.11m vs. 1.26±0.11m, p=0.001; males: 1.14±0.14m vs. 1.22±0.15m, p=0.04) and dual-task gait (females: 0.99±0.10m vs. 1.10±0.11m, p=0.001; males: 1.00±0.13m vs. 1.08±0.14m, p=0.04). Females demonstrated a significantly greater amount of cadence change between single-task and dual-task gait than males after a sport-related concussion. Thus, differential alterations may exist during gait among those with a concussion; gender may be one prominent factor affecting dual-task gait. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. High levels of time contraction in young children in dual tasks are related to their limited attention capacities.

    PubMed

    Hallez, Quentin; Droit-Volet, Sylvie

    2017-09-01

    Numerous studies have shown that durations are judged shorter in a dual-task condition than in a simple-task condition. The resource-based theory of time perception suggests that this is due to the processing of temporal information, which is a demanding cognitive task that consumes limited attention resources. Our study investigated whether this time contraction in a dual-task condition is greater in younger children and, if so, whether this is specifically related to their limited attention capacities. Children aged 5-7years were given a temporal reproduction task in a simple-task condition and a dual-task condition. In addition, different neuropsychological tests were used to assess not only their attention capacities but also their capacities in terms of working memory and information processing speed. The results showed a shortening of perceived time in the dual task compared with the simple task, and this increased as age decreased. The extent of this shortening effect was directly linked to younger children's limited attentional capacities; the lower their attentional capacities, the greater the time contraction. This study demonstrated that children's errors in time judgments are linked to their cognitive capacities rather than to capacities that are specific to time. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Using dual tasks to test immediate transfer of training between naturalistic movements: A proof-of-principle study

    PubMed Central

    Schaefer, Sydney Y.; Lang, Catherine E.

    2012-01-01

    Theories of motor learning predict that training a movement reduces the amount of attention needed for its performance (i.e. more automatic). If training one movement transfers, then the amount of attention needed for performing a second movement should also be reduced, as measured under dual task conditions. The purpose of this study was to test whether dual task paradigms are feasible for detecting transfer of training between two naturalistic movements. Immediately following motor training, subjects improved performance of a second untrained movement under both single and dual task conditions. Subjects with no training did not. Improved performance in the untrained movement was likely due to transfer, and suggests that dual tasks may be feasible for detecting transfer between naturalistic actions. PMID:22934682

  11. Single-task and dual-task tandem gait test performance after concussion.

    PubMed

    Howell, David R; Osternig, Louis R; Chou, Li-Shan

    2017-07-01

    To compare single-task and dual-task tandem gait test performance between athletes after concussion with controls on observer-timed, spatio-temporal, and center-of-mass (COM) balance control measurements. Ten participants (19.0±5.5years) were prospectively identified and completed a tandem gait test protocol within 72h of concussion and again 1 week, 2 weeks, 1 month, and 2 months post-injury. Seven uninjured controls (20.0±4.5years) completed the same protocol in similar time increments. Tandem gait test trials were performed with (dual-task) and without (single-task) concurrently performing a cognitive test as whole-body motion analysis was performed. Outcome variables included test completion time, average tandem gait velocity, cadence, and whole-body COM frontal plane displacement. Concussion participants took significantly longer to complete the dual-task tandem gait test than controls throughout the first 2 weeks post-injury (mean time=16.4 [95% CI: 13.4-19.4] vs. 10.1 [95% CI: 6.4-13.7] seconds; p=0.03). Single-task tandem gait times were significantly lower 72h post-injury (p=0.04). Dual-task cadence was significantly lower for concussion participants than controls (89.5 [95% CI: 68.6-110.4] vs. 127.0 [95% CI: 97.4-156.6] steps/minute; p=0.04). Moderately-high to high correlations between tandem gait test time and whole-body COM medial-lateral displacement were detected at each time point during dual-task gait (r s =0.70-0.93; p=0.03-0.001). Adding a cognitive task during the tandem gait test resulted in longer detectable deficits post-concussion compared to the traditional single-task tandem gait test. As a clinical tool to assess dynamic motor function, tandem gait may assist with return to sport decisions after concussion. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  12. Better dual-task processing in simultaneous interpreters

    PubMed Central

    Strobach, Tilo; Becker, Maxi; Schubert, Torsten; Kühn, Simone

    2015-01-01

    Simultaneous interpreting (SI) is a highly complex activity and requires the performance and coordination of multiple, simultaneous tasks: analysis and understanding of the discourse in a first language, reformulating linguistic material, storing of intermediate processing steps, and language production in a second language among others. It is, however, an open issue whether persons with experience in SI possess superior skills in coordination of multiple tasks and whether they are able to transfer these skills to lab-based dual-task situations. Within the present study, we set out to explore whether interpreting experience is associated with related higher-order executive functioning in the context of dual-task situations of the Psychological Refractory Period (PRP) type. In this PRP situation, we found faster reactions times in participants with experience in simultaneous interpretation in contrast to control participants without such experience. Thus, simultaneous interpreters possess superior skills in coordination of multiple tasks in lab-based dual-task situations. PMID:26528232

  13. Reliability and Validity of Dual-Task Mobility Assessments in People with Chronic Stroke

    PubMed Central

    Yang, Lei; He, Chengqi; Pang, Marco Yiu Chung

    2016-01-01

    Background The ability to perform a cognitive task while walking simultaneously (dual-tasking) is important in real life. However, the psychometric properties of dual-task walking tests have not been well established in stroke. Objective To assess the test-retest reliability, concurrent and known-groups validity of various dual-task walking tests in people with chronic stroke. Design Observational measurement study with a test-retest design. Methods Eighty-eight individuals with chronic stroke participated. The testing protocol involved four walking tasks (walking forward at self-selected and maximal speed, walking backward at self-selected speed, and crossing over obstacles) performed simultaneously with each of the three attention-demanding tasks (verbal fluency, serial 3 subtractions or carrying a cup of water). For each dual-task condition, the time taken to complete the walking task, the correct response rate (CRR) of the cognitive task, and the dual-task effect (DTE) for the walking time and CRR were calculated. Forty-six of the participants were tested twice within 3–4 days to establish test-retest reliability. Results The walking time in various dual-task assessments demonstrated good to excellent reliability [Intraclass correlation coefficient (ICC2,1) = 0.70–0.93; relative minimal detectable change at 95% confidence level (MDC95%) = 29%-45%]. The reliability of the CRR (ICC2,1 = 0.58–0.81) and the DTE in walking time (ICC2,1 = 0.11–0.80) was more varied. The reliability of the DTE in CRR (ICC2,1 = -0.31–0.40) was poor to fair. The walking time and CRR obtained in various dual-task walking tests were moderately to strongly correlated with those of the dual-task Timed-up-and-Go test, thus demonstrating good concurrent validity. None of the tests could discriminate fallers (those who had sustained at least one fall in the past year) from non-fallers. Limitation The results are generalizable to community-dwelling individuals with chronic stroke only

  14. Influence of dual-task constraints on the interaction between posture and movement during a lower limb pointing task.

    PubMed

    Silva, Marcelo Guimarães; Struber, Lucas; Brandão, José Geraldo T; Daniel, Olivier; Nougier, Vincent

    2018-04-01

    One of the challenges regarding human motor control is making the movement fluid and at a limited cognitive cost. The coordination between posture and movement is a necessary requirement to perform daily life tasks. The present experiment investigated this interaction in 20 adult men, aged 18-30 years. The cognitive costs associated to postural and movement control when kicking towards a target was estimated using a dual-task paradigm (secondary auditory task). Results showed that addition of the attentional demanding cognitive task yielded a decreased kicking accuracy and an increased timing to perform the movement, mainly during the backswing motion. In addition, significant differences between conditions were found for COP and COM displacement (increased amplitude, mean speed) on the anteroposterior axis. However, no significant differences between conditions were found on the mediolateral axis. Finally, EMG analysis showed that dual-task condition modified the way anticipatory postural adjustments (APAs) were generated. More specifically, we observed an increase of the peroneus longus activity, whereas the temporal EMG showed a decrease of its latency with respect to movement onset. These results suggested a functional adaptation resulting in an invariance of overall APAs, emphasizing that cognitive, postural, and motor processes worked dependently.

  15. Improving posture-motor dual-task with a supraposture-focus strategy in young and elderly adults.

    PubMed

    Yu, Shu-Han; Huang, Cheng-Ya

    2017-01-01

    In a postural-suprapostural task, appropriate prioritization is necessary to achieve task goals and maintain postural stability. A "posture-first" principle is typically favored by elderly people in order to secure stance stability, but this comes at the cost of reduced suprapostural performance. Using a postural-suprapostural task with a motor suprapostural goal, this study investigated differences between young and older adults in dual-task cost across varying task prioritization paradigms. Eighteen healthy young (mean age: 24.8 ± 5.2 years) and 18 older (mean age: 68.8 ± 3.7 years) adults executed a designated force-matching task from a stabilometer board using either a stabilometer stance (posture-focus strategy) or force-matching (supraposture-focus strategy) as the primary task. The dual-task effect (DTE: % change in dual-task condition; positive value: dual-task benefit, negative value: dual-task cost) of force-matching error and reaction time (RT), posture error, and approximate entropy (ApEn) of stabilometer movement were measured. When using the supraposture-focus strategy, young adults exhibited larger DTE values in each behavioral parameter than when using the posture-focus strategy. The older adults using the supraposture-focus strategy also attained larger DTE values for posture error, stabilometer movement ApEn, and force-matching error than when using the posture-focus strategy. These results suggest that the supraposture-focus strategy exerted an increased dual-task benefit for posture-motor dual-tasking in both healthy young and elderly adults. The present findings imply that the older adults should make use of the supraposture-focus strategy for fall prevention during dual-task execution.

  16. Improving posture-motor dual-task with a supraposture-focus strategy in young and elderly adults

    PubMed Central

    Yu, Shu-Han

    2017-01-01

    In a postural-suprapostural task, appropriate prioritization is necessary to achieve task goals and maintain postural stability. A “posture-first” principle is typically favored by elderly people in order to secure stance stability, but this comes at the cost of reduced suprapostural performance. Using a postural-suprapostural task with a motor suprapostural goal, this study investigated differences between young and older adults in dual-task cost across varying task prioritization paradigms. Eighteen healthy young (mean age: 24.8 ± 5.2 years) and 18 older (mean age: 68.8 ± 3.7 years) adults executed a designated force-matching task from a stabilometer board using either a stabilometer stance (posture-focus strategy) or force-matching (supraposture-focus strategy) as the primary task. The dual-task effect (DTE: % change in dual-task condition; positive value: dual-task benefit, negative value: dual-task cost) of force-matching error and reaction time (RT), posture error, and approximate entropy (ApEn) of stabilometer movement were measured. When using the supraposture-focus strategy, young adults exhibited larger DTE values in each behavioral parameter than when using the posture-focus strategy. The older adults using the supraposture-focus strategy also attained larger DTE values for posture error, stabilometer movement ApEn, and force-matching error than when using the posture-focus strategy. These results suggest that the supraposture-focus strategy exerted an increased dual-task benefit for posture-motor dual-tasking in both healthy young and elderly adults. The present findings imply that the older adults should make use of the supraposture-focus strategy for fall prevention during dual-task execution. PMID:28151943

  17. Older adults must hurry at pedestrian lights! A cross-sectional analysis of preferred and fast walking speed under single- and dual-task conditions

    PubMed Central

    Tomovic, Sara; Münzer, Thomas; de Bruin, Eling D.

    2017-01-01

    Slow walking speed is strongly associated with adverse health outcomes, including cognitive impairment, in the older population. Moreover, adequate walking speed is crucial to maintain older pedestrians’ mobility and safety in urban areas. This study aimed to identify the proportion of Swiss older adults that didn’t reach 1.2 m/s, which reflects the requirements to cross streets within the green–yellow phase of pedestrian lights, when walking fast under cognitive challenge. A convenience sample, including 120 older women (65%) and men, was recruited from the community (88%) and from senior residences and divided into groups of 70–79 years (n = 59, 74.8 ± 0.4 y; mean ± SD) and ≥80 years (n = 61, 85.5 ± 0.5 y). Steady state walking speed was assessed under single- and dual-task conditions at preferred and fast walking speed. Additionally, functional lower extremity strength (5-chair-rises test), subjective health rating, and retrospective estimates of fall frequency were recorded. Results showed that 35.6% of the younger and 73.8% of the older participants were not able to walk faster than 1.2 m/s under the fast dual-task walking condition. Fast dual-task walking speed was higher compared to the preferred speed single- and dual-task conditions (all p < .05, r = .31 to .48). Average preferred single-task walking speed was 1.19 ± 0.24 m/s (70–79 y) and 0.94 ± 0.27 m/s (≥80 y), respectively, and correlated with performance in the 5-chair-rises test (rs = −.49, p < .001), subjective health (τ = .27, p < .001), and fall frequency (τ = −.23, p = .002). We conclude that the fitness status of many older people is inadequate to safely cross streets at pedestrian lights and maintain mobility in the community’s daily life in urban areas. Consequently, training measures to improve the older population’s cognitive and physical fitness should be promoted to enhance walking speed and safety of older pedestrians. PMID:28759587

  18. Improving Sensitivity to Detect Mild Cognitive Impairment: Cognitive Load Dual-Task Gait Speed Assessment.

    PubMed

    MacAulay, Rebecca K; Wagner, Mark T; Szeles, Dana; Milano, Nicholas J

    2017-07-01

    Longitudinal research indicates that cognitive load dual-task gait assessment is predictive of cognitive decline and thus might provide a sensitive measure to screen for mild cognitive impairment (MCI). However, research among older adults being clinically evaluated for cognitive concerns, a defining feature of MCI, is lacking. The present study investigated the effect of performing a cognitive task on normal walking speed in patients presenting to a memory clinic with cognitive complaints. Sixty-one patients with a mean age of 68 years underwent comprehensive neuropsychological testing, clinical interview, and gait speed (simple- and dual-task conditions) assessments. Thirty-four of the 61 patients met criteria for MCI. Repeated measure analyses of covariance revealed that greater age and MCI both significantly associated with slower gait speed, ps<.05. Follow-up analysis indicated that the MCI group had significantly slower dual-task gait speed but did not differ in simple-gait speed. Multivariate linear regression across groups found that executive attention performance accounted for 27.4% of the variance in dual-task gait speed beyond relevant demographic and health risk factors. The present study increases the external validity of dual-task gait assessment of MCI. Differences in dual-task gait speed appears to be largely attributable to executive attention processes. These findings have clinical implications as they demonstrate expected patterns of gait-brain behavior relationships in response to a cognitive dual task within a clinically representative population. Cognitive load dual-task gait assessment may provide a cost efficient and sensitive measure to detect older adults at high risk of a dementia disorder. (JINS, 2017, 23, 493-501).

  19. Information access in a dual-task context: testing a model of optimal strategy selection.

    PubMed

    Wickens, C D; Seidler, K S

    1997-09-01

    Pilots were required to access information from a hierarchical aviation database by navigating under single-task conditions (Experiment 1) and when this task was time-shared with an altitude-monitoring task of varying bandwidth and priority (Experiment 2). In dual-task conditions, pilots had 2 viewports available, 1 always used for the information task and the other to be allocated to either task. Dual-task strategy, inferred from the decision of which task to allocate to the 2nd viewport, revealed that allocation was generally biased in favor of the monitoring task and was only partly sensitive to the difficulty of the 2 tasks and their relative priorities. Some dominant sources of navigational difficulties failed to adaptively influence selection strategy. The implications of the results are to provide tools for jumping to the top of the database, to provide 2 viewports into the common database, and to provide training as to the optimum viewport management strategy in a multitask environment.

  20. Information access in a dual-task context: testing a model of optimal strategy selection

    NASA Technical Reports Server (NTRS)

    Wickens, C. D.; Seidler, K. S.

    1997-01-01

    Pilots were required to access information from a hierarchical aviation database by navigating under single-task conditions (Experiment 1) and when this task was time-shared with an altitude-monitoring task of varying bandwidth and priority (Experiment 2). In dual-task conditions, pilots had 2 viewports available, 1 always used for the information task and the other to be allocated to either task. Dual-task strategy, inferred from the decision of which task to allocate to the 2nd viewport, revealed that allocation was generally biased in favor of the monitoring task and was only partly sensitive to the difficulty of the 2 tasks and their relative priorities. Some dominant sources of navigational difficulties failed to adaptively influence selection strategy. The implications of the results are to provide tools for jumping to the top of the database, to provide 2 viewports into the common database, and to provide training as to the optimum viewport management strategy in a multitask environment.

  1. The effects of dual tasking on gait synchronization during over-ground side-by-side walking.

    PubMed

    Zivotofsky, Ari Z; Bernad-Elazari, Hagar; Grossman, Pnina; Hausdorff, Jeffrey M

    2018-06-01

    Recent studies have shown that gait synchronization during natural walking is not merely anecdotal, but it is a repeatable phenomenon that is quantifiable and is apparently related to available sensory feedback modalities. However, the mechanisms underlying this phase-locking of gait have only recently begun to be investigated. For example, it is not known what role, if any, attention plays. We employed a dual tasking paradigm in order to investigate the role attention plays in gait synchronization. Sixteen pairs of subjects walked under six conditions that manipulated the available sensory feedback and the degree of difficulty of the dual task, i.e., the attention. Movement was quantified using a trunk-mounted tri-axial accelerometer. A gait synchronization index (GSI) was calculated in order to quantify the degree of synchronization of the gait pattern. A simple dual task resulted in an increased level of synchronization, whereas a more complex dual task lead to a reduction in synchronization. Handholding increased synchronization, compared to the same attention condition without handholding. These results indicate that in order for two walkers to synchronize, some level of attention is apparently required, such that a relatively complex dual task utilizes enough attentional resources to reduce the occurrence of synchronization. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Does dual-task coordination performance decline in later life?

    PubMed

    Sebastián, María V; Mediavilla, Roberto

    2017-05-01

    This cross-sectional study examined whether changes occur in people’s capacity to coordinate two simultaneous tasks (dual-task) when transitioning from adulthood to later life. The central executive, Baddeley’s working memory model component, is responsible for this coordination. Contradictory results have been reported regarding the relationship between ageing and dual-task performance; but these seem to be related to methodological issues that have been addressed in this study. Nine hundred and seventy-two participants, aged between 35 and 90 years old, volunteered to carry out a verbal digit span task, followed by single and concurrent (dual-task) tests: first, a box crossing task, then, the digit recall task in relation to their memory span, and finally, both these tests simultaneously. We found no difference in people’s capacity to coordinate their attention when doing two tasks in adulthood or healthy later life, including those in the oldest age groups. Furthermore, gender and educational level were not related to dual-task performance. The results support the normal functioning of the central executive in very old people. These data contrast with research with patients suffering from different types of dementia, which show a decrease in their dual-task performance.

  3. Transcranial Direct Current Stimulation to Enhance Dual-Task Gait Training in Parkinson's Disease: A Pilot RCT.

    PubMed

    Schabrun, Siobhan M; Lamont, Robyn M; Brauer, Sandra G

    2016-01-01

    To investigate the feasibility and safety of a combined anodal transcranial direct current stimulation (tDCS) and dual task gait training intervention in people with Parkinson's Disease (PD) and to provide data to support a sample size calculation for a fully powered trial should trends of effectiveness be present. A pilot, randomized, double-blind, sham-controlled parallel group trial with 12 week follow-up. A university physiotherapy department. Sixteen participants diagnosed with PD received nine dual task gait training sessions over 3 weeks. Participants were randomized to receive either active or sham tDCS applied for the first 20 minutes of each session. The primary outcome was gait speed while undertaking concurrent cognitive tasks (word lists, counting, conversation). Secondary measures included step length, cadence, Timed Up and Go, bradykinesia and motor speed. Gait speed, step length and cadence improved in both groups, under all dual task conditions. This effect was maintained at follow-up. There was no difference between the active and sham tDCS groups. Time taken to perform the TUGwords also improved, with no difference between groups. The active tDCS group did however increase their correct cognitive response rate during the TUGwords and TUGcount. Bradykinesia improved after training in both groups. Three weeks of dual task gait training resulted in improved gait under dual task conditions, and bradykinesia, immediately following training and at 12 weeks follow-up. The only parameter enhanced by tDCS was the number of correct responses while performing the dual task TUG. tDCS applied to M1 may not be an effective adjunct to dual task gait training in PD. Australia-New Zealand Clinical Trials Registry ACTRN12613001093774.

  4. Gait assessment in mild cognitive impairment and Alzheimer's disease: the effect of dual-task challenges across the cognitive spectrum.

    PubMed

    Muir, Susan W; Speechley, Mark; Wells, Jennie; Borrie, Michael; Gopaul, Karen; Montero-Odasso, Manuel

    2012-01-01

    Gait impairment is a prominent falls risk factor and a prevalent feature among older adults with cognitive impairment. However, there is a lack of comparative studies on gait performance and fall risk covering the continuum from normal cognition through mild cognitive impairment (MCI) to Alzheimer's disease (AD). We evaluated gait performance and the response to dual-task challenges in older adults with AD, MCI and normal cognition without a history of falls. We hypothesized that, in older people without history of falls, gait performance will deteriorate across the cognitive spectrum with changes being more evident under dual-tasking. Gait was assessed using an electronic walkway under single and three dual-tasks conditions. Gait velocity and stride time variability were not significantly different between the three groups under the single-task condition. By contrast, significant differences of decreasing velocity (p<0.0001), increasing stride time (p=0.0057) and increasing stride time variability (p=0.0037) were found under dual-task testing for people with MCI and AD. Less automatic and more complex dual-task tests, such as naming animals and serial subtraction by sevens from 100, created the greatest deterioration of gait performance. Gait changes under dual-tasking for the MCI and AD groups were statistically different from the cognitively normal controls. Dual-task assessment exposed gait impairments not obvious under a single-task test condition and may facilitate falls risk identification in cognitively impaired persons without a history of falls. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Brain Activations for Vestibular Stimulation and Dual Tasking Change with Spaceflight

    NASA Technical Reports Server (NTRS)

    Yuan, Peng; Koppelmans, Vincent; Reuter-Lorenz, Patricia; De Dios, Yiri; Gadd, Nichole; Wood, Scott; Riascos, Roy; Kofman, Igor; Bloomberg, Jacob; Mulavara, Ajitkumar; hide

    2017-01-01

    Previous studies have documented the effects of spaceflight on human physiology and behavior, including muscle mass, cardiovascular function, gait, balance, manual motor control, and cognitive performance. An understanding of spaceflight-related changes provides important information about human adaptive plasticity and facilitates future space travel. In the current study, we evaluated how brain activations associated with vestibular stimulation and dual tasking change as a function of spaceflight. Five crewmembers were included in this study. The durations of their spaceflight missions ranged from 3 months to 7 months. All of them completed at least two preflight assessments and at least one postflight assessment. The preflight sessions occurred, on average, about 198 days and 51 days before launch; the first postflight sessions were scheduled 5 days after return. Functional MRI was acquired during vestibular stimulation and dual tasking, at each session. Vestibular stimulation was administered via skull taps delivered by a pneumatic tactile pulse system placed over the lateral cheekbones. The magnitude of brain activations for vestibular stimulation increased with spaceflight relative to the preflight levels, in frontal areas and the precuneus. In addition, longer flight duration was associated with greater preflight-to-postflight increases in vestibular activation in frontal regions. Functional MRI for finger tapping was acquired during both single-task (finger tapping only) and dual-task (simultaneously performing finger tapping and a secondary counting task) conditions. Preflight-to-post-spaceflight decreases in brain activations for dual tasking were observed in the right postcentral cortex. An association between flight duration and amplitude of flight-related change in activations for dual tasking was observed in the parietal cortex. The spaceflight-related increase in vestibular brain activations suggests that after a long-term spaceflight, more neural

  6. Walking in School-Aged Children in a Dual-Task Paradigm Is Related to Age But Not to Cognition, Motor Behavior, Injuries, or Psychosocial Functioning

    PubMed Central

    Hagmann-von Arx, Priska; Manicolo, Olivia; Lemola, Sakari; Grob, Alexander

    2016-01-01

    Age-dependent gait characteristics and associations with cognition, motor behavior, injuries, and psychosocial functioning were investigated in 138 typically developing children aged 6.7–13.2 years (M = 10.0 years). Gait velocity, normalized velocity, and variability were measured using the walkway system GAITRite without an additional task (single task) and while performing a motor or cognitive task (dual task). Assessment of children’s cognition included tests for intelligence and executive functions; parents reported on their child’s motor behavior, injuries, and psychosocial functioning. Gait variability (an index of gait regularity) decreased with increasing age in both single- and dual-task walking. Dual-task gait decrements were stronger when children walked in the motor compared to the cognitive dual-task condition and decreased with increasing age in both dual-task conditions. Gait alterations from single- to dual-task conditions were not related to children’s cognition, motor behavior, injuries, or psychosocial functioning. PMID:27014158

  7. The Effect of Cognitive-Task Type and Walking Speed on Dual-Task Gait in Healthy Adults.

    PubMed

    Wrightson, James G; Ross, Emma Z; Smeeton, Nicholas J

    2016-01-01

    In a number of studies in which a dual-task gait paradigm was used, researchers reported a relationship between cognitive function and gait. However, it is not clear to what extent these effects are dependent on the type of cognitive and walking tasks used in the dual-task paradigm. This study examined whether stride-time variability (STV) and trunk range of motion (RoM) are affected by the type of cognitive task and walking speed used during dual-task gait. Participants walked at both their preferred walking speed and at 25% of their preferred walking speed and performed a serial subtraction and a working memory task at both speeds. Although both tasks significantly reduced STV at both walking speeds, there was no difference between the two tasks. Trunk RoM was affected by the walking speed and type of cognitive task used during dual-task gait: Mediolateral trunk RoM was increased at the slow walking speed, and anterior-posterior trunk RoM was higher only when performing the serial subtraction task at the slow walking speed. The reduction of STV, regardless of cognitive-task type, suggests that healthy adults may redirect cognitive processes away from gait toward cognitive-task performance during dual-task gait.

  8. Dual-Task Does Not Increase Slip and Fall Risk in Healthy Young and Older Adults during Walking

    PubMed Central

    Soangra, Rahul

    2017-01-01

    Dual-task tests can identify gait characteristics peculiar to fallers and nonfallers. Understanding the relationship between gait performance and dual-task related cognitive-motor interference is important for fall prevention. Dual-task adapted changes in gait instability/variability can adversely affect fall risks. Although implicated, it is unclear if healthy participants' fall risks are modified by dual-task walking conditions. Seven healthy young and seven healthy older adults were randomly assigned to normal walking and dual-task walking sessions with a slip perturbation. In the dual-task session, the participants walked and simultaneously counted backwards from a randomly provided number. The results indicate that the gait changes in dual-task walking have no destabilizing effect on gait and slip responses in healthy individuals. We also found that, during dual-tasking, healthy individuals adopted cautious gait mode (CGM) strategy that is characterized by reduced walking speed, shorter step length, increased step width, and reduced heel contact velocity and is likely to be an adaptation to minimize attentional demand and decrease slip and fall risk during limited available attentional resources. Exploring interactions between gait variability and cognitive functions while walking may lead to designing appropriate fall interventions among healthy and patient population with fall risk. PMID:28255224

  9. Static and dynamic single leg postural control performance during dual-task paradigms.

    PubMed

    Talarico, Maria K; Lynall, Robert C; Mauntel, Timothy C; Weinhold, Paul S; Padua, Darin A; Mihalik, Jason P

    2017-06-01

    Combining dynamic postural control assessments and cognitive tasks may give clinicians a more accurate indication of postural control under sport-like conditions compared to single-task assessments. We examined postural control, cognitive and squatting performance of healthy individuals during static and dynamic postural control assessments in single- and dual-task paradigms. Thirty participants (female = 22, male = 8; age = 20.8 ± 1.6 years, height = 157.9 ± 13.0 cm, mass = 67.8 ± 20.6 kg) completed single-leg stance and single-leg squat assessments on a force plate individually (single-task) and concurrently (dual-task) with two cognitive assessments, a modified Stroop test and the Brooks Spatial Memory Test. Outcomes included centre of pressure speed, 95% confidence ellipse, squat depth and speed and cognitive test measures (percentage of correct answers and reaction time). Postural control performance varied between postural control assessments and testing paradigms. Participants did not squat as deep and squatted slower (P < 0.001) during dual-task paradigms (≤12.69 ± 3.4 cm squat depth, ≤16.20 ± 4.6 cm · s -1 squat speed) compared to single-task paradigms (14.57 ± 3.6 cm squat depth, 19.65 ± 5.5 cm · s -1 squat speed). The percentage of correct answers did not change across testing conditions, but Stroop reaction time (725.81 ± 59.2 ms; F 2,58  = 7.725, P = 0.001) was slowest during single-leg squats compared to baseline (691.64 ± 80.1 ms; P = 0.038) and single-task paradigms (681.33 ± 51.5 ms; P < 0.001). Dynamic dual-task assessments may be more challenging to the postural control system and may better represent postural control performance during dynamic activities.

  10. Effect of type of cognitive task and walking speed on cognitive-motor interference during dual-task walking.

    PubMed

    Patel, P; Lamar, M; Bhatt, T

    2014-02-28

    We aimed to determine the effect of distinctly different cognitive tasks and walking speed on cognitive-motor interference of dual-task walking. Fifteen healthy adults performed four cognitive tasks: visuomotor reaction time (VMRT) task, word list generation (WLG) task, serial subtraction (SS) task, and the Stroop (STR) task while sitting and during walking at preferred-speed (dual-task normal walking) and slow-speed (dual-task slow-speed walking). Gait speed was recorded to determine effect on walking. Motor and cognitive costs were measured. Dual-task walking had a significant effect on motor and cognitive parameters. At preferred-speed, the motor cost was lowest for the VMRT task and highest for the STR task. In contrast, the cognitive cost was highest for the VMRT task and lowest for the STR task. Dual-task slow walking resulted in increased motor cost and decreased cognitive cost only for the STR task. Results show that the motor and cognitive cost of dual-task walking depends heavily on the type and perceived complexity of the cognitive task being performed. Cognitive cost for the STR task was low irrespective of walking speed, suggesting that at preferred-speed individuals prioritize complex cognitive tasks requiring higher attentional and processing resources over walking. While performing VMRT task, individuals preferred to prioritize more complex walking task over VMRT task resulting in lesser motor cost and increased cognitive cost for VMRT task. Furthermore, slow walking can assist in diverting greater attention towards complex cognitive tasks, improving its performance while walking. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Do frailty and cognitive impairment affect dual-task cost during walking in the oldest old institutionalized patients?

    PubMed

    Cadore, Eduardo L; Casas-Herrero, Alvaro; Zambom-Ferraresi, Fabricio; Martínez-Ramírez, Alicia; Millor, Nora; Gómez, Marisol; Moneo, Ana B Bays; Izquierdo, Mikel

    2015-12-01

    The objective of this study was to investigate dual-task costs in several elderly populations, including robust oldest old, frail oldest old with MCI, frail oldest old without MCI, and frail elderly with dementia. Sixty-four elderly men and women categorized into frail without MCI (age 93.4 ± 3.2 years, n = 20), frail with MCI (age 92.4 ± 4.2 years, n = 13), robust (age 88.2 ± 4.1 years, n = 10), and patients with dementia (age 88.1 ± 5.1 years, n = 21). Five-meter gait ability and timed-up-and-go (TUG) tests with single and dual-task performance were assessed in the groups. Dual-task cost in both 5-m habitual gait velocity test and TUG test was calculated by the time differences between single and dual-task performance. The robust group exhibited better 5-m gait and TUG test performances in the single and dual-task conditions compared with the other three groups (P < 0.001), and the frail and frail + MCI groups exhibited better performances than the dementia group (P < 0.001). No significant differences were observed between the frail and frail + MCI groups. However, all groups exhibited lower gait velocities in the verbal and arithmetic task conditions, but the dual-task cost of the groups were similar. Robust individuals exhibited superior single and dual-task walking performances than the other three groups, and the frail and frail + MCI individuals exhibited performances that were superior to those of the patients with dementia. However, the dual-task costs, i.e., the changes in gait performance when elderly participants switch from a single to a dual task, were similar among all four of the investigated groups. Therefore, these results demonstrated that the magnitude of the impairment in gait pattern is independent of frailty and cognitive impairment status.

  12. Gait disorders in the elderly and dual task gait analysis: a new approach for identifying motor phenotypes.

    PubMed

    Auvinet, Bernard; Touzard, Claude; Montestruc, François; Delafond, Arnaud; Goeb, Vincent

    2017-01-31

    Gait disorders and gait analysis under single and dual-task conditions are topics of great interest, but very few studies have looked for the relevance of gait analysis under dual-task conditions in elderly people on the basis of a clinical approach. An observational study including 103 patients (mean age 76.3 ± 7.2, women 56%) suffering from gait disorders or memory impairment was conducted. Gait analysis under dual-task conditions was carried out for all patients. Brain MRI was performed in the absence of contra-indications. Three main gait variables were measured: walking speed, stride frequency, and stride regularity. For each gait variable, the dual task cost was computed and a quartile analysis was obtained. Nonparametric tests were used for all the comparisons (Wilcoxon, Kruskal-Wallis, Fisher or Chi 2 tests). Four clinical subgroups were identified: gait instability (45%), recurrent falls (29%), memory impairment (18%), and cautious gait (8%). The biomechanical severity of these subgroups was ordered according to walking speed and stride regularity under both conditions, from least to most serious as follows: memory impairment, gait instability, recurrent falls, cautious gait (p < 0.01 for walking speed, p = 0.05 for stride regularity). According to the established diagnoses of gait disorders, 5 main pathological subgroups were identified (musculoskeletal diseases (n = 11), vestibular diseases (n = 6), mild cognitive impairment (n = 24), central nervous system pathologies, (n = 51), and without diagnosis (n = 8)). The dual task cost for walking speed, stride frequency and stride regularity were different among these subgroups (p < 0.01). The subgroups mild cognitive impairment and central nervous system pathologies both showed together a higher dual task cost for each variable compared to the other subgroups combined (p = 0.01). The quartile analysis of dual task cost for stride frequency and stride regularity

  13. Effect of subthalamic nucleus deep brain stimulation on dual-task cognitive and motor performance in isolated dystonia

    PubMed Central

    Mills, Kelly A; Markun, Leslie C; Luciano, Marta San; Rizk, Rami; Allen, I Elaine; Racine, Caroline A; Starr, Philip A; Alberts, Jay L; Ostrem, Jill L

    2015-01-01

    Objective Subthalamic nucleus (STN) deep brain stimulation (DBS) can improve motor complications of Parkinson's disease (PD) but may worsen specific cognitive functions. The effect of STN DBS on cognitive function in dystonia patients is less clear. Previous reports indicate that bilateral STN stimulation in patients with PD amplifies the decrement in cognitive-motor dual-task performance seen when moving from a single-task to dual-task paradigm. We aimed to determine if the effect of bilateral STN DBS on dual-task performance in isolated patients with dystonia, who have less cognitive impairment and no dementia, is similar to that seen in PD. Methods Eight isolated predominantly cervical patients with dystonia treated with bilateral STN DBS, with average dystonia duration of 10.5 years and Montreal Cognitive Assessment score of 26.5, completed working memory (n-back) and motor (forced-maintenance) tests under single-task and dual-task conditions while on and off DBS. Results A multivariate, repeated-measures analysis of variance showed no effect of stimulation status (On vs Off) on working memory (F=0.75, p=0.39) or motor function (F=0.22, p=0.69) when performed under single-task conditions, though as working memory task difficulty increased, stimulation disrupted the accuracy of force-tracking. There was a very small worsening in working memory performance (F=9.14, p=0.019) when moving from single-task to dual-tasks when using the ‘dual-task loss’ analysis. Conclusions This study suggests the effect of STN DBS on working memory and attention may be much less consequential in patients with dystonia than has been reported in PD. PMID:25012202

  14. Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults

    PubMed Central

    Banducci, Sarah E.; Daugherty, Ana M.; Fanning, Jason; Awick, Elizabeth A.; Porter, Gwenndolyn C.; Burzynska, Agnieszka; Shen, Sa; Kramer, Arthur F.; McAuley, Edward

    2017-01-01

    Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60–79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial). PMID:28255557

  15. Smartphone App–Based Assessment of Gait During Normal and Dual-Task Walking: Demonstration of Validity and Reliability

    PubMed Central

    Yu, Wanting; Zhu, Hao; Harrison, Rachel; Lo, On-Yee; Lipsitz, Lewis; Travison, Thomas; Pascual-Leone, Alvaro; Zhou, Junhong

    2018-01-01

    Background Walking is a complex cognitive motor task that is commonly completed while performing another task such as talking or making decisions. Gait assessments performed under normal and “dual-task” walking conditions thus provide important insights into health. Such assessments, however, are limited primarily to laboratory-based settings. Objective The objective of our study was to create and test a smartphone-based assessment of normal and dual-task walking for use in nonlaboratory settings. Methods We created an iPhone app that used the phone’s motion sensors to record movements during walking under normal conditions and while performing a serial-subtraction dual task, with the phone placed in the user’s pants pocket. The app provided the user with multimedia instructions before and during the assessment. Acquired data were automatically uploaded to a cloud-based server for offline analyses. A total of 14 healthy adults completed 2 laboratory visits separated by 1 week. On each visit, they used the app to complete three 45-second trials each of normal and dual-task walking. Kinematic data were collected with the app and a gold-standard–instrumented GAITRite mat. Participants also used the app to complete normal and dual-task walking trials within their homes on 3 separate days. Within laboratory-based trials, GAITRite-derived heel strikes and toe-offs of the phone-side leg aligned with smartphone acceleration extrema, following filtering and rotation to the earth coordinate system. We derived stride times—a clinically meaningful metric of locomotor control—from GAITRite and app data, for all strides occurring over the GAITRite mat. We calculated stride times and the dual-task cost to the average stride time (ie, percentage change from normal to dual-task conditions) from both measurement devices. We calculated similar metrics from home-based app data. For these trials, periods of potential turning were identified via custom-developed algorithms

  16. Investigation on the improvement and transfer of dual-task coordination skills.

    PubMed

    Strobach, Tilo; Frensch, Peter A; Soutschek, Alexander; Schubert, Torsten

    2012-11-01

    Recent research has demonstrated that dual-task performance in situations with two simultaneously presented tasks can be substantially improved with extensive practice. This improvement was related to the acquisition of task coordination skills. Earlier studies provided evidence that these skills result from hybrid practice, including dual and single tasks, but not from single-task practice. It is an open question, however, whether task coordination skills are independent from the specific practice situation and are transferable to new situations or whether they are non-transferable and task-specific. The present study, therefore, tested skill transfer in (1) a dual-task situation with identical tasks in practice and transfer, (2) a dual-task situation with two tasks changed from practice to transfer, and (3) a task switching situation with two sequentially presented tasks. Our findings are largely consistent with the assumption that task coordination skills are non-transferable and task-specific. We cannot, however, definitively reject the assumption of transferable skills when measuring error rates in the dual-task situation with two changed tasks after practice. In the task switching situation, single-task and hybrid practice both led to a transfer effect on mixing costs.

  17. The effects of cognitively demanding dual-task driving condition on elderly people's driving performance; Real driving monitoring.

    PubMed

    Ebnali, Mahdi; Ahmadnezhad, Pedram; Shateri, Alireza; Mazloumi, Adel; Ebnali Heidari, Majid; Nazeri, Ahmad Reza

    2016-09-01

    Using in-vehicle audio technologies such as audio systems and voice messages is regarded as a common secondary task. Such tasks, known as the sources of non-visual distraction, affect the driving performance. Given the elderly drivers' cognitive limitations, driving can be even more challenging to drivers. The current study examined how listening to economic news, as a cognitively demanding secondary task, affects elderly subjects' driving performance and whether their comprehension accuracy is associated with these effects. Participants of the study (N=22) drove in a real condition with and without listening to economic news. Measurements included driving performance (speed control, forward crash risk, and lateral lane position) and task performance (comprehension accuracy). The mean driving speed, duration of driving in unsafe zones and numbers of overtaking decreased significantly when drivers were engaged in the dual-task condition. Moreover, the cognitive secondary task led to a higher speed variability. Our results demonstrate that there was not a significant relationship between the lane changes and the activity of listening to economic news. However, a meaningful difference was observed between general comprehension and deep comprehension on the one hand and driving performance on the other. Another aspect of our study concerning the drivers' ages and their comprehension revealed a significant relationship between age above 75 and comprehension level. Drivers aging 75 and older showed a lower level of deep comprehension. Our study demonstrates that elderly drivers compensated driving performance with safety margin adoption while they were cognitively engaged. In this condition, however, maintaining speed proved more demanding for drivers aging 75 and older. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Age-Related Changes in the Processing of Emotional Faces in a Dual-Task Paradigm.

    PubMed

    Casares-Guillén, Carmen; García-Rodríguez, Beatriz; Delgado, Marisa; Ellgring, Heiner

    2016-01-01

    Background/ Study Context: Age-related changes appear to affect the ability to identify emotional facial expressions in dual-task conditions (i.e., while simultaneously performing a second visual task). The level of interference generated by the secondary task depends on the phase of emotional processing affected by the interference and the nature of the secondary task. The aim of the present study was to investigate the effect of these variables on age-related changes in the processing of emotional faces. The identification of emotional facial expressions (EFEs) was assessed in a dual-task paradigm using the following variables: (a) the phase during which interference was applied (encoding vs. retrieval phase); and (b) the nature of the interfering stimulus (visuospatial vs. verbal). The sample population consisted of 24 healthy aged adults (mean age = 75.38) and 40 younger adults (mean age = 26.90). The accuracy of EFE identification was calculated for all experimental conditions. Consistent with our hypothesis, the performance of the older group was poorer than that of the younger group in all experimental conditions. Dual-task performance was poorer when the interference occurred during the encoding phase of emotional face processing and when both tasks were of the same nature (i.e., when the experimental condition was more demanding in terms of attention). These results provide empirical evidence of age-related deficits in the identification of emotional facial expressions, which may be partially explained by the impairment of cognitive resources specific to this task. These findings may account for the difficulties experienced by the elderly during social interactions that require the concomitant processing of emotional and environmental information.

  19. Fatigue does not conjointly alter postural and cognitive performance when standing in a shooting position under dual-task conditions.

    PubMed

    Bermejo, José Luis; García-Massó, Xavier; Paillard, Thierry; Noé, Frédéric

    2018-02-01

    This study investigated the effects of fatigue on balance control and cognitive performance in a standing shooting position. Nineteen soldiers were asked to stand while holding a rifle (single task - ST). They also had to perform this postural task while simultaneously completing a cognitive task (dual task - DT). Both the ST and DT were performed in pre- and post-fatigue conditions. In pre-fatigue, participants achieved better balance control in the DT than in the ST, thus suggesting that the increased cognitive activity associated with the DT improves balance control by shifting the attentional focus away from a highly automatised activity. In post-fatigue, balance control was degraded in both the ST and DT, while reaction time was enhanced in the first minutes following the fatiguing exercise without affecting the accuracy of response in the cognitive task, which highlights the relative independent effects of fatigue on balance control and cognitive performance.

  20. Mood states determine the degree of task shielding in dual-task performance.

    PubMed

    Zwosta, Katharina; Hommel, Bernhard; Goschke, Thomas; Fischer, Rico

    2013-01-01

    Current models of multitasking assume that dual-task performance and the degree of multitasking are affected by cognitive control strategies. In particular, cognitive control is assumed to regulate the amount of shielding of the prioritised task from crosstalk from the secondary task. We investigated whether and how task shielding is influenced by mood states. Participants were exposed to two short film clips, one inducing high and one inducing low arousal, of either negative or positive content. Negative mood led to stronger shielding of the prioritised task (i.e., less crosstalk) than positive mood, irrespective of arousal. These findings support the assumption that emotional states determine the parameters of cognitive control and play an important role in regulating dual-task performance.

  1. Poorer divided attention in children born very preterm can be explained by difficulty with each component task, not the executive requirement to dual-task.

    PubMed

    Delane, Louise; Campbell, Catherine; Bayliss, Donna M; Reid, Corinne; Stephens, Amelia; French, Noel; Anderson, Mike

    2017-07-01

    Children born very preterm (VP, ≤ 32 weeks) exhibit poor performance on tasks of executive functioning. However, it is largely unknown whether this reflects the cumulative impact of non-executive deficits or a separable impairment in executive-level abilities. A dual-task paradigm was used in the current study to differentiate the executive processes involved in performing two simple attention tasks simultaneously. The executive-level contribution to performance was indexed by the within-subject cost incurred to single-task performance under dual-task conditions, termed dual-task cost. The participants included 77 VP children (mean age: 7.17 years) and 74 peer controls (mean age: 7.16 years) who completed Sky Search (selective attention), Score (sustained attention) and Sky Search DT (divided attention) from the Test of Everyday Attention for Children. The divided-attention task requires the simultaneous performance of the selective- and sustained-attention tasks. The VP group exhibited poorer performance on the selective- and divided-attention tasks, and showed a strong trend toward poorer performance on the sustained-attention task. However, there were no significant group differences in dual-task cost. These results suggest a cumulative impact of vulnerable lower-level cognitive processes on dual-tasking or divided attention in VP children, and fail to support the hypothesis that VP children show a separable impairment in executive-level abilities.

  2. Monitoring supports performance in a dual-task paradigm involving a risky decision-making task and a working memory task

    PubMed Central

    Gathmann, Bettina; Schiebener, Johannes; Wolf, Oliver T.; Brand, Matthias

    2015-01-01

    Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring—an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task). This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST) and the newly developed Balanced Switching Task (BST), measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task. PMID:25741308

  3. Smartphone App-Based Assessment of Gait During Normal and Dual-Task Walking: Demonstration of Validity and Reliability.

    PubMed

    Manor, Brad; Yu, Wanting; Zhu, Hao; Harrison, Rachel; Lo, On-Yee; Lipsitz, Lewis; Travison, Thomas; Pascual-Leone, Alvaro; Zhou, Junhong

    2018-01-30

    Walking is a complex cognitive motor task that is commonly completed while performing another task such as talking or making decisions. Gait assessments performed under normal and "dual-task" walking conditions thus provide important insights into health. Such assessments, however, are limited primarily to laboratory-based settings. The objective of our study was to create and test a smartphone-based assessment of normal and dual-task walking for use in nonlaboratory settings. We created an iPhone app that used the phone's motion sensors to record movements during walking under normal conditions and while performing a serial-subtraction dual task, with the phone placed in the user's pants pocket. The app provided the user with multimedia instructions before and during the assessment. Acquired data were automatically uploaded to a cloud-based server for offline analyses. A total of 14 healthy adults completed 2 laboratory visits separated by 1 week. On each visit, they used the app to complete three 45-second trials each of normal and dual-task walking. Kinematic data were collected with the app and a gold-standard-instrumented GAITRite mat. Participants also used the app to complete normal and dual-task walking trials within their homes on 3 separate days. Within laboratory-based trials, GAITRite-derived heel strikes and toe-offs of the phone-side leg aligned with smartphone acceleration extrema, following filtering and rotation to the earth coordinate system. We derived stride times-a clinically meaningful metric of locomotor control-from GAITRite and app data, for all strides occurring over the GAITRite mat. We calculated stride times and the dual-task cost to the average stride time (ie, percentage change from normal to dual-task conditions) from both measurement devices. We calculated similar metrics from home-based app data. For these trials, periods of potential turning were identified via custom-developed algorithms and omitted from stride-time analyses

  4. The ability of people with Parkinson's disease to modify dual-task performance in response to instructions during simple and complex walking tasks.

    PubMed

    Kelly, Valerie E; Shumway-Cook, Anne

    2014-01-01

    Gait impairments are a common and consequential motor symptom in Parkinson's disease (PD). A cognitive strategy that incorporates instructions to concentrate on specific parameters of walking is an effective approach to gait rehabilitation for persons with PD during single-task and simple dual-task walking conditions. This study examined the ability to modify dual-task walking in response to instructions during a complex walking task in people with PD compared to healthy older adults (HOA). Eleven people with PD and twelve HOA performed a cognitive task while walking with either a usual base or a narrow base of support. Dual-task walking and cognitive task performance were characterized under two conditions-when participants were instructed focus on walking and when they were instructed to focus on the cognitive task. During both usual base and narrow base walking, instructions affected cognitive task response latency, with slower performance when instructed to focus on walking compared to the cognitive task. Regardless of task or instructions, cognitive task performance was slower in participants with PD compared to HOA. During usual base walking, instructions influenced gait speed for both people with PD and HOA, with faster gait speed when instructed to focus on walking compared to the cognitive task. In contrast, during the narrow base walking, instructions affected gait speed only for HOA, but not for people with PD. This suggests that among people with PD the ability to modify walking in response to instructions depends on the complexity of the walking task.

  5. Dual-tasking and gait in people with Mild Cognitive Impairment. The effect of working memory

    PubMed Central

    Montero-Odasso, Manuel; Bergman, Howard; Phillips, Natalie A; Wong, Chek H; Sourial, Nadia; Chertkow, Howard

    2009-01-01

    Background Cognition and mobility in older adults are closely associated and they decline together with aging. Studies evaluating associations between cognitive factors and gait performance in people with Mild Cognitive Impairment (MCI) are scarce. In this study, our aim was to determine whether specific cognitive factors have a more identifiable effect on gait velocity during dual-tasking in people with MCI. Methods Fifty-five participants, mean age 77.7 (SD = 5.9), 45% women, with MCI were evaluated for global cognition, working memory, executive function, and attention. Gait Velocity (GV) was measured under a single-task condition (single GV) and under two dual-task conditions: 1) while counting backwards (counting GV), 2) while naming animals (verbal GV). Multivariable linear regression analysis was used to examine associations with an alpha-level of 0.05. Results Participants experienced a reduction in GV while engaging in dual-task challenges (p < 0.005). Low executive function and working memory performances were associated with slow single GV (p = 0.038), slow counting GV (p = 0.017), and slow verbal GV (p = 0.031). After adjustments, working memory was the only cognitive factor which remained significantly associated with a slow GV. Conclusion In older adults with MCI, low working memory performance was associated with slow GV. Dual-task conditions showed the strongest associations with gait slowing. Our findings suggest that cortical control of gait is associated with decline in working memory in people with MCI. PMID:19723315

  6. Effect of subthalamic nucleus deep brain stimulation on dual-task cognitive and motor performance in isolated dystonia.

    PubMed

    Mills, Kelly A; Markun, Leslie C; San Luciano, Marta; Rizk, Rami; Allen, I Elaine; Racine, Caroline A; Starr, Philip A; Alberts, Jay L; Ostrem, Jill L

    2015-04-01

    Subthalamic nucleus (STN) deep brain stimulation (DBS) can improve motor complications of Parkinson's disease (PD) but may worsen specific cognitive functions. The effect of STN DBS on cognitive function in dystonia patients is less clear. Previous reports indicate that bilateral STN stimulation in patients with PD amplifies the decrement in cognitive-motor dual-task performance seen when moving from a single-task to dual-task paradigm. We aimed to determine if the effect of bilateral STN DBS on dual-task performance in isolated patients with dystonia, who have less cognitive impairment and no dementia, is similar to that seen in PD. Eight isolated predominantly cervical patients with dystonia treated with bilateral STN DBS, with average dystonia duration of 10.5 years and Montreal Cognitive Assessment score of 26.5, completed working memory (n-back) and motor (forced-maintenance) tests under single-task and dual-task conditions while on and off DBS. A multivariate, repeated-measures analysis of variance showed no effect of stimulation status (On vs Off) on working memory (F=0.75, p=0.39) or motor function (F=0.22, p=0.69) when performed under single-task conditions, though as working memory task difficulty increased, stimulation disrupted the accuracy of force-tracking. There was a very small worsening in working memory performance (F=9.14, p=0.019) when moving from single-task to dual-tasks when using the 'dual-task loss' analysis. This study suggests the effect of STN DBS on working memory and attention may be much less consequential in patients with dystonia than has been reported in PD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Dividing Attention Between Tasks: Testing Whether Explicit Payoff Functions Elicit Optimal Dual-Task Performance.

    PubMed

    Farmer, George D; Janssen, Christian P; Nguyen, Anh T; Brumby, Duncan P

    2018-04-01

    We test people's ability to optimize performance across two concurrent tasks. Participants performed a number entry task while controlling a randomly moving cursor with a joystick. Participants received explicit feedback on their performance on these tasks in the form of a single combined score. This payoff function was varied between conditions to change the value of one task relative to the other. We found that participants adapted their strategy for interleaving the two tasks, by varying how long they spent on one task before switching to the other, in order to achieve the near maximum payoff available in each condition. In a second experiment, we show that this behavior is learned quickly (within 2-3 min over several discrete trials) and remained stable for as long as the payoff function did not change. The results of this work show that people are adaptive and flexible in how they prioritize and allocate attention in a dual-task setting. However, it also demonstrates some of the limits regarding people's ability to optimize payoff functions. Copyright © 2017 The Authors. Cognitive Science published by Wiley Periodicals, Inc. on behalf of Cognitive Science Society.

  8. Closed head injury and perceptual processing in dual-task situations.

    PubMed

    Hein, G; Schubert, T; von Cramon, D Y

    2005-01-01

    Using a classical psychological refractory period (PRP) paradigm we investigated whether increased interference between dual-task input processes is one possible source of dual-task deficits in patients with closed-head injury (CHI). Patients and age-matched controls were asked to give speeded motor reactions to an auditory and a visual stimulus. The perceptual difficulty of the visual stimulus was manipulated by varying its intensity. The results of Experiment 1 showed that CHI patients suffer from increased interference between dual-task input processes, which is related to the salience of the visual stimulus. A second experiment indicated that this input interference may be specific to brain damage following CHI. It is not evident in other groups of neurological patients like Parkinson's disease patients. We conclude that the non-interfering processing of input stages in dual-tasks requires cognitive control. A decline in the control of input processes should be considered as one source of dual-task deficits in CHI patients.

  9. A cognitive-motor intervention using a dance video game to enhance foot placement accuracy and gait under dual task conditions in older adults: a randomized controlled trial.

    PubMed

    Pichierri, Giuseppe; Murer, Kurt; de Bruin, Eling D

    2012-12-14

    Computer-based interventions have demonstrated consistent positive effects on various physical abilities in older adults. This study aims to compare two training groups that achieve similar amounts of strength and balance exercise where one group receives an intervention that includes additional dance video gaming. The aim is to investigate the different effects of the training programs on physical and psychological parameters in older adults. Thirty-one participants (mean age ± SD: 86.2 ± 4.6 years), residents of two Swiss hostels for the aged, were randomly assigned to either the dance group (n = 15) or the control group (n = 16). The dance group absolved a twelve-week cognitive-motor exercise program twice weekly that comprised progressive strength and balance training supplemented with additional dance video gaming. The control group performed only the strength and balance exercises during this period. Outcome measures were foot placement accuracy, gait performance under single and dual task conditions, and falls efficacy. After the intervention between-group comparison revealed significant differences for gait velocity (U = 26, P = .041, r = .45) and for single support time (U = 24, P = .029, r = .48) during the fast walking dual task condition in favor of the dance group. No significant between-group differences were observed either in the foot placement accuracy test or in falls efficacy. There was a significant interaction in favor of the dance video game group for improvements in step time. Significant improved fast walking performance under dual task conditions (velocity, double support time, step length) was observed for the dance video game group only. These findings suggest that in older adults a cognitive-motor intervention may result in more improved gait under dual task conditions in comparison to a traditional strength and balance exercise program. This trial has been registered under ISRCTN05350123 (www.controlled-trials.com)

  10. Short-term memory and dual task performance

    NASA Technical Reports Server (NTRS)

    Regan, J. E.

    1982-01-01

    Two hypotheses concerning the way in which short-term memory interacts with another task in a dual task situation are considered. It is noted that when two tasks are combined, the activity of controlling and organizing performance on both tasks simultaneously may compete with either task for a resource; this resource may be space in a central mechanism or general processing capacity or it may be some task-specific resource. If a special relationship exists between short-term memory and control, especially if there is an identity relationship between short-term and a central controlling mechanism, then short-term memory performance should show a decrement in a dual task situation. Even if short-term memory does not have any particular identity with a controlling mechanism, but both tasks draw on some common resource or resources, then a tradeoff between the two tasks in allocating resources is possible and could be reflected in performance. The persistent concurrence cost in memory performance in these experiments suggests that short-term memory may have a unique status in the information processing system.

  11. Musical training, bilingualism, and executive function: a closer look at task switching and dual-task performance.

    PubMed

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-07-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician) were matched on age and socioeconomic status and administered task switching and dual-task paradigms. Results demonstrated reduced global and local switch costs in musicians compared with non-musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets. On dual-task performance, musicians also outperformed non-musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest additive effects of both types of experience. These findings demonstrate that long-term musical training is associated with improvements in task switching and dual-task performance. Copyright © 2014 Cognitive Science Society, Inc.

  12. Dual-Task Interference When A Response is Not Required

    NASA Technical Reports Server (NTRS)

    VanSelst, Mark; Johnston, James C.; Shafto, Michael (Technical Monitor)

    2002-01-01

    When subjects are required to respond to two stimuli presented in rapid succession, responses to the second stimulus are delayed. Such dual-task interference has been attributed to a fundamental processing bottleneck preventing simultaneous processing on both tasks. Two experiments show dual-task interference even when the first task does not require a response. The observed interference is caused by a bottleneck in central cognitive processing, rather than in response initiation or execution.

  13. Building a Framework for a Dual Task Taxonomy

    PubMed Central

    McIsaac, Tara L.; Lamberg, Eric M.; Muratori, Lisa M.

    2015-01-01

    The study of dual task interference has gained increasing attention in the literature for the past 35 years, with six MEDLINE citations in 1979 growing to 351 citations indexed in 2014 and a peak of 454 cited papers in 2013. Increasingly, researchers are examining dual task cost in individuals with pathology, including those with neurodegenerative diseases. While the influence of these papers has extended from the laboratory to the clinic, the field has evolved without clear definitions of commonly used terms and with extreme variations in experimental procedures. As a result, it is difficult to examine the interference literature as a single body of work. In this paper we present a new taxonomy for classifying cognitive-motor and motor-motor interference within the study of dual task behaviors that connects traditional concepts of learning and principles of motor control with current issues of multitasking analysis. As a first step in the process we provide an operational definition of dual task, distinguishing it from a complex single task. We present this new taxonomy, inclusive of both cognitive and motor modalities, as a working model; one that we hope will generate discussion and create a framework from which one can view previous studies and develop questions of interest. PMID:25961027

  14. Entorhinal Cortex Volume Is Associated With Dual-Task Gait Cost Among Older Adults With MCI: Results From the Gait and Brain Study.

    PubMed

    Sakurai, Ryota; Bartha, Robert; Montero-Odasso, Manuel

    2018-05-15

    Low dual-task gait performance (the slowing of gait speed while performing a demanding cognitive task) is associated with low cognitive performance and an increased risk of progression to dementia in older adults with mild cognitive impairment. However, the reason for this remains unclear. This study aimed to examine the relationship between dual-task cost and regional brain volume, focusing on the hippocampus, parahippocampal gyrus, entorhinal cortex, and motor and lateral frontal cortices in older adults with mild cognitive impairment. Forty older adults with mild cognitive impairment from the "Gait and Brain Study" were included in this study. Gait velocity was measured during single-task (ie, walking alone) and dual-task (ie, counting backwards, subtracting serial sevens, and naming animals, in addition to walking) conditions, using an electronic walkway. Regional brain volumes were derived by automated segmentation, using 3T magnetic resonance imaging. Partial rank correlation analyses demonstrated that a smaller volume of the left entorhinal cortex was associated with higher dual-task costs in counting backwards and subtracting serial sevens conditions. Subsequent logistic regression analyses demonstrated that a smaller volume of the left entorhinal cortex was independently associated with higher dual-task cost (slowing down >20% when performing cognitive task) in these two conditions. There were no other significant associations. Our results show that lower dual-task gait performance is associated with volume reduction in the entorhinal cortex. Cognitive and motor dysfunction in older adults with mild cognitive impairment may reflect a shared pathogenic mechanism, and dual-task-related gait changes might be a surrogate motor marker for Alzheimer's disease pathology.

  15. Cognitive demand of human sensorimotor performance during an extended space mission: a dual-task study.

    PubMed

    Bock, Otmar; Weigelt, Cornelia; Bloomberg, Jacob J

    2010-09-01

    Two previous single-case studies found that the dual-task costs of manual tracking plus memory search increased during a space mission, and concluded that sensorimotor deficits during spaceflight may be related to cognitive overload. Since dual-task costs were insensitive to the difficulty of memory search, the authors argued that the overload may reflect stress-related problems of multitasking, rather than a scarcity of specific cognitive resources. Here we expand the available database and compare different types of concurrent task. Three subjects were repeatedly tested before, during, and after an extended mission on the International Space Station (ISS). They performed an unstable tracking task and four reaction-time tasks, both separately and concurrently. Inflight data could only be obtained during later parts of the mission. The tracking error increased from pre- to in flight by a factor of about 2, both under single- and dual-task conditions. The dual-task costs with a reaction-time task requiring rhythm production was 2.4 times higher than with a reaction-time task requiring visuo-spatial transformations, and 8 times higher than with a regular choice reaction-time task. Long-term sensorimotor deficits during spaceflight may reflect not only stress, but also a scarcity of resources related to complex motor programming; possibly those resources are tied up by sensorimotor adaptation to the space environment.

  16. Neurophysiological Modulations of Non-Verbal and Verbal Dual-Tasks Interference during Word Planning.

    PubMed

    Fargier, Raphaël; Laganaro, Marina

    2016-01-01

    Running a concurrent task while speaking clearly interferes with speech planning, but whether verbal vs. non-verbal tasks interfere with the same processes is virtually unknown. We investigated the neural dynamics of dual-task interference on word production using event-related potentials (ERPs) with either tones or syllables as concurrent stimuli. Participants produced words from pictures in three conditions: without distractors, while passively listening to distractors and during a distractor detection task. Production latencies increased for tasks with higher attentional demand and were longer for syllables relative to tones. ERP analyses revealed common modulations by dual-task for verbal and non-verbal stimuli around 240 ms, likely corresponding to lexical selection. Modulations starting around 350 ms prior to vocal onset were only observed when verbal stimuli were involved. These later modulations, likely reflecting interference with phonological-phonetic encoding, were observed only when overlap between tasks was maximal and the same underlying neural circuits were engaged (cross-talk).

  17. Motor-cognitive dual-task deficits in individuals with early-mid stage Huntington disease.

    PubMed

    Fritz, Nora E; Hamana, Katy; Kelson, Mark; Rosser, Anne; Busse, Monica; Quinn, Lori

    2016-09-01

    Huntington disease (HD) results in a range of cognitive and motor impairments that progress throughout the disease stages; however, little research has evaluated specific dual-task abilities in this population, and the degree to which they may be related to functional ability. The purpose of this study was to a) examine simple and complex motor-cognitive dual-task performance in individuals with HD, b) determine relationships between dual-task walking ability and disease-specific measures of motor, cognitive and functional ability, and c) examine the relationship of dual-task measures to falls in individuals with HD. Thirty-two individuals with HD were evaluated for simple and complex dual-task ability using the Walking While Talking Test. Demographics and disease-specific measures of motor, cognitive and functional ability were also obtained. Individuals with HD had impairments in simple and complex dual-task ability. Simple dual-task walking was correlated to disease-specific motor scores as well as cognitive performance, but complex dual-task walking was correlated with total functional capacity, as well as a range of cognitive measures. Number of prospective falls was moderately-strongly correlated to dual-task measures. Our results suggest that individuals with HD have impairments in cognitive-motor dual-task ability that are related to disease progression and specifically functional ability. Dual-task measures appear to evaluate a unique construct in individuals with early to mid-stage HD, and may have value in improving the prediction of falls risk in this population. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. On the importance of Task 1 and error performance measures in PRP dual-task studies.

    PubMed

    Strobach, Tilo; Schütz, Anja; Schubert, Torsten

    2015-01-01

    The psychological refractory period (PRP) paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and Task 2) are presented with variable stimulus onset asynchronies (SOAs) and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e., decreasing SOAs do not increase reaction times (RTs) and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates) show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/or error rates in Task 1). This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects.

  19. On the importance of Task 1 and error performance measures in PRP dual-task studies

    PubMed Central

    Strobach, Tilo; Schütz, Anja; Schubert, Torsten

    2015-01-01

    The psychological refractory period (PRP) paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and Task 2) are presented with variable stimulus onset asynchronies (SOAs) and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e., decreasing SOAs do not increase reaction times (RTs) and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates) show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/or error rates in Task 1). This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects. PMID:25904890

  20. Limited Benefits of Heterogeneous Dual-Task Training on Transfer Effects in Older Adults.

    PubMed

    Lussier, Maxime; Brouillard, Philippe; Bherer, Louis

    2017-09-01

    It has often been reported that cognitive training has limited transfer effects. The present study addresses training context variability as a factor that could increase transfer effects, as well as the manifestation through time of transfer effects. Fifty-eight older adults were assigned to an active placebo or two dual-task training conditions, one in which the training context varies between sessions (heterogeneous training) and the other in a fixed training context (homogeneous training). Transfer was assessed with near and far-modality transfer tasks. Results show that heterogeneous and homogeneous training led to larger near-modality transfer effects than an active placebo (computer lessons). Transfer effects were roughly comparable in both training groups, but heterogeneous training led to a steeper improvement of the dual-task coordination learning curve within training sessions. Also, results indicated that dual-task cost did not improve in the active placebo group from the pre- to the post-training sessions. Heterogeneous training showed modest advantages over homogeneous training. Results also suggest that transfer effects on dual-task cost induced by training take place early on in the post-training session. These findings provide valuable insights on benefits arising from variability in the training protocol for maximizing transfer effects. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Effects of Aging on Arm Swing during Gait: The Role of Gait Speed and Dual Tasking.

    PubMed

    Mirelman, Anat; Bernad-Elazari, Hagar; Nobel, Tomer; Thaler, Avner; Peruzzi, Agnese; Plotnik, Meir; Giladi, Nir; Hausdorff, Jeffrey M

    2015-01-01

    Healthy walking is characterized by pronounced arm swing and axial rotation. Aging effects on gait speed, stride length and stride time variability have been previously reported, however, less is known about aging effects on arm swing and axial rotation and their relationship to age-associated gait changes during usual walking and during more challenging conditions like dual tasking. Sixty healthy adults between the ages of 30-77 were included in this study designed to address this gap. Lightweight body fixed sensors were placed on each wrist and lower back. Participants walked under 3 walking conditions each of 1 minute: 1) comfortable speed, 2) walking while serially subtracting 3's (Dual Task), 3) walking at fast speed. Aging effects on arm swing amplitude, range, symmetry, jerk and axial rotation amplitude and jerk were compared between decades of age (30-40; 41-50; 51-60; 61-77 years). As expected, older adults walked slower (p = 0.03) and with increased stride variability (p = 0.02). Arm swing amplitude decreased with age under all conditions (p = 0.04). In the oldest group, arm swing decreased during dual task and increased during the fast walking condition (p<0.0001). Similarly, arm swing asymmetry increased during the dual task in the older groups (p<0.004), but not in the younger groups (p = 0.67). Significant differences between groups and within conditions were observed in arm swing jerk (p<0.02), axial rotation amplitude (p<0.02) and axial jerk (p<0.001). Gait speed, arm swing amplitude of the dominant arm, arm swing asymmetry and axial rotation jerk were all independent predictors of age in a multivariate model. These findings suggest that the effects of gait speed and dual tasking on arm swing and axial rotation during walking are altered among healthy older adults. Follow-up work is needed to examine if these effects contribute to reduced stability in aging.

  2. Effects of Aging on Arm Swing during Gait: The Role of Gait Speed and Dual Tasking

    PubMed Central

    Mirelman, Anat; Bernad-Elazari, Hagar; Nobel, Tomer; Thaler, Avner; Peruzzi, Agnese; Plotnik, Meir; Giladi, Nir; Hausdorff, Jeffrey M.

    2015-01-01

    Healthy walking is characterized by pronounced arm swing and axial rotation. Aging effects on gait speed, stride length and stride time variability have been previously reported, however, less is known about aging effects on arm swing and axial rotation and their relationship to age-associated gait changes during usual walking and during more challenging conditions like dual tasking. Sixty healthy adults between the ages of 30–77 were included in this study designed to address this gap. Lightweight body fixed sensors were placed on each wrist and lower back. Participants walked under 3 walking conditions each of 1 minute: 1) comfortable speed, 2) walking while serially subtracting 3’s (Dual Task), 3) walking at fast speed. Aging effects on arm swing amplitude, range, symmetry, jerk and axial rotation amplitude and jerk were compared between decades of age (30–40; 41–50; 51–60; 61–77 years). As expected, older adults walked slower (p = 0.03) and with increased stride variability (p = 0.02). Arm swing amplitude decreased with age under all conditions (p = 0.04). In the oldest group, arm swing decreased during dual task and increased during the fast walking condition (p<0.0001). Similarly, arm swing asymmetry increased during the dual task in the older groups (p<0.004), but not in the younger groups (p = 0.67). Significant differences between groups and within conditions were observed in arm swing jerk (p<0.02), axial rotation amplitude (p<0.02) and axial jerk (p<0.001). Gait speed, arm swing amplitude of the dominant arm, arm swing asymmetry and axial rotation jerk were all independent predictors of age in a multivariate model. These findings suggest that the effects of gait speed and dual tasking on arm swing and axial rotation during walking are altered among healthy older adults. Follow-up work is needed to examine if these effects contribute to reduced stability in aging. PMID:26305896

  3. Measuring treatment effects on dual-task performance: a framework for research and clinical practice

    PubMed Central

    Plummer, Prudence; Eskes, Gail

    2015-01-01

    The relevance of dual-task walking to everyday ambulation is widely acknowledged, and numerous studies have demonstrated that dual-task interference can significantly impact recovery of functional walking in people with neurological disorders. The magnitude and direction of dual-task interference is influenced by the interaction between the two tasks, including how individuals spontaneously prioritize their attention. Therefore, to accurately interpret and characterize dual-task interference and identify changes over time, it is imperative to evaluate single and dual-task performance in both tasks, as well as the tasks relative to each other. Yet, reciprocal dual-task effects (DTE) are frequently ignored. The purpose of this perspective paper is to present a framework for measuring treatment effects on dual-task interference, specifically taking into account the interactions between the two tasks and how this can provide information on whether overall dual-task capacity has improved or a different attentional strategy has been adopted. In discussing the clinical implications of using this framework, we provide specific examples of using this method and provide some explicit recommendations for research and clinical practice. PMID:25972801

  4. The Influence of a Cognitive Dual Task on the Gait Parameters of Healthy Older Adults: A Systematic Review and Meta-Analysis.

    PubMed

    Smith, Erin; Cusack, Tara; Cunningham, Caitriona; Blake, Catherine

    2017-10-01

    This review examines the effect of a dual task on the gait parameters of older adults with a mean gait speed of 1.0 m/s or greater, and the effect of type and complexity of task. A systematic review of Web of Science, PubMed, SCOPUS, Embase, and PsycINFO was performed in July 2016. Twenty-three studies (28 data sets) were reviewed and pooled for meta-analysis. The effect size on seven gait parameters was measured as the raw mean difference between single- and dual-task performance. Gait speed significantly reduced with the addition of a dual task, with increasing complexity showing greater decrements. Cadence, stride time, and measures of gait variability were all negatively affected under the dual-task condition. In older adults, the addition of a dual task significantly reduces gait speed and cadence, with possible implications for the assessment of older people, as the addition of a dual task may expose deficits not observed under single-task assessment.

  5. Effects of Single Compared to Dual Task Practice on Learning a Dynamic Balance Task in Young Adults

    PubMed Central

    Kiss, Rainer; Brueckner, Dennis; Muehlbauer, Thomas

    2018-01-01

    Background: In everyday life, people engage in situations involving the concurrent processing of motor (balance) and cognitive tasks (i.e., “dual task situations”) that result in performance declines in at least one of the given tasks. The concurrent practice of both the motor and cognitive task may counteract these performance decrements. The purpose of this study was to examine the effects of single task (ST) compared to dual task (DT) practice on learning a dynamic balance task. Methods: Forty-eight young adults were randomly assigned to either a ST (i.e., motor or cognitive task training only) or a DT (i.e., motor-cognitive training) practice condition. The motor task required participants to stand on a platform and keeping the platform as close to horizontal as possible. In the cognitive task, participants were asked to recite serial subtractions of three. For 2 days, participants of the ST groups practiced the motor or cognitive task only, while the participants of the DT group concurrently performed both. Root-mean-square error (RMSE) for the motor and total number of correct calculations for the cognitive task were computed. Results: During practice, all groups improved their respective balance and/or cognitive task performance. With regard to the assessment of learning on day 3, we found significantly smaller RMSE values for the ST motor (d = 1.31) and the DT motor-cognitive (d = 0.76) practice group compared to the ST cognitive practice group but not between the ST motor and the DT motor-cognitive practice group under DT test condition. Further, we detected significantly larger total numbers of correct calculations under DT test condition for the ST cognitive (d = 2.19) and the DT motor-cognitive (d = 1.55) practice group compared to the ST motor practice group but not between the ST cognitive and the DT motor-cognitive practice group. Conclusion: We conclude that ST practice resulted in an effective modulation of the trained domain (i.e., motor or

  6. Neurofeedback training improves the dual-task performance ability in stroke patients.

    PubMed

    Lee, Young-Shin; Bae, Sea-Hyun; Lee, Sung-Hee; Kim, Kyung-Yoon

    2015-05-01

    Owing to the reduced capacity for information processing following a stroke, patients commonly present with difficulties in performing activities of daily living that combine two or more tasks. To address this problem, in the present study, we investigated the effects of neurofeedback training on the abilities of stroke patients to perform dual motor tasks. We randomly assigned 20 patients who had sustained a stroke within the preceding 6 months to either a pseudo-neurofeedback (n = 10) or neurofeedback (n = 10) group. Both groups participated in a general exercise intervention for 8 weeks, three times a week for 30 min per session, under the same conditions. An electrode was secured to the scalp over the region of the central lobe (Cz), in compliance with the International 10-20 System. The electrode was inactive for the pseudo-training group. Participants in the neurofeedback training group received the 30-min neurofeedback training per session for reinforcing the sensorimotor rhythm. Electroencephalographic activity of the two groups was compared. In addition, selected parameters of gait (velocity, cadence [step/min], stance phase [%], and foot pressure) were analyzed using a 10-m walk test, attention-demanding task, walk task and quantified by the SmartStep system. The neurofeedback group showed significantly improved the regulation of the sensorimotor rhythm (p < 0.001) and ability to execute dual tasks (p < 0.01). Significant improvements on selected gait parameters (velocity and cadence; p < 0.05) were also observed. We thus propose that the neurofeedback training is effective to improve the dual-task performance in stroke patients.

  7. Obstacle crossing with dual tasking is a danger for individuals with Alzheimer's disease and for healthy older people.

    PubMed

    Simieli, Lucas; Barbieri, Fabio Augusto; Orcioli-Silva, Diego; Lirani-Silva, Ellen; Stella, Florindo; Gobbi, Lilian Teresa Bucken

    2015-01-01

    The aim of this study was to analyze the effects of dual tasking on obstacle crossing during walking by individuals with Alzheimer's disease (AD) and by healthy older people. Thirty four elderly individuals (16 healthy subjects and 18 individuals with AD) were recruited to participate in this study. Three AD individuals and one control participant were excluded due to exclusion criteria. The participants were instructed to walk barefoot at their own speed along an 8 m long pathway. Each participant performed five trials for each condition (unobstructed walking, unobstructed walking with dual tasking, and obstacle crossing during walking with dual tasking). The trials were completely randomized for each participant. The mid-pathway stride was measured in the unobstructed walking trials and the stride that occurred during the obstacle avoidance was measured in the trials that involved obstacle crossing. The behavior of the healthy elderly subjects and individuals with AD was similar for obstacle crossing during walking with dual tasking. Both groups used the "posture first" strategy to prioritize stability and showed decreased attention to executive tasking while walking. Additionally, AD had a strong influence on the modifications that are made by the elderly while walking under different walking conditions.

  8. Effects of a no-go Task 2 on Task 1 performance in dual - tasking: From benefits to costs.

    PubMed

    Janczyk, Markus; Huestegge, Lynn

    2017-04-01

    When two tasks are combined in a dual-task experiment, characteristics of Task 2 can influence Task 1 performance, a phenomenon termed the backward crosstalk effect (BCE). Besides instances depending on the (spatial) compatibility of both responses, a particularly interesting example was introduced by Miller (2006): If Task 2 was a no-go task (i.e., one not requiring any action at all), responses were slowed in Task 1. Subsequent work, however, also reported the opposite result-that is, faster Task 1 responses in cases of no-go Task 2 trials. We report three experiments aiming to more precisely identify the conditions under which a no-go Task 2 facilitates or impedes Task 1 performance. The results suggest that an adverse no-go BCE is only observed when the Task 2 response(s) are sufficiently prepared in advance, yielding strong inhibitory control demands for Task 2 that eventually hamper Task 1 processing as well (i.e., inhibitory costs). If this is not the case, encountering a no-go Task 2 trial facilitates Task 1 performance, suggesting that the underlying task representation is reduced to a single - task. These results are discussed in the context of other recent work on BCEs and of recently suggested accounts of the no-go BCE.

  9. Dual-task interference with equal task emphasis: graded capacity sharing or central postponement?

    NASA Technical Reports Server (NTRS)

    Ruthruff, Eric; Pashler, Harold E.; Hazeltine, Eliot

    2003-01-01

    Most studies using the psychological refractory period (PRP) design suggest that dual-task performance is limited by a central bottleneck. Because subjects are usually told to emphasize Task 1, however, the bottleneck might reflect a strategic choice rather than a structural limitation. To evaluate the possibility that central operations can proceed in parallel, albeit with capacity limitations, we conducted two dual-task experiments with equal task emphasis. In both experiments, subjects tended to either group responses together or respond to one task well before the other. In addition, stimulus-response compatibility effects were roughly constant across stimulus onset asynchronies (SOAs). At the short SOA, compatibility effects also carried over onto response times for the other task. This pattern of results is difficult to reconcile with the possibility that subjects share capacity roughly equally between simultaneous central operations. However, this pattern is consistent with the existence of a structural central bottleneck.

  10. The effects of voice and manual control mode on dual task performance

    NASA Technical Reports Server (NTRS)

    Wickens, C. D.; Zenyuh, J.; Culp, V.; Marshak, W.

    1986-01-01

    Two fundamental principles of human performance, compatibility and resource competition, are combined with two structural dichotomies in the human information processing system, manual versus voice output, and left versus right cerebral hemisphere, in order to predict the optimum combination of voice and manual control with either hand, for time-sharing performance of a dicrete and continuous task. Eight right handed male subjected performed a discrete first-order tracking task, time-shared with an auditorily presented Sternberg Memory Search Task. Each task could be controlled by voice, or by the left or right hand, in all possible combinations except for a dual voice mode. When performance was analyzed in terms of a dual-task decrement from single task control conditions, the following variables influenced time-sharing efficiency in diminishing order of magnitude, (1) the modality of control, (discrete manual control of tracking was superior to discrete voice control of tracking and the converse was true with the memory search task), (2) response competition, (performance was degraded when both tasks were responded manually), (3) hemispheric competition, (performance degraded whenever two tasks were controlled by the left hemisphere) (i.e., voice or right handed control). The results confirm the value of predictive models invoice control implementation.

  11. The source of dual-task limitations: Serial or parallel processing of multiple response selections?

    PubMed Central

    Marois, René

    2014-01-01

    Although it is generally recognized that the concurrent performance of two tasks incurs costs, the sources of these dual-task costs remain controversial. The serial bottleneck model suggests that serial postponement of task performance in dual-task conditions results from a central stage of response selection that can only process one task at a time. Cognitive-control models, by contrast, propose that multiple response selections can proceed in parallel, but that serial processing of task performance is predominantly adopted because its processing efficiency is higher than that of parallel processing. In the present study, we empirically tested this proposition by examining whether parallel processing would occur when it was more efficient and financially rewarded. The results indicated that even when parallel processing was more efficient and was incentivized by financial reward, participants still failed to process tasks in parallel. We conclude that central information processing is limited by a serial bottleneck. PMID:23864266

  12. Selective impairment of masked priming in dual-task performance.

    PubMed

    Fischer, Rico; Kiesel, Andrea; Kunde, Wilfried; Schubert, Torsten

    2011-03-01

    This study investigated the impact of divided attention on masked priming. In a dual-task setting, two tasks had to be carried out in close temporal succession: a tone discrimination task and a masked priming task. The order of the tasks was varied between experiments, and attention was always allocated to the first task-that is, the first task was prioritized. The priming task was the second (nonprioritized) task in Experiment 1 and the first (prioritized) task in Experiment 2. In both experiments, "novel" prime stimuli associated with semantic processing were essentially ineffective. However, there was intact priming by another type of prime stimuli associated with response priming. Experiment 3 showed that all these prime stimuli can reveal significant priming effects during a task-switching paradigm in which both tasks were performed consecutively. We conclude that dual-task specific interference processes (e.g., the simultaneous coordination of multiple stimulus-response rules) selectively impair priming that is assumed to rely on semantic processing.

  13. Psychometric Functions of Dual-Task Paradigms for Measuring Listening Effort.

    PubMed

    Wu, Yu-Hsiang; Stangl, Elizabeth; Zhang, Xuyang; Perkins, Joanna; Eilers, Emily

    The purpose of the study was to characterize the psychometric functions that describe task performance in dual-task listening effort measures as a function of signal to noise ratio (SNR). Younger adults with normal hearing (YNH, n = 24; experiment 1) and older adults with hearing impairment (n = 24; experiment 2) were recruited. Dual-task paradigms wherein the participants performed a primary speech recognition task simultaneously with a secondary task were conducted at a wide range of SNRs. Two different secondary tasks were used: an easy task (i.e., a simple visual reaction-time task) and a hard task (i.e., the incongruent Stroop test). The reaction time (RT) quantified the performance of the secondary task. For both participant groups and for both easy and hard secondary tasks, the curves that described the RT as a function of SNR were peak shaped. The RT increased as SNR changed from favorable to intermediate SNRs, and then decreased as SNRs moved from intermediate to unfavorable SNRs. The RT reached its peak (longest time) at the SNRs at which the participants could understand 30 to 50% of the speech. In experiments 1 and 2, the dual-task trials that had the same SNR were conducted in one block. To determine if the peak shape of the RT curves was specific to the blocked SNR presentation order used in these experiments, YNH participants were recruited (n = 25; experiment 3) and dual-task measures, wherein the SNR was varied from trial to trial (i.e., nonblocked), were conducted. The results indicated that, similar to the first two experiments, the RT curves had a peak shape. Secondary task performance was poorer at the intermediate SNRs than at the favorable and unfavorable SNRs. This pattern was observed for both YNH and older adults with hearing impairment participants and was not affected by either task type (easy or hard secondary task) or SNR presentation order (blocked or nonblocked). The shorter RT at the unfavorable SNRs (speech intelligibility < 30

  14. Cognitive structure, flexibility, and plasticity in human multitasking-An integrative review of dual-task and task-switching research.

    PubMed

    Koch, Iring; Poljac, Edita; Müller, Hermann; Kiesel, Andrea

    2018-06-01

    Numerous studies showed decreased performance in situations that require multiple tasks or actions relative to appropriate control conditions. Because humans often engage in such multitasking activities, it is important to understand how multitasking affects performance. In the present article, we argue that research on dual-task interference and sequential task switching has proceeded largely separately using different experimental paradigms and methodology. In our article we aim at organizing this complex set of research in terms of three complementary research perspectives on human multitasking. One perspective refers to structural accounts in terms of cognitive bottlenecks (i.e., critical processing stages). A second perspective refers to cognitive flexibility in terms of the underlying cognitive control processes. A third perspective emphasizes cognitive plasticity in terms of the influence of practice on human multitasking abilities. With our review article we aimed at highlighting the value of an integrative position that goes beyond isolated consideration of a single theoretical research perspective and that broadens the focus from single experimental paradigms (dual task and task switching) to favor instead a view that emphasizes the fundamental similarity of the underlying cognitive mechanisms across multitasking paradigms. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  15. Word Effects in Dual-Task Studies Using Lexical Decision and Naming as Task 2

    NASA Technical Reports Server (NTRS)

    Remington, Roger; McCann, Robert S.; VanSelst, Mark; Shafto, Michael (Technical Monitor)

    1997-01-01

    Word frequency effects in dual-task, lexical decision are variously reported to be additive or under-additive across SOA. We replicate and extend earlier lexical decision studies and find word frequency to be additive across SOA. To more directly capture lexical processing, we examine dual-task naming. Once again we find word frequency to be additive across SOA. Lexical processing appears to be constrained by central processing limitations.

  16. Cognitive pitfall! Videogame players are not immune to dual-task costs.

    PubMed

    Donohue, Sarah E; James, Brittany; Eslick, Andrea N; Mitroff, Stephen R

    2012-07-01

    With modern technological advances, we often find ourselves dividing our attention between multiple tasks. While this may seem a productive way to live, our attentional capacity is limited, and this yields costs in one or more of the many tasks that we try to do. Some people believe that they are immune to the costs of multitasking and commonly engage in potentially dangerous behavior, such as driving while talking on the phone. But are some groups of individuals indeed immune to dual-task costs? This study examines whether avid action videogame players, who have been shown to have heightened attentional capacities, are particularly adept multitaskers. Participants completed three visually demanding experimental paradigms (a driving videogame, a multiple-object-tracking task, and a visual search), with and without answering unrelated questions via a speakerphone (i.e., with and without a dual-task component). All of the participants, videogame players and nonvideogame players alike, performed worse while engaging in the additional dual task for all three paradigms. This suggests that extensive videogame experience may not offer immunity from dual-task costs.

  17. Influence of dual-tasking with different levels of attention diversion on characteristics of the movement-related cortical potential.

    PubMed

    Aliakbaryhosseinabadi, Susan; Kamavuako, Ernest Nlandu; Jiang, Ning; Farina, Dario; Mrachacz-Kersting, Natalie

    2017-11-01

    Dual tasking is defined as performing two tasks concurrently and has been shown to have a significant effect on attention directed to the performance of the main task. In this study, an attention diversion task with two different levels was administered while participants had to complete a cue-based motor task consisting of foot dorsiflexion. An auditory oddball task with two levels of complexity was implemented to divert the user's attention. Electroencephalographic (EEG) recordings were made from nine single channels. Event-related potentials (ERPs) confirmed that the oddball task of counting a sequence of two tones decreased the auditory P300 amplitude more than the oddball task of counting one target tone among three different tones. Pre-movement features quantified from the movement-related cortical potential (MRCP) were changed significantly between single and dual-task conditions in motor and fronto-central channels. There was a significant delay in movement detection for the case of single tone counting in two motor channels only (237.1-247.4ms). For the task of sequence counting, motor cortex and frontal channels showed a significant delay in MRCP detection (232.1-250.5ms). This study investigated the effect of attention diversion in dual-task conditions by analysing both ERPs and MRCPs in single channels. The higher attention diversion lead to a significant reduction in specific MRCP features of the motor task. These results suggest that attention division in dual-tasking situations plays an important role in movement execution and detection. This has important implications in designing real-time brain-computer interface systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Posture-Motor and Posture-Ideomotor Dual-Tasking: A Putative Marker of Psychomotor Retardation and Depressive Rumination in Patients With Major Depressive Disorder.

    PubMed

    Aftanas, Lyubomir I; Bazanova, Olga M; Novozhilova, Nataliya V

    2018-01-01

    Background: Recent studies have demonstrated that the assessment of postural performance may be a potentially reliable and objective marker of the psychomotor retardation (PMR) in the major depressive disorder (MDD). One of the important facets of MDD-related PMR is reflected in disrupted central mechanisms of psychomotor control, heavily influenced by compelling maladaptive depressive rumination. In view of this we designed a research paradigm that included sequential execution of simple single-posture task followed by more challenging divided attention posture tasks, involving concurring motor and ideomotor workloads. Another difficulty dimension assumed executing of all the tasks with eyes open (EO) (easy) and closed (EC) (difficult) conditions. We aimed at investigating the interplay between the severity of MDD, depressive rumination, and efficiency of postural performance. Methods: Compared with 24 age- and body mass index-matched healthy controls (HCs), 26 patients with MDD sequentially executed three experimental tasks: (1) single-posture task of maintaining a quiet stance (ST), (2) actual posture-motor dual task (AMT); and (3) mental/imaginary posture-motor dual task (MMT). All the tasks were performed in the EO and the EC conditions. The primary dependent variable was the amount of kinetic energy ( E ) expended for the center of pressure deviations (CoPDs), whereas the absolute divided attention cost index showed energy cost to the dual-tasking vs. the single-posture task according to the formula: Δ E = ( E Dual-task - E Single-task ). Results: The signs of PMR in the MDD group were objectively indexed by deficient posture control in the EC condition along with overall slowness of fine motor and ideomotor activity. Another important and probably more challenging feature of the findings was that the posture deficit manifested in the ST condition was substantially and significantly attenuated in the MMT and AMT performance dual-tasking activity. A multiple

  19. The Neurocognitive Basis for Impaired Dual-Task Performance in Senior Fallers.

    PubMed

    Nagamatsu, Lindsay S; Hsu, C Liang; Voss, Michelle W; Chan, Alison; Bolandzadeh, Niousha; Handy, Todd C; Graf, Peter; Beattie, B Lynn; Liu-Ambrose, Teresa

    2016-01-01

    Falls are a major health-care concern, and while dual-task performance is widely recognized as being impaired in those at-risk for falls, the underlying neurocognitive mechanisms remain unknown. A better understanding of the underlying mechanisms could lead to the refinement and development of behavioral, cognitive, or neuropharmacological interventions for falls prevention. Therefore, we conducted a cross-sectional study with community-dwelling older adults aged 70-80 years with a history of falls (i.e., two or more falls in the past 12 months) or no history of falls (i.e., zero falls in the past 12 months); n = 28 per group. We compared functional activation during cognitive-based dual-task performance between fallers and non-fallers using functional magnetic resonance imaging (fMRI). Executive cognitive functioning was assessed via Stroop, Trail Making, and Digit Span. Mobility was assessed via the Timed Up and Go test (TUG). We found that non-fallers exhibited significantly greater functional activation compared with fallers during dual-task performance in key regions responsible for resolving dual-task interference, including precentral, postcentral, and lingual gyri. Further, we report slower reaction times during dual-task performance in fallers and significant correlations between level of functional activation and independent measures of executive cognitive functioning and mobility. Our study is the first neuroimaging study to examine dual-task performance in fallers, and supports the notion that fallers have reduced functional brain activation compared with non-fallers. Given that dual-task performance-and the underlying neural concomitants-appears to be malleable with relevant training, our study serves as a launching point for promising strategies to reduce falls in the future.

  20. Gait analysis with cognitive-motor dual tasks to distinguish fallers from nonfallers among rehabilitating stroke patients.

    PubMed

    Baetens, Tina; De Kegel, Alexandra; Palmans, Tanneke; Oostra, Kristine; Vanderstraeten, Guy; Cambier, Dirk

    2013-04-01

    To evaluate fall risk in stroke patients based on single- and dual-task gait analyses, and to investigate the difference between 2 cognitive tasks in the dual-task paradigm. Prospective cohort study. Rehabilitation hospitals. Subacute stroke patients (N=32), able to walk without physical/manual help with or without walking aids, while performing a verbal task. Not applicable. Functional gait measures were Functional Ambulation Categories (FAC) and use of a walking aid. Gait measures were evaluated by an electronic walkway system under single- and dual-task (DT) conditions. For the single-task, subjects were instructed to walk at their usual speed. One of the DTs was a verbal fluency dual task, whereby subjects had to walk while simultaneously enumerating as many different animals as possible. For the other DT (counting dual task), participants had to walk while performing serial subtractions. After inclusion, participants kept a 6-month falls diary. Eighteen (56.3%) of the 32 included patients fell. Ten (31.3%) were single fallers (SFs), and 8 (25%) were multiple fallers (MFs). Fallers (Fs) more frequently used a walking aid and more frequently needed an observatory person for walking safely (FAC score of 3) than nonfallers (NFs). Two gait decrement parameters in counting dual task could distinguish potential Fs from NFs: decrement in stride length percentage (P=.043) and nonparetic step length percentage (P=.047). Regarding the division in 3 groups (NFs, SFs, and MFs), only MFs had a significantly higher percentage of decrement for paretic step length (P=.023) than SFs. Examining the decrement of spatial gait characteristics (stride length and paretic and nonparetic step length) during a DT addressing working memory can identify fall-prone subacute stroke patients. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  1. Stopping while Going! Response Inhibition Does Not Suffer Dual-Task Interference

    ERIC Educational Resources Information Center

    Yamaguchi, Motonori; Logan, Gordon D.; Bissett, Patrick G.

    2012-01-01

    Although dual-task interference is ubiquitous in a variety of task domains, stop-signal studies suggest that response inhibition is not subject to such interference. Nevertheless, no study has directly examined stop-signal performance in a dual-task setting. In two experiments, stop-signal performance was examined in a psychological refractory…

  2. Effects of alcohol on attention orienting and dual-task performance during simulated driving: an event-related potential study.

    PubMed

    Wester, Anne E; Verster, Joris C; Volkerts, Edmund R; Böcker, Koen B E; Kenemans, J Leon

    2010-09-01

    Driving is a complex task and is susceptible to inattention and distraction. Moreover, alcohol has a detrimental effect on driving performance, possibly due to alcohol-induced attention deficits. The aim of the present study was to assess the effects of alcohol on simulated driving performance and attention orienting and allocation, as assessed by event-related potentials (ERPs). Thirty-two participants completed two test runs in the Divided Attention Steering Simulator (DASS) with blood alcohol concentrations (BACs) of 0.00%, 0.02%, 0.05%, 0.08% and 0.10%. Sixteen participants performed the second DASS test run with a passive auditory oddball to assess alcohol effects on involuntary attention shifting. Sixteen other participants performed the second DASS test run with an active auditory oddball to assess alcohol effects on dual-task performance and active attention allocation. Dose-dependent impairments were found for reaction times, the number of misses and steering error, even more so in dual-task conditions, especially in the active oddball group. ERP amplitudes to novel irrelevant events were also attenuated in a dose-dependent manner. The P3b amplitude to deviant target stimuli decreased with blood alcohol concentration only in the dual-task condition. It is concluded that alcohol increases distractibility and interference from secondary task stimuli, as well as reduces attentional capacity and dual-task integrality.

  3. A Combined Cognitive Stimulation and Physical Exercise Programme (MINDVital) in Early Dementia: Differential Effects on Single- and Dual-Task Gait Performance.

    PubMed

    Tay, Laura; Lim, Wee Shiong; Chan, Mark; Ali, Noorhazlina; Chong, Mei Sian

    2016-01-01

    Gait disorders are common in early dementia, with particularly pronounced dual-task deficits, contributing to the increased fall risk and mobility decline associated with cognitive impairment. This study examines the effects of a combined cognitive stimulation and physical exercise programme (MINDVital) on gait performance under single- and dual-task conditions in older adults with mild dementia. Thirty-nine patients with early dementia participated in a multi-disciplinary rehabilitation programme comprising both physical exercise and cognitive stimulation. The programme was conducted in 8-week cycles with participants attending once weekly, and all participants completed 2 successive cycles. Cognitive, functional performance and behavioural symptoms were assessed at baseline and at the end of each 8-week cycle. Gait speed was examined under both single- (Timed Up and Go and 6-metre walk tests) and dual-task (animal category and serial counting) conditions. A random effects model was performed for the independent effect of MINDVital on the primary outcome variable of gait speed under dual-task conditions. The mean age of patients enroled in the rehabilitation programme was 79 ± 6.2 years; 25 (64.1%) had a diagnosis of Alzheimer's dementia, and 26 (66.7%) were receiving a cognitive enhancer therapy. There was a significant improvement in cognitive performance [random effects coefficient (standard error) = 0.90 (0.31), p = 0.003] and gait speed under both dual-task situations [animal category: random effects coefficient = 0.04 (0.02), p = 0.039; serial counting: random effects coefficient = 0.05 (0.02), p = 0.013], with reduced dual-task cost for gait speed [serial counting: random effects coefficient = -4.05 (2.35), p = 0.086] following successive MINDVital cycles. No significant improvement in single-task gait speed was observed. Improved cognitive performance over time was a significant determinant of changes in dual-task gait speed [random effects coefficients

  4. Determining Reliability of a Dual-Task Functional Mobility Protocol for Individuals With Lower Extremity Amputation.

    PubMed

    Hunter, Susan W; Frengopoulos, Courtney; Holmes, Jeff; Viana, Ricardo; Payne, Michael W

    2018-04-01

    To determine the relative and absolute reliability of a dual-task functional mobility assessment. Cross-sectional study. Academic rehabilitation hospital. Individuals (N=60) with lower extremity amputation attending an outpatient amputee clinic (mean age, 58.21±12.59y; 18, 80% male) who were stratified into 3 groups: (1) transtibial amputation of vascular etiology (n=20); (2) transtibial amputation of nonvascular etiology (n=20); and (3) transfemoral or bilateral amputation of any etiology (n=20). Not applicable. Time to complete the L Test measured functional mobility under single- and dual-task conditions. The addition of a cognitive task (serial subtractions by 3's) created dual-task conditions. Single-task performance on the cognitive task was also reported. Intraclass correlation coefficients (ICCs) measured relative reliability; SEM and minimal detectable change with a 95% confidence interval (MDC 95 ) measured absolute reliability. Bland-Altman plots measured agreement between assessments. Relative reliability results were excellent for all 3 groups. Values for the dual-task L Test for those with transtibial amputation of vascular etiology (n=20; mean age, 60.36±7.84y; 19, 90% men) were ICC=.98 (95% confidence interval [CI], .94-.99), SEM=1.36 seconds, and MDC 95 =3.76 seconds; for those with transtibial amputation of nonvascular etiology (n=20; mean age, 55.85±14.08y; 17, 85% men), values were ICC=.93 (95% CI, .80-.98), SEM=1.34 seconds, and MDC 95 =3.71 seconds; and for those with transfemoral or bilateral amputation (n=20; mean age, 58.21±14.88y; 13, 65% men), values were ICC=.998 (95% CI, .996-.999), SEM=1.03 seconds, and MDC 95 =2.85 seconds. Bland-Altman plots indicated that assessments did not vary systematically for each group. This dual-task assessment protocol achieved approved levels of relative reliability values for the 3 groups tested. This protocol may be used clinically or in research settings to assess the interaction between cognition

  5. Association of Dual-Task Gait With Incident Dementia in Mild Cognitive Impairment: Results From the Gait and Brain Study.

    PubMed

    Montero-Odasso, Manuel M; Sarquis-Adamson, Yanina; Speechley, Mark; Borrie, Michael J; Hachinski, Vladimir C; Wells, Jennie; Riccio, Patricia M; Schapira, Marcelo; Sejdic, Ervin; Camicioli, Richard M; Bartha, Robert; McIlroy, William E; Muir-Hunter, Susan

    2017-07-01

    Gait performance is affected by neurodegeneration in aging and has the potential to be used as a clinical marker for progression from mild cognitive impairment (MCI) to dementia. A dual-task gait test evaluating the cognitive-motor interface may predict dementia progression in older adults with MCI. To determine whether a dual-task gait test is associated with incident dementia in MCI. The Gait and Brain Study is an ongoing prospective cohort study of community-dwelling older adults that enrolled 112 older adults with MCI. Participants were followed up for 6 years, with biannual visits including neurologic, cognitive, and gait assessments. Data were collected from July 2007 to March 2016. Incident all-cause dementia was the main outcome measure, and single- and dual-task gait velocity and dual-task gait costs were the independent variables. A neuropsychological test battery was used to assess cognition. Gait velocity was recorded under single-task and 3 separate dual-task conditions using an electronic walkway. Dual-task gait cost was defined as the percentage change between single- and dual-task gait velocities: ([single-task gait velocity - dual-task gait velocity]/ single-task gait velocity) × 100. Cox proportional hazard models were used to estimate the association between risk of progression to dementia and the independent variables, adjusted for age, sex, education, comorbidities, and cognition. Among 112 study participants with MCI, mean (SD) age was 76.6 (6.9) years, 55 were women (49.1%), and 27 progressed to dementia (24.1%), with an incidence rate of 121 per 1000 person-years. Slow single-task gait velocity (<0.8 m/second) was not associated with progression to dementia (hazard ratio [HR], 3.41; 95% CI, 0.99-11.71; P = .05)while high dual-task gait cost while counting backward (HR, 3.79; 95% CI, 1.57-9.15; P = .003) and naming animals (HR, 2.41; 95% CI, 1.04-5.59; P = .04) were associated with dementia progression (incidence rate, 155 per

  6. A Novel Eye-Tracking Method to Assess Attention Allocation in Individuals with and without Aphasia Using a Dual-Task Paradigm

    PubMed Central

    Heuer, Sabine; Hallowell, Brooke

    2015-01-01

    Numerous authors report that people with aphasia have greater difficulty allocating attention than people without neurological disorders. Studying how attention deficits contribute to language deficits is important. However, existing methods for indexing attention allocation in people with aphasia pose serious methodological challenges. Eye-tracking methods have great potential to address such challenges. We developed and assessed the validity of a new dual-task method incorporating eye tracking to assess attention allocation. Twenty-six adults with aphasia and 33 control participants completed auditory sentence comprehension and visual search tasks. To test whether the new method validly indexes well-documented patterns in attention allocation, demands were manipulated by varying task complexity in single- and dual-task conditions. Differences in attention allocation were indexed via eye-tracking measures. For all participants significant increases in attention allocation demands were observed from single- to dual-task conditions and from simple to complex stimuli. Individuals with aphasia had greater difficulty allocating attention with greater task demands. Relationships between eye-tracking indices of comprehension during single and dual tasks and standardized testing were examined. Results support the validity of the novel eye-tracking method for assessing attention allocation in people with and without aphasia. Clinical and research implications are discussed. PMID:25913549

  7. Word Frequency Effects in Dual-Task Studies Using Lexical Decision and Naming as Task 2

    NASA Technical Reports Server (NTRS)

    Remington, Roger W.; McCann, Robert S.; VanSelst, Mark; Shafto, Michael G. (Technical Monitor)

    1997-01-01

    Word frequency effects in dual-task lexical decision are variously reported to be additive or underadditive across SOA. We replicate and extend earlier lexical decision studies and find word frequency to be additive across SOA. To more directly capture lexical processing, we examine dual-task naming. Once again, we find word frequency to be additive across SOA. Lexical processing appears to be constrained by central processing limitations.

  8. Dual Task Gait Performance in Frail Individuals with and without Mild Cognitive Impairment.

    PubMed

    Martínez-Ramírez, Alicia; Martinikorena, Ion; Lecumberri, Pablo; Gómez, Marisol; Millor, Nora; Casas-Herrero, Alvaro; Zambom-Ferraresi, Fabrício; Izquierdo, Mikel

    2016-01-01

    Several studies have stated that frailty is associated with cognitive impairment. Based on various studies, cognition impairment has been considered as a component of frailty. Other authors have shown that physical frailty is associated with low cognitive performance. Dual task gait tests are used as a strong predictor of falls in either dementia or frailty. Consequently, it is important to investigate dual task walking tests in elderly populations including control robust oldest old, frail oldest old with mild cognitive impairment (MCI) and frail oldest old without MCI. Dual task walking tests were carried out to examine the association between frailty and cognitive impairment in a population with advanced age. Forty-one elderly men and women participated in this study. The subjects from control, frail with MCI and frail without MCI groups, completed the 5-meter walk test at their own gait velocity. Arithmetic and verbal dual task walking performance was also assessed. Kinematic data were acquired from a unique tri-axial inertial sensor. The spatiotemporal and frequency parameters related to gait disorders did not show any significant differences between frail with and without MCI groups. The evaluation of these parameters extracted from the acceleration signals led us to conclude that these results expand the knowledge regarding the common conditions in frailty and MCI and may highlight the idea that the impairment in walking performance does not depend of frailty and cognitive status. © 2016 S. Karger AG, Basel.

  9. The reliability of the quantitative timed up and go test (QTUG) measured over five consecutive days under single and dual-task conditions in community dwelling older adults.

    PubMed

    Smith, Erin; Walsh, Lorcan; Doyle, Julie; Greene, Barry; Blake, Catherine

    2016-01-01

    The timed up and go (TUG) test is a commonly used assessment in older people with variations including the addition of a motor or cognitive dual-task, however in high functioning older adults it is more difficult to assess change. The quantified TUG (QTUG) uses inertial sensors to detect test and gait parameters during the test. If it is to be used in the longitudinal assessment of older adults, it is important that we know which parameters are reliable and under which conditions. This study aims to examine the relative reliability of the QTUG over five consecutive days under single, motor and cognitive dual-task conditions. Twelve community dwelling older adults (10 females, mean age 74.17 (3.88)) performed the QTUG under three conditions for five consecutive days. The relative reliability of each of the gait parameters was assessed using intra-class correlation coefficient (ICC 3,1) and standard error of measurement (SEM). Five of the measures demonstrated excellent reliability (ICC>0.70) under all three conditions (time to complete test, walk time, number of gait cycles, number of steps and return from turn time). Measures of variability and turn derived parameters demonstrated weak reliability under all three conditions (ICC=0.05-0.49). For the most reliable parameters under single-task conditions, the addition of a cognitive task resulted in a reduction in reliability suggesting caution when interpreting results under these conditions. Certain sensor derived parameters during the QTUG test may provide an additional resource in the longitudinal assessment of older people and earlier identification of falls risk. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Operation Compatibility: A Neglected Contribution to Dual-Task Costs

    ERIC Educational Resources Information Center

    Pannebakker, Merel M.; Band, Guido P. H.; Ridderinkhof, K. Richard

    2009-01-01

    Traditionally, dual-task interference has been attributed to the consequences of task load exceeding capacity limitations. However, the current study demonstrates that in addition to task load, the mutual compatibility of the concurrent processes modulates whether 2 tasks can be performed in parallel. In 2 psychological refractory period…

  11. Effects of Hearing Loss on Dual-Task Performance in an Audiovisual Virtual Reality Simulation of Listening While Walking.

    PubMed

    Lau, Sin Tung; Pichora-Fuller, M Kathleen; Li, Karen Z H; Singh, Gurjit; Campos, Jennifer L

    2016-07-01

    Most activities of daily living require the dynamic integration of sights, sounds, and movements as people navigate complex environments. Nevertheless, little is known about the effects of hearing loss (HL) or hearing aid (HA) use on listening during multitasking challenges. The objective of the current study was to investigate the effect of age-related hearing loss (ARHL) on word recognition accuracy in a dual-task experiment. Virtual reality (VR) technologies in a specialized laboratory (Challenging Environment Assessment Laboratory) were used to produce a controlled and safe simulated environment for listening while walking. In a simulation of a downtown street intersection, participants completed two single-task conditions, listening-only (standing stationary) and walking-only (walking on a treadmill to cross the simulated intersection with no speech presented), and a dual-task condition (listening while walking). For the listening task, they were required to recognize words spoken by a target talker when there was a competing talker. For some blocks of trials, the target talker was always located at 0° azimuth (100% probability condition); for other blocks, the target talker was more likely (60% of trials) to be located at the center (0° azimuth) and less likely (40% of trials) to be located at the left (270° azimuth). The participants were eight older adults with bilateral HL (mean age = 73.3 yr, standard deviation [SD] = 8.4; three males) who wore their own HAs during testing and eight controls with normal hearing (NH) thresholds (mean age = 69.9 yr, SD = 5.4; two males). No participant had clinically significant visual, cognitive, or mobility impairments. Word recognition accuracy and kinematic parameters (head and trunk angles, step width and length, stride time, cadence) were analyzed using mixed factorial analysis of variances with group as a between-subjects factor. Task condition (single versus dual) and probability (100% versus 60%) were within

  12. Dual-Task Crosstalk between Saccades and Manual Responses

    ERIC Educational Resources Information Center

    Huestegge, Lynn; Koch, Iring

    2009-01-01

    Between-task crosstalk has been discussed as an important source for dual-task costs. In this study, the authors examine concurrently performed saccades and manual responses as a means of studying the role of response-code conflict between 2 tasks. In Experiment 1, participants responded to an imperative auditory stimulus with a left or a right…

  13. Effects of dual-task balance training on postural performance in patients with Multiple Sclerosis: a double-blind, randomized controlled pilot trial.

    PubMed

    Monjezi, Saeideh; Negahban, Hossein; Tajali, Shirin; Yadollahpour, Nava; Majdinasab, Nastaran

    2017-02-01

    To investigate the effects of dual-task balance training on postural performance in patients with multiple sclerosis as compared with single-task balance training. Double-blind, pretest-posttest, randomized controlled pilot trial. Local Multiple Sclerosis Society. A total of 47 patients were randomly assigned to two equal groups labeled as single-task training and dual-task training groups. All patients received supervised balance training sessions, 3 times per week for 4 weeks. The patients in the single-task group performed balance activities, alone. However, patients in dual-task group practiced balance activities while simultaneously performing cognitive tasks. The 10-Meter Walk Test and Timed Up-and-Go under single-task and dual-task conditions, in addition to Activities-specific Balance Confidence, Berg Balance Scale, and Functional Gait Assessment were assessed pre-, and post intervention and also 6-weeks after the end of intervention. Only 38 patients completed the treatment plan. There was no difference in the amount of improvement seen between the two study groups. In both groups there was a significant effect of time for dual-10 Meter Walk Test (F 1, 36 =11.33, p=0.002) and dual-Timed Up-and-Go (F 1, 36 =14.27, p=0.001) but not for their single-tasks. Moreover, there was a significant effect of time for Activities-specific Balance Confidence, Berg Balance Scale, and Functional Gait Assessment ( P<0.01). This pilot study did not show more benefits from undertaking dual-task training than single-task training. A power analysis showed 71 patients per group would be needed to determine whether there was a clinically relevant difference for dual-task gait speed between the groups.

  14. Dual-task and anticipation impact lower limb biomechanics during a single-leg cut with body borne load.

    PubMed

    Seymore, Kayla D; Cameron, Sarah E; Kaplan, Jonathan T; Ramsay, John W; Brown, Tyler N

    2017-12-08

    This study quantified how a dual cognitive task impacts lower limb biomechanics during anticipated and unanticipated single-leg cuts with body borne load. Twenty-four males performed anticipated and unanticipated cuts with and without a dual cognitive task with three load conditions: no load (∼6 kg), medium load (15% of BW), and heavy load (30% of BW). Lower limb biomechanics were submitted to a repeated measures linear mixed model to test the main and interaction effects of load, anticipation, and dual task. With body borne load, participants increased peak stance (PS) hip flexion (p = .004) and hip internal rotation (p = .001) angle, and PS hip flexion (p = .001) and internal rotation (p = .018), and knee flexion (p = .016) and abduction (p = .001) moments. With the dual task, participants decreased PS knee flexion angle (p < .001) and hip flexion moment (p = .027), and increased PS knee external rotation angle (p = .034). During the unanticipated cut, participants increased PS hip (p = .040) and knee flexion angle (p < .001), and decreased PS hip adduction (p = .001), and knee abduction (p = .005) and external rotation (p = .026) moments. Adding body borne load produces lower limb biomechanical adaptations thought to increase risk of musculoskeletal injury, but neither anticipation nor dual task exaggerated those biomechanical adaptations. With a dual task, participants adopted biomechanics known to increase injury risk; whereas, participants used lower limb biomechanics thought to decrease injury risk during unanticipated cuts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Predicting dual-task performance with the Multiple Resources Questionnaire (MRQ).

    PubMed

    Boles, David B; Bursk, Jonathan H; Phillips, Jeffrey B; Perdelwitz, Jason R

    2007-02-01

    The objective was to assess the validity of the Multiple Resources Questionnaire (MRQ) in predicting dual-task interference. Subjective workload measures such as the Subjective Workload Assessment Technique (SWAT) and NASA Task Load Index are sensitive to single-task parameters and dual-task loads but have not attempted to measure workload in particular mental processes. An alternative is the MRQ. In Experiment 1, participants completed simple laboratory tasks and the MRQ after each. Interference between tasks was then correlated to three different task similarity metrics: profile similarity, based on r(2) between ratings; overlap similarity, based on summed minima; and overall demand, based on summed ratings. Experiment 2 used similar methods but more complex computer-based games. In Experiment 1 the MRQ moderately predicted interference (r = +.37), with no significant difference between metrics. In Experiment 2 the metric effect was significant, with overlap similarity excelling in predicting interference (r = +.83). Mean ratings showed high diagnosticity in identifying specific mental processing bottlenecks. The MRQ shows considerable promise as a cognitive-process-sensitive workload measure. Potential applications of the MRQ include the identification of dual-processing bottlenecks as well as process overloads in single tasks, preparatory to redesign in areas such as air traffic management, advanced flight displays, and medical imaging.

  16. Dual Tasking and Working Memory in Alcoholism: Relation to Frontocerebellar Circuitry

    PubMed Central

    Chanraud, Sandra; Pitel, Anne-Lise; Rohlfing, Torsten; Pfefferbaum, Adolf; Sullivan, Edith V

    2010-01-01

    Controversy exists regarding the role of cerebellar systems in cognition and whether working memory compromise commonly marking alcoholism can be explained by compromise of nodes of corticocerebellar circuitry. We tested 17 alcoholics and 31 age-matched controls with dual-task, working memory paradigms. Interference tasks competed with verbal and spatial working memory tasks using low (three item) or high (six item) memory loads. Participants also underwent structural MRI to obtain volumes of nodes of the frontocerebellar system. On the verbal working memory task, both groups performed equally. On the spatial working memory with the high-load task, the alcoholic group was disproportionately more affected by the arithmetic distractor than were controls. In alcoholics, volumes of the left thalamus and left cerebellar Crus I volumes were more robust predictors of performance in the spatial working memory task with the arithmetic distractor than the left frontal superior cortex. In controls, volumes of the right middle frontal gyrus and right cerebellar Crus I were independent predictors over the left cerebellar Crus I, left thalamus, right superior parietal cortex, or left middle frontal gyrus of spatial working memory performance with tracking interference. The brain–behavior correlations suggest that alcoholics and controls relied on the integrity of certain nodes of corticocerebellar systems to perform these verbal and spatial working memory tasks, but that the specific pattern of relationships differed by group. The resulting brain structure–function patterns provide correlational support that components of this corticocerebellar system not typically related to normal performance in dual-task conditions may be available to augment otherwise dampened performance by alcoholics. PMID:20410871

  17. Age difference in dual-task interference effects on procedural learning in children.

    PubMed

    Lejeune, Caroline; Desmottes, Lise; Catale, Corinne; Meulemans, Thierry

    2015-01-01

    The current study aimed to investigate the role played by explicit mechanisms during procedural learning in two age groups of children (7 and 10 years) using a dual-task paradigm. To do this, we explored the effect of an interference task during the early and late phases of a mirror tracing learning task. The results showed a differential impact of the secondary task on the two age groups, but only during the first learning phase; the performance of 10-year-olds was affected by the second task, whereas in 7-year-olds no performance difference was found between the single- and dual-task conditions. Overall, our study suggests that there are differences in the amount of effortful processing in which 7- and 10-year-olds engage at the beginning of the learning process; procedural learning in young children is mainly implicit, as attested by its lesser sensitivity to an interference task, whereas high-level explicit mechanisms seem to contribute to the procedural performance of 10-year-olds. However, these explicit mechanisms, even if they have an effect on performance, might not have an impact on the learning curve given that no difference in rate of acquisition was found between age groups. These findings are discussed in the light of classical conceptions of procedural learning. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Does Working Memory Enhance or Interfere With Speech Fluency in Adults Who Do and Do Not Stutter? Evidence From a Dual-Task Paradigm.

    PubMed

    Eichorn, Naomi; Marton, Klara; Schwartz, Richard G; Melara, Robert D; Pirutinsky, Steven

    2016-06-01

    The present study examined whether engaging working memory in a secondary task benefits speech fluency. Effects of dual-task conditions on speech fluency, rate, and errors were examined with respect to predictions derived from three related theoretical accounts of disfluencies. Nineteen adults who stutter and twenty adults who do not stutter participated in the study. All participants completed 2 baseline tasks: a continuous-speaking task and a working-memory (WM) task involving manipulations of domain, load, and interstimulus interval. In the dual-task portion of the experiment, participants simultaneously performed the speaking task with each unique combination of WM conditions. All speakers showed similar fluency benefits and decrements in WM accuracy as a result of dual-task conditions. Fluency effects were specific to atypical forms of disfluency and were comparable across WM-task manipulations. Changes in fluency were accompanied by reductions in speaking rate but not by corresponding changes in overt errors. Findings suggest that WM contributes to disfluencies regardless of stuttering status and that engaging WM resources while speaking enhances fluency. Further research is needed to verify the cognitive mechanism involved in this effect and to determine how these findings can best inform clinical intervention.

  19. The Influence of Audio-Visual Cueing (Traffic Light) on Dual Task Walking in Healthy Older Adults and Older Adults with Balance Impairments.

    PubMed

    Kaewkaen, Kitchana; Wongsamud, Phongphat; Ngaothanyaphat, Jiratchaya; Supawarapong, Papawarin; Uthama, Suraphong; Ruengsirarak, Worasak; Chanabun, Suthin; Kaewkaen, Pratchaya

    2018-02-01

    The walking gait of older adults with balance impairment is affected by dual tasking. Several studies have shown that external cues can stimulate improvement in older adults' performance. There is, however, no current evidence to support the usefulness of external cues, such as audio-visual cueing, in dual task walking in older adults. Thus, the aim of this study was to investigate the influence of an audio-visual cue (simulated traffic light) on dual task walking in healthy older adults and in older adults with balance impairments. A two-way repeated measures study was conducted on 14 healthy older adults and 14 older adults with balance impairment, who were recruited from the community in Chiang Rai, Thailand. Their walking performance was assessed using a four-metre walking test at their preferred gait speed and while walking under two further gait conditions, in randomised order: dual task walking and dual task walking with a simulated traffic light. Each participant was tested individually, with the testing taking between 15 and 20 minutes to perform, including two-minute rest periods between walking conditions. Two Kinect cameras recorded the spatio-temporal parameters using MFU gait analysis software. Each participant was tested for each condition twice. The mean parameters for each condition were analysed using a two-way repeated measures analysis of variance (ANOVA) with participant group and gait condition as factors. There was no significant between-group effect for walking speed, stride length and cadence. There were also no significant effects between gait condition and stride length or cadence. However, the effect between gait condition and walking speed was found to be significant [F(1.557, 40.485) = 4.568, P = 0.024, [Formula: see text

  20. Increased alertness, better than posture prioritization, explains dual-task performance in prosthesis users and controls under increasing postural and cognitive challenge.

    PubMed

    Howard, Charla L; Perry, Bonnie; Chow, John W; Wallace, Chris; Stokic, Dobrivoje S

    2017-11-01

    Sensorimotor impairments after limb amputation impose a threat to stability. Commonly described strategies for maintaining stability are the posture first strategy (prioritization of balance) and posture second strategy (prioritization of concurrent tasks). The existence of these strategies was examined in 13 below-knee prosthesis users and 15 controls during dual-task standing under increasing postural and cognitive challenge by evaluating path length, 95% sway area, and anterior-posterior and medial-lateral amplitudes of the center of pressure. The subjects stood on two force platforms under usual (hard surface/eyes open) and difficult (soft surface/eyes closed) conditions, first alone and while performing a cognitive task without and then with instruction on cognitive prioritization. During standing alone, sway was not significantly different between groups. After adding the cognitive task without prioritization instruction, prosthesis users increased sway more under the dual-task than single-task standing (p ≤ 0.028) during both usual and difficult conditions, favoring the posture second strategy. Controls, however, reduced dual-task sway under a greater postural challenge (p ≤ 0.017), suggesting the posture first strategy. With prioritization of the cognitive task, sway was unchanged or reduced in prosthesis users, suggesting departure from the posture second strategy, whereas controls maintained the posture first strategy. Individual analysis of dual tasking revealed that greater postural demand in controls and greater cognitive challenge in prosthesis users led to both reduced sway and improved cognitive performance, suggesting cognitive-motor facilitation. Thus, activation of additional resources through increased alertness, rather than posture prioritization, may explain dual-task performance in both prosthesis users and controls under increasing postural and cognitive challenge.

  1. The Association between Dual-Task Gait after Concussion and Prolonged Symptom Duration.

    PubMed

    Howell, David R; Brilliant, Anna; Berkstresser, Brant; Wang, Francis; Fraser, Joana; Meehan, William P

    2017-12-01

    Quantitative gait measurements can identify persistent postconcussion impairments. However, their prognostic utility after injury to identify the likelihood of prolonged concussion symptoms remains unknown. Our objective was to examine if dual-task gait performance measures are independently associated with persistent (> 28 days) concussion symptoms among a sample of athletes. Sixty individuals diagnosed with a sport-related concussion were assessed within 10 days of their injury. Each participant completed a postconcussion symptom scale, an injury history questionnaire, and a single/dual-task gait examination. They were followed until they no longer reported symptoms, and the duration of time required for symptom resolution was calculated. A binary multivariable logistic regression model determined the independent association between dual-task gait and symptom duration (≤ 28 days vs. >28 days) while controlling for the effect of gender, age, symptom severity, injury-to-examination time, and history of concussion. Seventeen (28%) participants reported a symptom duration >28 days. The dual-task cost for average gait speed (-25.9 ± 9.5% vs. -19.8 ± 8.9%; p = 0.027) and cadence (-18.0 ± 2.9% vs. -12.0 ± 7.7%; p = 0.029) was significantly greater among participants who experienced symptoms for >28 days. After adjusting for potential confounding variables, greater dual-task average gait speed costs were independently associated with prolonged symptom duration (aOR = 0.908; 95% CI = 0.835-0.987). Examinations of dual-task gait may provide useful information during multifaceted concussion examinations. Quantitative assessments that simultaneously test multiple domains, such as dual tasks, may be clinically valuable after a concussion to identify those more likely to experience symptoms for >28 days after injury.

  2. Individual Differences in Dual Task Performance. Final Report.

    ERIC Educational Resources Information Center

    Lansman, Marcy; Hunt, Earl

    This report summarizes the research results and provides a reference. The basic question addressed was, "Is performance on multi-component tasks predicted by performance on the individual components performed separately?" In the first series of experiments, a dual task involving memory and verbal processing components to predict a…

  3. The effects of stimulus modality and task integrality: Predicting dual-task performance and workload from single-task levels

    NASA Technical Reports Server (NTRS)

    Hart, S. G.; Shively, R. J.; Vidulich, M. A.; Miller, R. C.

    1986-01-01

    The influence of stimulus modality and task difficulty on workload and performance was investigated. The goal was to quantify the cost (in terms of response time and experienced workload) incurred when essentially serial task components shared common elements (e.g., the response to one initiated the other) which could be accomplished in parallel. The experimental tasks were based on the Fittsberg paradigm; the solution to a SternBERG-type memory task determines which of two identical FITTS targets are acquired. Previous research suggested that such functionally integrated dual tasks are performed with substantially less workload and faster response times than would be predicted by suming single-task components when both are presented in the same stimulus modality (visual). The physical integration of task elements was varied (although their functional relationship remained the same) to determine whether dual-task facilitation would persist if task components were presented in different sensory modalities. Again, it was found that the cost of performing the two-stage task was considerably less than the sum of component single-task levels when both were presented visually. Less facilitation was found when task elements were presented in different sensory modalities. These results suggest the importance of distinguishing between concurrent tasks that complete for limited resources from those that beneficially share common resources when selecting the stimulus modalities for information displays.

  4. Simultaneous dual-task performance reveals parallel response selection after practice

    NASA Technical Reports Server (NTRS)

    Hazeltine, Eliot; Teague, Donald; Ivry, Richard B.

    2002-01-01

    E. H. Schumacher, T. L. Seymour, J. M. Glass, D. E. Kieras, and D. E. Meyer (2001) reported that dual-task costs are minimal when participants are practiced and give the 2 tasks equal emphasis. The present research examined whether such findings are compatible with the operation of an efficient response selection bottleneck. Participants trained until they were able to perform both tasks simultaneously without interference. Novel stimulus pairs produced no reaction time costs, arguing against the development of compound stimulus-response associations (Experiment 1). Manipulating the relative onsets (Experiments 2 and 4) and durations (Experiments 3 and 4) of response selection processes did not lead to dual-task costs. The results indicate that the 2 tasks did not share a bottleneck after practice.

  5. Residual standard deviation: Validation of a new measure of dual-task cost in below-knee prosthesis users.

    PubMed

    Howard, Charla L; Wallace, Chris; Abbas, James; Stokic, Dobrivoje S

    2017-01-01

    We developed and evaluated properties of a new measure of variability in stride length and cadence, termed residual standard deviation (RSD). To calculate RSD, stride length and cadence are regressed against velocity to derive the best fit line from which the variability (SD) of the distance between the actual and predicted data points is calculated. We examined construct, concurrent, and discriminative validity of RSD using dual-task paradigm in 14 below-knee prosthesis users and 13 age- and education-matched controls. Subjects walked first over an electronic walkway while performing separately a serial subtraction and backwards spelling task, and then at self-selected slow, normal, and fast speeds used to derive the best fit line for stride length and cadence against velocity. Construct validity was demonstrated by significantly greater increase in RSD during dual-task gait in prosthesis users than controls (group-by-condition interaction, stride length p=0.0006, cadence p=0.009). Concurrent validity was established against coefficient of variation (CV) by moderate-to-high correlations (r=0.50-0.87) between dual-task cost RSD and dual-task cost CV for both stride length and cadence in prosthesis users and controls. Discriminative validity was documented by the ability of dual-task cost calculated from RSD to effectively differentiate prosthesis users from controls (area under the receiver operating characteristic curve, stride length 0.863, p=0.001, cadence 0.808, p=0.007), which was better than the ability of dual-task cost CV (0.692, 0.648, respectively, not significant). These results validate RSD as a new measure of variability in below-knee prosthesis users. Future studies should include larger cohorts and other populations to ascertain its generalizability. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. The role of judgment frames and task precision in object attention: Reduced template sharpness limits dual-object performance.

    PubMed

    Liu, Shiau-Hua; Dosher, Barbara Anne; Lu, Zhong-Lin

    2009-06-01

    Multiple attributes of a single-object are often processed more easily than attributes of different objects-a phenomenon associated with object attention. Here we investigate the influence of two factors, judgment frames and judgment precision, on dual-object report deficits as an index of object attention. [Han, S., Dosher, B., & Lu, Z.-L. (2003). Object attention revisited: Identifying mechanisms and boundary conditions. Psychological Science, 14, 598-604] predicted that consistency of the frame for judgments about two separate objects could reduce or eliminate the expression of object attention limitations. The current studies examine the effects of judgment frames and of task precision in orientation identification and find that dual-object report deficits within one feature are indeed affected modestly by the congruency of the judgments and more substantially by the required precision of judgments. The observed dual-object deficits affected contrast thresholds for incongruent frame conditions and for high precision judgments and reduce psychometric asymptotes. These dual-object deficits reflect a combined effect of multiplicative noise and external noise exclusion in dual-object conditions, both related to the effects of attention on the tuning of perceptual templates. These results have implications for modification of object attention theory, for understanding limitations on concurrent tasks.

  7. On the costs of parallel processing in dual-task performance: The case of lexical processing in word production.

    PubMed

    Paucke, Madlen; Oppermann, Frank; Koch, Iring; Jescheniak, Jörg D

    2015-12-01

    Previous dual-task picture-naming studies suggest that lexical processes require capacity-limited processes and prevent other tasks to be carried out in parallel. However, studies involving the processing of multiple pictures suggest that parallel lexical processing is possible. The present study investigated the specific costs that may arise when such parallel processing occurs. We used a novel dual-task paradigm by presenting 2 visual objects associated with different tasks and manipulating between-task similarity. With high similarity, a picture-naming task (T1) was combined with a phoneme-decision task (T2), so that lexical processes were shared across tasks. With low similarity, picture-naming was combined with a size-decision T2 (nonshared lexical processes). In Experiment 1, we found that a manipulation of lexical processes (lexical frequency of T1 object name) showed an additive propagation with low between-task similarity and an overadditive propagation with high between-task similarity. Experiment 2 replicated this differential forward propagation of the lexical effect and showed that it disappeared with longer stimulus onset asynchronies. Moreover, both experiments showed backward crosstalk, indexed as worse T1 performance with high between-task similarity compared with low similarity. Together, these findings suggest that conditions of high between-task similarity can lead to parallel lexical processing in both tasks, which, however, does not result in benefits but rather in extra performance costs. These costs can be attributed to crosstalk based on the dual-task binding problem arising from parallel processing. Hence, the present study reveals that capacity-limited lexical processing can run in parallel across dual tasks but only at the expense of extraordinary high costs. (c) 2015 APA, all rights reserved).

  8. Effect of a dual task on quantitative Timed Up and Go performance in community-dwelling older adults: A preliminary study.

    PubMed

    Smith, Erin; Walsh, Lorcan; Doyle, Julie; Greene, Barry; Blake, Catherine

    2017-08-01

    The Timed Up and Go test (TUG) is used as a measure of functional ability in older adults; however, the method of measurement does not allow us to determine which aspects of the test deficits occur in. The aim of the present study was to examine the ability of the quantitative TUG (QTUG) to measure performance during the TUG test under three different conditions - single task, motor task and cognitive dual task - and to compare performance between fallers and non-fallers in high-functioning community-dwelling older adults. A total of 37 community-dwelling older adults, 16 with a self-reported falls history in the previous year, were recruited. Participants underwent a falls risk assessment with a physiotherapist including the QTUG under three conditions (single task, motor task, cognitive dual-task). A total of 10 clinical parameters were chosen for analysis using mancova and a series of ancova, with age, sex and body mass index included as covariates. The mancova analysis showed a significant difference across the three task conditions (Wilk's Lambda F 20,186  = 3.37, P < 0.001. No overall significant difference between faller and non-faller groups (Wilk's Lambda F 10,96  = 1.469, P = 0.163) or significant interaction between task and faller status (Wilk's Lambda F 20,192  = 1.131, P = 0.321) was found. ancova results for each of the parameters showed overall differences between single, motor and cognitive tasks for all of the variables, except time in double support. When faller and non-faller differences were explored, cadence and stride velocity was greater, and stride time longer in those with a prior history of falls. In community-dwelling older adults, these preliminary results show that a cognitive dual-task significantly (P < 0.025) affects QTUG performance in almost all parameters, with a significant (P < 0.025) reduction in time-to-stand observed with a motor task. Although no statistical difference was found between

  9. Age-Related Differences in Reorganization of Functional Connectivity for a Dual Task with Increasing Postural Destabilization

    PubMed Central

    Huang, Cheng-Ya; Lin, Linda L.; Hwang, Ing-Shiou

    2017-01-01

    The aged brain may not make good use of central resources, so dual task performance may be degraded. From the brain connectome perspective, this study investigated dual task deficits of older adults that lead to task failure of a suprapostural motor task with increasing postural destabilization. Twelve younger (mean age: 25.3 years) and 12 older (mean age: 65.8 years) adults executed a designated force-matching task from a level-surface or a stabilometer board. Force-matching error, stance sway, and event-related potential (ERP) in the preparatory period were measured. The force-matching accuracy and the size of postural sway of the older adults tended to be more vulnerable to stance configuration than that of the young adults, although both groups consistently showed greater attentional investment on the postural task as sway regularity increased in the stabilometer condition. In terms of the synchronization likelihood (SL) of the ERP, both younger and older adults had net increases in the strengths of the functional connectivity in the whole brain and in the fronto-sensorimotor network in the stabilometer condition. Also, the SL in the fronto-sensorimotor network of the older adults was greater than that of the young adults for both stance conditions. However, unlike the young adults, the older adults did not exhibit concurrent deactivation of the functional connectivity of the left temporal-parietal-occipital network for postural-suprapostural task with increasing postural load. In addition, the older adults potentiated functional connectivity of the right prefrontal area to cope with concurrent force-matching with increasing postural load. In conclusion, despite a universal negative effect on brain volume conduction, our preliminary results showed that the older adults were still capable of increasing allocation of neural sources, particularly via compensatory recruitment of the right prefrontal loop, for concurrent force-matching under the challenging postural

  10. Effects of dual-task training on balance and executive functions in Parkinson's disease: A pilot study.

    PubMed

    Fernandes, Ângela; Rocha, Nuno; Santos, Rubim; Tavares, João Manuel R S

    2015-01-01

    The aim of this study was to analyze the efficacy of cognitive-motor dual-task training compared with single-task training on balance and executive functions in individuals with Parkinson's disease. Fifteen subjects, aged between 39 and 75 years old, were randomly assigned to the dual-task training group (n = 8) and single-task training group (n = 7). The training was run twice a week for 6 weeks. The single-task group received balance training and the dual-task group performed cognitive tasks simultaneously with the balance training. There were no significant differences between the two groups at baseline. After the intervention, the results for mediolateral sway with eyes closed were significantly better for the dual-task group and anteroposterior sway with eyes closed was significantly better for the single-task group. The results suggest superior outcomes for the dual-task training compared to the single-task training for static postural control, except in anteroposterior sway with eyes closed.

  11. Measuring the effects of a visual or auditory Stroop task on dual-task costs during obstacle crossing.

    PubMed

    Worden, Timothy A; Mendes, Matthew; Singh, Pratham; Vallis, Lori Ann

    2016-10-01

    Successful planning and execution of motor strategies while concurrently performing a cognitive task has been previously examined, but unfortunately the varied and numerous cognitive tasks studied has limited our fundamental understanding of how the central nervous system successfully integrates and executes these tasks simultaneously. To gain a better understanding of these mechanisms we used a set of cognitive tasks requiring similar central executive function processes and response outputs but requiring different perceptual mechanisms to perform the motor task. Thirteen healthy young adults (20.6±1.6years old) were instrumented with kinematic markers (60Hz) and completed 5 practice, 10 single-task obstacle walking trials and two 40 trial experimental blocks. Each block contained 20 trials of seated (single-task) trials followed by 20 cognitive and obstacle (30% lower leg length) crossing trials (dual-task). Blocks were randomly presented and included either an auditory Stroop task (AST; central interference only) or a visual Stroop task (VST; combined central and structural interference). Higher accuracy rates and shorter response times were observed for the VST versus AST single-task trials (p<0.05). Conversely, for the obstacle stepping performance, larger dual task costs were observed for the VST as compared to the AST for clearance measures (the VST induced larger clearance values for both the leading and trailing feet), indicating VST tasks caused greater interference for obstacle crossing (p<0.05). These results supported the hypothesis that structural interference has a larger effect on motor performance in a dual-task situation compared to cognitive tasks that pose interference at only the central processing stage. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Developmental changes in children's abilities to share and allocate attention in a dual task.

    PubMed

    Irwin-Chase, H; Burns, B

    2000-09-01

    Characterizing developmental changes in children's dual-task performance has been problematic because differences in divided attention abilities are easily confounded with differences in overall capacity. Two experiments showed that after individual differences in children's capacity for single-task performance were controlled for, age differences between second- (M = 8.1 years) and fifth-grade (M = 11.1 years) children did not exist in dual-task performance when tasks were of equal priority. However, when tasks had different priorities, only fifth-grade children could differentially allocate attention in the dual task. Results are discussed within the coordination hypothesis framework (see A. F. Kramer & J. L. Larish, 1996), which suggests that changes in dual-task performance with aging are due to changes in the ability to coordinate and control the allocation of attention. It is argued that linking the investigations of children's attention with research on attention and aging provides both methodological and theoretical benefits. Copyright 2000 Academic Press.

  13. Effects of dual task difficulty in motor and cognitive performance: Differences between adults and adolescents.

    PubMed

    Bustillo-Casero, Pilar; Villarrasa-Sapiña, Israel; García-Massó, Xavier

    2017-10-01

    In the present study our aim was to compare dual-task performance in thirteen adolescents and fifteen young adults while concurrently performing a cognitive and a motor task. The postural control variables were obtained under three different conditions: i) bipedal stance, ii) tandem stance and iii) unipedal stance. The cognitive task consisted of a backward digit span test in which the participants were asked to memorize a sequence of numbers and then repeat the number in reverse order at three different difficulty levels (i.e. with 3, 4 and 5 digits). The difficulty of the cognitive task was seen to have different effects on adolescents and young adults. Adolescents seem to prioritize postural control during high difficulty postural conditions while a cross-domain competition model appeared in easy postural conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Dual-tasks and walking fast: relationship to extra-pyramidal signs in advanced Alzheimer disease.

    PubMed

    Camicioli, Richard; Bouchard, Thomas; Licis, Lisa

    2006-10-25

    Extra-pyramidal signs (EPS) and cadence predicted falls risk in patients with advanced Alzheimer disease (AD). Dual task performance predicts falls with variable success. Dual-task performance and walking fast were examined in advanced AD patients with EPS (EPS+, >3 modified Unified Parkinson's Disease Rating Scale [UPDRS] signs) or without EPS (EPS-, three or less UPDRS signs). Demographics, mental and functional status, behavioral impairment, EPS, and quantitative gait measures (GaitRite) were determined. The effects of an automatic dual-task (simple counting) and of walking fast on spatial and temporal gait characteristics were compared between EPS+ and EPS- subjects using a repeated measures design. Cadence decreased, while stride time, swing time and variability in swing time increased with the dual task. Results were insignificant after adjusting for secondary task performance. With walking fast, speed, cadence and stride length increased while stride time, swing time and double support time decreased. Although EPS+ subjects were slower and had decreased stride length, dual task and walking fast effects did not differ from EPS- subjects. Patient characteristics, the type of secondary task and the specific gait measures examined vary in the literature. In this moderately to severely demented population, EPS did not affect "unconscious" (dual task) or "conscious" (walking fast) gait modulation. Given their high falls risk, and retained ability to modulate walking, EPS+ AD patients may be ideal candidates for interventions aimed at preventing falls.

  15. The effect of cognitive-motor dual task training with the biorescue force platform on cognition, balance and dual task performance in institutionalized older adults: a randomized controlled trial

    PubMed Central

    Delbroek, Tom; Vermeylen, Wietse; Spildooren, Joke

    2017-01-01

    [Purpose] This study investigates whether cognition, balance and dual task performance in institutionalized older adults improves by a virtual reality dual task training. [Subjects and Methods] Randomized controlled trial; Twenty institutionalized older adults with mild cognitive impairment (13 female, 7 male; average age, 87.2 ± 5.96 years) were randomized to the intervention (i.e. Virtual reality dual-task training using the BioRescue) or control group (no additional training). The intervention group took part in a 6-week training program while the elderly in the control group maintained their daily activities. Balance was measured with the Instrumented Timed Up-and-Go Test with and without a cognitive task. The Observed Emotion Rating Scale and Intrinsic Motivation Inventory were administered to evaluate the emotions and motivation regarding the exergaming program. [Results] The intervention group improved significantly on the total Timed Up-and-Go duration and the turn-to-sit duration during single-task walking in comparison to the control group who received no additional training. Participants found the virtual reality dual task training pleasant and useful for their concentration, memory and balance. Pleasure and alertness were the two emotions which were mostly seen during the intervention. [Conclusion] The BioRescue is a pleasant and interesting treatment method, well suited for institutionalized older adults in need of lifelong physical therapy. PMID:28744033

  16. Does a multicomponent exercise program improve dual-task performance in amnestic mild cognitive impairment? A randomized controlled trial.

    PubMed

    Makizako, Hyuma; Doi, Takehiko; Shimada, Hiroyuki; Yoshida, Daisuke; Tsutsumimoto, Kota; Uemura, Kazuki; Suzuki, Takao

    2012-12-01

    There has been much interest in exercise interventions as a primary behavioral prevention strategy against cognitive decline. The aim of this study was to evaluate the effect of a multicomponent exercise program on physical and dual-task performances in community-dwelling older adults with amnestic mild cognitive impairment (aMCI). Fifty older adults (23 women) with aMCI (mean age, 76 years) were randomized to an intervention (n=25) or a control group (n=25). The intervention group received a multicomponent exercise program for 90 minutes/day, 2 days/week, or 40 times over six months. The multicomponent exercises included aerobic exercise, muscle strength training and postural balance retraining, which was conducted under multi-task conditions to stimulate attention and memory. Participants in the control group attended two health promotion education classes within six months. Physical and dual-task performances were measured before randomization and after six months. Dual-task performances using reaction times with balance and cognitive demands were measured. The improvement effects on dual-task performances with both balance and cognitive demands were not statistically significant: reaction time with balance demand F1,45=3.3, p=0.07, and cognitive demand F1,45=2.6, p=0.12. However, there was a significant group-by-time interaction on maximal walking speed, which decreased significantly in the control group (F1,45=5.9, p=0.02). This six-month multicomponent exercise program improved maximal walking speed in older adults with aMCI; however, it did not improve dual-task performances assessed by reaction times.

  17. Return to activity after concussion affects dual-task gait balance control recovery.

    PubMed

    Howell, David R; Osternig, Louis R; Chou, Li-Shan

    2015-04-01

    Recent work has identified deficits in dual-task gait balance control for up to 2 months after adolescent concussion; however, how resumption of preinjury physical activities affects recovery is unknown. The objective of this study is to examine how return to activity (RTA) affects recovery from concussion on measures of symptom severity, cognition, and balance control during single-task and dual-task walking. Nineteen adolescents with concussion who returned to preinjury activity within 2 months after injury and 19 uninjured, matched controls completed symptom inventories, computerized cognitive testing, and single-task and dual-task gait analyses. Concussion participants were assessed at five time points: within 72 h, 1 wk, 2 wk, 1 month, and 2 months postinjury. Control participants were assessed at the same time points as their matched concussion counterparts. RTA day was documented as the postinjury day in which physical activity participation was allowed. The effect of returning to physical activity was assessed by examining the percent change on each dependent variable across time before and directly after the RTA. Data were analyzed by two-way mixed effects ANOVAs. After the RTA day, concussion participants significantly increased their total center-of-mass medial/lateral displacement (P = 0.009, ηp = .175) and peak velocity (P = 0.048, ηp = 0.104) during dual-task walking when compared with pre-RTA data, whereas no changes for the concussion group or between groups were detected on measures of single-task walking, forward movement, or cognition. Adolescents with concussion displayed increased center-of-mass medial/lateral displacement and velocity during dual-task walking after RTA, suggesting a regression of recovery in gait balance control. This study reinforces the need for a multifaceted approach to concussion management and continued monitoring beyond the point of clinical recovery.

  18. EEG measures reveal dual-task interference in postural performance in young adults

    PubMed Central

    Woollacott, Marjorie

    2014-01-01

    The study used a dual-task (DT) postural paradigm (two tasks performed at once) that included electroencephalography (EEG) to examine cortical interference when a visual working memory (VWM) task was paired with a postural task. The change detection task was used, as it requires storage of information without updating or manipulation and predicts VWM capacity. Ground reaction forces (GRFs) (horizontal and vertical), EMG, and EEG elements, time locked to support surface perturbations, were used to infer the active neural processes underlying the automatic control of balance in 14 young adults. A significant reduction was seen between single task (ST) and DT conditions in VWM capacity (F(1,13) = 6.175, p < 0.05, r = 0.6) and event-related potential (ERP) N1 component amplitude over the L motor (p < 0.001) and R sensory (p < 0.05) cortical areas. In addition, a significant increase in the COP trajectory peak (pkcopx) was seen in the DT versus ST condition. Modulation of VWM capacity as well as ERP amplitude and pkcopx in DT conditions provided evidence of an interference pattern, suggesting that the two modalities shared a similar set of attentional resources. The results provide direct evidence of the competition for central processing attentional resources between the two modalities, through the reduction in amplitude of the ERP evoked by the postural perturbation. PMID:25273924

  19. Static and dynamic posture control in postlingual cochlear implanted patients: effects of dual-tasking, visual and auditory inputs suppression

    PubMed Central

    Bernard-Demanze, Laurence; Léonard, Jacques; Dumitrescu, Michel; Meller, Renaud; Magnan, Jacques; Lacour, Michel

    2014-01-01

    Posture control is based on central integration of multisensory inputs, and on internal representation of body orientation in space. This multisensory feedback regulates posture control and continuously updates the internal model of body's position which in turn forwards motor commands adapted to the environmental context and constraints. The peripheral localization of the vestibular system, close to the cochlea, makes vestibular damage possible following cochlear implant (CI) surgery. Impaired vestibular function in CI patients, if any, may have a strong impact on posture stability. The simple postural task of quiet standing is generally paired with cognitive activity in most day life conditions, leading therefore to competition for attentional resources in dual-tasking, and increased risk of fall particularly in patients with impaired vestibular function. This study was aimed at evaluating the effects of postlingual cochlear implantation on posture control in adult deaf patients. Possible impairment of vestibular function was assessed by comparing the postural performance of patients to that of age-matched healthy subjects during a simple postural task performed in static (stable platform) and dynamic (platform in translation) conditions, and during dual-tasking with a visual or auditory memory task. Postural tests were done in eyes open (EO) and eyes closed (EC) conditions, with the CI activated (ON) or not (OFF). Results showed that the postural performance of the CI patients strongly differed from the controls, mainly in the EC condition. The CI patients showed significantly reduced limits of stability and increased postural instability in static conditions. In dynamic conditions, they spent considerably more energy to maintain equilibrium, and their head was stabilized neither in space nor on trunk: they behaved dynamically without vision like an inverted pendulum while the controls showed a whole body rigidification strategy. Hearing (prosthesis on) as well

  20. Static and dynamic posture control in postlingual cochlear implanted patients: effects of dual-tasking, visual and auditory inputs suppression.

    PubMed

    Bernard-Demanze, Laurence; Léonard, Jacques; Dumitrescu, Michel; Meller, Renaud; Magnan, Jacques; Lacour, Michel

    2013-01-01

    Posture control is based on central integration of multisensory inputs, and on internal representation of body orientation in space. This multisensory feedback regulates posture control and continuously updates the internal model of body's position which in turn forwards motor commands adapted to the environmental context and constraints. The peripheral localization of the vestibular system, close to the cochlea, makes vestibular damage possible following cochlear implant (CI) surgery. Impaired vestibular function in CI patients, if any, may have a strong impact on posture stability. The simple postural task of quiet standing is generally paired with cognitive activity in most day life conditions, leading therefore to competition for attentional resources in dual-tasking, and increased risk of fall particularly in patients with impaired vestibular function. This study was aimed at evaluating the effects of postlingual cochlear implantation on posture control in adult deaf patients. Possible impairment of vestibular function was assessed by comparing the postural performance of patients to that of age-matched healthy subjects during a simple postural task performed in static (stable platform) and dynamic (platform in translation) conditions, and during dual-tasking with a visual or auditory memory task. Postural tests were done in eyes open (EO) and eyes closed (EC) conditions, with the CI activated (ON) or not (OFF). Results showed that the postural performance of the CI patients strongly differed from the controls, mainly in the EC condition. The CI patients showed significantly reduced limits of stability and increased postural instability in static conditions. In dynamic conditions, they spent considerably more energy to maintain equilibrium, and their head was stabilized neither in space nor on trunk: they behaved dynamically without vision like an inverted pendulum while the controls showed a whole body rigidification strategy. Hearing (prosthesis on) as well

  1. Reduced Dual-Task Performance in MS Patients Is Further Decreased by Muscle Fatigue.

    PubMed

    Wolkorte, Ria; Heersema, Dorothea J; Zijdewind, Inge

    2015-06-01

    Multiple sclerosis (MS) can be accompanied by motor, cognitive, and sensory impairments. Additionally, MS patients often report fatigue as one of their most debilitating symptoms. It is, therefore, expected that MS patients will have difficulties in performing cognitive-motor dual tasks (DTs), especially in a fatiguing condition. To determine whether MS patients are more challenged by a DT than controls in a fatiguing and less-fatiguing condition and whether DT performance is associated with perceived fatigue. A group of 19 MS patients and 19 age-, sex-, and education-matched controls performed a cognitive task (2-choice reaction time task) separately or concurrent with a low-force or a high-force motor task (index finger abduction at 10% or 30% maximal voluntary contraction). MS patients performed less well on a cognitive task than controls. Cognitive task performance under DT conditions decreased more for MS patients. Moreover, under high-force DT conditions, cognitive performance declined in both groups but to a larger degree for MS patients. Besides a decline in cognitive task performance, MS patients also showed a stronger decrease in motor performance under high-force DT conditions. DT costs were positively related to perceived fatigue as measured by questionnaires. Compared with controls, MS patients performed less well on DTs as demonstrated by a reduction in both cognitive and motor performances. This performance decrease was stronger under fatiguing conditions and was related to the sense of fatigue of MS patients. These data illustrate problems that MS patients may encounter in daily life because of their fatigue. © The Author(s) 2014.

  2. Attentional Modulation of Word Recognition by Children in a Dual-Task Paradigm

    ERIC Educational Resources Information Center

    Choi, Sangsook; Lotto, Andrew; Lewis, Dawna; Hoover, Brenda; Stelmachowicz, Patricia

    2008-01-01

    Purpose: This study investigated an account of limited short-term memory capacity for children's speech perception in noise using a dual-task paradigm. Method: Sixty-four normal-hearing children (7-14 years of age) participated in this study. Dual tasks were repeating monosyllabic words presented in noise at 8 dB signal-to-noise ratio and…

  3. The development of children's knowledge of attention and resource allocation in single and dual tasks.

    PubMed

    Dossett, D; Burns, B

    2000-06-01

    Developmental changes in kindergarten, 1st-, and 4th-grade children's knowledge about the variables that affect attention sharing and resource allocation were examined. Findings from the 2 experiments showed that kindergartners understood that person and strategy variables affect performance in attention-sharing tasks. However, knowledge of how task variables affect performance was not evident to them and was inconsistent for 1st and 4th graders. Children's knowledge about resource allocation revealed a different pattern and varied according to the dissimilarity of task demands in the attention-sharing task. In Experiment 1, in which the dual attention tasks were similar (i.e., visual detection), kindergarten and 1st-grade children did not differentiate performance in single and dual tasks. Fourth graders demonstrated knowledge that performance on a single task would be better than performance on the dual tasks for only 2 of the variables examined. In Experiment 2, in which the dual attention tasks were dissimilar (i.e., visual and auditory detection), kindergarten and 1st-grade children demonstrated knowledge that performance in the single task would be better than in the dual tasks for 1 of the task variables examined. However, 4th-grade children consistently gave higher ratings for performance on the single than on the dual attention tasks for all variables examined. These findings (a) underscore that children's meta-attention is not unitary and (b) demonstrate that children's knowledge about variables affecting attention sharing and resource allocation have different developmental pathways. Results show that knowledge about attention sharing and about the factors that influence the control of attention develops slowly and undergoes reorganization in middle childhood.

  4. The effects of glucose dose and dual-task performance on memory for emotional material.

    PubMed

    Brandt, Karen R; Sünram-Lea, Sandra I; Jenkinson, Paul M; Jones, Emma

    2010-07-29

    Whilst previous research has shown that glucose administration can boost memory performance, research investigating the effects of glucose on memory for emotional material has produced mixed findings. Whereas some research has shown that glucose impairs memory for emotional material, other research has shown that glucose has no effect on emotional items. The aim of the present research was therefore to provide further investigation of the role of glucose on the recognition of words with emotional valence by exploring effects of dose and dual-task performance, both of which affect glucose facilitation effects. The results replicated past research in showing that glucose administration, regardless of dose or dual-task conditions, did not affect the memorial advantage enjoyed by emotional material. This therefore suggests an independent relationship between blood glucose levels and memory for emotional material. Copyright 2010 Elsevier B.V. All rights reserved.

  5. The Effects of Combining Videogame Dancing and Pelvic Floor Training to Improve Dual-Task Gait and Cognition in Women with Mixed-Urinary Incontinence.

    PubMed

    Fraser, Sarah A; Elliott, Valerie; de Bruin, Eling D; Bherer, Louis; Dumoulin, Chantal

    2014-06-01

    Many women over 65 years of age suffer from mixed urinary incontinence (MUI) and executive function (EF) deficits. Both incontinence and EF declines increase fall risk. The current study assessed EF and dual-task gait after a multicomponent intervention that combined pelvic floor muscle (PFM) training and videogame dancing (VGD). Baseline (Pre1), pretraining (Pre2), and post-training (Post) neuropsychological and dual-task gait assessments were completed by 23 women (mean age, 70.4 years) with MUI. During the dual-task, participants walked and performed an auditory n-back task. From Pre2 to Post, all women completed 12 weeks of combined PFM and VGD training. After training (Pre2 to Post), the number of errors in the Inhibition/Switch Stroop condition decreased significantly, the Trail Making Test difference score improved marginally, and the number of n-back errors during dual-task gait significantly decreased. A subgroup analysis based on continence improvements (pad test) revealed that only those subjects who improved in the pad test had significantly reduced numbers of n-back errors during dual-task gait. The results of this study suggest that a multicomponent intervention can improve EFs and the dual-task gait of older women with MUI. Future research is needed to determine if the training-induced improvements in these factors reduce fall risk.

  6. Dual Learning Processes in Interactive Skill Acquisition

    ERIC Educational Resources Information Center

    Fu, Wai-Tat; Anderson, John R.

    2008-01-01

    Acquisition of interactive skills involves the use of internal and external cues. Experiment 1 showed that when actions were interdependent, learning was effective with and without external cues in the single-task condition but was effective only with the presence of external cues in the dual-task condition. In the dual-task condition, actions…

  7. Musical dual-task training in patients with mild-to-moderate dementia: a randomized controlled trial

    PubMed Central

    Chen, Yu-Ling; Pei, Yu-Cheng

    2018-01-01

    Background/aims Dual-task training may improve dual-task gait performance, balance, and cognition in older adults with and without cognitive impairment. Although music has been widely utilized in dementia management, there are no existing protocols for music-based dual-task training. This randomized controlled study developed a Musical Dual-Task Training (MDTT) protocol that patients with dementia can use to practice walking and making music simultaneously, to enhance attention control in patients during dual-tasking. Methods Twenty-eight adults diagnosed with mild-to-moderate dementia were assigned to the MDTT (n=15) or control groups (n=13). The MDTT group received MDTT, while the control group participated in non-musical cognitive and walking activities. The effects of MDTT were evaluated through the primary outcome of attention control, and secondary outcomes of dual-task performance, balance, falls efficacy, and agitation. Results The MDTT group showed a significant improvement in attention control, while the control group did not (P<0.001). A significant effect favored MDTT over control treatment for the secondary outcome of falls efficacy (P=0.02) and agitation (P<0.01). Conclusion MDTT, a music therapy intervention that demands a high level of cognitive processing, enhances attention control, falls efficacy, and helps alleviate agitation in patients with mild-to-moderate dementia. PMID:29881275

  8. Musical dual-task training in patients with mild-to-moderate dementia: a randomized controlled trial.

    PubMed

    Chen, Yu-Ling; Pei, Yu-Cheng

    2018-01-01

    Dual-task training may improve dual-task gait performance, balance, and cognition in older adults with and without cognitive impairment. Although music has been widely utilized in dementia management, there are no existing protocols for music-based dual-task training. This randomized controlled study developed a Musical Dual-Task Training (MDTT) protocol that patients with dementia can use to practice walking and making music simultaneously, to enhance attention control in patients during dual-tasking. Twenty-eight adults diagnosed with mild-to-moderate dementia were assigned to the MDTT (n=15) or control groups (n=13). The MDTT group received MDTT, while the control group participated in non-musical cognitive and walking activities. The effects of MDTT were evaluated through the primary outcome of attention control, and secondary outcomes of dual-task performance, balance, falls efficacy, and agitation. The MDTT group showed a significant improvement in attention control, while the control group did not ( P <0.001). A significant effect favored MDTT over control treatment for the secondary outcome of falls efficacy ( P =0.02) and agitation ( P <0.01). MDTT, a music therapy intervention that demands a high level of cognitive processing, enhances attention control, falls efficacy, and helps alleviate agitation in patients with mild-to-moderate dementia.

  9. Does the radiologically isolated syndrome exist? A dual-task cost pilot study.

    PubMed

    Dattola, Vincenzo; Logiudice, Anna Lisa; Bonanno, Lilla; Famà, Fausto; Milardi, Demetrio; Chillemi, Gaetana; D'Aleo, Giangaetano; Marino, Silvia; Calabrò, Rocco Salvatore; Russo, Margherita

    2017-11-01

    Simultaneous performance of motor and cognitive tasks may compete for common brain network resources in aging or patients with some neurological diseases, suggesting the occurrence of a cognitive-motor interference. While this phenomenon has been well described for multiple sclerosis (MS) patients, it never has been tested on asymptomatic subject with magnetic resonance imaging (MRI) findings suggestive of demyelinating disease (i.e., radiologically isolated syndrome: RIS). In this pilot study, 10 RIS subjects and 10 sex/age-matched healthy controls were tested by means of static posturography under eyes opened (single-task trial) and while performing two different cognitive tasks (semantic modified word list generation for first dual-task trial and phonemic semantic modified word list generation for second dual-task trial), to estimate the dual-task cost (DTC) of standing balance. In our sample, under cognitive interference (without any substantial differences between semantic and phonemic modified word list generation), the RIS group showed significance differences in CoP (center of pressure) total sway area, ellipse eccentricity, CoP sway path length, CoP median sway velocity along the AP (anteroposterior) axis and along the ML (mediolateral) axis, reflecting a higher negative DTC respect to healthy subjects (which have simply shown a statistical trend, failing to reach a significance, in some trials). The phenomenon of cognitive-motor interference might be unmasked by a dual-task posturography in RIS subjects, too. We hypothesize that this approach could be useful to early reveal the presence of a demyelinating disease and to reach a MS diagnosis in subjects otherwise classified as RIS.

  10. Dual-task training effects on motor and cognitive functional abilities in individuals with stroke: a systematic review.

    PubMed

    He, Ying; Yang, Lei; Zhou, Jing; Yao, Liqing; Pang, Marco Yiu Chung

    2018-02-01

    This systematic review aimed to examine the effects of dual-task balance and mobility training in people with stroke. An extensive electronic databases literature search was conducted using MEDLINE, PubMed, EBSCO, The Cochrane Library, Web of Science, SCOPUS, and Wiley Online Library. Randomized controlled studies that assessed the effects of dual-task training in stroke patients were included for the review (last search in December 2017). The methodological quality was evaluated using the Cochrane Collaboration recommendation, and level of evidence was determined according to the criteria described by the Oxford Center for Evidence-Based Medicine. About 13 articles involving 457 participants were included in this systematic review. All had substantial risk of bias and thus provided level IIb evidence only. Dual-task mobility training was found to induce more improvement in single-task walking function (standardized effect size = 0.14-2.24), when compared with single-task mobility training. Its effect on dual-task walking function was not consistent. Cognitive-motor balance training was effective in improving single-task balance function (standardized effect size = 0.27-1.82), but its effect on dual-task balance ability was not studied. The beneficial effect of dual-task training on cognitive function was provided by one study only and thus inconclusive. There is some evidence that dual-task training can improve single-task walking and balance function in individuals with stroke. However, any firm recommendation cannot be made due to the weak methodology of the studies reviewed.

  11. Effects of nicotine on electroencephalographic (EEG) and behavioural measures of visual working memory in non-smokers during a dual-task paradigm.

    PubMed

    Fisher, Derek J; Knobelsdorf, Amy; Jaworska, Natalia; Daniels, Richelle; Knott, Verner J

    2013-01-01

    Research in smokers has shown that nicotine may have the ability to improve certain aspects of cognitive performance, including working memory and attention, processes which implicate frontal and frontal-parietal brain networks. There is limited research on the cognitive effects of nicotine and their associated neural underpinnings in non-smokers. This study examined the effects of acute nicotine on a working memory task alone or combined with a visual detection task (single- and dual-task conditions) using electroencephalographic (EEG) recordings and behavioural performance measures. Twenty non-smokers (13 females; 7 males) received nicotine gum (6 mg) in a double-blind, randomized, placebo-controlled, repeated measures design. Spectral EEG, together with response speed and accuracy measures, were obtained while participants completed a series of N-Back tasks under single- and dual-task conditions. Nicotine failed to exert any significant effects on performance measures, however, EEG changes were observed, primarily in frontal recordings, which varied with memory load, task condition and hemisphere. These findings, discussed in relation to previous studies in smokers, support the notion that nicotine may modulate central executive systems and contribute to smoking behaviour. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. New normative standards of conditional reasoning and the dual-source model

    PubMed Central

    Singmann, Henrik; Klauer, Karl Christoph; Over, David

    2014-01-01

    There has been a major shift in research on human reasoning toward Bayesian and probabilistic approaches, which has been called a new paradigm. The new paradigm sees most everyday and scientific reasoning as taking place in a context of uncertainty, and inference is from uncertain beliefs and not from arbitrary assumptions. In this manuscript we present an empirical test of normative standards in the new paradigm using a novel probabilized conditional reasoning task. Our results indicated that for everyday conditional with at least a weak causal connection between antecedent and consequent only the conditional probability of the consequent given antecedent contributes unique variance to predicting the probability of conditional, but not the probability of the conjunction, nor the probability of the material conditional. Regarding normative accounts of reasoning, we found significant evidence that participants' responses were confidence preserving (i.e., p-valid in the sense of Adams, 1998) for MP inferences, but not for MT inferences. Additionally, only for MP inferences and to a lesser degree for DA inferences did the rate of responses inside the coherence intervals defined by mental probability logic (Pfeifer and Kleiter, 2005, 2010) exceed chance levels. In contrast to the normative accounts, the dual-source model (Klauer et al., 2010) is a descriptive model. It posits that participants integrate their background knowledge (i.e., the type of information primary to the normative approaches) and their subjective probability that a conclusion is seen as warranted based on its logical form. Model fits showed that the dual-source model, which employed participants' responses to a deductive task with abstract contents to estimate the form-based component, provided as good an account of the data as a model that solely used data from the probabilized conditional reasoning task. PMID:24860516

  13. New normative standards of conditional reasoning and the dual-source model.

    PubMed

    Singmann, Henrik; Klauer, Karl Christoph; Over, David

    2014-01-01

    There has been a major shift in research on human reasoning toward Bayesian and probabilistic approaches, which has been called a new paradigm. The new paradigm sees most everyday and scientific reasoning as taking place in a context of uncertainty, and inference is from uncertain beliefs and not from arbitrary assumptions. In this manuscript we present an empirical test of normative standards in the new paradigm using a novel probabilized conditional reasoning task. Our results indicated that for everyday conditional with at least a weak causal connection between antecedent and consequent only the conditional probability of the consequent given antecedent contributes unique variance to predicting the probability of conditional, but not the probability of the conjunction, nor the probability of the material conditional. Regarding normative accounts of reasoning, we found significant evidence that participants' responses were confidence preserving (i.e., p-valid in the sense of Adams, 1998) for MP inferences, but not for MT inferences. Additionally, only for MP inferences and to a lesser degree for DA inferences did the rate of responses inside the coherence intervals defined by mental probability logic (Pfeifer and Kleiter, 2005, 2010) exceed chance levels. In contrast to the normative accounts, the dual-source model (Klauer et al., 2010) is a descriptive model. It posits that participants integrate their background knowledge (i.e., the type of information primary to the normative approaches) and their subjective probability that a conclusion is seen as warranted based on its logical form. Model fits showed that the dual-source model, which employed participants' responses to a deductive task with abstract contents to estimate the form-based component, provided as good an account of the data as a model that solely used data from the probabilized conditional reasoning task.

  14. The effect of processing code, response modality and task difficulty on dual task performance and subjective workload in a manual system

    NASA Technical Reports Server (NTRS)

    Liu, Yili; Wickens, Christopher D.

    1987-01-01

    This paper reports on the first experiment of a series studying the effect of task structure and difficulty demand on time-sharing performance and workload in both automated and corresponding manual systems. The experimental task involves manual control time-shared with spatial and verbal decisions tasks of two levels of difficulty and two modes of response (voice or manual). The results provide strong evidence that tasks and processes competing for common processing resources are time shared less effecively and have higher workload than tasks competing for separate resources. Subjective measures and the structure of multiple resources are used in conjunction to predict dual task performance. The evidence comes from both single-task and from dual-task performance.

  15. [Features of dual--postural and calculation--task performance in patients with consequences of traumatic brain injury].

    PubMed

    Zharikova, A V; Zhavoronkova, L A; Maksakova, O A; Kuptsova, S V

    2012-01-01

    Dual tasks with voluntary postural control and calculation have been done by 14 patients (25.7 +/- 4.7 yo.) after traumatic brain injury and 40 healthy volunteers (29.8 +/- 2.5 y.o.). Complex clinical (MMSE, FIM, MPAI-3 and Berg scales) and stabilographic evaluation has been performed. According to clinical evaluation 8 patients were included into group 1 with less severe functional deficit and 6 patients formed group 2 with more severe deficit. Parameters of motor and especially cognitive sub-tasks in patients were lower than in healthy subjects in both separate and dual tasks. In group 2 these parameters were lower than in group 1. Certain types of dual task where the quality of sub-tasks, especially of the motor-one increased in healthy subjects and patients of the first group were revealed. The complex of stabilographic parameters which could be used for estimation of quality of sub-tasks performance has been revealed. Dual tasks could be an additional method of evaluation of patients' adaptive possibilities and certain type of dual task could become a promising approach to recovery at late period of rehabilitation.

  16. Information presentation through a head-worn display (“smart glasses”) has a smaller influence on the temporal structure of gait variability during dual-task gait compared to handheld displays (paper-based system and smartphone)

    PubMed Central

    Sedighi, Alireza; Ulman, Sophia M.

    2018-01-01

    The need to complete multiple tasks concurrently is a common occurrence both daily life and in occupational activities, which can often include simultaneous cognitive and physical demands. As one example, there is increasing availability of head-worn display technologies that can be employed when a user is mobile (e.g., while walking). This new method of information presentation may, however, introduce risks of adverse outcomes such as a decrement to gait performance. The goal of this study was thus to quantify the effects of a head-worn display (i.e., smart glasses) on motor variability during gait and to compare these effects with those of other common information displays (i.e., smartphone and paper-based system). Twenty participants completed four walking conditions, as a single task and in three dual-task conditions (three information displays). In the dual-task conditions, the information display was used to present several cognitive tasks. Three different measures were used to quantify variability in gait parameters for each walking condition (using the cycle-to-cycle standard deviation, sample entropy, and the “goal-equivalent manifold” approach). Our results indicated that participants used less adaptable gait strategies in dual-task walking using the paper-based system and smartphone conditions compared with single-task walking. Gait performance, however, was less affected during dual-task walking with the smart glasses. We conclude that the risk of an adverse gait event (e.g., a fall) in head-down walking conditions (i.e., the paper-based system and smartphone conditions) were higher than in single-task walking, and that head-worn displays might help reduce the risk of such events during dual-task gait conditions. PMID:29630614

  17. Ginkgo biloba special extract LI 1370 improves dual-task walking in patients with MCI: a randomised, double-blind, placebo-controlled exploratory study.

    PubMed

    Gschwind, Yves J; Bridenbaugh, Stephanie A; Reinhard, Sarah; Granacher, Urs; Monsch, Andreas U; Kressig, Reto W

    2017-08-01

    In patients with mild cognitive impairment (MCI), gait instability, particularly in dual-task situations, has been associated with impaired executive function and an increased fall risk. Ginkgo biloba extract (GBE) could be an effective mean to improve gait stability. This study investigated the effect of GBE on spatio-temporal gait parameters of MCI patients while walking under single and dual-task conditions. Fifty patients aged 50-85 years with MCI and associated dual-task-related gait impairment participated in this randomised, double-blind, placebo-controlled, exploratory phase IV drug trial. Intervention group (IG) patients received GBE (Symfona ® forte 120 mg) twice-daily for 6 months while control group (CG) patients received placebo capsules. A 6-month open-label phase with identical GBE dosage followed. Gait was quantified at months 0, 3, 6 and 12. After 6 months, dual-task-related cadence increased in the IG compared to the CG (p = 0.019, d = 0.71). No significant changes, but GBE-associated numerical non-significant trends were found after 6-month treatment for dual-task-related gait velocity and stride time variability. Findings suggest that 120 mg of GBE twice-daily for at least 6 months may improve dual-task-related gait performance in patients with MCI. The observed gait improvements add to the understanding of the self-reported unspecified improvements among MCI patients when treated with standardised GBE.

  18. Dual-task effects of simulated lane navigation and story recall in older adults with and without memory impairment

    PubMed Central

    Cook, Sarah E.; Sisco, Shannon M.; Marsiske, Michael

    2013-01-01

    While driving is a complex task, it becomes relatively automatic over time although unfamiliar situations require increased cognitive effort. Much research has examined driving risk in cognitively impaired elders and found little effect. This study assessed whether mildly memory impaired elders made disproportionate errors in driving or story recall, under simultaneous simulated driving and story recall. Forty-six healthy (61% women; mean age = 76.4) and 15 memory impaired (66% women, mean age = 79.4) elders participated. Cognitive status was determined by neuropsychological performance. Results showed that during dual-task conditions, participants stayed in lane more, and recalled stories more poorly, than when they did the tasks separately. Follow-up analysis revealed that verbatim recall, in particular, was reduced while driving for healthy participants. While memory impaired participants performed more poorly than healthy controls on both tasks, cognitive status was not associated with greater dual-task costs when driving and story recall were combined. PMID:23043546

  19. Dual-task effects of simulated lane navigation and story recall in older adults with and without memory impairment.

    PubMed

    Cook, Sarah E; Sisco, Shannon M; Marsiske, Michael

    2013-01-01

    While driving is a complex task, it becomes relatively automatic over time although unfamiliar situations require increased cognitive effort. Much research has examined driving risk in cognitively impaired elders and found little effect. This study assessed whether mildly memory impaired elders made disproportionate errors in driving or story recall, under simultaneous simulated driving and story recall. Forty-six healthy (61% women; mean age = 76.4) and 15 memory impaired (66% women, mean age = 79.4) elders participated. Cognitive status was determined by neuropsychological performance. Results showed that during dual-task conditions, participants stayed in lane more, and recalled stories more poorly, than when they did the tasks separately. Follow-up analysis revealed that verbatim recall, in particular, was reduced while driving for healthy participants. While memory impaired participants performed more poorly than healthy controls on both tasks, cognitive status was not associated with greater dual-task costs when driving and story recall were combined.

  20. Toward an understanding of the neural mechanisms underlying dual-task performance: Contribution of comparative approaches using animal models.

    PubMed

    Watanabe, Kei; Funahashi, Shintaro

    2018-01-01

    The study of dual-task performance in human subjects has received considerable interest in cognitive neuroscience because it can provide detailed insights into the neural mechanisms underlying higher-order cognitive control. Despite many decades of research, our understanding of the neurobiological basis of dual-task performance is still limited, and some critical questions are still under debate. Recently, behavioral and neurophysiological studies of dual-task performance in animals have begun to provide intriguing evidence regarding how dual-task information is processed in the brain. In this review, we first summarize key evidence in neuroimaging and neuropsychological studies in humans and discuss possible reasons for discrepancies across studies. We then provide a comprehensive review of the literature on dual-task studies in animals and provide a novel working hypothesis that may reconcile the divergent results in human studies toward a unified view of the mechanisms underlying dual-task processing. Finally, we propose possible directions for future dual-task experiments in the framework of comparative cognitive neuroscience. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Association between educational status and dual-task performance in young adults.

    PubMed

    Voos, Mariana Callil; Pimentel Piemonte, Maria Elisa; Castelli, Lilian Zanchetta; Andrade Machado, Mariane Silva; Dos Santos Teixeira, Patrícia Pereira; Caromano, Fátima Aparecida; Ribeiro Do Valle, Luiz Eduardo

    2015-04-01

    The influence of educational status on perceptual-motor performance has not been investigated. The single- and dual-task performances of 15 Low educated adults (9 men, 6 women; M age=24.1 yr.; 6-9 yr. of education) and 15 Higher educated adults (8 men, 7 women; M age=24.7 yr.; 10-13 yr. of education) were compared. The perceptual task consisted of verbally classifying two figures (equal or different). The motor task consisted of alternating steps from the floor to a stool. Tasks were assessed individually and simultaneously. Two analyses of variance (2 groups×4 blocks) compared the errors and steps. The Low education group committed more errors and had less improvement on the perceptual task than the High education group. During and after the perceptual-motor task performance, errors increased only in the Low education group. Education correlated to perceptual and motor performance. The Low education group showed more errors and less step alternations on the perceptual-motor task compared to the High education group. This difference on the number of errors was also observed after the dual-task, when the perceptual task was performed alone.

  2. Associations between physical function, dual-task performance and cognition in patients with mild Alzheimer's disease.

    PubMed

    Sobol, Nanna Aue; Hoffmann, Kristine; Vogel, Asmus; Lolk, Annette; Gottrup, Hanne; Høgh, Peter; Hasselbalch, Steen G; Beyer, Nina

    2016-11-01

    Alzheimer's disease (AD) causes a gradual decline in cognition, limitations of dual-tasking and physical function leading to total dependence. Hence, information about the interaction between physical function, dual-task performance and cognition may lead to new treatment strategies with the purpose of preserving function and quality of life. The objective of this study was to investigate the associations between physical function, dual-task performance and cognition in community-dwelling patients with mild AD. Baseline results from 185 participants (50-90 years old) in the single blinded multicenter RCT 'ADEX' (Alzheimer's disease: the effect of physical exercise) were used. Assessments included tests of physical function: 400-m walk test, 10-m walk test, Timed Up and Go test and 30-s chair stand test; dual-task performance, i.e., 10-m walk while counting backwards from 50 or naming the months backwards; and cognition, i.e., Mini Mental State Examination, Symbol Digit Modalities Test, the Stroop Color and Word Test, and Lexical verbal fluency test. Results in the 30-s chair stand test correlated significantly with all tests of cognition (r = .208-.242) while the other physical function tests only randomly correlated with tests of cognition. Results in the dual-task counting backwards correlated significantly with results in all tests of cognition (r = .259-.388), which accounted for 7%-15% of the variation indicating that a faster time to complete dual-task performance was associated with better cognitive performance. The evidence of the associations between physical function, dual-task performance and cognition is important when creating new rehabilitation interventions to patients with mild AD.

  3. Musical Training, Bilingualism, and Executive Function: A Closer Look at Task Switching and Dual-Task Performance

    ERIC Educational Resources Information Center

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-01-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician)…

  4. Reliability of spatial-temporal gait parameters during dual-task interference in people with multiple sclerosis. A cross-sectional study.

    PubMed

    Monticone, Marco; Ambrosini, Emilia; Fiorentini, Roberta; Rocca, Barbara; Liquori, Valentina; Pedrocchi, Alessandra; Ferrante, Simona

    2014-09-01

    To evaluate the reliability and minimum detectable change (MDC) of spatial-temporal gait parameters in subjects with multiple sclerosis (MS) during dual tasking. This cross-sectional study involved 25 healthy subjects (mean age 49.9 ± 15.8 years) and 25 people with MS (mean age 49.2 ± 11.5 years). Gait under motor-cognitive and motor-motor dual tasking conditions was evaluated in two sessions separated by a one-day interval using the GAITRite Walkway System. Test-retest reliability was assessed using intraclass correlation coefficients (ICCs), standard errors of measurement (SEM), and coefficients of variation (CV). MDC scores were computed for the velocity, cadence, step and stride length, step and stride time, double support time, the % of gait cycle for single support and stance phase, and base of support. All of the gait parameters reported good to excellent ICCs under both conditions, with healthy subject values of >0.69 and MS subject values of >0.84. SEM values were always below 18% for both groups of subjects. The gait patterns of the people with MS were slightly more variable than those of the normal controls (CVs: 5.88-41.53% vs 2.84-30.48%). The assessment of quantitative gait parameters in healthy subjects and people with MS is highly reliable under both of the investigated dual tasking conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Changes in dual-task performance after 5 months of karate and fitness training for older adults to enhance fall prevention.

    PubMed

    Pliske, Gerald; Emmermacher, Peter; Weinbeer, Veronika; Witte, Kerstin

    2016-12-01

    Demographic changes resulting in an aging population are major factors for an increase of fall-related injuries. Especially in situations where dual tasks such as walking whilst talking have to be performed simultaneously the risk of a fall-related injury increases. It is well known that some types of martial art (e.g. Tai Chi) can reduce the risk of a fall. It is unknown if the same is true for karate. In this randomized, controlled study 68 people with a mean age of 69 years underwent 5-month karate training, 5-month fitness training or were part of a control group. Before and after the time of intervention a gait analysis with normal walk, a cognitive dual task and a motor dual task were performed. The gait parameter step frequency, walking speed, single-step time and single-step length were investigated. It could be seen that all groups improved their gait parameters after a 5-month period, even the control group. A sporty intervention seems to affect mainly the temporal gait parameters positively. This effect was especially demonstrated for normal walk and cognitive dual task. An improvement of the human walk seems to be possible through karate and fitness training, even under dual-task conditions. A prolonged intervention time with multiple repetitions of gait analysis could give better evidence if karate is a useful tool to increase fall prevention.

  6. Pigeons may not use dual coding in the radial maze analog task.

    PubMed

    DiGian, Kelly A; Zentall, Thomas R

    2007-07-01

    Using a radial maze analog task, T. R. Zentall, J. N. Steirn, and P. Jackson-Smith (1990) found evidence that when a delay was interpolated early in a trial, pigeons coded locations retrospectively, but when the delay was interpolated late in the trial, they coded locations prospectively (support for a dual coding hypothesis). In Experiment 1 of the present study, the authors replicated the original finding of dual coding. In Experiments 2 and 3, they used a 2-alternative test procedure that does not require the assumption that pigeons' choice criterion, which changes over the course of the trial, is the same on delay and control trials. Under these conditions, the pigeons no longer showed evidence for dual coding. Instead, there was some evidence that they showed prospective coding, but a more parsimonious account of the results may be that the delay produced a relatively constant decrement in performance at all points of delay interpolation. The original finding of dual coding by Zentall et al. might have been biased by more impulsive choices early in control trials but not in delay trials and by a more stringent choice criterion late in delay trials. ((c) 2007 APA, all rights reserved).

  7. Stiffness Control of Balance during Dual Task and Prospective Falls in Older Adults: The MOBILIZE Boston Study

    PubMed Central

    Kang, Hyun Gu; Quach, Lien; Li, Wenjun; Lipsitz, Lewis A.

    2013-01-01

    Outdoor fallers differ from indoor fallers substantially in demographics, lifestyle, health condition and physical function. Biomechanical predictors of outdoor falls have not been well characterized. Current validated measures of postural deficits, which describe only the overall postural behavior, are predictive of indoor falls but not outdoor falls. We hypothesized that a model-based description of postural muscle tone and reflexes, particularly during dual tasking, would predict outdoor falls. We tested whether postural stiffness and damping from an inverted pendulum model were predictive of future indoor and outdoor falls among older adults from the MOBILIZE Boston Study. The center of pressure data during standing were obtained from 717 participants aged 77.9±5.3 years. Participants stood barefoot with eyes open for 30 seconds per trial, in two sets of five standing trials. One set included a serial subtractions task. Postural stiffness and damping values were determined from the postural sway data. After the postural measurements, falls were monitored prospectively using a monthly mail-in calendar over 6-36 months. Associations of postural measures with fall rates were determined using negative binomial regressions. After covariate adjustments, postural stiffness (p=0.02-0.05) and damping (p=0.007-0.1) were associated with lower outdoor falls risk, but not with indoor falls. Results were invariant by direction (anteroposterior versus mediolateral) or by condition (quiet standing versus dual task). Outdoor fall risk may be tied to postural control more so than indoor falls. Dual tasking is likely related to fall risk among older and sicker older adults, but not those relatively healthy. PMID:23623606

  8. The Effect of Prior Concussion History on Dual-Task Gait following a Concussion.

    PubMed

    Howell, David R; Beasley, Michael; Vopat, Lisa; Meehan, William P

    2017-02-15

    Sustaining repeated concussions has been associated with worse outcomes after additional injuries. This effect has been identified using symptom inventories and neurocognitive tests; however, few investigations have examined how a prior concussion history affects gait soon after a subsequent concussion. We examined the gait characteristics of athletes with no documented concussion history (n = 31), athletes recovering from their first lifetime concussion (n = 15), and athletes recovering from their second or greater lifetime concussion (n = 22). All participants completed a single-task and dual-task gait examination, a medical history questionnaire, and a postconcussion symptom scale. Multivariate analyses of covariance (MANCOVA) models were used to evaluate mean gait differences among groups, and Spearman's ρ analyses were used to assess correlations between the number of lifetime concussions and gait characteristics. Patients reporting to the clinic with their second or greater lifetime concussion demonstrated smaller stride lengths than healthy control participants during dual-task walking (p = 0.01; d = 0.70). A moderate but insignificant correlation was detected between dual-task gait speed and the number of prior concussions (ρ = 0.41, p = 0.07). These results indicate that a cumulative effect of concussions across the lifetime may contribute to worsening dual-task dynamic motor function after concussion.

  9. Effects of dual task on turning ability in stroke survivors and older adults.

    PubMed

    Hollands, K L; Agnihotri, D; Tyson, S F

    2014-09-01

    Turning is an integral component of independent mobility in which stroke survivors frequently fall. This study sought to measure the effects of competing cognitive demands on the stepping patterns of stroke survivors, compared to healthy age-match adults, during turning as a putative mechanism for falls. Walking and turning (90°) was assessed under single (walking and turning alone) and dual task (subtracting serial 3s while walking and turning) conditions using an electronic, pressure-sensitive walkway. Dependent measures were time to turn, variability in time to turn, step length, step width and single support time during three steps of the turn. Turning ability in single and dual task conditions was compared between stroke survivors (n=17, mean ± SD: 59 ± 113 months post-stroke, 64 ± 10 years of age) and age-matched healthy counterparts (n=15). Both groups took longer, were more variable, tended to widen the second step and, crucially, increased single support time on the inside leg of the turn while turning and distracted. Increased single support time during turning may represent biomechanical mechanism, within stepping patterns of turning under distraction, for increased risk of falls for both stroke survivors and older adults. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  10. Central as well as Peripheral Attentional Bottlenecks in Dual-Task Performance Activate Lateral Prefrontal Cortices

    PubMed Central

    Szameitat, André J.; Vanloo, Azonya; Müller, Hermann J.

    2016-01-01

    Human information processing suffers from severe limitations in parallel processing. In particular, when required to respond to two stimuli in rapid succession, processing bottlenecks may appear at central and peripheral stages of task processing. Importantly, it has been suggested that executive functions are needed to resolve the interference arising at such bottlenecks. The aims of the present study were to test whether central attentional limitations (i.e., bottleneck at the decisional response selection stage) as well as peripheral limitations (i.e., bottleneck at response initiation) both demand executive functions located in the lateral prefrontal cortex. For this, we re-analyzed two previous studies, in which a total of 33 participants performed a dual-task according to the paradigm of the psychological refractory period (PRP) during functional magnetic resonance imaging (fMRI). In one study (N = 17), the PRP task consisted of two two-choice response tasks known to suffer from a central bottleneck (CB group). In the other study (N = 16), the PRP task consisted of two simple-response tasks known to suffer from a peripheral bottleneck (PB group). Both groups showed considerable dual-task costs in form of slowing of the second response in the dual-task (PRP effect). Imaging results are based on the subtraction of both single-tasks from the dual-task within each group. In the CB group, the bilateral middle frontal gyri and inferior frontal gyri were activated. Higher activation in these areas was associated with lower dual-task costs. In the PB group, the right middle frontal and inferior frontal gyrus (IFG) were activated. Here, higher activation was associated with higher dual-task costs. In conclusion we suggest that central and peripheral bottlenecks both demand executive functions located in lateral prefrontal cortices (LPFC). Differences between the CB and PB groups with respect to the exact prefrontal areas activated and the correlational patterns

  11. Comparison of Psychophysiological and Dual-Task Measures of Listening Effort

    ERIC Educational Resources Information Center

    Seeman, Scott; Sims, Rebecca

    2015-01-01

    Purpose: We wished to make a comparison of psychophysiological measures of listening effort with subjective and dual-task measures of listening effort for a diotic-dichotic-digits and a sentences-in-noise task. Method: Three groups of young adults (18-38 years old) with normal hearing participated in three experiments: two psychophysiological…

  12. Relative and absolute reliability of the clinical version of the Narrow Path Walking Test (NPWT) under single and dual task conditions.

    PubMed

    Gimmon, Yoav; Jacob, Grinshpon; Lenoble-Hoskovec, Constanze; Büla, Christophe; Melzer, Itshak

    2013-01-01

    Decline in gait stability has been associated with increased fall risk in older adults. Reliable and clinically feasible methods of gait instability assessment are needed. This study evaluated the relative and absolute reliability and concurrent validity of the testing procedure of the clinical version of the Narrow Path Walking Test (NPWT) under single task (ST) and dual task (DT) conditions. Thirty independent community-dwelling older adults (65-87 years) were tested twice. Participants were instructed to walk within the 6-m narrow path without stepping out. Trial time, number of steps, trial velocity, number of step errors, and number of cognitive task errors were determined. Intraclass correlation coefficients (ICCs) were calculated as indices of agreement, and a graphic approach called "mountain plot" was applied to help interpret the direction and magnitude of disagreements between testing procedures. Smallest detectable change and smallest real difference (SRD) were computed to determine clinically relevant improvement at group and individual levels, respectively. Concurrent validity was assessed using Performance Oriented Mobility Assessment Tool (POMA) and the Short Physical Performance Battery (SPPB). Test-retest agreement (ICC1,2) varied from 0.77 to 0.92 in ST and from 0.78 to 0.92 in DT conditions, with no apparent systematic differences between testing procedures demonstrated by the mountain plot graphs. Smallest detectable change and smallest real change were small for motor task performance and larger for cognitive errors. Significant correlations were observed for trial velocity and trial time with POMA and SPPB. The present results indicate that the NPWT testing procedure is highly reliable and reproducible. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  13. Near-infrared imaging of the effects of glucose ingestion and regulation on prefrontal activation during dual-task execution in healthy fasting older adults.

    PubMed

    Gagnon, Christine; Desjardins-Crépeau, Laurence; Tournier, Isabelle; Desjardins, Michèle; Lesage, Frédéric; Greenwood, Carol E; Bherer, Louis

    2012-06-15

    Glucose enhancing effects in older adults have mostly been observed for episodic memory, but have recently been found for attentional control performance. Yet, brain activation patterns underlying these effects are still unknown. The present study examined the acute effects of glucose ingestion on prefrontal brain activation during the execution of a divided attention task in fasting non-diabetic older adults. Twenty older adults (60 years and older) took part in the study that included two experimental sessions. After an overnight fast, participants received either a glucose drink (50 g) or a placebo (saccharin) drink, following which they completed a dual-task. During task execution, prefrontal activation was recorded with functional near-infrared spectroscopy (fNIRS). A repeated-measures design was used such that each participant served as his or her own control. The two experimental sessions were counterbalanced among participants and were performed two weeks apart. When participants were in the glucose condition, they showed similar dual-task costs for both tasks, whereas in the placebo condition they prioritized one task over the other, with a significantly larger dual-task cost for the non-prioritized task (p<0.01). Differential brain activation was also observed in right ventral-lateral prefrontal regions for oxygenated hemoglobin and deoxygenated hemoglobin, with more activation apparent in the glucose condition (p<0.05). Furthermore, behavioral and activation data were influenced by individual differences in glucose regulation. Glucose ingestion appears to momentarily enhance fasting seniors' capacity to coordinate more equally two concurrent tasks and this is reflected in brain activation patterns. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Human performance evaluation in dual-axis critical task tracking

    NASA Technical Reports Server (NTRS)

    Ritchie, M. L.; Nataraj, N. S.

    1975-01-01

    A dual axis tracking using a multiloop critical task was set up to evaluate human performance. The effects of control stick variation and display formats are evaluated. A secondary loading was used to measure the degradation in tracking performance.

  15. Stiffness control of balance during dual task and prospective falls in older adults: the MOBILIZE Boston Study.

    PubMed

    Kang, Hyun Gu; Quach, Lien; Li, Wenjun; Lipsitz, Lewis A

    2013-09-01

    Outdoor fallers differ from indoor fallers substantially in demographics, lifestyle, health condition and physical function. Biomechanical predictors of outdoor falls have not been well characterized. Current validated measures of postural deficits, which describe only the overall postural behavior, are predictive of indoor falls but not outdoor falls. We hypothesized that a model-based description of postural muscle tone and reflexes, particularly during dual tasking, would predict outdoor falls. We tested whether postural stiffness and damping from an inverted pendulum model were predictive of future indoor and outdoor falls among older adults from the MOBILIZE Boston Study. The center of pressure data during standing were obtained from 717 participants aged 77.9±5.3 years. Participants stood barefoot with eyes open for 30s per trial, in two sets of five standing trials. One set included a serial subtractions task. Postural stiffness and damping values were determined from the postural sway data. After the postural measurements, falls were monitored prospectively using a monthly mail-in calendar over 6-36 months. Associations of postural measures with fall rates were determined using negative binomial regressions. After covariate adjustments, postural stiffness (p=0.02-0.05) and damping (p=0.007-0.1) were associated with lower outdoor falls risk, but not with indoor falls. Results were invariant by direction (anteroposterior versus mediolateral) or by condition (quiet standing versus dual task). Outdoor fall risk may be tied to postural control more so than indoor falls. Dual tasking is likely related to fall risk among older and sicker older adults, but not those relatively healthy. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Older Adults Pay an Additional Cost When Texting and Walking: Effects of Age, Environment, and Use of Mixed Reality on Dual-Task Performance.

    PubMed

    Krasovsky, Tal; Weiss, Patrice L; Kizony, Rachel

    2018-04-06

    Texting while walking (TeWW) has become common among people of all ages, and mobile phone use during gait is increasingly associated with pedestrian injury. Although dual-task walking performance is known to decline with age, data regarding the effect of age on dual-task performance in ecological settings are limited. The objective of this study was to evaluate the effect of age, environment (indoors/outdoors), and mixed reality (merging of real and virtual environments) on TeWW performance. A cross-sectional design was used. Young (N = 30; 27.8 ± 4.4 years) and older (N = 20; 68.9 ± 3.9 years) adults performed single and dual-task texting and walking indoors and outdoors, with and without a mixed reality display. Participants also completed evaluations of visual scanning and cognitive flexibility (Trail Making Test) and functional mobility (Timed Up and Go). Indoors, similar interference to walking and texting occurred for both groups, but only older adults' gait variability increased under dual task conditions. Outdoors, TeWW was associated with larger age-related differences in gait variability, texting accuracy, and gait dual-task costs. Young adults with better visual scanning and cognitive flexibility performed TeWW with lower gait costs (r = 0.52 to r = 0.65). The mixed reality display was unhelpful and did not modify walking or texting. Older adults tested in this study were relatively high-functioning. Gaze of participants was not directly monitored. Although young and older adults possess the resources necessary for TeWW, older adults pay an additional "price" when dual-tasking, especially outdoors. TeWW may have potential as an ecologically-valid assessment and/or an intervention paradigm for dual task performance among older adults as well as for clinical populations.

  17. Neural correlates of dual-task effect on belief-bias syllogistic reasoning: a near-infrared spectroscopy study.

    PubMed

    Tsujii, Takeo; Watanabe, Shigeru

    2009-09-01

    Recent dual-process reasoning theories have explained the belief-bias effect, the tendency for human reasoning to be erroneously biased when logical conclusions are incongruent with beliefs about the world, by proposing a belief-based automatic heuristic system and logic-based demanding analytic system. Although these claims are supported by the behavioral finding that high-load secondary tasks enhance the belief-bias effect, the neural correlates of dual-task reasoning remain unknown. The present study therefore examined the relationship between dual-task effect and activity in the inferior frontal cortex (IFC) during belief-bias reasoning by near-infrared spectroscopy (NIRS). Forty-eight subjects participated in this study (MA=23.46 years). They were required to perform congruent and incongruent reasoning trials while responding to high- and low-load secondary tasks. Behavioral analysis showed that the high-load secondary task impaired only incongruent reasoning performance. NIRS analysis found that the high-load secondary task decreased right IFC activity during incongruent trials. Correlation analysis showed that subjects with enhanced right IFC activity could perform better in the incongruent reasoning trials, though subjects for whom right IFC activity was impaired by the secondary task could not maintain better reasoning performance. These findings suggest that the right IFC may be responsible for the dual-task effect in conflicting reasoning processes. When secondary tasks impair right IFC activity, subjects may rely on the automatic heuristic system, which results in belief-bias responses. We therefore offer the first demonstration of neural correlates of dual-task effect on IFC activity in belief-bias reasoning.

  18. Dual-task results and the lateralization of spatial orientation: artifact of test selection?

    PubMed

    Bowers, C A; Milham, L M; Price, C

    1998-01-01

    An investigation was conducted to identify the degree to which results regarding the lateralization of spatial orientation among men and women are artifacts of test selection. A dual-task design was used to study possible lateralization differences, providing baseline and dual-task measures of spatial-orientation performance, right- and left-hand tapping, and vocalization of "cat, dog, horse." The Guilford-Zimmerman Test (Guilford & Zimmerman, 1953), the Eliot-Price Test (Eliot & Price, 1976), and the Stumpf-Fay Cube Perspectives Test (Stumpf & Fay, 1983) were the three spatial-orientation tests used to investigate possible artifacts of test selection. Twenty-eight right-handed male and 39 right-handed female undergraduates completed random baseline and dual-task sessions. Analyses indicated no significant sex-related differences in spatial-orientation ability for all three tests. Furthermore, there was no evidence of differential lateralization of spatial orientation between the sexes.

  19. E-learning, dual-task, and cognitive load: The anatomy of a failed experiment.

    PubMed

    Van Nuland, Sonya E; Rogers, Kem A

    2016-01-01

    The rising popularity of commercial anatomy e-learning tools has been sustained, in part, due to increased annual enrollment and a reduction in laboratory hours across educational institutions. While e-learning tools continue to gain popularity, the research methodologies used to investigate their impact on learning remain imprecise. As new user interfaces are introduced, it is critical to understand how functionality can influence the load placed on a student's memory resources, also known as cognitive load. To study cognitive load, a dual-task paradigm wherein a learner performs two tasks simultaneously is often used, however, its application within educational research remains uncommon. Using previous paradigms as a guide, a dual-task methodology was developed to assess the cognitive load imposed by two commercial anatomical e-learning tools. Results indicate that the standard dual-task paradigm, as described in the literature, is insensitive to the cognitive load disparities across e-learning tool interfaces. Confounding variables included automation of responses, task performance tradeoff, and poor understanding of primary task cognitive load requirements, leading to unreliable quantitative results. By modifying the secondary task from a basic visual response to a more cognitively demanding task, such as a modified Stroop test, the automation of secondary task responses can be reduced. Furthermore, by recording baseline measures for the primary task as well as the secondary task, it is possible for task performance tradeoff to be detected. Lastly, it is imperative that the cognitive load of the primary task be designed such that it does not overwhelm the individual's ability to learn new material. © 2015 American Association of Anatomists.

  20. Predicting the language proficiency of Chinese student pilots within American airspace: Single-task versus dual-task English-language assessment

    NASA Astrophysics Data System (ADS)

    Noble, Clifford Elliott, II

    2002-09-01

    The problem. The purpose of this study was to investigate the ability of three single-task instruments---(a) the Test of English as a Foreign Language, (b) the Aviation Test of Spoken English, and (c) the Single Manual-Tracking Test---and three dual-task instruments---(a) the Concurrent Manual-Tracking and Communication Test, (b) the Certified Flight Instructor's Test, and (c) the Simulation-Based English Test---to predict the language performance of 10 Chinese student pilots speaking English as a second language when operating single-engine and multiengine aircraft within American airspace. Method. This research implemented a correlational design to investigate the ability of the six described instruments to predict the mean score of the criterion evaluation, which was the Examiner's Test. This test assessed the oral communication skill of student pilots on the flight portion of the terminal checkride in the Piper Cadet, Piper Seminole, and Beechcraft King Air airplanes. Results. Data from the Single Manual-Tracking Test, as well as the Concurrent Manual-Tracking and Communication Test, were discarded due to performance ceiling effects. Hypothesis 1, which stated that the average correlation between the mean scores of the dual-task evaluations and that of the Examiner's Test would predict the mean score of the criterion evaluation with a greater degree of accuracy than that of single-task evaluations, was not supported. Hypothesis 2, which stated that the correlation between the mean scores of the participants on the Simulation-Based English Test and the Examiner's Test would predict the mean score of the criterion evaluation with a greater degree of accuracy than that of all single- and dual-task evaluations, was also not supported. The findings suggest that single- and dual-task assessments administered after initial flight training are equivalent predictors of language performance when piloting single-engine and multiengine aircraft.

  1. Child–Adult Differences in Using Dual-Task Paradigms to Measure Listening Effort

    PubMed Central

    Charles, Lauren M.; Ricketts, Todd A.

    2017-01-01

    Purpose The purpose of the project was to investigate the effects modifying the secondary task in a dual-task paradigm to measure objective listening effort. To be specific, the complexity and depth of processing were increased relative to a simple secondary task. Method Three dual-task paradigms were developed for school-age children. The primary task was word recognition. The secondary task was a physical response to a visual probe (simple task), a physical response to a complex probe (increased complexity), or word categorization (increased depth of processing). Sixteen adults (22–32 years, M = 25.4) and 22 children (9–17 years, M = 13.2) were tested using the 3 paradigms in quiet and noise. Results For both groups, manipulations of the secondary task did not affect word recognition performance. For adults, increasing depth of processing increased the calculated effect of noise; however, for children, results with the deep secondary task were the least stable. Conclusions Manipulations of the secondary task differentially affected adults and children. Consistent with previous findings, increased depth of processing enhanced paradigm sensitivity for adults. However, younger participants were more likely to demonstrate the expected effects of noise on listening effort using a secondary task that did not require deep processing. PMID:28346816

  2. Protocol for a randomized comparison of integrated versus consecutive dual task practice in Parkinson’s disease: the DUALITY trial

    PubMed Central

    2014-01-01

    Background Multiple tasking is an integral part of daily mobility. Patients with Parkinson’s disease have dual tasking difficulties due to their combined motor and cognitive deficits. Two contrasting physiotherapy interventions have been proposed to alleviate dual tasking difficulties: either to discourage simultaneous execution of dual tasks (consecutive training); or to practice their concurrent use (integrated training). It is currently unclear which of these training methods should be adopted to achieve safe and consolidated dual task performance in daily life. Therefore, the proposed randomized controlled trial will compare the effects of integrated versus consecutive training of dual tasking (tested by combining walking with cognitive exercises). Methods and design Hundred and twenty patients with Parkinson’s disease will be recruited to participate in this multi-centered, single blind, randomized controlled trial. Patients in Hoehn & Yahr stage II-III, with or without freezing of gait, and who report dual task difficulties will be included. All patients will undergo a six-week control period without intervention after which they will be randomized to integrated or consecutive task practice. Training will consist of standardized walking and cognitive exercises delivered at home four times a week during six weeks. Treatment is guided by a physiotherapist twice a week and consists of two sessions of self-practice using an MP3 player. Blinded testers will assess patients before and after the control period, after the intervention period and after a 12-week follow-up period. The primary outcome measure is dual task gait velocity, i.e. walking combined with a novel untrained cognitive task to evaluate the consolidation of learning. Secondary outcomes include several single and dual task gait and cognitive measures, functional outcomes and a quality of life scale. Falling will be recorded as a possible adverse event using a weekly phone call for the entire

  3. Dual learning processes in interactive skill acquisition.

    PubMed

    Fu, Wai-Tat; Anderson, John R

    2008-06-01

    Acquisition of interactive skills involves the use of internal and external cues. Experiment 1 showed that when actions were interdependent, learning was effective with and without external cues in the single-task condition but was effective only with the presence of external cues in the dual-task condition. In the dual-task condition, actions closer to the feedback were learned faster than actions farther away but this difference was reversed in the single-task condition. Experiment 2 tested how knowledge acquired in single and dual-task conditions would transfer to a new reward structure. Results confirmed the two forms of learning mediated by the secondary task: A declarative memory encoding process that simultaneously assigned credits to actions and a reinforcement-learning process that slowly propagated credits backward from the feedback. The results showed that both forms of learning were engaged during training, but only at the response selection stage, one form of knowledge may dominate over the other depending on the availability of attentional resources. (c) 2008 APA, all rights reserved

  4. Detecting gait abnormalities after concussion or mild traumatic brain injury: A systematic review of single-task, dual-task, and complex gait.

    PubMed

    Fino, Peter C; Parrington, Lucy; Pitt, Will; Martini, Douglas N; Chesnutt, James C; Chou, Li-Shan; King, Laurie A

    2018-05-01

    While a growing number of studies have investigated the effects of concussion or mild traumatic brain injury (mTBI) on gait, many studies use different experimental paradigms and outcome measures. The path for translating experimental studies for objective clinical assessments of gait is unclear. This review asked 2 questions: 1) is gait abnormal after concussion/mTBI, and 2) what gait paradigms (single-task, dual-task, complex gait) detect abnormalities after concussion. Data sources included MEDLINE/PubMed, Scopus, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) accessed on March 14, 2017. Original research articles reporting gait outcomes in people with concussion or mTBI were included. Studies of moderate, severe, or unspecified TBI, and studies without a comparator were excluded. After screening 233 articles, 38 studies were included and assigned to one or more sections based on the protocol and reported outcomes. Twenty-six articles reported single-task simple gait outcomes, 24 reported dual-task simple gait outcomes, 21 reported single-task complex gait outcomes, and 10 reported dual-task complex gait outcomes. Overall, this review provides evidence for two conclusions: 1) gait is abnormal acutely after concussion/mTBI but generally resolves over time; and 2) the inconsistency of findings, small sample sizes, and small number of studies examining homogenous measures at the same time-period post-concussion highlight the need for replication across independent populations and investigators. Future research should concentrate on dual-task and complex gait tasks, as they showed promise for detecting abnormal locomotor function outside of the acute timeframe. Additionally, studies should provide detailed demographic and clinical characteristics to enable more refined comparisons across studies. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Executive function deficits in team sport athletes with a history of concussion revealed by a visual-auditory dual task paradigm.

    PubMed

    Tapper, Anthony; Gonzalez, Dave; Roy, Eric; Niechwiej-Szwedo, Ewa

    2017-02-01

    The purpose of this study was to examine executive functions in team sport athletes with and without a history of concussion. Executive functions comprise many cognitive processes including, working memory, attention and multi-tasking. Past research has shown that concussions cause difficulties in vestibular-visual and vestibular-auditory dual-tasking, however, visual-auditory tasks have been examined rarely. Twenty-nine intercollegiate varsity ice hockey athletes (age = 19.13, SD = 1.56; 15 females) performed an experimental dual-task paradigm that required simultaneously processing visual and auditory information. A brief interview, event description and self-report questionnaires were used to assign participants to each group (concussion, no-concussion). Eighteen athletes had a history of concussion and 11 had no concussion history. The two tests involved visuospatial working memory (i.e., Corsi block test) and auditory tone discrimination. Participants completed both tasks individually, then simultaneously. Two outcome variables were measured, Corsi block memory span and auditory tone discrimination accuracy. No differences were shown when each task was performed alone; however, athletes with a history of concussion had a significantly worse performance on the tone discrimination task in the dual-task condition. In conclusion, long-term deficits in executive functions were associated with a prior history of concussion when cognitive resources were stressed. Evaluations of executive functions and divided attention appear to be helpful in discriminating participants with and without a history concussion.

  6. The effects of display-control I/O, compatibility, and integrality on dual-task performance and subjective workload

    NASA Technical Reports Server (NTRS)

    Tsang, Pamela S.; Hart, Sandra G.; Vidulich, Michael A.

    1987-01-01

    The utility of speech technology was evaluated in terms of three dual task principles: resource competition between the time shared tasks, stimulus central processing response compatibility, and task integrality. Empirical support for these principles was reviewed. Two studies investigating the interactive effects of the three principles were described. Objective performance and subjective workload ratings for both single and dual tasks were examined. It was found that the single task measures were not necessarily good predictors for the dual task measures. It was shown that all three principles played an important role in determining an optimal task configuration. This was reflected in both the performance measures and the subjective measures. Therefore, consideration of all three principles is required to insure proper use of speech technology in a complex environment.

  7. Revisiting the Development of Time Sharing Using a Dual Motor Task Performance

    ERIC Educational Resources Information Center

    Getchell, Nancy; Pabreja, Priya

    2006-01-01

    In this article, the authors discuss and examine how to develop time sharing using a dual motor task and its effects. They state that when one is required to perform two tasks at the same time (time sharing), an individual may experience difficulty in expressing one or both of the tasks. This phenomenon, known as interference, has been studied…

  8. Specific transfer effects following variable priority dual-task training in older adults.

    PubMed

    Lussier, Maxime; Bugaiska, Aurélia; Bherer, Louis

    2017-01-01

    Past divided attention training studies in older adults have suggested that variable priority training (VPT) tends to show larger improvement than fixed priority training (FPT). However, it remains unclear whether VPT leads to larger transfer effects. In this study, eighty-three older adults aged between 55 and 65 received five 1-hour sessions of VPT, FPT or of an active placebo. VPT and FPT subjects trained on a complex dual-task condition with variable stimulus timings in order to promote more flexible and self-guided strategies with regard to attentional priority devoted to the concurrent tasks. Real-time individualized feedback was provided to encourage improvement. The active placebo group attended computer classes. Near and far modality transfer tasks were used to assess the generalization of transfer effects. Results showed that VPT induced significantly larger transfer effects than FPT on a near modality transfer task. Evidence for larger transfer effects in VPT than FPT on a far modality transfer task was also observed. Furthermore, the superiority of VPT on FPT in transfer effects was specific to the ability to coordinate two concurrent tasks. Results of this study help better understand the benefits of VPT attentional training on transfer effects, which is an essential outcome for cognitive training effectiveness and relevancy.

  9. Age Differences between Children and Young Adults in the Dynamics of Dual-Task Prioritization: Body (Balance) versus Mind (Memory)

    ERIC Educational Resources Information Center

    Schaefer, Sabine; Krampe, Ralf Th.; Lindenberger, Ulman; Baltes, Paul B.

    2008-01-01

    Task prioritization can lead to trade-off patterns in dual-task situations. The authors compared dual-task performances in 9- and 11-year-old children and young adults performing a cognitive task and a motor task concurrently. The motor task required balancing on an ankle-disc board. Two cognitive tasks measured working memory and episodic memory…

  10. Effect of the cognitive-motor dual-task using auditory cue on balance of surviviors with chronic stroke: a pilot study.

    PubMed

    Choi, Wonjae; Lee, GyuChang; Lee, Seungwon

    2015-08-01

    To investigate the effect of a cognitive-motor dual-task using auditory cues on the balance of patients with chronic stroke. Randomized controlled trial. Inpatient rehabilitation center. Thirty-seven individuals with chronic stroke. The participants were randomly allocated to the dual-task group (n=19) and the single-task group (n=18). The dual-task group performed a cognitive-motor dual-task in which they carried a circular ring from side to side according to a random auditory cue during treadmill walking. The single-task group walked on a treadmill only. All subjects completed 15 min per session, three times per week, for four weeks with conventional rehabilitation five times per week over the four weeks. Before and after intervention, both static and dynamic balance were measured with a force platform and using the Timed Up and Go (TUG) test. The dual-task group showed significant improvement in all variables compared to the single-task group, except for anteroposterior (AP) sway velocity with eyes open and TUG at follow-up: mediolateral (ML) sway velocity with eye open (dual-task group vs. single-task group: 2.11 mm/s vs. 0.38 mm/s), ML sway velocity with eye close (2.91 mm/s vs. 1.35 mm/s), AP sway velocity with eye close (4.84 mm/s vs. 3.12 mm/s). After intervention, all variables showed significant improvement in the dual-task group compared to baseline. The study results suggest that the performance of a cognitive-motor dual-task using auditory cues may influence balance improvements in chronic stroke patients. © The Author(s) 2014.

  11. Effect of aquatic dual-task training on balance and gait in stroke patients

    PubMed Central

    Kim, Kyoung; Lee, Dong-Kyu; Kim, Eun-Kyung

    2016-01-01

    [Purpose] The purpose of this study was to determine the effect of aquatic dual-task training on balance and gait in stroke patients. [Subjects and Methods] Twenty stroke patients were divided into the experimental (n=10) and control (n=10) groups. Both groups underwent neurodevelopmental treatment. The experimental group additionally underwent aquatic dual-task training for 30 minutes a day, 5 days a week, for 6 weeks. Balance was measured using the Berg balance scale, Five Times Sit-to Stand Test, and Functional Reach Test. Gait was measured using the 10-Meter Walk Test, Timed Up and Go Test, and Functional Gait Assessment. [Results] For intragroup comparison, the experimental group showed a significant change after the experiment in all balance and gait assessment tests. For intergroup comparison, the experimental group showed relatively more significant change after the experiment in all balance and gait assessment tests. [Conclusion] Our results showed that aquatic dual-task training has a positive effect on balance and gait in stroke patients. PMID:27512261

  12. Effect of aquatic dual-task training on balance and gait in stroke patients.

    PubMed

    Kim, Kyoung; Lee, Dong-Kyu; Kim, Eun-Kyung

    2016-07-01

    [Purpose] The purpose of this study was to determine the effect of aquatic dual-task training on balance and gait in stroke patients. [Subjects and Methods] Twenty stroke patients were divided into the experimental (n=10) and control (n=10) groups. Both groups underwent neurodevelopmental treatment. The experimental group additionally underwent aquatic dual-task training for 30 minutes a day, 5 days a week, for 6 weeks. Balance was measured using the Berg balance scale, Five Times Sit-to Stand Test, and Functional Reach Test. Gait was measured using the 10-Meter Walk Test, Timed Up and Go Test, and Functional Gait Assessment. [Results] For intragroup comparison, the experimental group showed a significant change after the experiment in all balance and gait assessment tests. For intergroup comparison, the experimental group showed relatively more significant change after the experiment in all balance and gait assessment tests. [Conclusion] Our results showed that aquatic dual-task training has a positive effect on balance and gait in stroke patients.

  13. A systematic review of interventions conducted in clinical or community settings to improve dual-task postural control in older adults.

    PubMed

    Agmon, Maayan; Belza, Basia; Nguyen, Huong Q; Logsdon, Rebecca G; Kelly, Valerie E

    2014-01-01

    Injury due to falls is a major problem among older adults. Decrements in dual-task postural control performance (simultaneously performing two tasks, at least one of which requires postural control) have been associated with an increased risk of falling. Evidence-based interventions that can be used in clinical or community settings to improve dual-task postural control may help to reduce this risk. THE AIMS OF THIS SYSTEMATIC REVIEW ARE: 1) to identify clinical or community-based interventions that improved dual-task postural control among older adults; and 2) to identify the key elements of those interventions. Studies were obtained from a search conducted through October 2013 of the following electronic databases: PubMed, CINAHL, PsycINFO, and Web of Science. Randomized and nonrandomized controlled studies examining the effects of interventions aimed at improving dual-task postural control among community-dwelling older adults were selected. All studies were evaluated based on methodological quality. Intervention characteristics including study purpose, study design, and sample size were identified, and effects of dual-task interventions on various postural control and cognitive outcomes were noted. Twenty-two studies fulfilled the selection criteria and were summarized in this review to identify characteristics of successful interventions. The ability to synthesize data was limited by the heterogeneity in participant characteristics, study designs, and outcome measures. Dual-task postural control can be modified by specific training. There was little evidence that single-task training transferred to dual-task postural control performance. Further investigation of dual-task training using standardized outcome measurements is needed.

  14. Effects of aging on the relationship between cognitive demand and step variability during dual-task walking.

    PubMed

    Decker, Leslie M; Cignetti, Fabien; Hunt, Nathaniel; Potter, Jane F; Stergiou, Nicholas; Studenski, Stephanie A

    2016-08-01

    A U-shaped relationship between cognitive demand and gait control may exist in dual-task situations, reflecting opposing effects of external focus of attention and attentional resource competition. The purpose of the study was twofold: to examine whether gait control, as evaluated from step-to-step variability, is related to cognitive task difficulty in a U-shaped manner and to determine whether age modifies this relationship. Young and older adults walked on a treadmill without attentional requirement and while performing a dichotic listening task under three attention conditions: non-forced (NF), forced-right (FR), and forced-left (FL). The conditions increased in their attentional demand and requirement for inhibitory control. Gait control was evaluated by the variability of step parameters related to balance control (step width) and rhythmic stepping pattern (step length and step time). A U-shaped relationship was found for step width variability in both young and older adults and for step time variability in older adults only. Cognitive performance during dual tasking was maintained in both young and older adults. The U-shaped relationship, which presumably results from a trade-off between an external focus of attention and competition for attentional resources, implies that higher-level cognitive processes are involved in walking in young and older adults. Specifically, while these processes are initially involved only in the control of (lateral) balance during gait, they become necessary for the control of (fore-aft) rhythmic stepping pattern in older adults, suggesting that attentional resources turn out to be needed in all facets of walking with aging. Finally, despite the cognitive resources required by walking, both young and older adults spontaneously adopted a "posture second" strategy, prioritizing the cognitive task over the gait task.

  15. Transfer Effects to a Multimodal Dual-Task after Working Memory Training and Associated Neural Correlates in Older Adults - A Pilot Study.

    PubMed

    Heinzel, Stephan; Rimpel, Jérôme; Stelzel, Christine; Rapp, Michael A

    2017-01-01

    Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60-72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality ( p < 0.05) and the auditory modality ( p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination.

  16. Isolating the Neural Mechanisms of Interference During Continuous Multisensory Dual-task Performance

    DTIC Science & Technology

    2014-01-01

    sion accuracy in each task, the signal detection theory sensitivity measure of d0 was used (Macmillan & Creelman , 1991; Green & Swets, 1966). First...J. (1998). Sources of dual-task interference: Evidence from human electrophysiology. Psychological Science, 9, 223–227. Macmillan, N. A., & Creelman

  17. Are gamers better crossers? An examination of action video game experience and dual task effects in a simulated street crossing task.

    PubMed

    Gaspar, John G; Neider, Mark B; Crowell, James A; Lutz, Aubrey; Kaczmarski, Henry; Kramer, Arthur F

    2014-05-01

    A high-fidelity street crossing simulator was used to test the hypothesis that experienced action video game players are less vulnerable than non-gamers to dual task costs in complex tasks. Previous research has shown that action video game players outperform nonplayers on many single task measures of perception and attention. It is unclear, however, whether action video game players outperform nonplayers in complex, divided attention tasks. Experienced action video game players and nongamers completed a street crossing task in a high-fidelity simulator. Participants walked on a manual treadmill to cross the street. During some crossings, a cognitively demanding working memory task was added. Dividing attention resulted in more collisions and increased decision making time. Of importance, these dual task costs were equivalent for the action video game players and the nongamers. These results suggest that action video game players are equally susceptible to the costs of dividing attention in a complex task. Perceptual and attentional benefits associated with action video game experience may not translate to performance benefits in complex, real-world tasks.

  18. Does It Really Matter Where You Look When Walking on Stairs? Insights from a Dual-Task Study

    PubMed Central

    Miyasike-daSilva, Veronica; McIlroy, William E.

    2012-01-01

    Although the visual system is known to provide relevant information to guide stair locomotion, there is less understanding of the specific contributions of foveal and peripheral visual field information. The present study investigated the specific role of foveal vision during stair locomotion and ground-stairs transitions by using a dual-task paradigm to influence the ability to rely on foveal vision. Fifteen healthy adults (26.9±3.3 years; 8 females) ascended a 7-step staircase under four conditions: no secondary tasks (CONTROL); gaze fixation on a fixed target located at the end of the pathway (TARGET); visual reaction time task (VRT); and auditory reaction time task (ART). Gaze fixations towards stair features were significantly reduced in TARGET and VRT compared to CONTROL and ART. Despite the reduced fixations, participants were able to successfully ascend stairs and rarely used the handrail. Step time was increased during VRT compared to CONTROL in most stair steps. Navigating on the transition steps did not require more gaze fixations than the middle steps. However, reaction time tended to increase during locomotion on transitions suggesting additional executive demands during this phase. These findings suggest that foveal vision may not be an essential source of visual information regarding stair features to guide stair walking, despite the unique control challenges at transition phases as highlighted by phase-specific challenges in dual-tasking. Instead, the tendency to look at the steps in usual conditions likely provides a stable reference frame for extraction of visual information regarding step features from the entire visual field. PMID:22970297

  19. Does Working Memory Enhance or Interfere with Speech Fluency in Adults Who Do and Do Not Stutter? Evidence from a Dual-Task Paradigm

    ERIC Educational Resources Information Center

    Eichorn, Naomi; Marton, Klara; Schwartz, Richard G.; Melara, Robert D.; Pirutinsky, Steven

    2016-01-01

    Purpose: The present study examined whether engaging working memory in a secondary task benefits speech fluency. Effects of dual-task conditions on speech fluency, rate, and errors were examined with respect to predictions derived from three related theoretical accounts of disfluencies. Method: Nineteen adults who stutter and twenty adults who do…

  20. A systematic review of interventions conducted in clinical or community settings to improve dual-task postural control in older adults

    PubMed Central

    Agmon, Maayan; Belza, Basia; Nguyen, Huong Q; Logsdon, Rebecca G; Kelly, Valerie E

    2014-01-01

    Background Injury due to falls is a major problem among older adults. Decrements in dual-task postural control performance (simultaneously performing two tasks, at least one of which requires postural control) have been associated with an increased risk of falling. Evidence-based interventions that can be used in clinical or community settings to improve dual-task postural control may help to reduce this risk. Purpose The aims of this systematic review are: 1) to identify clinical or community-based interventions that improved dual-task postural control among older adults; and 2) to identify the key elements of those interventions. Data sources Studies were obtained from a search conducted through October 2013 of the following electronic databases: PubMed, CINAHL, PsycINFO, and Web of Science. Study selection Randomized and nonrandomized controlled studies examining the effects of interventions aimed at improving dual-task postural control among community-dwelling older adults were selected. Data extraction All studies were evaluated based on methodological quality. Intervention characteristics including study purpose, study design, and sample size were identified, and effects of dual-task interventions on various postural control and cognitive outcomes were noted. Data synthesis Twenty-two studies fulfilled the selection criteria and were summarized in this review to identify characteristics of successful interventions. Limitations The ability to synthesize data was limited by the heterogeneity in participant characteristics, study designs, and outcome measures. Conclusion Dual-task postural control can be modified by specific training. There was little evidence that single-task training transferred to dual-task postural control performance. Further investigation of dual-task training using standardized outcome measurements is needed. PMID:24741296

  1. Effect of Tai Chi Training on Dual-Tasking Performance That Involves Stepping Down among Stroke Survivors: A Pilot Study.

    PubMed

    Chan, Wing-Nga; Tsang, William Wai-Nam

    2017-01-01

    Descending stairs demands attention and neuromuscular control, especially with dual-tasking. Studies have demonstrated that stroke often degrades a survivor's ability to descend stairs. Tai Chi has been shown to improve dual-tasking performance of healthy older adults, but no such study has been conducted in stroke survivors. This study investigated the effect of Tai Chi training on dual-tasking performance that involved stepping down and compared it with that of conventional exercise among stroke survivors. Subjects were randomized into Tai Chi ( n = 9), conventional exercise ( n = 8), and control ( n = 9) groups. Those in the former two groups received 12-week training. Assessments included auditory Stroop test, stepping down test, and dual-tasking test involving both simultaneously. They were evaluated before training (time-1), after training (time-2), and one month after training (time-3). Tai Chi group showed significant improvement in the auditory Stroop test from time-1 to time-3 and the performance was significantly better than that of the conventional exercise group in time-3. No significant effect was found in the stepping down task or dual-tasking in the control group. These results suggest a beneficial effect of Tai Chi training on cognition among stroke survivors without compromising physical task performance in dual-tasking. The effect was better than the conventional exercise group. Nevertheless, further research with a larger sample is warranted.

  2. Post-traumatic stress disorder is associated with limited executive resources in a working memory task

    PubMed Central

    Honzel, Nikki; Justus, Timothy; Swick, Diane

    2015-01-01

    Patients with post-traumatic stress disorder (PTSD) can show declines in working memory. A dual-task design was used to determine if these impairments are linked to executive control limitations. Participants performed a Sternberg memory task with either one or four letters. In the dual-task condition, the maintenance period was filled with an arrow flanker task. PTSD patients were less accurate on the working memory task than controls, especially in the dual-task condition. In the single-task condition, both groups showed similar patterns of brain potentials from 300–500 ms when discriminating old and new probes. However, when taxed with an additional task, the event-related potentials (ERPs) of the PTSD group no longer differentiated old and new probes. In contrast, interference resolution processes in both the single- and dual-task conditions of the flanker were intact. The lack of differentiation in the ERPs reflects impaired working memory performance under more difficult dual-task conditions. Exacerbated difficulty in performing a working memory task with concurrent task demands suggests a specific limitation in executive control resources in PTSD. PMID:24165904

  3. Video game practice optimizes executive control skills in dual-task and task switching situations.

    PubMed

    Strobach, Tilo; Frensch, Peter A; Schubert, Torsten

    2012-05-01

    We examined the relation of action video game practice and the optimization of executive control skills that are needed to coordinate two different tasks. As action video games are similar to real life situations and complex in nature, and include numerous concurrent actions, they may generate an ideal environment for practicing these skills (Green & Bavelier, 2008). For two types of experimental paradigms, dual-task and task switching respectively; we obtained performance advantages for experienced video gamers compared to non-gamers in situations in which two different tasks were processed simultaneously or sequentially. This advantage was absent in single-task situations. These findings indicate optimized executive control skills in video gamers. Similar findings in non-gamers after 15 h of action video game practice when compared to non-gamers with practice on a puzzle game clarified the causal relation between video game practice and the optimization of executive control skills. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. The role of gender in the association between personality and task priority in older adults' dual-tasking while walking.

    PubMed

    Agmon, Maayan; Armon, Galit; Denesh, Shani; Doumas, Mihalis

    2018-01-02

    Falls are a major problem for older adults. Many falls occur when a person's attention is divided between two tasks, such as a dual task (DT) involving walking. Most recently, the role of personality in walking performance was addressed; however, its association with DT performance remains to be determined. This cross-sectional study of 73 older, community-dwelling adults explores the association between personality and DT walking and the role of gender in this relationship. Personality was evaluated using the five-factor model. Single-task (ST) and DT assessment of walking-cognitive DT performance comprised a 1-min walking task and an arithmetic task performed separately (ST) and concurrently (DT). Dual-task costs (DTCs), reflecting the proportional difference between ST and DT performance, were also calculated. Gender plays a role in the relationship between personality and DT. Extraversion was negatively associated with DTC-motor for men (ΔR 2  = 0.06, p < 0.05). Conscientiousness was positively associated with DTC-cognition for women (ΔR 2  = 0.08, p < 0.01). These findings may lead to effective personality-based early detection and intervention for fall prevention.

  5. Comparing capacity coefficient and dual task assessment of visual multitasking workload

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blaha, Leslie M.

    Capacity coefficient analysis could offer a theoretically grounded alternative approach to subjective measures and dual task assessment of cognitive workload. Workload capacity or workload efficiency is a human information processing modeling construct defined as the amount of information that can be processed by the visual cognitive system given a specified of amount of time. In this paper, I explore the relationship between capacity coefficient analysis of workload efficiency and dual task response time measures. To capture multitasking performance, I examine how the relatively simple assumptions underlying the capacity construct generalize beyond the single visual decision making tasks. The fundamental toolsmore » for measuring workload efficiency are the integrated hazard and reverse hazard functions of response times, which are defined by log transforms of the response time distribution. These functions are used in the capacity coefficient analysis to provide a functional assessment of the amount of work completed by the cognitive system over the entire range of response times. For the study of visual multitasking, capacity coefficient analysis enables a comparison of visual information throughput as the number of tasks increases from one to two to any number of simultaneous tasks. I illustrate the use of capacity coefficients for visual multitasking on sample data from dynamic multitasking in the modified Multi-attribute Task Battery.« less

  6. The Use of Cognitive Cues for Anticipatory Strategies in a Dynamic Postural Control Task - Validation of a Novel Approach to Dual-Task Testing.

    PubMed

    Laessoe, Uffe; Grarup, Bo; Bangshaab, Jette

    2016-01-01

    Dual-task testing is relevant in the assessment of postural control. A combination of a primary (motor) and a secondary (distracting cognitive) tasks is most often used. It remains a challenge however, to standardize and monitor the cognitive task. In this study a new dual-task testing approach with a facilitating, rather than distracting, cognitive component was evaluated. Thirty-one community-dwelling elderly and fifteen young people were tested with respect to their ability to use anticipatory postural control strategies. The motor task consisted of twenty-five repetitive tasks in which the participants needed to exceed their limit of stability in order to touch one out of eight lights. The participants performed three tests. In two of the tests the color cues of the lights allowed the participants to utilize cognitive strategies to plan their next movement and improve their performance time. The young performed the baseline motor task test in an average of 29 seconds, while the average time for the elderly was 44 seconds. When comparing the performance time with a leading cue to the time with no cue, the young group improved their performance time significantly better than the elderly did: young: 17% (5), elderly: 5% (8); p<0.001. Similar differences were seen with a more complicated leading cue: young: 12% (5), elderly: 4% (9); p<0.01. The reliability of the test showed moderate to substantial agreement (ICC = 0.74), with a small learning effect between two sessions. The dual-task test was sensitive enough to discriminate between elderly and young people. It revealed that the elderly did not utilize cognitive cues for their anticipatory postural control strategies as well as the young were able to. The test procedure was feasible and comprehensible for the participants, and it may be relevant to standardize a similar test for an alternative dual-task approach in the clinical setting.

  7. Anatomically ordered tapping interferes more with one-digit addition than two-digit addition: a dual-task fMRI study.

    PubMed

    Soylu, Firat; Newman, Sharlene D

    2016-02-01

    Fingers are used as canonical representations for numbers across cultures. In previous imaging studies, it was shown that arithmetic processing activates neural resources that are known to participate in finger movements. Additionally, in one dual-task study, it was shown that anatomically ordered finger tapping disrupts addition and subtraction more than multiplication, possibly due to a long-lasting effect of early finger counting experiences on the neural correlates and organization of addition and subtraction processes. How arithmetic task difficulty and tapping complexity affect the concurrent performance is still unclear. If early finger counting experiences have bearing on the neural correlates of arithmetic in adults, then one would expect anatomically and non-anatomically ordered tapping to have different interference effects, given that finger counting is usually anatomically ordered. To unravel these issues, we studied how (1) arithmetic task difficulty and (2) the complexity of the finger tapping sequence (anatomical vs. non-anatomical ordering) affect concurrent performance and use of key neural circuits using a mixed block/event-related dual-task fMRI design with adult participants. The results suggest that complexity of the tapping sequence modulates interference on addition, and that one-digit addition (fact retrieval), compared to two-digit addition (calculation), is more affected from anatomically ordered tapping. The region-of-interest analysis showed higher left angular gyrus BOLD response for one-digit compared to two-digit addition, and in no-tapping conditions than dual tapping conditions. The results support a specific association between addition fact retrieval and anatomically ordered finger movements in adults, possibly due to finger counting strategies that deploy anatomically ordered finger movements early in the development.

  8. Reliability and validity of a dual-task test for skill proficiency in roundhouse kicks in elite taekwondo athletes.

    PubMed

    Chen, Chung-Yu; Dai, Jing; Chen, I-Fan; Chou, Kuei-Ming; Chang, Chen-Kang

    2015-01-01

    The dual-task methodology, conducting two tasks simultaneously, may provide better validity than the traditional single-task tests in the environment that is closely related to real sport competitions. The purpose of this study is to determine the reliability and validity of a dual-task test that aims to measure the reaction time and skill proficiency in roundhouse kicks in elite and sub-elite taekwondo athletes. The dual-task results were compared to those in the single-task movements with various levels of complexity. The single-task movements A, B, and C were composed of one, three, and five roundhouse kicks, respectively. The dual-task movement D was composed of movement C and a push of a button in response to a light stimulus as the secondary task. The subjects were 12 elite and 12 sub-elite male taekwondo athletes. The test included four movements with five repeats of each movement in a randomized order. Each subject conducted the same test on two consecutive days. The intraclass correlation coefficient (ICC) showed moderate-to-high correlation in the premotor time (ICC =0.439-0.634 in elite and ICC =0.681-0.824 in sub-elite), motor time (ICC =0.861-0.956 in elite and ICC =0.721-0.931 in sub-elite), and reaction time (ICC =0.692 in elite and ICC =0.676 in sub-elite) in the secondary task in both groups. The elite athletes had significantly faster premotor time than their sub-elite counterparts in all the four movements (all P<0.05). The largest difference lies in the reaction time in the secondary task, in which the elite group (0.248±0.026 seconds) was 33.0% faster than the sub-elite group (0.370±0.081 seconds) (P<0.001). This study shows that the test developed in this study has reasonable reliability and validity in both single- and dual-task methods. In addition, the dual-task method may be a more appropriate way to assess the reaction time and skill proficiency in taekwondo athletes.

  9. Detection of Acute and Long-Term Effects of Concussion: Dual-Task Gait Balance Control Versus Computerized Neurocognitive Test.

    PubMed

    Howell, David R; Osternig, Louis R; Chou, Li-Shan

    2018-02-16

    To examine the acute (within 72h of injury) and long-term (2mo postinjury) independent associations between objective dual-task gait balance and neurocognitive measurements among adolescents and young adults with a concussion and matched controls. Longitudinal case-control. Motion analysis laboratory. A total of 95 participants completed the study: 51 who sustained a concussion (mean age, 17.5±3.3y; 71% men) and 44 controls (mean age, 17.7±2.9y; 72% men). Participants who sustained a concussion underwent a dual-task gait analysis and computerized neurocognitive testing within 72 hours of injury and again 2 months later. Uninjured controls also completed the same test protocol in similar time increments. Not applicable. We compared dual-task gait balance control and computerized neurocognitive test performance between groups using independent samples t tests. Multivariable binary logistic regression models were then constructed for each testing time to determine the association between group membership (concussion vs control), dual-task gait balance control, and neurocognitive function. Medial-lateral center-of-mass displacement during dual-task gait was independently associated with group membership at the initial test (adjusted odds ratio [aOR], 2.432; 95% confidence interval [CI], 1.269-4.661) and 2-month follow-up test (aOR, 1.817; 95% CI, 1.014-3.256) tests. Visual memory composite scores were significantly associated with group membership at the initial hour postinjury time point (aOR, .953; 95% CI, .833-.998). However, the combination of computerized neurocognitive test variables did not predict dual-task gait balance control for participants with concussion, and no single neurocognitive variable was associated with dual-task gait balance control at either testing time. Dual-task assessments concurrently evaluating gait and cognitive performance may allow for the detection of persistent deficits beyond those detected by computerized neurocognitive deficits

  10. Transfer Effects to a Multimodal Dual-Task after Working Memory Training and Associated Neural Correlates in Older Adults – A Pilot Study

    PubMed Central

    Heinzel, Stephan; Rimpel, Jérôme; Stelzel, Christine; Rapp, Michael A.

    2017-01-01

    Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60–72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality (p < 0.05) and the auditory modality (p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination. PMID:28286477

  11. Brain Activation for Language Dual-Tasking: Listening to Two People Speak at the Same Time and a Change in Network Timing

    PubMed Central

    Buchweitz, Augusto; Keller, Timothy A.; Meyler, Ann; Just, Marcel Adam

    2011-01-01

    The study used fMRI to investigate brain activation in participants who were able to listen to and successfully comprehend two people speaking at the same time (dual-tasking). The study identified brain mechanisms associated with high-level, concurrent dual-tasking, as compared to comprehending a single message. Results showed an increase in the functional connectivity among areas of the language network in the dual task. The increase in synchronization of brain activation for dual-tasking was brought about primarily by a change in the timing of left inferior frontal gyrus (LIFG) activation relative to posterior temporal activation, bringing the LIFG activation into closer correspondence with temporal activation. The results show that the change in LIFG timing was greater in participants with lower working memory capacity, and that recruitment of additional activation in the dual-task occurred only in the areas adjacent to the language network that was activated in the single task. The shift in LIFG activation may be a brain marker of how the brain adapts to high-level dual-tasking. PMID:21618666

  12. Brain activation for language dual-tasking: listening to two people speak at the same time and a change in network timing.

    PubMed

    Buchweitz, Augusto; Keller, Timothy A; Meyler, Ann; Just, Marcel Adam

    2012-08-01

    The study used fMRI to investigate brain activation in participants who were able to listen to and successfully comprehend two people speaking at the same time (dual-tasking). The study identified brain mechanisms associated with high-level, concurrent dual-tasking, as compared with comprehending a single message. Results showed an increase in the functional connectivity among areas of the language network in the dual task. The increase in synchronization of brain activation for dual-tasking was brought about primarily by a change in the timing of left inferior frontal gyrus (LIFG) activation relative to posterior temporal activation, bringing the LIFG activation into closer correspondence with temporal activation. The results show that the change in LIFG timing was greater in participants with lower working memory capacity, and that recruitment of additional activation in the dual-task occurred only in the areas adjacent to the language network that was activated in the single task. The shift in LIFG activation may be a brain marker of how the brain adapts to high-level dual-tasking. Copyright © 2011 Wiley Periodicals, Inc.

  13. Effects of narrow-base walking and dual tasking on gait spatiotemporal characteristics in anterior cruciate ligament-injured adults compared to healthy adults.

    PubMed

    Mazaheri, Masood; Negahban, Hossein; Soltani, Maryam; Mehravar, Mohammad; Tajali, Shirin; Hessam, Masumeh; Salavati, Mahyar; Kingma, Idsart

    2017-08-01

    The present experiment was conducted to examine the hypothesis that challenging control through narrow-base walking and/or dual tasking affects ACL-injured adults more than healthy control adults. Twenty male ACL-injured adults and twenty healthy male adults walked on a treadmill at a comfortable speed under two base-of-support conditions, normal-base versus narrow-base, with and without a cognitive task. Gait patterns were assessed using mean and variability of step length and mean and variability of step velocity. Cognitive performance was assessed using the number of correct counts in a backward counting task. Narrow-base walking resulted in a larger decrease in step length and a more pronounced increase in variability of step length and of step velocity in ACL-injured adults than in healthy adults. For most of the gait parameters and for backward counting performance, the dual-tasking effect was similar between the two groups. ACL-injured adults adopt a more conservative and more unstable gait pattern during narrow-base walking. This can be largely explained by deficits of postural control in ACL-injured adults, which impairs gait under more balance-demanding conditions. The observation that the dual-tasking effect did not differ between the groups may be explained by the fact that walking is an automatic process that involves minimal use of attentional resources, even after ACL injury. Clinicians should consider the need to include aspects of terrain complexity, such as walking on a narrow walkway, in gait assessment and training of patients with ACL injury. III.

  14. Interval Timing Deficits Assessed by Time Reproduction Dual Tasks as Cognitive Endophenotypes for Attention-Deficit/Hyperactivity Disorder

    PubMed Central

    Hwang-Gu, Shoou-Lian; Gau, Susan Shur-Fen

    2015-01-01

    The literature has suggested timing processing as a potential endophenotype for attention deficit/hyperactivity disorder (ADHD); however, whether the subjective internal clock speed presented by verbal estimation and limited attention capacity presented by time reproduction could be endophenotypes for ADHD is still unknown. We assessed 223 youths with DSM-IV ADHD (age range: 10-17 years), 105 unaffected siblings, and 84 typically developing (TD) youths using psychiatric interviews, intelligence tests, verbal estimation and time reproduction tasks (single task and simple and difficult dual tasks) at 5-second, 12-second, and 17-second intervals. We found that youths with ADHD tended to overestimate time in verbal estimation more than their unaffected siblings and TD youths, implying that fast subjective internal clock speed might be a characteristic of ADHD, rather than an endophenotype for ADHD. Youths with ADHD and their unaffected siblings were less precise in time reproduction dual tasks than TD youths. The magnitude of estimated errors in time reproduction was greater in youths with ADHD and their unaffected siblings than in TD youths, with an increased time interval at the 17-second interval and with increased task demands on both simple and difficult dual tasks versus the single task. Increased impaired time reproduction in dual tasks with increased intervals and task demands were shown in youths with ADHD and their unaffected siblings, suggesting that time reproduction deficits explained by limited attention capacity might be a useful endophenotype of ADHD. PMID:25992899

  15. Performance of basic manipulation and intracorporeal suturing tasks in a robotic surgical system: single- versus dual-monitor views.

    PubMed

    Shah, Rachit D; Cao, Alex; Golenberg, Lavie; Ellis, R Darin; Auner, Gregory W; Pandya, Abhilash K; Klein, Michael D

    2009-04-01

    Technical advances in the application of laparoscopic and robotic surgical systems have improved platform usability. The authors hypothesized that using two monitors instead of one would lead to faster performance with fewer errors. All tasks were performed using a surgical robot in a training box. One of the monitors was a standard camera with two preset zoom levels (zoomed in and zoomed out, single-monitor condition). The second monitor provided a static panoramic view of the whole surgical field. The standard camera was static at the zoomed-in level for the dual-monitor condition of the study. The study had two groups of participants: 4 surgeons proficient in both robotic and advanced laparoscopic skills and 10 lay persons (nonsurgeons) who were given adequate time to train and familiarize themselves with the equipment. Running a 50-cm rope was the basic task. Advanced tasks included running a suture through predetermined points and intracorporeal knot tying with 3-0 silk. Trial completion times and errors, categorized into three groups (orientation, precision, and task), were recorded. The trial completion times for all the tasks, basic and advanced, in the two groups were not significantly different. Fewer orientation errors occurred in the nonsurgeon group during knot tying (p=0.03) and in both groups during suturing (p=0.0002) in the dual-monitor arm of the study. Differences in precision and task error were not significant. Using two camera views helps both surgeons and lay persons perform complex tasks with fewer errors. These results may be due to better awareness of the surgical field with regard to the location of the instruments, leading to better field orientation. This display setup has potential for use in complex minimally invasive surgeries such as esophagectomy and gastric bypass. This technique also would be applicable to open microsurgery.

  16. Effects of the Addition of a Dual Task to a Supervised Physical Exercise Program on Older Adults' Cognitive Performance.

    PubMed

    Ansai, Juliana Hotta; de Andrade, Larissa Pires; de Souza Buto, Marcele Stephanie; de Vassimon Barroso, Verena; Farche, Ana Claudia Silva; Rossi, Paulo Giusti; de Medeiros Takahashi, Anielle Cristhine

    2017-04-01

    The purpose of this study was to investigate the effects of the addition of a dual task to multicomponent training on cognition of active older adults. Eighty physically active older adults were divided into an intervention group (IG) and a control group (CG). Both groups performed multicomponent training over 12 weeks. The IG simultaneously performed exercises and cognitive tasks. The Mini-Mental State Examination, the Montreal Cognitive Assessment, and the Clock Drawing Test were used for cognitive assessments. The Timed Up and Go Test associated with a cognitive task was used for dual-task assessment. Significant interactions were not observed between groups in terms of the cognitive variables or the dual-task performance. An interaction was observed only for Timed Up and Go Test performance, which was better in the CG than in the IG. Active older adults showed no improvement in cognition following the addition of the dual task to the multicomponent training.

  17. Enhancing performance of P300-Speller under mental workload by incorporating dual-task data during classifier training.

    PubMed

    Chen, Yuqian; Ke, Yufeng; Meng, Guifang; Jiang, Jin; Qi, Hongzhi; Jiao, Xuejun; Xu, Minpeng; Zhou, Peng; He, Feng; Ming, Dong

    2017-12-01

    As one of the most important brain-computer interface (BCI) paradigms, P300-Speller was shown to be significantly impaired once applied in practical situations due to effects of mental workload. This study aims to provide a new method of building training models to enhance performance of P300-Speller under mental workload. Three experiment conditions based on row-column P300-Speller paradigm were performed including speller-only, 3-back-speller and mental-arithmetic-speller. Data under dual-task conditions were introduced to speller-only data respectively to build new training models. Then performance of classifiers with different models was compared under the same testing condition. The results showed that when tasks of imported training data and testing data were the same, character recognition accuracies and round accuracies of P300-Speller with mixed-data training models significantly improved (FDR, p < 0.005). When they were different, performance significantly improved when tested on mental-arithmetic-speller (FDR, p < 0.05) while the improvement was modest when tested on n-back-speller (FDR, p < 0.1). The analysis of ERPs revealed that ERP difference between training data and testing data was significantly diminished when the dual-task data was introduced to training data (FDR, p < 0.05). The new method of training classifier on mixed data proved to be effective in enhancing performance of P300-Speller under mental workload, confirmed the feasibility to build a universal training model and overcome the effects of mental workload in its practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Single- and Dual-Task Balance Training Are Equally Effective in Youth.

    PubMed

    Lüder, Benjamin; Kiss, Rainer; Granacher, Urs

    2018-01-01

    Due to maturation of the postural control system and secular declines in motor performance, adolescents experience deficits in postural control during standing and walking while concurrently performing cognitive interference tasks. Thus, adequately designed balance training programs may help to counteract these deficits. While the general effectiveness of youth balance training is well-documented, there is hardly any information available on the specific effects of single-task (ST) versus dual-task (DT) balance training. Therefore, the objectives of this study were (i) to examine static/dynamic balance performance under ST and DT conditions in adolescents and (ii) to study the effects of ST versus DT balance training on static/dynamic balance under ST and DT conditions in adolescents. Twenty-eight healthy girls and boys aged 12-13 years were randomly assigned to either 8 weeks of ST or DT balance training. Before and after training, postural sway and spatio-temporal gait parameters were registered under ST (standing/walking only) and DT conditions (standing/walking while concurrently performing an arithmetic task). At baseline, significantly slower gait speed ( p < 0.001, d = 5.1), shorter stride length ( p < 0.001, d = 4.8), and longer stride time ( p < 0.001, d = 3.8) were found for DT compared to ST walking but not standing. Training resulted in significant pre-post decreases in DT costs for gait velocity ( p < 0.001, d = 3.1), stride length (-45%, p < 0.001, d = 2.4), and stride time (-44%, p < 0.01, d = 1.9). Training did not induce any significant changes ( p > 0.05, d = 0-0.1) in DT costs for all parameters of secondary task performance during standing and walking. Training produced significant pre-post increases ( p = 0.001; d = 1.47) in secondary task performance while sitting. The observed increase was significantly greater for the ST training group ( p = 0.04; d = 0.81). For standing, no significant changes were found over time irrespective of the

  19. Task Integration Facilitates Multitasking.

    PubMed

    de Oliveira, Rita F; Raab, Markus; Hegele, Mathias; Schorer, Jörg

    2017-01-01

    The aim of this study was to investigate multi-task integration in a continuous tracking task. We were particularly interested in how manipulating task structure in a dual-task situation affects learning of a constant segment embedded in a pursuit-tracking task. Importantly, we examined if dual-task effects could be attributed to task integration by varying the structural similarity and difficulty of the primary and secondary tasks. In Experiment 1 participants performed a pursuit tracking task while counting high-pitched tones and ignoring low-pitched tones. The tones were either presented randomly or structurally 250 ms before each tracking turn. Experiment 2 increased the motor load of the secondary tasks by asking participants to tap their feet to the tones. Experiment 3 further increased motor load of the primary task by increasing its speed and having participants tracking with their non-dominant hand. The results show that dual-task interference can be moderated by secondary task conditions that match the structure of the primary task. Therefore our results support proposals of task integration in continuous tracking paradigms. We conclude that multi-tasking is not always detrimental for motor learning but can be facilitated through task-integration.

  20. Temporal dynamics of interference in Simon and Eriksen tasks considered within the context of a dual-process model.

    PubMed

    Mansfield, Karen L; van der Molen, Maurits W; Falkenstein, Michael; van Boxtel, Geert J M

    2013-08-01

    Behavioral and brain potential measures were employed to compare interference in Eriksen and Simon tasks. Assuming a dual-process model of interference elicited in speeded response tasks, we hypothesized that only lateralized stimuli in the Simon task induce fast S-R priming via direct unconditional processes, while Eriksen interference effects are induced later via indirect conditional processes. Delays to responses for incongruent trials were indeed larger in the Eriksen than in the Simon task. Only lateralized stimuli in the Simon task elicited early S-R priming, maximal at parietal areas. Incongruent flankers in the Eriksen task elicited interference later, visible as a lateralized N2. Eriksen interference also elicited an additional component (N350), which accounted for the larger behavioral interference effects in the Eriksen task. The findings suggest that interference and its resolution involve different processes for Simon and Eriksen tasks. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Can Dual Task Walking Improve in Parkinson's Disease After External Focus of Attention Exercise? A Single Blind Randomized Controlled Trial.

    PubMed

    Beck, Eric N; Intzandt, Brittany N; Almeida, Quincy J

    2018-01-01

    It may be possible to use attention-based exercise to decrease demands associated with walking in Parkinson's disease (PD), and thus improve dual task walking ability. For example, an external focus of attention (focusing on the effect of an action on the environment) may recruit automatic control processes degenerated in PD, whereas an internal focus (limb movement) may recruit conscious (nonautomatic) control processes. Thus, we aimed to investigate how externally and internally focused exercise influences dual task walking and symptom severity in PD. Forty-seven participants with PD were randomized to either an Externally (n = 24) or Internally (n = 23) focused group and completed 33 one-hour attention-based exercise sessions over 11 weeks. In addition, 16 participants were part of a control group. Before, after, and 8 weeks following the program (pre/post/washout), gait patterns were measured during single and dual task walking (digit-monitoring task, ie, walking while counting numbers announced by an audio-track), and symptom severity (UPDRS-III) was assessed ON and OFF dopamine replacement. Pairwise comparisons (95% confidence intervals [CIs]) and repeated-measures analyses of variance were conducted. Pre to post: Dual task step time decreased in the external group (Δ = 0.02 seconds, CI 0.01-0.04). Dual task step length (Δ = 2.3 cm, CI 0.86-3.75) and velocity (Δ = 4.5 cm/s, CI 0.59-8.48) decreased (became worse) in the internal group. UPDRS-III scores (ON and OFF) decreased (improved) in only the External group. Pre to washout: Dual task step time ( P = .005) and percentage in double support ( P = .014) significantly decreased (improved) in both exercise groups, although only the internal group increased error on the secondary counting task (ie, more errors monitoring numbers). UPDRS-III scores in both exercise groups significantly decreased ( P = .001). Since dual task walking improvements were found immediately, and 8 weeks after the cessation of an

  2. Speech responses and dual-task performance - Better time-sharing or asymmetric transfer?

    NASA Technical Reports Server (NTRS)

    Vidulich, Michael A.

    1988-01-01

    The value of speech controls in a dual-task experiment that also evaluated asymmetric transfer effects is considered. There was no evidence of asymmetric transfer in spite of significant effects supporting the advantage of mixing manual and speech responses. The data suggest that speech controls can be used to enhance performance in operational multiple-task environments.

  3. Association Between Gait and Dual Task With Cognitive Domains in Older People With Cognitive Impairment.

    PubMed

    Ansai, Juliana Hotta; Andrade, Larissa Pires de; Rossi, Paulo Giusti; Almeida, Mariana Luciano; Carvalho Vale, Francisco Assis; Rebelatto, José Rubens

    2017-09-13

    The authors investigated whether impaired gait and dual-task performances are associated with specific cognitive domains among older people with preserved cognition (PC), mild cognitive impairment (MCI), and mild Alzheimer's disease (AD). The sample comprised 40 older adults with PC, 40 with MCI, and 38 with mild AD. The assessment consisted of gait (measured by 10-m walk test and Timed Up and Go Test [TUGT]), dual task (measured by TUGT associated with a cognitive-motor task of calling a phone number), and cognition (domains of the Addenbrooke Cognitive Examination-Revised and Frontal Assessment Battery [FAB]). For data analysis, the Pearson product-moment correlation and the backward stepwise linear regression were conducted. Language, fluency, and visuospatial domains predicted the 10-m walk test measure specifically in PC, MCI, and AD groups. Only the visuospatial domain was independently associated with the TUGT measure in the MCI and AD groups. FAB score, language domain, and FAB score and fluency domain were the strongest predictors for the isolated cognitive-motor task measure in the PC, MCI, and AD groups, respectively. The visuospatial domain was independently associated with the dual-task test measure in all 3 groups. The study findings demonstrate the influence of specific cognitive domains in daily mobility tasks in people with different cognitive profiles.

  4. Improving balance, mobility, and dual-task performance in an adolescent with cerebral palsy: A case report.

    PubMed

    Fisher-Pipher, Sarah; Kenyon, Lisa K; Westman, Marci

    2017-07-01

    Improving functional mobility is often a desired outcome for adolescents with cerebral palsy (CP). Traditional neurorehabilitation approaches are frequently directed at impairments; however, improvements may not be carried over into functional mobility. The purpose of this case report was to describe the examination, intervention, and outcomes of a task-oriented physical therapy intervention program to improve dynamic balance, functional mobility, and dual-task performance in an adolescent with CP. The participant was a 15-year-old girl with spastic triplegic CP (Gross Motor Classification System Level II). Examination procedures included the Canadian Occupational Performance Measure, 6-minute walk test, Muscle Power Sprint Test, 10 x 5-meter sprint test, Timed Up and Down Stairs Test, Gross Motor Function Measure, Gillette Functional Assessment Questionnaire, and functional lower extremity strength tests. Intervention focused on task-oriented dynamic balance and mobility tasks that incorporated coordination and speed demands as well as task-specific lower extremity and trunk strengthening activities. Dual task demands were integrated into all intervention activities. Post-intervention testing revealed improvements in cardiovascular endurance, anaerobic power, agility, stair climbing, gross motor skills, and mobility. The participant appeared to benefit from a task-oriented program to improve dynamic balance, functional mobility, and dual-task performance.

  5. Reliability and validity of a dual-task test for skill proficiency in roundhouse kicks in elite taekwondo athletes

    PubMed Central

    Chen, Chung-Yu; Dai, Jing; Chen, I-Fan; Chou, Kuei-Ming; Chang, Chen-Kang

    2015-01-01

    The dual-task methodology, conducting two tasks simultaneously, may provide better validity than the traditional single-task tests in the environment that is closely related to real sport competitions. The purpose of this study is to determine the reliability and validity of a dual-task test that aims to measure the reaction time and skill proficiency in roundhouse kicks in elite and sub-elite taekwondo athletes. The dual-task results were compared to those in the single-task movements with various levels of complexity. The single-task movements A, B, and C were composed of one, three, and five roundhouse kicks, respectively. The dual-task movement D was composed of movement C and a push of a button in response to a light stimulus as the secondary task. The subjects were 12 elite and 12 sub-elite male taekwondo athletes. The test included four movements with five repeats of each movement in a randomized order. Each subject conducted the same test on two consecutive days. The intraclass correlation coefficient (ICC) showed moderate-to-high correlation in the premotor time (ICC =0.439–0.634 in elite and ICC =0.681–0.824 in sub-elite), motor time (ICC =0.861–0.956 in elite and ICC =0.721–0.931 in sub-elite), and reaction time (ICC =0.692 in elite and ICC =0.676 in sub-elite) in the secondary task in both groups. The elite athletes had significantly faster premotor time than their sub-elite counterparts in all the four movements (all P<0.05). The largest difference lies in the reaction time in the secondary task, in which the elite group (0.248±0.026 seconds) was 33.0% faster than the sub-elite group (0.370±0.081 seconds) (P<0.001). This study shows that the test developed in this study has reasonable reliability and validity in both single- and dual-task methods. In addition, the dual-task method may be a more appropriate way to assess the reaction time and skill proficiency in taekwondo athletes. PMID:26150736

  6. Intrusive images and voluntary memory for affective pictures: contextualization and dual-task interference.

    PubMed

    Krans, Julie; Langner, Oliver; Reinecke, Andrea; Pearson, David G

    2013-12-01

    The present study addressed the role of context information and dual-task interference during the encoding of negative pictures on intrusion development and voluntary recall. Healthy participants were shown negative pictures with or without context information. Pictures were either viewed alone or concurrently with a visuospatial or verbal task. Participants reported their intrusive images of the pictures in a diary. At follow-up, perceptual and contextual memory was tested. Participants in the context group reported more intrusive images and perceptual voluntary memory than participants in the no context group. No effects of the concurrent tasks were found on intrusive image frequency, but perceptual and contextual memory was affected according to the cognitive load of the task. The analogue method cannot be generalized to real-life trauma and the secondary tasks may differ in cognitive load. The findings challenge a dual memory model of PTSD but support an account in which retrieval strategy, rather than encoding processes, accounts for the experience of involuntary versus voluntary recall. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Automatic-heuristic and executive-analytic processing during reasoning: Chronometric and dual-task considerations.

    PubMed

    De Neys, Wim

    2006-06-01

    Human reasoning has been shown to overly rely on intuitive, heuristic processing instead of a more demanding analytic inference process. Four experiments tested the central claim of current dual-process theories that analytic operations involve time-consuming executive processing whereas the heuristic system would operate automatically. Participants solved conjunction fallacy problems and indicative and deontic selection tasks. Experiment 1 established that making correct analytic inferences demanded more processing time than did making heuristic inferences. Experiment 2 showed that burdening the executive resources with an attention-demanding secondary task decreased correct, analytic responding and boosted the rate of conjunction fallacies and indicative matching card selections. Results were replicated in Experiments 3 and 4 with a different secondary-task procedure. Involvement of executive resources for the deontic selection task was less clear. Findings validate basic processing assumptions of the dual-process framework and complete the correlational research programme of K. E. Stanovich and R. F. West (2000).

  8. High-Frequency Binaural Beats Increase Cognitive Flexibility: Evidence from Dual-Task Crosstalk.

    PubMed

    Hommel, Bernhard; Sellaro, Roberta; Fischer, Rico; Borg, Saskia; Colzato, Lorenza S

    2016-01-01

    Increasing evidence suggests that cognitive-control processes can be configured to optimize either persistence of information processing (by amplifying competition between decision-making alternatives and top-down biasing of this competition) or flexibility (by dampening competition and biasing). We investigated whether high-frequency binaural beats, an auditory illusion suspected to act as a cognitive enhancer, have an impact on cognitive-control configuration. We hypothesized that binaural beats in the gamma range bias the cognitive-control style toward flexibility, which in turn should increase the crosstalk between tasks in a dual-task paradigm. We replicated earlier findings that the reaction time in the first-performed task is sensitive to the compatibility between the responses in the first and the second task-an indication of crosstalk. As predicted, exposing participants to binaural beats in the gamma range increased this effect as compared to a control condition in which participants were exposed to a continuous tone of 340 Hz. These findings provide converging evidence that the cognitive-control style can be systematically biased by inducing particular internal states; that high-frequency binaural beats bias the control style toward more flexibility; and that different styles are implemented by changing the strength of local competition and top-down bias.

  9. Observing prioritization effects on cognition and gait: The effect of increased cognitive load on cognitively healthy older adults' dual-task performance.

    PubMed

    Maclean, Linda M; Brown, Laura J E; Khadra, H; Astell, Arlene J

    2017-03-01

    Previous studies exploring the effects of attention-prioritization on cognitively healthy older adults' gait and cognitive dual task (DT) performance have shown DT cost in gait outcomes but inconsistent effects on cognitive performance, which may reflect task difficulty (the cognitive load). This study aimed to identify whether changing the cognitive load during a walking and counting DT improved the challenge/sensitivity of the cognitive task to observe prioritization effects on concurrent gait and cognitive performance outcomes. Seventy-two cognitively healthy older adults (Mean=73years) walked 15m, counted backwards in 3s and 7s as single tasks (ST), and concurrently walked and counted backwards as DTs. Attention-prioritization was examined in Prioritizing Walking (PW) and Prioritizing Counting (PC) DT conditions. Dual-task performance costs (DTC) were calculated for number of correct cognitive responses (CCR) in the counting tasks, and step-time variability and velocity in the gait task. All DT conditions showed a benefit (DTB) for cognitive outcomes with trade-off cost to gait. In the Serial 3s task, the cognitive DTBs increased in PC over the PW condition (p<0.05), with a greater cost to walking velocity (p<0.05). DT effects were more pronounced in the Serial 7s with a lower cognitive DTB when PC than when PW, (p<0.05) with no trade-off increase in cost to gait outcomes (p<0.05). The findings suggest that increased cognitive load during a gait and cognitive DT produces more pronounced gait measures of attention-prioritization in cognitively healthy older adults. A cognitive load effect was also observed in the cognitive outcomes, with unexpected results. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Integrating the behavioral and neural dynamics of response selection in a dual-task paradigm: a dynamic neural field model of Dux et al. (2009).

    PubMed

    Buss, Aaron T; Wifall, Tim; Hazeltine, Eliot; Spencer, John P

    2014-02-01

    People are typically slower when executing two tasks than when only performing a single task. These dual-task costs are initially robust but are reduced with practice. Dux et al. (2009) explored the neural basis of dual-task costs and learning using fMRI. Inferior frontal junction (IFJ) showed a larger hemodynamic response on dual-task trials compared with single-task trial early in learning. As dual-task costs were eliminated, dual-task hemodynamics in IFJ reduced to single-task levels. Dux and colleagues concluded that the reduction of dual-task costs is accomplished through increased efficiency of information processing in IFJ. We present a dynamic field theory of response selection that addresses two questions regarding these results. First, what mechanism leads to the reduction of dual-task costs and associated changes in hemodynamics? We show that a simple Hebbian learning mechanism is able to capture the quantitative details of learning at both the behavioral and neural levels. Second, is efficiency isolated to cognitive control areas such as IFJ, or is it also evident in sensory motor areas? To investigate this, we restrict Hebbian learning to different parts of the neural model. None of the restricted learning models showed the same reductions in dual-task costs as the unrestricted learning model, suggesting that efficiency is distributed across cognitive control and sensory motor processing systems.

  11. The dual task-cost of standing balance affects quality of life in mildly disabled MS people.

    PubMed

    Castelli, Letizia; De Luca, Francesca; Marchetti, Maria Rita; Sellitto, Giovanni; Fanelli, Fulvia; Prosperini, Luca

    2016-05-01

    The aim of this study was to explore the correlations between the dual-task cost (DTC) of standing balance and quality of life (QoL) in mildly disabled patients with multiple sclerosis (MS). In this cross-sectional study, patients affected by MS with an expanded disability status scale (EDSS) score of 3.0 or less and without an overt balance impairment were tested by means of static posturography under eyes-opened (single-task condition) and while performing the Stroop word-color test (dual-task condition), to estimate the DTC of standing balance. The self-reported 54-item MS quality of life questionnaire (MSQoL-54) was also administered to obtain a MS-specific assessment of health-related QoL. Among the 120 screened patients, 75 (53 women, 22 men) were tested. Although there was no impact of the DTC of standing balance on the physical and mental composite scores of MSQoL-54, patients who had a greater DTC of standing balance scored worse on role limitations due to physical problems (p = 0.007) and social function (p < 0.001), irrespective of demographic and other clinical characteristics including walking performance and cognitive status. However, the EDSS step and fatigue also contributed to reduced scores in these two QoL domains (p-values < 0.01). In conclusion, the phenomenon of cognitive-motor interference, investigated as DTC of standing balance, may affect specific QoL domains even in mildly disabled patients with MS and in the absence of an overt balance dysfunction.

  12. Dual-Task Processing in Younger and Older Adults: Similarities and Differences Revealed by fMRI

    ERIC Educational Resources Information Center

    Hartley, Alan A.; Jonides, John; Sylvester, Ching-Yune C.

    2011-01-01

    fMRI was used to explore age differences in the neural substrate of dual-task processing. Brain activations when there was a 100 ms SOA between tasks, and task overlap was high, were contrasted with activations when there was a 1000 ms SOA, and first task processing was largely complete before the second task began. Younger adults (M = 21 yrs)…

  13. Resting State Default Mode Network Connectivity, Dual Task Performance, Gait Speed, and Postural Sway in Older Adults with Mild Cognitive Impairment

    PubMed Central

    Crockett, Rachel A.; Hsu, Chun Liang; Best, John R.; Liu-Ambrose, Teresa

    2017-01-01

    Aging is associated with an increased risk of falling. In particular, older adults with mild cognitive impairment (MCI) are more vulnerable to falling compared with their healthy counterparts. Major contributors to this increased falls risk include a decline in dual task performance, gait speed, and postural sway. Recent evidence highlights the potential influence of the default mode network (DMN), the frontoparietal network (FPN), and the supplementary motor area (SMA) on dual task performance, gait speed, and postural sway. The DMN is active during rest and deactivates during task-oriented processes, to maintain attention and stay on task. The FPN and SMA are involved in top-down attentional control, motor planning, and motor execution. The DMN shows less deactivation during task in older adults with MCI. This lack of deactivation is theorized to increase competition for resources between the DMN and task-related brain regions (e.g., the FPN and SMA), increasing distraction from the task and reducing task performance. However, no study has yet investigated the relationship between the between-network connectivity of the DMN with these regions and dual task walking, gait speed or postural sway. We hypothesized that greater functional connectivity both within the DMN and between DMN–FPN and DMN–SMA, will be associated with poorer performance during dual task walking, slower gait speed, and greater postural sway in older adults with MCI. Forty older adults with MCI were measured on a dual task-walking paradigm, gait speed over a 4-m walk, and postural sway using a sway-meter. Greater within-DMN connectivity was significantly correlated with poorer dual task performance. Furthermore, greater inter-network connectivity between the DMN and SMA was significantly correlated with slower gait speed and greater postural sway on the eyes open floor sway task. Thus, greater resting state DMN functional connectivity may be an underlying neural mechanism for reduced dual

  14. Resting State Default Mode Network Connectivity, Dual Task Performance, Gait Speed, and Postural Sway in Older Adults with Mild Cognitive Impairment.

    PubMed

    Crockett, Rachel A; Hsu, Chun Liang; Best, John R; Liu-Ambrose, Teresa

    2017-01-01

    Aging is associated with an increased risk of falling. In particular, older adults with mild cognitive impairment (MCI) are more vulnerable to falling compared with their healthy counterparts. Major contributors to this increased falls risk include a decline in dual task performance, gait speed, and postural sway. Recent evidence highlights the potential influence of the default mode network (DMN), the frontoparietal network (FPN), and the supplementary motor area (SMA) on dual task performance, gait speed, and postural sway. The DMN is active during rest and deactivates during task-oriented processes, to maintain attention and stay on task. The FPN and SMA are involved in top-down attentional control, motor planning, and motor execution. The DMN shows less deactivation during task in older adults with MCI. This lack of deactivation is theorized to increase competition for resources between the DMN and task-related brain regions (e.g., the FPN and SMA), increasing distraction from the task and reducing task performance. However, no study has yet investigated the relationship between the between-network connectivity of the DMN with these regions and dual task walking, gait speed or postural sway. We hypothesized that greater functional connectivity both within the DMN and between DMN-FPN and DMN-SMA, will be associated with poorer performance during dual task walking, slower gait speed, and greater postural sway in older adults with MCI. Forty older adults with MCI were measured on a dual task-walking paradigm, gait speed over a 4-m walk, and postural sway using a sway-meter. Greater within-DMN connectivity was significantly correlated with poorer dual task performance. Furthermore, greater inter-network connectivity between the DMN and SMA was significantly correlated with slower gait speed and greater postural sway on the eyes open floor sway task. Thus, greater resting state DMN functional connectivity may be an underlying neural mechanism for reduced dual task

  15. Contrasting single and multi-component working-memory systems in dual tasking.

    PubMed

    Nijboer, Menno; Borst, Jelmer; van Rijn, Hedderik; Taatgen, Niels

    2016-05-01

    Working memory can be a major source of interference in dual tasking. However, there is no consensus on whether this interference is the result of a single working memory bottleneck, or of interactions between different working memory components that together form a complete working-memory system. We report a behavioral and an fMRI dataset in which working memory requirements are manipulated during multitasking. We show that a computational cognitive model that assumes a distributed version of working memory accounts for both behavioral and neuroimaging data better than a model that takes a more centralized approach. The model's working memory consists of an attentional focus, declarative memory, and a subvocalized rehearsal mechanism. Thus, the data and model favor an account where working memory interference in dual tasking is the result of interactions between different resources that together form a working-memory system. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Task-specificity of unilateral anodal and dual-M1 tDCS effects on motor learning.

    PubMed

    Karok, Sophia; Fletcher, David; Witney, Alice G

    2017-01-08

    Task-specific effects of transcranial direct current stimulation (tDCS) on motor learning were investigated in 30 healthy participants. In a sham-controlled, mixed design, participants trained on 3 different motor tasks (Purdue Pegboard Test, Visuomotor Grip Force Tracking Task and Visuomotor Wrist Rotation Speed Control Task) over 3 consecutive days while receiving either unilateral anodal over the right primary motor cortex (M1), dual-M1 or sham stimulation. Retention sessions were administered 7 and 28 days after the end of training. In the Purdue Pegboard Test, both anodal and dual-M1 stimulation reduced average completion time approximately equally, an improvement driven by online learning effects and maintained for about 1 week. The Visuomotor Grip Force Tracking Task and the Visuomotor Wrist Rotation Speed Control Task were associated with an advantage of dual-M1 tDCS in consolidation processes both between training sessions and when testing at long-term retention; both were maintained for at least 1 month. This study demonstrates that M1-tDCS enhances and sustains motor learning with different electrode montages. Stimulation-induced effects emerged at different learning phases across the tasks, which strongly suggests that the influence of tDCS on motor learning is dynamic with respect to the functional recruitment of the distributed motor system at the time of stimulation. Divergent findings regarding M1-tDCS effects on motor learning may partially be ascribed to task-specific consequences and the effects of offline consolidation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Driven to distraction: dual-Task studies of simulated driving and conversing on a cellular telephone.

    PubMed

    Strayer, D L; Johnston, W A

    2001-11-01

    Dual-task studies assessed the effects of cellular-phone conversations on performance of a simulated driving task. Performance was not disrupted by listening to radio broadcasts or listening to a book on tape. Nor was it disrupted by a continuous shadowing task using a handheld phone, ruling out, in this case, dual-task interpretations associated with holding the phone, listening, or speaking, However significant interference was observed in a word-generation variant of the shadowing task, and this deficit increased with the difficulty of driving. Moreover unconstrained conversations using either a handheld or a hands-free cell phone resulted in a twofold increase in the failure to detect simulated traffic signals and slower reactions to those signals that were detected. We suggest that cellular-phone use disrupts performance by diverting attention to an engaging cognitive context other than the one immediately associated with driving.

  18. Concurrent deployment of visual attention and response selection bottleneck in a dual-task: Electrophysiological and behavioural evidence.

    PubMed

    Reimer, Christina B; Strobach, Tilo; Schubert, Torsten

    2017-12-01

    Visual attention and response selection are limited in capacity. Here, we investigated whether visual attention requires the same bottleneck mechanism as response selection in a dual-task of the psychological refractory period (PRP) paradigm. The dual-task consisted of an auditory two-choice discrimination Task 1 and a conjunction search Task 2, which were presented at variable temporal intervals (stimulus onset asynchrony, SOA). In conjunction search, visual attention is required to select items and to bind their features resulting in a serial search process around the items in the search display (i.e., set size). We measured the reaction time of the visual search task (RT2) and the N2pc, an event-related potential (ERP), which reflects lateralized visual attention processes. If the response selection processes in Task 1 influence the visual attention processes in Task 2, N2pc latency and amplitude would be delayed and attenuated at short SOA compared to long SOA. The results, however, showed that latency and amplitude were independent of SOA, indicating that visual attention was concurrently deployed to response selection. Moreover, the RT2 analysis revealed an underadditive interaction of SOA and set size. We concluded that visual attention does not require the same bottleneck mechanism as response selection in dual-tasks.

  19. Objects and events as determinants of parallel processing in dual tasks: evidence from the backward compatibility effect.

    PubMed

    Ellenbogen, Ravid; Meiran, Nachshon

    2011-02-01

    The backward-compatibility effect (BCE) is a major index of parallel processing in dual tasks and is related to the dependency of Task 1 performance on Task 2 response codes (Hommel, 1998). The results of four dual-task experiments showed that a BCE occurs when the stimuli of both tasks are included in the same visual object (Experiments 1 and 2) or belong to the same perceptual event (Experiments 3 and 4). Thus, the BCE may be modulated by factors that influence whether both task stimuli are included in the same perceptual event (objects, as studied in cognitive experiments, being special cases of events). As with objects, drawing attention to a (selected) event results in the processing of its irrelevant features and may interfere with task execution. (c) 2010 APA, all rights reserved.

  20. Semantic interference in picture naming during dual-task performance does not vary with reading ability.

    PubMed

    Piai, Vitória; Roelofs, Ardi; Roete, Ingeborg

    2015-01-01

    Previous dual-task studies examining the locus of semantic interference of distractor words in picture naming have obtained diverging results. In these studies, participants manually responded to tones and named pictures while ignoring distractor words (picture-word interference, PWI) with varying stimulus onset asynchrony (SOA) between tone and PWI stimulus. Whereas some studies observed no semantic interference at short SOAs, other studies observed effects of similar magnitude at short and long SOAs. The absence of semantic interference in some studies may perhaps be due to better reading skill of participants in these than in the other studies. According to such a reading-ability account, participants' reading skill should be predictive of the magnitude of their interference effect at short SOAs. To test this account, we conducted a dual-task study with tone discrimination and PWI tasks and measured participants' reading ability. The semantic interference effect was of similar magnitude at both short and long SOAs. Participants' reading ability was predictive of their naming speed but not of their semantic interference effect, contrary to the reading ability account. We conclude that the magnitude of semantic interference in picture naming during dual-task performance does not depend on reading skill.

  1. Gait, dual task and history of falls in elderly with preserved cognition, mild cognitive impairment, and mild Alzheimer's disease.

    PubMed

    Ansai, Juliana H; Andrade, Larissa P; Rossi, Paulo G; Takahashi, Anielle C M; Vale, Francisco A C; Rebelatto, José R

    Studies with functional and applicable methods and new cognitive demands involving executive function are needed to improve screening, prevention and rehabilitation of cognitive impairment and falls. to identify differences in gait, dual task performances, and history of falls between elderly people with preserved cognition, mild cognitive impairment and mild Alzheimer's disease. A cross-sectional study was conducted. The sample consisted of 40 community-dwelling older adults with preserved cognition, 40 older adults with mild cognitive impairment, and 38 older adults with mild Alzheimer's disease. The assessment consisted of anamneses, gait (measured by the 10-meter walk test), dual task (measured by the Timed Up and Go Test associated with the motor-cognitive task of calling a phone number), and history of falls in the past year. There were no differences among all groups for all variables. However, the Alzheimer's disease Group performed significantly worse in the dual task than the other groups. No item of dual task could distinguish people with preserved cognition from those with mild cognitive impairment. The groups with cognitive impairment included more fallers, and specific characteristics in history of falls between groups were identified. Dual task could distinguish Alzheimer's disease patients specifically from other cognitive profiles. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  2. Lexical Access and Dual-Task Performance: Determining the Locus of the Bottleneck

    NASA Technical Reports Server (NTRS)

    Allen, Phil

    2004-01-01

    During the two years of funding for NASA Grant "NCC21325, Lexical access and dual-task performance: Determining the locus of the bottleneck," we completed three experiments involving the psychological refractory period (PRP) and word frequency.

  3. Single- and Dual-Task Balance Training Are Equally Effective in Youth

    PubMed Central

    Lüder, Benjamin; Kiss, Rainer; Granacher, Urs

    2018-01-01

    Due to maturation of the postural control system and secular declines in motor performance, adolescents experience deficits in postural control during standing and walking while concurrently performing cognitive interference tasks. Thus, adequately designed balance training programs may help to counteract these deficits. While the general effectiveness of youth balance training is well-documented, there is hardly any information available on the specific effects of single-task (ST) versus dual-task (DT) balance training. Therefore, the objectives of this study were (i) to examine static/dynamic balance performance under ST and DT conditions in adolescents and (ii) to study the effects of ST versus DT balance training on static/dynamic balance under ST and DT conditions in adolescents. Twenty-eight healthy girls and boys aged 12–13 years were randomly assigned to either 8 weeks of ST or DT balance training. Before and after training, postural sway and spatio-temporal gait parameters were registered under ST (standing/walking only) and DT conditions (standing/walking while concurrently performing an arithmetic task). At baseline, significantly slower gait speed (p < 0.001, d = 5.1), shorter stride length (p < 0.001, d = 4.8), and longer stride time (p < 0.001, d = 3.8) were found for DT compared to ST walking but not standing. Training resulted in significant pre–post decreases in DT costs for gait velocity (p < 0.001, d = 3.1), stride length (-45%, p < 0.001, d = 2.4), and stride time (-44%, p < 0.01, d = 1.9). Training did not induce any significant changes (p > 0.05, d = 0–0.1) in DT costs for all parameters of secondary task performance during standing and walking. Training produced significant pre–post increases (p = 0.001; d = 1.47) in secondary task performance while sitting. The observed increase was significantly greater for the ST training group (p = 0.04; d = 0.81). For standing, no significant changes were found over time irrespective of the

  4. Cognitive-motor dual-task ability of athletes with and without intellectual impairment.

    PubMed

    Van Biesen, Debbie; Jacobs, Lore; McCulloch, Katina; Janssens, Luc; Vanlandewijck, Yves C

    2018-03-01

    Cognition is important in many sports, for example, making split-second-decisions under pressure, or memorising complex movement sequences. The dual-task (DT) paradigm is an ecologically valid approach for the assessment of cognitive function in conjunction with motor demands. This study aimed to determine the impact of impaired intelligence on DT performance. The motor task required balancing on one leg on a beam, and the cognitive task was a multiple-object-tracking (MOT) task assessing dynamic visual-search capacity. The sample included 206 well-trained athletes with and without intellectual impairment (II), matched for sport, age and training volume (140 males, 66 females, M age = 23.2 ± 4.1 years, M training experience = 12.3 ± 5.7 years). In the single-task condition, II-athletes showed reduced balance control (F = 55.9, P < .001, η 2  = .23) and reduced MOT (F = 86.3, P < .001, η 2  = .32) compared to the control group. A mixed-model ANCOVA revealed significant differences in DT performance for the balance and the MOT task between both groups. The DT costs were significantly larger for the II-athletes (-8.28% versus -1.34% for MOT and -33.13% versus -12.89% for balance). The assessment of MOT in a DT paradigm provided insight in how impaired intelligence constrains the ability of II-athletes to successfully perform at the highest levels in the complex and dynamical sport-environment.

  5. Attentional demands of movement observation as tested by a dual task approach.

    PubMed

    Saucedo Marquez, Cinthia M; Ceux, Tanja; Wenderoth, Nicole

    2011-01-01

    Movement observation (MO) has been shown to activate the motor cortex of the observer as indicated by an increase of corticomotor excitability for muscles involved in the observed actions. Moreover, behavioral work has strongly suggested that this process occurs in a near-automatic manner. Here we further tested this proposal by applying transcranial magnetic stimulation (TMS) when subjects observed how an actor lifted objects of different weights as a single or a dual task. The secondary task was either an auditory discrimination task (experiment 1) or a visual discrimination task (experiment 2). In experiment 1, we found that corticomotor excitability reflected the force requirements indicated in the observed movies (i.e. higher responses when the actor had to apply higher forces). Interestingly, this effect was found irrespective of whether MO was performed as a single or a dual task. By contrast, no such systematic modulations of corticomotor excitability were observed in experiment 2 when visual distracters were present. We conclude that interference effects might arise when MO is performed while competing visual stimuli are present. However, when a secondary task is situated in a different modality, neural responses are in line with the notion that the observers motor system responds in a near-automatic manner. This suggests that MO is a task with very low cognitive demands which might be a valuable supplement for rehabilitation training, particularly, in the acute phase after the incident or in patients suffering from attention deficits. However, it is important to keep in mind that visual distracters might interfere with the neural response in M1.

  6. A training program to improve gait while dual tasking in patients with Parkinson's disease: a pilot study.

    PubMed

    Yogev-Seligmann, Galit; Giladi, Nir; Brozgol, Marina; Hausdorff, Jeffrey M

    2012-01-01

    Impairments in the ability to perform another task while walking (ie, dual tasking [DT]) are associated with an increased risk of falling. Here we describe a program we developed specifically to improve DT performance while walking based on motor learning principles and task-specific training. We examined feasibility, potential efficacy, retention, and transfer to the performance of untrained tasks in a pilot study among 7 patients with Parkinson's disease (PD). Seven patients (Hoehn and Yahr stage, 2.1±0.2) were evaluated before, after, and 1 month after 4 weeks of DT training. Gait speed and gait variability were measured during usual walking and during 4 DT conditions. The 4-week program of one-on-one training included walking while performing several distinct cognitive tasks. Gait speed and gait variability during DT significantly improved. Improvements were also seen in the DT conditions that were not specifically trained and were retained 1 month after training. These initial findings support the feasibility of applying a task-specific DT gait training program for patients with PD and suggest that it positively affects DT gait, even in untrained tasks. The present results are also consistent with the possibility that DT gait training enhances divided attention abilities during walking. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  7. The Effect of a Six-Month Dancing Program on Motor-Cognitive Dual-Task Performance in Older Adults.

    PubMed

    Hamacher, Dennis; Hamacher, Daniel; Rehfeld, Kathrin; Hökelmann, Anita; Schega, Lutz

    2015-10-01

    Dancing is a complex sensorimotor activity involving physical and mental elements which have positive effects on cognitive functions and motor control. The present randomized controlled trial aims to analyze the effects of a dancing program on the performance on a motor-cognitive dual task. Data of 35 older adults, who were assigned to a dancing group or a health-related exercise group, are presented in the study. In pretest and posttest, we assessed cognitive performance and variability of minimum foot clearance, stride time, and stride length while walking. Regarding the cognitive performance and the stride-to-stride variability of minimum foot clearance, interaction effects have been found, indicating that dancing lowers gait variability to a higher extent than conventional health-related exercise. The data show that dancing improves minimum foot clearance variability and cognitive performance in a dual-task situation. Multi-task exercises (like dancing) might be a powerful tool to improve motor-cognitive dual-task performance.

  8. Assessing language and visuospatial functions with one task: a "dual use" approach to performing fMRI in children.

    PubMed

    Ebner, Kathina; Lidzba, Karen; Hauser, Till-Karsten; Wilke, Marko

    2011-10-01

    In order to increase the rate of successful functional MR studies in children it is helpful to shorten the time spent in the scanner. To this effect, assessing two cognitive functions with one task seems to be a promising approach. The hypothesis of this study was that the control condition of an established language task (vowel identification task, VIT) requires visuospatial processing and that the control condition (VIT(CC)) therefore may also be applicable to localize visuospatial functions. As a reference task, a visual search task (VST, previously established for use in children) was employed. To test this hypothesis, 43 children (19 f, 24 m; 12.0±2.6, range 7.9 to 17.8 years) were recruited and scanned using both tasks. Second-level random effects group analyses showed activation of left inferior-frontal cortex in the active condition of the VIT, as in previous studies. Additionally, analysis of the VIT(CC) demonstrated activation in right-dominant superior parietal and high-frontal brain regions, classically associated with visuospatial functions; activation seen in the VST was similar with a substantial overlap. However, lateralization in the parietal lobe was significantly more bilateral in the VST than in the VIT(CC). This suggests that the VIT can not only be applied to assess language functions (using the active>control contrast), but also that the control>active condition is useful for assessing visuospatial functions. Future task design may benefit from such a "dual use" approach to performing fMRI not only, but also particularly in children. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Gait Adaptability Training Improves Both Postural Stability and Dual-Tasking Ability

    NASA Technical Reports Server (NTRS)

    Brady, Rachel A.; Batson, Crystal D.; Peters, Brian T.; Ploutz-Snyder, Robert J.; Mulavara, Ajitkumar P.; Bloomberg, Jacob J.

    2010-01-01

    After spaceflight, the process of readapting to Earth's gravity commonly presents crewmembers with a variety of locomotor challenges. Our recent work has shown that the ability to adapt to a novel discordant sensorimotor environment can be increased through preflight training, so one focus of our laboratory has been the development of a gait training countermeasure to expedite the return of normal locomotor function after spaceflight. We used a training system comprising a treadmill mounted on a motion base facing a virtual visual scene that provided a variety of sensory challenges. As part of their participation in a larger retention study, 10 healthy adults completed 3 training sessions during which they walked on a treadmill at 1.1 m/s while receiving discordant support-surface and visual manipulations. After a single training session, subjects stride frequencies improved, and after 2 training sessions their auditory reaction times improved, where improvement was indicated by a return toward baseline values. Interestingly, improvements in reaction time came after stride frequency improvements plateaued. This finding suggests that postural stability was given a higher priority than a competing cognitive task. Further, it demonstrates that improvement in both postural stability and dual-tasking can be achieved with multiple training exposures. We conclude that, with training, individuals become more proficient at walking in discordant sensorimotor conditions and are able to devote more attention to competing tasks.

  10. Over-focused? The relation between patients' inclination for conscious control and single- and dual-task motor performance after stroke.

    PubMed

    Denneman, R P M; Kal, E C; Houdijk, H; Kamp, J van der

    2018-05-01

    Many stroke patients are inclined to consciously control their movements. This is thought to negatively affect patients' motor performance, as it disrupts movement automaticity. However, it has also been argued that conscious control may sometimes benefit motor performance, depending on the task or patientś motor or cognitive capacity. To assess whether stroke patients' inclination for conscious control is associated with motor performance, and explore whether the putative association differs as a function of task (single- vs dual) or patientś motor and cognitive capacity. Univariate and multivariate linear regression analysis were used to assess associations between patients' disposition to conscious control (i.e., Conscious Motor Processing subscale of Movement-Specific Reinvestment Scale; MSRS-CMP) and single-task (Timed-up-and-go test; TuG) and motor dual-task costs (TuG while tone counting; motor DTC%). We determined whether these associations were influenced by patients' walking speed (i.e., 10-m-walk test) and cognitive capacity (i.e., working memory, attention, executive function). Seventy-eight clinical stroke patients (<6 months post-stroke) participated. Patients' conscious control inclination was not associated with single-task TuG performance. However, patients with a strong inclination for conscious control showed higher motor DTC%. These associations were irrespective of patients' motor and cognitive abilities. Patients' disposition for conscious control was not associated with single task motor performance, but was associated with higher motor dual task costs, regardless of patients' motor or cognitive abilities. Therapists should be aware that patients' conscious control inclination can influence their dual-task performance while moving. Longitudinal studies are required to test whether reducing patients' disposition for conscious control would improve dual-tasking post-stroke. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. High-Frequency Binaural Beats Increase Cognitive Flexibility: Evidence from Dual-Task Crosstalk

    PubMed Central

    Hommel, Bernhard; Sellaro, Roberta; Fischer, Rico; Borg, Saskia; Colzato, Lorenza S.

    2016-01-01

    Increasing evidence suggests that cognitive-control processes can be configured to optimize either persistence of information processing (by amplifying competition between decision-making alternatives and top-down biasing of this competition) or flexibility (by dampening competition and biasing). We investigated whether high-frequency binaural beats, an auditory illusion suspected to act as a cognitive enhancer, have an impact on cognitive-control configuration. We hypothesized that binaural beats in the gamma range bias the cognitive-control style toward flexibility, which in turn should increase the crosstalk between tasks in a dual-task paradigm. We replicated earlier findings that the reaction time in the first-performed task is sensitive to the compatibility between the responses in the first and the second task—an indication of crosstalk. As predicted, exposing participants to binaural beats in the gamma range increased this effect as compared to a control condition in which participants were exposed to a continuous tone of 340 Hz. These findings provide converging evidence that the cognitive-control style can be systematically biased by inducing particular internal states; that high-frequency binaural beats bias the control style toward more flexibility; and that different styles are implemented by changing the strength of local competition and top-down bias. PMID:27605922

  12. Does dual task training improve walking performance of older adults with concern of falling?

    PubMed

    Wollesen, B; Schulz, S; Seydell, L; Delbaere, K

    2017-09-11

    Older adults with concerns of falling show decrements of gait stability under single (ST) and dual task (DT) conditions. To compare the effects of a DT training integrating task managing strategies for independent living older adults with and without concern about falling (CoF) to a non-training control group on walking performance under ST and DT conditions. Single center parallel group single blind randomized controlled trial with group-based interventions (DT-managing balance training) compared to a control group (Ninety-five independent living older adults; 71.5 ± 5.2 years). A progressive DT training (12 sessions; 60 min each; 12 weeks) including task-managing strategies was compared to a non-training control group. group based intervention for independent living elderly in a gym. ST and DT walking (visual verbal Stroop task) were measured on a treadmill. Gait parameters (step length, step width, and gait line) and cognitive performance while walking were compared with a 2x2x2 Repeated Measures Analyses of Variance. Participants in the intervention group showed an increased step length under ST and DT conditions following the intervention, for both people with and without CoF compared to their respective control groups. Foot rolling movement and cognitive performance while walking however only improved in participants without CoF. The results showed that DT managing training can improve walking performance under ST and DT conditions in people with and without CoF. Additional treatment to directly address CoF, such as cognitive behavioural therapy, should be considered to further improve the cautious gait pattern (as evidenced by reduced foot rolling movements). The study was retrospectively registered in the German Clinical Trials Register (DRKS; Identification number DRKS00012382 , 11.05.2017).

  13. Dual-Task Performance: Influence of Frailty, Level of Physical Activity, and Cognition.

    PubMed

    Giusti Rossi, Paulo; Pires de Andrade, Larissa; Hotta Ansai, Juliana; Silva Farche, Ana Claudia; Carnaz, Leticia; Dalpubel, Daniela; Ferriolli, Eduardo; Assis Carvalho Vale, Francisco; de Medeiros Takahashi, Anielle Cristhine

    2018-03-08

    Cognition and level of physical activity have been associated with frailty syndrome. The development of tools that assess deficits related to physical and cognitive frailties simultaneously are of common interest. However, little is known about how much these aspects influence the performance of dual-task tests. Our aims were (a) to verify the influence of frailty syndrome and objectively measured physical activity and cognition on the Timed Up and Go (TUG) test and Timed Up and Go associated with dual-task (TUG-DT) performances; and (b) to compare TUG and TUG-DT performances between older adults who develop frailty syndrome. Sixty-four community-dwelling older adults were divided into frail, prefrail, and nonfrail groups, according to frailty phenotype. Assessments included anamnesis, screening of frailty syndrome, cognitive assessment (Addenbrooke's cognitive examination), placement of a triaxial accelerometer to assess level of physical activity, and TUG and TUG-DT (TUG associated with a motor-cognitive task of calling a phone number) performances. After 7 days, the accelerometer was removed. A multiple linear regression was applied to identify which independent variables could explain performances in the TUG and TUG-DT. Subsequently, the analysis of covariance test, adjusted for age, cognition, and level of physical activity covariates, was used to compare test performances. There were no differences in cognition between groups. Significant differences in the level of physical activity were found in the frail group. Compared with the frail group, the nonfrail group required less time and fewer steps to complete the TUG. Regarding the TUG-DT, cognition and age influenced the time spent and number of steps, respectively; however, no differences were found between groups. Frail older adults presented worse performance in the TUG when compared with nonfrail older adults. The dual-task test does not differentiate older adults with frailty syndrome, regardless of

  14. Effects of fear of falling and activity restriction on normal and dual task walking in community dwelling older adults.

    PubMed

    Donoghue, Orna A; Cronin, Hilary; Savva, George M; O'Regan, Claire; Kenny, Rose Anne

    2013-05-01

    Fear of falling (FOF) is associated with poor physical and psychosocial health and can have debilitating consequences especially when it leads to activity restriction. This study examined whether normal and dual task gait disruptions were independently associated with FOF and activity restriction or if they were fully explained by impaired health status. Data was obtained from The Irish Longitudinal Study on Ageing (TILDA). Community dwelling adults ≥65 years, with a Mini-Mental State Examination score ≥18 and who completed a gait assessment (n=1307) were divided into three groups: no FOF, FOF but no activity restriction (FOF-NAR), FOF with activity restriction (FOF-AR). Physical, psychosocial and cognitive measures were obtained and gait characteristics were assessed using a GAITRite(®) mat during normal and dual task (cognitive) walking. After adjusting for sociodemographics, physical, mental and cognitive health, FOF was associated with reduced gait speed and stride length and increased double support phase and step width in normal and dual task conditions; these changes were most pronounced in those who restrict activities as a result of FOF. These gait changes may be associated with an increased fall risk, however some changes especially increased step width may also reflect positive, compensatory adaptations to FOF. The results also highlight the importance of treating underlying health impairments and preventing the transition from FOF to activity restriction. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Measuring prefrontal cortical activity during dual task walking in patients with Parkinson's disease: feasibility of using a new portable fNIRS device.

    PubMed

    Nieuwhof, Freek; Reelick, Miriam F; Maidan, Inbal; Mirelman, Anat; Hausdorff, Jeffrey M; Olde Rikkert, Marcel G M; Bloem, Bastiaan R; Muthalib, Makii; Claassen, Jurgen A H R

    2016-01-01

    Many patients with Parkinson's disease (PD) have difficulties in performing a second task during walking (i.e., dual task walking). Functional near-infrared spectroscopy (fNIRS) is a promising approach to study the presumed contribution of dysfunction within the prefrontal cortex (PFC) to such difficulties. In this pilot study, we examined the feasibility of using a new portable and wireless fNIRS device to measure PFC activity during different dual task walking protocols in PD. Specifically, we tested whether PD patients were able to perform the protocol and whether we were able to measure the typical fNIRS signal of neuronal activity. We included 14 PD patients (age 71.2 ± 5.4 years, Hoehn and Yahr stage II/III). The protocol consisted of five repetitions of three conditions: walking while (i) counting forwards, (ii) serially subtracting, and (iii) reciting digit spans. Ability to complete this protocol, perceived exertion, burden of the fNIRS devices, and concentrations of oxygenated (O 2 Hb) and deoxygenated (HHb) hemoglobin from the left and right PFC were measured. Two participants were unable to complete the protocol due to fatigue and mobility safety concerns. The remaining 12 participants experienced no burden from the two fNIRS devices and completed the protocol with ease. Bilateral PFC O 2 Hb concentrations increased during walking while serially subtracting (left PFC 0.46 μmol/L, 95 % confidence interval (CI) 0.12-0.81, right PFC 0.49 μmol/L, 95 % CI 0.14-0.84) and reciting digit spans (left PFC 0.36 μmol/L, 95 % CI 0.03-0.70, right PFC 0.44 μmol/L, 95 % CI 0.09-0.78) when compared to rest. HHb concentrations did not differ between the walking tasks and rest. These findings suggest that a new wireless fNIRS device is a feasible measure of PFC activity in PD during dual task walking. Future studies should reduce the level of noise and inter-individual variability to enable measuring differences in PFC activity between different dual

  16. The Association between High Neuroticism-Low Extraversion and Dual-Task Performance during Walking While Talking in Non-demented Older Adults

    PubMed Central

    LeMonda, Brittany C.; Mahoney, Jeannette R.; Verghese, Joe; Holtzer, Roee

    2016-01-01

    The Walking While Talking (WWT) dual-task paradigm is a mobility stress test that predicts major outcomes, including falls, frailty, disability, and mortality in aging. Certain personality traits, such as neuroticism, extraversion, and their combination, have been linked to both cognitive and motor outcomes. We examined whether individual differences in personality dimensions of neuroticism and extraversion predicted dual-task performance decrements (both motor and cognitive) on a WWT task in non-demented older adults. We hypothesized that the combined effect of high neuroticism-low extraversion would be related to greater dual-task costs in gait velocity and cognitive performance in non-demented older adults. Participants (N = 295; age range, = 65–95 years; female = 164) completed the Big Five Inventory and WWT task involving concurrent gait and a serial 7's subtraction task. Gait velocity was obtained using an instrumented walkway. The high neuroticism-low extraversion group incurred greater dual-task costs (i.e., worse performance) in both gait velocity {95% confidence interval (CI) [−17.68 to −3.07]} and cognitive performance (95% CI [−19.34 to −2.44]) compared to the low neuroticism-high extraversion group, suggesting that high neuroticism-low extraversion interferes with the allocation of attentional resources to competing task demands during the WWT task. Older individuals with high neuroticism-low extraversion may be at higher risk for falls, mobility decline and other adverse outcomes in aging. PMID:26527241

  17. Age-Related Changes in Brain Activation Underlying Single- and Dual-Task Performance: Visuomanual Drawing and Mental Arithmetic

    ERIC Educational Resources Information Center

    Van Impe, A.; Coxon, J. P.; Goble, D. J.; Wenderoth, N.; Swinnen, S. P.

    2011-01-01

    Depending on task combination, dual-tasking can either be performed successfully or can lead to performance decrements in one or both tasks. Interference is believed to be caused by limitations in central processing, i.e. structural interference between the neural activation patterns associated with each task. In the present study, single- and…

  18. Dual-task as a predictor of falls in older people with mild cognitive impairment and mild Alzheimer's disease: a prospective cohort study.

    PubMed

    Gonçalves, Jessica; Ansai, Juliana Hotta; Masse, Fernando Arturo Arriagada; Vale, Francisco Assis Carvalho; Takahashi, Anielle Cristhine de Medeiros; Andrade, Larissa Pires de

    2018-04-04

    A dual-task tool with a challenging and daily secondary task, which involves executive functions, could facilitate the screening for risk of falls in older people with mild cognitive impairment or mild Alzheimer's disease. To verify if a motor-cognitive dual-task test could predict falls in older people with mild cognitive impairment or mild Alzheimer's disease, and to establish cutoff scores for the tool for both groups. A prospective study was conducted with community-dwelling older adults, including 40 with mild cognitive impairment and 38 with mild Alzheimer's disease. The dual-task test consisted of the Timed up and Go Test associated with a motor-cognitive task using a phone to call. Falls were recorded during six months by calendar and monthly telephone calls and the participants were categorized as fallers or non-fallers. In the Mild cognitive impairment Group, fallers presented higher values in time (35.2s), number of steps (33.7 steps) and motor task cost (116%) on dual-task compared to non-fallers. Time, number of steps and motor task cost were significantly associated with falls in people with mild cognitive impairment. Multivariate analysis identified higher number of steps spent on the test to be independently associated with falls. A time greater than 23.88s (sensitivity=80%; specificity=61%) and a number of steps over 29.50 (sensitivity=65%; specificity=83%) indicated prediction of risk of falls in the Mild cognitive impairment Group. Among people with Alzheimer's disease, no differences in dual-task between fallers and non-fallers were found and no variable of the tool was able to predict falls. The dual-task predicts falls only in older people with mild cognitive impairment. Copyright © 2018 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  19. Using Dual-Task Methodology to Dissociate Automatic from Nonautomatic Processes Involved in Artificial Grammar Learning

    ERIC Educational Resources Information Center

    Hendricks, Michelle A.; Conway, Christopher M.; Kellogg, Ronald T.

    2013-01-01

    Previous studies have suggested that both automatic and intentional processes contribute to the learning of grammar and fragment knowledge in artificial grammar learning (AGL) tasks. To explore the relative contribution of automatic and intentional processes to knowledge gained in AGL, we utilized dual-task methodology to dissociate automatic and…

  20. Brain activation during dual-task processing is associated with cardiorespiratory fitness and performance in older adults

    PubMed Central

    Wong, Chelsea N.; Chaddock-Heyman, Laura; Voss, Michelle W.; Burzynska, Agnieszka Z.; Basak, Chandramallika; Erickson, Kirk I.; Prakash, Ruchika S.; Szabo-Reed, Amanda N.; Phillips, Siobhan M.; Wojcicki, Thomas; Mailey, Emily L.; McAuley, Edward; Kramer, Arthur F.

    2015-01-01

    Higher cardiorespiratory fitness is associated with better cognitive performance and enhanced brain activation. Yet, the extent to which cardiorespiratory fitness-related brain activation is associated with better cognitive performance is not well understood. In this cross-sectional study, we examined whether the association between cardiorespiratory fitness and executive function was mediated by greater prefrontal cortex activation in healthy older adults. Brain activation was measured during dual-task performance with functional magnetic resonance imaging in a sample of 128 healthy older adults (59–80 years). Higher cardiorespiratory fitness was associated with greater activation during dual-task processing in several brain areas including the anterior cingulate and supplementary motor cortex (ACC/SMA), thalamus and basal ganglia, right motor/somatosensory cortex and middle frontal gyrus, and left somatosensory cortex, controlling for age, sex, education, and gray matter volume. Of these regions, greater ACC/SMA activation mediated the association between cardiorespiratory fitness and dual-task performance. We provide novel evidence that cardiorespiratory fitness may support cognitive performance by facilitating brain activation in a core region critical for executive function. PMID:26321949

  1. Vanishing dual-task interference after practice: has the bottleneck been eliminated or is it merely latent?

    NASA Technical Reports Server (NTRS)

    Ruthruff, Eric; Johnston, James C.; Van Selst, Mark; Whitsell, Shelly; Remington, Roger

    2003-01-01

    Practice can, in some cases, largely eliminate measured dual-task interference. Does this absence of interference indicate the absence of a processing bottleneck (defined as an inability to carry out certain stages in parallel)? The authors show that a bottleneck need not produce any observable interference, provided that there is no temporal overlap in the demand for bottleneck stages on the 2 tasks. Such a "latent" bottleneck is especially likely after practice, when central stages are short. The authors provide new evidence that a latent bottleneck occurred for a participant who produced no interference in M. Van Selst, E. Ruthruff, and J. C. Johnston (1999). These findings demonstrate that the absence of dual-task interference does not necessarily indicate the absence of a processing bottleneck.

  2. Associations between cognitive and gait performance during single- and dual-task walking in people with Parkinson disease.

    PubMed

    Stegemöller, Elizabeth L; Wilson, Jonathan P; Hazamy, Audrey; Shelley, Mack C; Okun, Michael S; Altmann, Lori J P; Hass, Chris J

    2014-06-01

    Cognitive impairments in Parkinson disease (PD) manifest as deficits in speed of processing, working memory, and executive function and attention abilities. The gait impairment in PD is well documented to include reduced speed, shortened step lengths, and increased step-to-step variability. However, there is a paucity of research examining the relationship between overground walking and cognitive performance in people with PD. This study sought to examine the relationship between both the mean and variability of gait spatiotemporal parameters and cognitive performance across a broad range of cognitive domains. A cross-sectional design was used. Thirty-five participants with no dementia and diagnosed with idiopathic PD completed a battery of 12 cognitive tests that yielded 3 orthogonal factors: processing speed, working memory, and executive function and attention. Participants completed 10 trials of overground walking (single-task walking) and 5 trials of overground walking while counting backward by 3's (dual-task walking). All gait measures were impaired by the dual task. Cognitive processing speed correlated with stride length and walking speed. Executive function correlated with step width variability. There were no significant associations with working memory. Regression models relating speed of processing to gait spatiotemporal variables revealed that including dual-task costs in the model significantly improved the fit of the model. Participants with PD were tested only in the on-medication state. Different characteristics of gait are related to distinct types of cognitive processing, which may be differentially affected by dual-task walking due to the pathology of PD. © 2014 American Physical Therapy Association.

  3. Locus of Semantic Interference in Picture Naming: Evidence from Dual-Task Performance

    ERIC Educational Resources Information Center

    Piai, Vitória; Roelofs, Ardi; Schriefers, Herbert

    2014-01-01

    Disagreement exists regarding the functional locus of semantic interference of distractor words in picture naming. This effect is a cornerstone of modern psycholinguistic models of word production, which assume that it arises in lexical response-selection. However, recent evidence from studies of dual-task performance suggests a locus in…

  4. Parkinsonian gait improves with bilateral subthalamic nucleus deep brain stimulation during cognitive multi-tasking.

    PubMed

    Chenji, Gaurav; Wright, Melissa L; Chou, Kelvin L; Seidler, Rachael D; Patil, Parag G

    2017-05-01

    Gait impairment in Parkinson's disease reduces mobility and increases fall risk, particularly during cognitive multi-tasking. Studies suggest that bilateral subthalamic deep brain stimulation, a common surgical therapy, degrades motor performance under cognitive dual-task conditions, compared to unilateral stimulation. To measure the impact of bilateral versus unilateral subthalamic deep brain stimulation on walking kinematics with and without cognitive dual-tasking. Gait kinematics of seventeen patients with advanced Parkinson's disease who had undergone bilateral subthalamic deep brain stimulation were examined off medication under three stimulation states (bilateral, unilateral left, unilateral right) with and without a cognitive challenge, using an instrumented walkway system. Consistent with earlier studies, gait performance declined for all six measured parameters under cognitive dual-task conditions, independent of stimulation state. However, bilateral stimulation produced greater improvements in step length and double-limb support time than unilateral stimulation, and achieved similar performance for other gait parameters. Contrary to expectations from earlier studies of dual-task motor performance, bilateral subthalamic deep brain stimulation may assist in maintaining temporal and spatial gait performance under cognitive dual-task conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Ecological Relevance Determines Task Priority in Older Adults' Multitasking.

    PubMed

    Doumas, Michail; Krampe, Ralf Th

    2015-05-01

    Multitasking is a challenging aspect of human behavior, especially if the concurrently performed tasks are different in nature. Several studies demonstrated pronounced performance decrements (dual-task costs) in older adults for combinations of cognitive and motor tasks. However, patterns of costs among component tasks differed across studies and reasons for participants' resource allocation strategies remained elusive. We investigated young and older adults' multitasking of a working memory task and two sensorimotor tasks, one with low (finger force control) and one with high ecological relevance (postural control). The tasks were performed in single-, dual-, and triple-task contexts. Working memory accuracy was reduced in dual-task contexts with either sensorimotor task and deteriorated further under triple-task conditions. Postural and force performance deteriorated with age and task difficulty in dual-task contexts. However, in the triple-task context with its maximum resource demands, older adults prioritized postural control over both force control and memory. Our results identify ecological relevance as the key factor in older adults' multitasking. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Reduced dual-task gait speed is associated with visual Go/No-Go brain network activation in children and adolescents with concussion.

    PubMed

    Howell, David R; Meehan, William P; Barber Foss, Kim D; Reches, Amit; Weiss, Michal; Myer, Gregory D

    2018-05-31

    To investigate the association between dual-task gait performance and brain network activation (BNA) using an electroencephalography (EEG)-based Go/No-Go paradigm among children and adolescents with concussion. Participants with a concussion completed a visual Go/No-Go task with collection of electroencephalogram brain activity. Data were treated with BNA analysis, which involves an algorithmic approach to EEG-ERP activation quantification. Participants also completed a dual-task gait assessment. The relationship between dual-task gait speed and BNA was assessed using multiple linear regression models. Participants (n = 20, 13.9 ± 2.3 years of age, 50% female) were tested at a mean of 7.0 ± 2.5 days post-concussion and were symptomatic at the time of testing (post-concussion symptom scale = 40.4 ± 21.9). Slower dual-task average gait speed (mean = 82.2 ± 21.0 cm/s) was significantly associated with lower relative time BNA scores (mean = 39.6 ± 25.8) during the No-Go task (β = 0.599, 95% CI = 0.214, 0.985, p = 0.005, R 2  = 0.405), while controlling for the effect of age and gender. Among children and adolescents with a concussion, slower dual-task gait speed was independently associated with lower BNA relative time scores during a visual Go/No-Go task. The relationship between abnormal gait behaviour and brain activation deficits may be reflective of disruption to multiple functional abilities after concussion.

  7. Effects of Physical-Cognitive Dual Task Training on Executive Function and Gait Performance in Older Adults: A Randomized Controlled Trial

    PubMed Central

    Falbo, S.; Condello, G.; Capranica, L.; Forte, R.

    2016-01-01

    Physical and cognitive training seem to counteract age-related decline in physical and mental function. Recently, the possibility of integrating cognitive demands into physical training has attracted attention. The purpose of this study was to evaluate the effects of twelve weeks of designed physical-cognitive training on executive cognitive function and gait performance in older adults. Thirty-six healthy, active individuals aged 72.30 ± 5.84 years were assigned to two types of physical training with major focus on physical single task (ST) training (n = 16) and physical-cognitive dual task (DT) training (n = 20), respectively. They were tested before and after the intervention for executive function (inhibition, working memory) through Random Number Generation and for gait (walking with/without negotiating hurdles) under both single and dual task (ST, DT) conditions. Gait performance improved in both groups, while inhibitory performance decreased after exercise training with ST focus but tended to increase after training with physical-cognitive DT focus. Changes in inhibition performance were correlated with changes in DT walking performance with group differences as a function of motor task complexity (with/without hurdling). The study supports the effectiveness of group exercise classes for older individuals to improve gait performance, with physical-cognitive DT training selectively counteracting the age-related decline in a core executive function essential for daily living. PMID:28053985

  8. Effects of Physical-Cognitive Dual Task Training on Executive Function and Gait Performance in Older Adults: A Randomized Controlled Trial.

    PubMed

    Falbo, S; Condello, G; Capranica, L; Forte, R; Pesce, C

    2016-01-01

    Physical and cognitive training seem to counteract age-related decline in physical and mental function. Recently, the possibility of integrating cognitive demands into physical training has attracted attention. The purpose of this study was to evaluate the effects of twelve weeks of designed physical-cognitive training on executive cognitive function and gait performance in older adults. Thirty-six healthy, active individuals aged 72.30 ± 5.84 years were assigned to two types of physical training with major focus on physical single task (ST) training ( n = 16) and physical-cognitive dual task (DT) training ( n = 20), respectively. They were tested before and after the intervention for executive function (inhibition, working memory) through Random Number Generation and for gait (walking with/without negotiating hurdles) under both single and dual task (ST, DT) conditions. Gait performance improved in both groups, while inhibitory performance decreased after exercise training with ST focus but tended to increase after training with physical-cognitive DT focus. Changes in inhibition performance were correlated with changes in DT walking performance with group differences as a function of motor task complexity (with/without hurdling). The study supports the effectiveness of group exercise classes for older individuals to improve gait performance, with physical-cognitive DT training selectively counteracting the age-related decline in a core executive function essential for daily living.

  9. Serial or overlapping processing in multitasking as individual preference: Effects of stimulus preview on task switching and concurrent dual-task performance.

    PubMed

    Reissland, Jessika; Manzey, Dietrich

    2016-07-01

    Understanding the mechanisms and performance consequences of multitasking has long been in focus of scientific interest, but has been investigated by three research lines more or less isolated from each other. Studies in the fields of the psychological refractory period, task switching, and interruptions have scored with a high experimental control, but usually do not give participants many degrees of freedom to self-organize the processing of two concurrent tasks. Individual strategies as well as their impact on efficiency have mainly been neglected. Self-organized multitasking has been investigated in the field of human factors, but primarily with respect to overall performance without detailed investigation of how the tasks are processed. The current work attempts to link aspects of these research lines. All of them, explicitly or implicitly, provide hints about an individually preferred type of task organization, either more cautious trying to work strictly serially on only one task at a time or more daring with a focus on task interleaving and, if possible, also partially overlapping (parallel) processing. In two experiments we investigated different strategies of task organization and their impact on efficiency using a new measure of overall multitasking efficiency. Experiment 1 was based on a classical task switching paradigm with two classification tasks, but provided one group of participants with a stimulus preview of the task to switch to next, enabling at least partial overlapping processing. Indeed, this preview led to a reduction of switch costs and to an increase of dual-task efficiency, but only for a subgroup of participants. They obviously exploited the possibility of overlapping processing, while the others worked mainly serially. While task-sequence was externally guided in the first experiment, Experiment 2 extended the approach by giving the participants full freedom of task organization in concurrent performance of the same tasks. Fine

  10. Dual Arm Work Package performance estimates and telerobot task network simulation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Draper, J.V.; Blair, L.M.

    1997-02-01

    This paper describes the methodology and results of a network simulation study of the Dual Arm Work Package (DAWP), to be employed for dismantling the Argonne National Laboratory CP-5 reactor. The development of the simulation model was based upon the results of a task analysis for the same system. This study was performed by the Oak Ridge National Laboratory (ORNL), in the Robotics and Process Systems Division. Funding was provided the US Department of Energy`s Office of Technology Development, Robotics Technology Development Program (RTDP). The RTDP is developing methods of computer simulation to estimate telerobotic system performance. Data were collectedmore » to provide point estimates to be used in a task network simulation model. Three skilled operators performed six repetitions of a pipe cutting task representative of typical teleoperation cutting operations.« less

  11. Neural Correlates of Single- and Dual-Task Walking in the Real World

    PubMed Central

    Pizzamiglio, Sara; Naeem, Usman; Abdalla, Hassan; Turner, Duncan L.

    2017-01-01

    Recent developments in mobile brain-body imaging (MoBI) technologies have enabled studies of human locomotion where subjects are able to move freely in more ecologically valid scenarios. In this study, MoBI was employed to describe the behavioral and neurophysiological aspects of three different commonly occurring walking conditions in healthy adults. The experimental conditions were self-paced walking, walking while conversing with a friend and lastly walking while texting with a smartphone. We hypothesized that gait performance would decrease with increased cognitive demands and that condition-specific neural activation would involve condition-specific brain areas. Gait kinematics and high density electroencephalography (EEG) were recorded whilst walking around a university campus. Conditions with dual tasks were accompanied by decreased gait performance. Walking while conversing was associated with an increase of theta (θ) and beta (β) neural power in electrodes located over left-frontal and right parietal regions, whereas walking while texting was associated with a decrease of β neural power in a cluster of electrodes over the frontal-premotor and sensorimotor cortices when compared to walking whilst conversing. In conclusion, the behavioral “signatures” of common real-life activities performed outside the laboratory environment were accompanied by differing frequency-specific neural “biomarkers”. The current findings encourage the study of the neural biomarkers of disrupted gait control in neurologically impaired patients. PMID:28959199

  12. Is language necessary for human spatial reorientation? Reconsidering evidence from dual task paradigms.

    PubMed

    Ratliff, Kristin R; Newcombe, Nora S

    2008-03-01

    Being able to reorient to the spatial environment after disorientation is a basic adaptive challenge. There is clear evidence that reorientation uses geometric information about the shape of the surrounding space. However, there has been controversy concerning whether use of geometry is a modular function, and whether use of features is dependent on human language. A key argument for the role of language comes from shadowing findings where adults engaged in a linguistic task during reorientation ignored a colored wall feature and only used geometric information to reorient [Hermer-Vazquez, L., Spelke, E., & Katsnelson, A. (1999). Sources of flexibility in human cognition: Dual task studies of space and language. Cognitive Psychology, 39, 3-36]. We report three studies showing: (a) that the results of Hermer-Vazques et al. [Hermer-Vazquez, L., Spelke, E., & Katsnelson, A. (1999). Sources of flexibility in human cognition: Dual task studies of space and language. Cognitive Psychology, 39, 3-36] are obtained in incidental learning but not with explicit instructions, (b) that a spatial task impedes use of features at least as much as a verbal shadowing task, and (c) that neither secondary task impedes use of features in a room larger than that used by Hermer-Vazquez et al. These results suggest that language is not necessary for successful use of features in reorientation. In fact, whether or not there is an encapsulated geometric module is currently unsettled. The current findings support an alternative to modularity; the adaptive combination view hypothesizes that geometric and featural information are utilized in varying degrees, dependent upon the certainty and variance with which the two kinds of information are encoded, along with their salience and perceived usefulness.

  13. The performance of stroke survivors in turning-while-walking while carrying out a concurrent cognitive task compared with controls.

    PubMed

    Chan, Wing-Nga; Tsang, William Wai-Nam

    2017-01-01

    Turning-while-walking is one of the commonest causes of falls in stroke survivors. It involves cognitive processing and may be challenging when performed concurrently with a cognitive task. Previous studies of dual-tasking involving turning-while-walking in stroke survivors show that the performance of physical tasks is compromised. However, the design of those studies did not address the response of stroke survivors under dual-tasking condition without specifying the task-preference and its effect on the performance of the cognitive task. First, to compare the performance of single-tasking and dual-tasking in stroke survivors. Second, to compare the performance of stroke survivors with non-stroke controls. Fifty-nine stroke survivors and 45 controls were assessed with an auditory Stroop test, a turning-while-walking test, and a combination of the two single tasks. The outcome of the cognitive task was measured by the reaction time and accuracy of the task. The physical task was evaluated by measuring the turning duration, number of steps to turn, and time to complete the turning-while-walking test. Stroke survivors showed a significantly reduced accuracy in the auditory Stroop test when dual-tasking, but there was no change in the reaction time. Their performance in the turning-while-walking task was similar under both single-tasking and dual-tasking condition. Additionally, stroke survivors demonstrated a significantly longer reaction time and lower accuracy than the controls both when single-tasking and dual-tasking. They took longer to turn, with more steps, and needed more time to complete the turning-while-walking task in both tasking conditions. The results show that stroke survivors with high mobility function performed the auditory Stroop test less accurately while preserving simultaneous turning-while-walking performance. They also demonstrated poorer performance in both single-tasking and dual-tasking as compared with controls.

  14. A dual task priming investigation of right hemisphere inhibition for people with left hemisphere lesions

    PubMed Central

    2012-01-01

    Background During normal semantic processing, the left hemisphere (LH) is suggested to restrict right hemisphere (RH) performance via interhemispheric suppression. However, a lesion in the LH or the use of concurrent tasks to overload the LH's attentional resource balance has been reported to result in RH disinhibition with subsequent improvements in RH performance. The current study examines variations in RH semantic processing in the context of unilateral LH lesions and the manipulation of the interhemispheric processing resource balance, in order to explore the relevance of RH disinhibition to hemispheric contributions to semantic processing following a unilateral LH lesion. Methods RH disinhibition was examined for nine participants with a single LH lesion and 13 matched controls using the dual task paradigm. Hemispheric performance on a divided visual field lexical decision semantic priming task was compared over three verbal memory load conditions, of zero-, two- and six-words. Related stimuli consisted of categorically related, associatively related, and categorically and associatively related prime-target pairs. Response time and accuracy data were recorded and analyzed using linear mixed model analysis, and planned contrasts were performed to compare priming effects in both visual fields, for each of the memory load conditions. Results Control participants exhibited significant bilateral visual field priming for all related conditions (p < .05), and a LH advantage over all three memory load conditions. Participants with LH lesions exhibited an improvement in RH priming performance as memory load increased, with priming for the categorically related condition occurring only in the 2- and 6-word memory conditions. RH disinhibition was also reflected for the LH damage (LHD) group by the removal of the LH performance advantage following the introduction of the memory load conditions. Conclusions The results from the control group are consistent with

  15. Effects of Backpack Carriage on Dual-Task Performance in Children During Standing and Walking.

    PubMed

    Beurskens, Rainer; Muehlbauer, Thomas; Grabow, Lena; Kliegl, Reinhold; Granacher, Urs

    2016-01-01

    Primary school children perform parts of their everyday activities while carrying school supplies and being involved in attention-demanding situations. Twenty-eight children (8-10 years old) performed a 1-legged stance and a 10 m walking test under single- and dual-task situations in unloaded (i.e., no backpack) and loaded conditions (i.e., backpack with 20% of body mass). Results showed that load carriage did not significantly influence children's standing and walking performance (all p > .05), while divided attention affected all proxies of walking (all p < .001). Last, no significant load by attention interactions was detected. The single application of attentional but not load demand negatively affects children's walking performance. A combined application of both did not further deteriorate their gait behavior.

  16. The Source of Execution-Related Dual-Task Interference: Motor Bottleneck or Response Monitoring?

    ERIC Educational Resources Information Center

    Bratzke, Daniel; Rolke, Bettina; Ulrich, Rolf

    2009-01-01

    The present study assessed the underlying mechanism of execution-related dual-task interference in the psychological refractory period (PRP) paradigm. The motor bottleneck hypothesis attributes this interference to a processing limitation at the motor level. By contrast, the response monitoring hypothesis attributes it to a bottleneck process that…

  17. Dual-Tasking Alleviated Sleep Deprivation Disruption in Visuomotor Tracking: An fMRI Study

    ERIC Educational Resources Information Center

    Gazes, Yunglin; Rakitin, Brian C.; Steffener, Jason; Habeck, Christian; Butterfield, Brady; Basner, Robert C.; Ghez, Claude; Stern, Yaakov

    2012-01-01

    Effects of dual-responding on tracking performance after 49-h of sleep deprivation (SD) were evaluated behaviorally and with functional magnetic resonance imaging (fMRI). Continuous visuomotor tracking was performed simultaneously with an intermittent color-matching visual detection task in which a pair of color-matched stimuli constituted a…

  18. The influence of spatial congruency and movement preparation time on saccade curvature in simultaneous and sequential dual-tasks.

    PubMed

    Moehler, Tobias; Fiehler, Katja

    2015-11-01

    Saccade curvature represents a sensitive measure of oculomotor inhibition with saccades curving away from covertly attended locations. Here we investigated whether and how saccade curvature depends on movement preparation time when a perceptual task is performed during or before saccade preparation. Participants performed a dual-task including a visual discrimination task at a cued location and a saccade task to the same location (congruent) or to a different location (incongruent). Additionally, we varied saccade preparation time (time between saccade cue and Go-signal) and the occurrence of the discrimination task (during saccade preparation=simultaneous vs. before saccade preparation=sequential). We found deteriorated perceptual performance in incongruent trials during simultaneous task performance while perceptual performance was unaffected during sequential task performance. Saccade accuracy and precision were deteriorated in incongruent trials during simultaneous and, to a lesser extent, also during sequential task performance. Saccades consistently curved away from covertly attended non-saccade locations. Saccade curvature was unaffected by movement preparation time during simultaneous task performance but decreased and finally vanished with increasing movement preparation time during sequential task performance. Our results indicate that the competing saccade plan to the covertly attended non-saccade location is maintained during simultaneous task performance until the perceptual task is solved while in the sequential condition, in which the discrimination task is solved prior to the saccade task, oculomotor inhibition decays gradually with movement preparation time. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Neural Correlates of Task Cost for Stance Control with an Additional Motor Task: Phase-Locked Electroencephalogram Responses

    PubMed Central

    Hwang, Ing-Shiou; Huang, Cheng-Ya

    2016-01-01

    With appropriate reallocation of central resources, the ability to maintain an erect posture is not necessarily degraded by a concurrent motor task. This study investigated the neural control of a particular postural-suprapostural procedure involving brain mechanisms to solve crosstalk between posture and motor subtasks. Participants completed a single posture task and a dual-task while concurrently conducting force-matching and maintaining a tilted stabilometer stance at a target angle. Stabilometer movements and event-related potentials (ERPs) were recorded. The added force-matching task increased the irregularity of postural response rather than the size of postural response prior to force-matching. In addition, the added force-matching task during stabilometer stance led to marked topographic ERP modulation, with greater P2 positivity in the frontal and sensorimotor-parietal areas of the N1-P2 transitional phase and in the sensorimotor-parietal area of the late P2 phase. The time-frequency distribution of the ERP primary principal component revealed that the dual-task condition manifested more pronounced delta (1–4 Hz) and beta (13–35 Hz) synchronizations but suppressed theta activity (4–8 Hz) before force-matching. The dual-task condition also manifested coherent fronto-parietal delta activity in the P2 period. In addition to a decrease in postural regularity, this study reveals spatio-temporal and temporal-spectral reorganizations of ERPs in the fronto-sensorimotor-parietal network due to the added suprapostural motor task. For a particular set of postural-suprapostural task, the behavior and neural data suggest a facilitatory role of autonomous postural response and central resource expansion with increasing interregional interactions for task-shift and planning the motor-suprapostural task. PMID:27010634

  20. Age-related cognitive task effects on gait characteristics: do different working memory components make a difference?

    PubMed

    Qu, Xingda

    2014-10-27

    Though it is well recognized that gait characteristics are affected by concurrent cognitive tasks, how different working memory components contribute to dual task effects on gait is still unknown. The objective of the present study was to investigate dual-task effects on gait characteristics, specifically the application of cognitive tasks involving different working memory components. In addition, we also examined age-related differences in such dual-task effects. Three cognitive tasks (i.e. 'Random Digit Generation', 'Brooks' Spatial Memory', and 'Counting Backward') involving different working memory components were examined. Twelve young (6 males and 6 females, 20 ~ 25 years old) and 12 older participants (6 males and 6 females, 60 ~ 72 years old) took part in two phases of experiments. In the first phase, each cognitive task was defined at three difficulty levels, and perceived difficulty was compared across tasks. The cognitive tasks perceived to be equally difficult were selected for the second phase. In the second phase, four testing conditions were defined, corresponding to a baseline and the three equally difficult cognitive tasks. Participants walked on a treadmill at their self-selected comfortable speed in each testing condition. Body kinematics were collected during treadmill walking, and gait characteristics were assessed using spatial-temporal gait parameters. Application of the concurrent Brooks' Spatial Memory task led to longer step times compared to the baseline condition. Larger step width variability was observed in both the Brooks' Spatial Memory and Counting Backward dual-task conditions than in the baseline condition. In addition, cognitive task effects on step width variability differed between two age groups. In particular, the Brooks' Spatial Memory task led to significantly larger step width variability only among older adults. These findings revealed that cognitive tasks involving the visuo-spatial sketchpad interfered with

  1. Effects of Dual-Task Management and Resistance Training on Gait Performance in Older Individuals: A Randomized Controlled Trial.

    PubMed

    Wollesen, Bettina; Mattes, Klaus; Schulz, Sören; Bischoff, Laura L; Seydell, L; Bell, Jeffrey W; von Duvillard, Serge P

    2017-01-01

    Background: Dual-task (DT) training is a well-accepted modality for fall prevention in older adults. DT training should include task-managing strategies such as task switching or task prioritization to improve gait performance under DT conditions. Methods: We conducted a randomized controlled trial to evaluate a balance and task managing training (BDT group) in gait performance compared to a single task (ST) strength and resistance training and a control group, which received no training. A total of 78 older individuals (72.0 ± 4.9 years) participated in this study. The DT group performed task managing training incorporating balance and coordination tasks while the ST group performed resistance training only. Training consisted of 12 weekly sessions, 60 min each, for 12 weeks. We assessed the effects of ST and BDT training on walking performance under ST and DT conditions in independent living elderly adults. ST and DT walking (visual verbal Stroop task) were measured utilizing a treadmill at self-selected walking speed (mean for all groups: 4.4 ± 1 km h -1 ). Specific gait variables, cognitive performance, and fear of falling were compared between all groups. > Results: Training improved gait performance for step length ( p < 0.001) and gait-line (ST: p < 0.01; DT p < 0.05) in both training groups. The BDT training group showed greater improvements in step length ( p < 0.001) and gait-line ( p < 0.01) during DT walking but did not have changes in cognitive performance. Both interventions reduced fear of falling ( p < 0.05). Conclusion: Implementation of task management strategies into balance and strength training in our population revealed a promising modality to prevent falls in older individuals. Trial registration: German register of clinical trials DRKS00012382.

  2. Investigating the visual span in comparative search: the effects of task difficulty and divided attention.

    PubMed

    Pomplun, M; Reingold, E M; Shen, J

    2001-09-01

    In three experiments, participants' visual span was measured in a comparative visual search task in which they had to detect a local match or mismatch between two displays presented side by side. Experiment 1 manipulated the difficulty of the comparative visual search task by contrasting a mismatch detection task with a substantially more difficult match detection task. In Experiment 2, participants were tested in a single-task condition involving only the visual task and a dual-task condition in which they concurrently performed an auditory task. Finally, in Experiment 3, participants performed two dual-task conditions, which differed in the difficulty of the concurrent auditory task. Both the comparative search task difficulty (Experiment 1) and the divided attention manipulation (Experiments 2 and 3) produced strong effects on visual span size.

  3. Working memory in wayfinding-a dual task experiment in a virtual city.

    PubMed

    Meilinger, Tobias; Knauff, Markus; Bülthoff, Heinrich H

    2008-06-01

    This study examines the working memory systems involved in human wayfinding. In the learning phase, 24 participants learned two routes in a novel photorealistic virtual environment displayed on a 220° screen while they were disrupted by a visual, a spatial, a verbal, or-in a control group-no secondary task. In the following wayfinding phase, the participants had to find and to "virtually walk" the two routes again. During this wayfinding phase, a number of dependent measures were recorded. This research shows that encoding wayfinding knowledge interfered with the verbal and with the spatial secondary task. These interferences were even stronger than the interference of wayfinding knowledge with the visual secondary task. These findings are consistent with a dual-coding approach of wayfinding knowledge. 2008 Cognitive Science Society, Inc.

  4. Group-based exercise combined with dual-task training improves gait but not vascular health in active older adults without dementia.

    PubMed

    Gregory, Michael A; Gill, Dawn P; Zou, Guangyong; Liu-Ambrose, Teresa; Shigematsu, Ryosuke; Fitzgerald, Clara; Hachinski, Vladimir; Shoemaker, Kevin; Petrella, Robert J

    2016-01-01

    Gait abnormalities and vascular disease risk factors are associated with cognitive impairment in aging. To determine the impact of group-based exercise and dual-task training on gait and vascular health, in active community-dwelling older adults without dementia. Participants [n=44, mean (SD) age: 73.5 (7.2) years, 68% female] were randomized to either intervention (exercise+dual-task; EDT) or control (exercise only; EO). Each week, for 26 weeks, both groups accumulated 50 or 75 min of aerobic exercise from group-based classes and 45 min of beginner-level square stepping exercise (SSE). Participants accumulating only 50 min of aerobic exercise were instructed to participate in an additional 25 min each week outside of class. The EDT group also answered cognitively challenging questions while performing SSE (i.e., dual-task training). The effect of the interventions on gait and vascular health was compared between groups using linear mixed effects models. At 26 weeks, the EDT group demonstrated increased dual-task (DT) gait velocity [difference between groups in mean change from baseline (95% CI): 0.29 m/s (0.16-0.43), p<0.001], DT step length [5.72 cm (2.19-9.24), p =0.002], and carotid intima-media thickness [0.10mm (0.003-0.20), p=0.04], as well as reduced DT stride time variability [8.31 coefficient of variation percentage points (-12.92 to -3.70), p<0.001], when compared to the EO group. Group-based exercise combined with dual-task training can improve DT gait characteristics in active older adults without dementia. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Dual design resistor for high voltage conditioning and transmission lines

    DOEpatents

    Siggins, Timothy Lynn [Newport News, VA; Murray, Charles W [Hayes, VA; Walker, Richard L [Norfolk, VA

    2007-01-23

    A dual resistor for eliminating the requirement for two different value resistors. The dual resistor includes a conditioning resistor at a high resistance value and a run resistor at a low resistance value. The run resistor can travel inside the conditioning resistor. The run resistor is capable of being advanced by a drive assembly until an electrical path is completed through the run resistor thereby shorting out the conditioning resistor and allowing the lower resistance run resistor to take over as the current carrier.

  6. The Role of Control Functions in Mentalizing: Dual-Task Studies of Theory of Mind and Executive Function

    ERIC Educational Resources Information Center

    Bull, Rebecca; Phillips, Louise H.; Conway, Claire A.

    2008-01-01

    Conflicting evidence has arisen from correlational studies regarding the role of executive control functions in Theory of Mind. The current study used dual-task manipulations of executive functions (inhibition, updating and switching) to investigate the role of these control functions in mental state and non-mental state tasks. The "Eyes"…

  7. Do Aging and Dual-Tasking Impair the Capacity to Store and Retrieve Visuospatial Information Needed to Guide Perturbation-Evoked Reach-To-Grasp Reactions?

    PubMed Central

    Cheng, Kenneth C.; Pratt, Jay; Maki, Brian E.

    2013-01-01

    A recent study involving young adults showed that rapid perturbation-evoked reach-to-grasp balance-recovery reactions can be guided successfully with visuospatial-information (VSI) retained in memory despite: 1) a reduction in endpoint accuracy due to recall-delay (time between visual occlusion and perturbation-onset, PO) and 2) slowing of the reaction when performing a concurrent cognitive task during the recall-delay interval. The present study aimed to determine whether this capacity is compromised by effects of aging. Ten healthy older adults were tested with the previous protocol and compared with the previously-tested young adults. Reactions to recover balance by grasping a small handhold were evoked by unpredictable antero-posterior platform-translation (barriers deterred stepping reactions), while using liquid-crystal goggles to occlude vision post-PO and for varying recall-delay times (0-10s) prior to PO (the handhold was moved unpredictably to one of four locations 2s prior to vision-occlusion). Subjects also performed a spatial- or non-spatial-memory cognitive task during the delay-time in a subset of trials. Results showed that older adults had slower reactions than the young across all experimental conditions. Both age groups showed similar reduction in medio-lateral end-point accuracy when recall-delay was longest (10s), but differed in the effect of recall delay on vertical hand elevation. For both age groups, engaging in either the non-spatial or spatial-memory task had similar (slowing) effects on the arm reactions; however, the older adults also showed a dual-task interference effect (poorer cognitive-task performance) that was specific to the spatial-memory task. This provides new evidence that spatial working memory plays a role in the control of perturbation-evoked balance-recovery reactions. The delays in completing the reaction that occurred when performing either cognitive task suggest that such dual-task situations in daily life could

  8. A comparison of the effects of temporary hippocampal lesions on single and dual context versions of the olfactory sequence memory task.

    PubMed

    Sill, Orriana C; Smith, David M

    2012-08-01

    In recent years, many animal models of memory have focused on one or more of the various components of episodic memory. For example, the odor sequence memory task requires subjects to remember individual items and events (the odors) and the temporal aspects of the experience (the sequence of odor presentation). The well-known spatial context coding function of the hippocampus, as exemplified by place cell firing, may reflect the "where" component of episodic memory. In the present study, we added a contextual component to the odor sequence memory task by training rats to choose the earlier odor in one context and the later odor in another context and we compared the effects of temporary hippocampal lesions on performance of the original single context task and the new dual context task. Temporary lesions significantly impaired the single context task, although performance remained significantly above chance levels. In contrast, performance dropped all the way to chance when temporary lesions were used in the dual context task. These results demonstrate that rats can learn a dual context version of the odor sequence learning task that requires the use of contextual information along with the requirement to remember the "what" and "when" components of the odor sequence. Moreover, the addition of the contextual component made the task fully dependent on the hippocampus.

  9. Analysis of the impact of a cognitive task on the posture of elderly subjects with depression compared with healthy elderly subjects.

    PubMed

    Casteran, Matthieu; Putot, Alain; Pfitzenmeyer, François; Thomas, Elizabeth; Manckoundia, Patrick

    2016-11-01

    While previous studies have demonstrated that depressive elderly subjects (DES) experience difficulties in the processing of simultaneous cognitive tasks, few have examined the coupling of cognitive tasks with seemingly 'automatic' tasks, such as standing upright. Current patient management focuses on pharmacological treatments and cognitive-behavioral therapies. Healthy elderly (HES) and non-treated DES were included. Postural sway in DES was compared with that in HES while in single-task and dual-task conditions. The single-task consisted of standing upright. For the dual-task, the subjects recalled various items from memory or counted while standing upright. Postural sway was evaluated by computing the center of pressure (CoP) area and path length. DES showed greater postural sway than HES in all conditions. The HES showed a greater CoP area in the dual-task than in the single-task conditions. In DES, the CoP area in the single-task condition was similar to that in the dual-task condition. The greater postural sway observed in DES may be a cause of a greater risk of falls. We showed that even seemingly automatic tasks, such as maintaining an upright posture, are affected by depression. These results are important for the management of DES. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Concurrent processing of vehicle lane keeping and speech comprehension tasks.

    PubMed

    Cao, Shi; Liu, Yili

    2013-10-01

    With the growing prevalence of using in-vehicle devices and mobile devices while driving, a major concern is their impact on driving performance and safety. However, the effects of cognitive load such as conversation on driving performance are still controversial and not well understood. In this study, an experiment was conducted to investigate the concurrent performance of vehicle lane keeping and speech comprehension tasks with improved experimental control of the confounding factors identified in previous studies. The results showed that the standard deviation of lane position (SDLP) was increased when the driving speed was faster (0.30 m at 36 km/h; 0.36 m at 72 km/h). The concurrent comprehension task had no significant effect on SDLP (0.34 m on average) or the standard deviation of steering wheel angle (SDSWA; 5.20° on average). The correct rate of the comprehension task was reduced in the dual-task condition (from 93.4% to 91.3%) compared with the comprehension single-task condition. Mental workload was significantly higher in the dual-task condition compared with the single-task conditions. Implications for driving safety were discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Does Combined Physical and Cognitive Training Improve Dual-Task Balance and Gait Outcomes in Sedentary Older Adults?

    PubMed Central

    Fraser, Sarah A.; Li, Karen Z.-H.; Berryman, Nicolas; Desjardins-Crépeau, Laurence; Lussier, Maxime; Vadaga, Kiran; Lehr, Lora; Minh Vu, Thien Tuong; Bosquet, Laurent; Bherer, Louis

    2017-01-01

    Everyday activities like walking and talking can put an older adult at risk for a fall if they have difficulty dividing their attention between motor and cognitive tasks. Training studies have demonstrated that both cognitive and physical training regimens can improve motor and cognitive task performance. Few studies have examined the benefits of combined training (cognitive and physical) and whether or not this type of combined training would transfer to walking or balancing dual-tasks. This study examines the dual-task benefits of combined training in a sample of sedentary older adults. Seventy-two older adults (≥60 years) were randomly assigned to one of four training groups: Aerobic + Cognitive training (CT), Aerobic + Computer lessons (CL), Stretch + CT and Stretch + CL. It was expected that the Aerobic + CT group would demonstrate the largest benefits and that the active placebo control (Stretch + CL) would show the least benefits after training. Walking and standing balance were paired with an auditory n-back with two levels of difficulty (0- and 1-back). Dual-task walking and balance were assessed with: walk speed (m/s), cognitive accuracy (% correct) and several mediolateral sway measures for pre- to post-test improvements. All groups demonstrated improvements in walk speed from pre- (M = 1.33 m/s) to post-test (M = 1.42 m/s, p < 0.001) and in accuracy from pre- (M = 97.57%) to post-test (M = 98.57%, p = 0.005).They also increased their walk speed in the more difficult 1-back (M = 1.38 m/s) in comparison to the 0-back (M = 1.36 m/s, p < 0.001) but reduced their accuracy in the 1-back (M = 96.39%) in comparison to the 0-back (M = 99.92%, p < 0.001). Three out of the five mediolateral sway variables (Peak, SD, RMS) demonstrated significant reductions in sway from pre to post test (p-values < 0.05). With the exception of a group difference between Aerobic + CT and Stretch + CT in accuracy, there were no significant group differences after training. Results

  12. Spatial release of cognitive load measured in a dual-task paradigm in normal-hearing and hearing-impaired listeners.

    PubMed

    Xia, Jing; Nooraei, Nazanin; Kalluri, Sridhar; Edwards, Brent

    2015-04-01

    This study investigated whether spatial separation between talkers helps reduce cognitive processing load, and how hearing impairment interacts with the cognitive load of individuals listening in multi-talker environments. A dual-task paradigm was used in which performance on a secondary task (visual tracking) served as a measure of the cognitive load imposed by a speech recognition task. Visual tracking performance was measured under four conditions in which the target and the interferers were distinguished by (1) gender and spatial location, (2) gender only, (3) spatial location only, and (4) neither gender nor spatial location. Results showed that when gender cues were available, a 15° spatial separation between talkers reduced the cognitive load of listening even though it did not provide further improvement in speech recognition (Experiment I). Compared to normal-hearing listeners, large individual variability in spatial release of cognitive load was observed among hearing-impaired listeners. Cognitive load was lower when talkers were spatially separated by 60° than when talkers were of different genders, even though speech recognition was comparable in these two conditions (Experiment II). These results suggest that a measure of cognitive load might provide valuable insight into the benefit of spatial cues in multi-talker environments.

  13. A Comparison of the Effects of Temporary Hippocampal Lesions on Single and Dual Context Versions of the Olfactory Sequence Memory Task

    PubMed Central

    Sill, Orriana C.; Smith, David M.

    2012-01-01

    In recent years, many animal models of memory have focused on one or more of the various components of episodic memory. For example, the odor sequence memory task requires subjects to remember individual items and events (the odors) and the temporal aspects of the experience (the sequence of odor presentation). The well-known spatial context coding function of the hippocampus, as exemplified by place cell firing, may reflect the ‘where’ component of episodic memory. In the present study, we added a contextual component to the odor sequence memory task by training rats to choose the earlier odor in one context and the later odor in another context and we compared the effects of temporary hippocampal lesions on performance of the original single context task and the new dual context task. Temporary lesions significantly impaired the single context task, although performance remained significantly above chance levels. In contrast, performance dropped all the way to chance when temporary lesions were used in the dual context task. These results demonstrate that rats can learn a dual context version of the odor sequence learning task which requires the use of contextual information along with the requirement to remember the ‘what’ and ‘when’ components of the odor sequence. Moreover, the additional requirement of context-dependent expression of the ‘what-when’ memory made the task fully dependent on the hippocampus. Moreover, the addition of the contextual component made the task fully dependent on the hippocampus. PMID:22687149

  14. Identifying optimum performance trade-offs using a cognitively bounded rational analysis model of discretionary task interleaving.

    PubMed

    Janssen, Christian P; Brumby, Duncan P; Dowell, John; Chater, Nick; Howes, Andrew

    2011-01-01

    We report the results of a dual-task study in which participants performed a tracking and typing task under various experimental conditions. An objective payoff function was used to provide explicit feedback on how participants should trade off performance between the tasks. Results show that participants' dual-task interleaving strategy was sensitive to changes in the difficulty of the tracking task and resulted in differences in overall task performance. To test the hypothesis that people select strategies that maximize payoff, a Cognitively Bounded Rational Analysis model was developed. This analysis evaluated a variety of dual-task interleaving strategies to identify the optimal strategy for maximizing payoff in each condition. The model predicts that the region of optimum performance is different between experimental conditions. The correspondence between human data and the prediction of the optimal strategy is found to be remarkably high across a number of performance measures. This suggests that participants were honing their behavior to maximize payoff. Limitations are discussed. Copyright © 2011 Cognitive Science Society, Inc.

  15. Postural stability in the elderly during sensory perturbations and dual tasking: the influence of refractive blur.

    PubMed

    Anand, Vijay; Buckley, John G; Scally, Andy; Elliott, David B

    2003-07-01

    To determine the influence of refractive blur on postural stability during somatosensory and vestibular system perturbation and dual tasking. Fifteen healthy, elderly subjects (mean age, 71 +/- 5 years), who had no history of falls and had normal vision, were recruited. Postural stability during standing was assessed using a force platform, and was determined as the root mean square (RMS) of the center of pressure (COP) signal in the anterior-posterior (A-P) and medial-lateral directions collected over a 30-second period. Data were collected under normal standing conditions and with somatosensory and vestibular system perturbations. Measurements were repeated with an additional physical and/or cognitive task. Postural stability was measured under conditions of binocular refractive blur of 0, 1, 2, 4, and 8 D and with eyes closed. The data were analyzed with a population-averaged linear model. The greatest increases in postural instability were due to disruptions of the somatosensory and vestibular systems. Increasing refractive blur caused increasing postural instability, and its effect was greater when the input from the other sensory systems was disrupted. Performing an additional cognitive and physical task increased A-P RMS COP further. All these detrimental effects on postural stability were cumulative. The findings highlight the multifactorial nature of postural stability and indicate why the elderly, many of whom have poor vision and musculoskeletal and central nervous system degeneration, are at greater risk of falling. The findings also highlight that standing instability in both normal and perturbed conditions was significantly increased with refractive blur. Correcting visual impairment caused by uncorrected refractive error could be a useful intervention strategy to help prevent falls and fall-related injuries in the elderly.

  16. Soldier-Based Assessment of a Dual-Row Tactor Display during Simultaneous Navigational and Robot-Monitoring Tasks

    DTIC Science & Technology

    2015-08-01

    Navigational and Robot -Monitoring Tasks by Gina Pomranky-Hartnett, Linda R Elliott, Bruce JP Mortimer, Greg R Mort, Rodger A Pettitt, and Gary A...Tactor Display during Simultaneous Navigational and Robot -Monitoring Tasks by Gina Pomranky-Hartnett, Linda R Elliott, and Rodger A Pettitt...2014–31 March 2015 4. TITLE AND SUBTITLE Soldier-Based Assessment of a Dual-Row Tactor Display during Simultaneous Navigational and Robot -Monitoring

  17. Cognitive-motor interference during fine and gross motor tasks in children with Developmental Coordination Disorder (DCD).

    PubMed

    Schott, Nadja; El-Rajab, Inaam; Klotzbier, Thomas

    2016-10-01

    While typically developing children produce relatively automatized postural control processes, children with DCD seem to exhibit an automatization deficit. Dual tasks with various cognitive loads seem to be an effective way to assess the automatic deficit hypothesis. The aims of the study were: (1) to examine the effect of a concurrent cognitive task on fine and gross motor tasks in children with DCD, and (2) to determine whether the effect varied with different difficulty levels of the concurrent task. We examined dual-task performance (Trail-Making-Test, Trail-Walking-Test) in 20 children with DCD and 39 typically developing children. Based on the idea of the Trail-Making-Test, participants walked along a fixed pathway, following a prescribed path, delineated by target markers of (1) increasing sequential numbers, and (2) increasing sequential numbers and letters. The motor and cognitive dual-task effects (DTE) were calculated for each task. Regardless of the cognitive task, children with DCD performed equally well in fine and gross motor tasks, and were slower in the dual task conditions than under single task-conditions, compared with children without DCD. Increased cognitive task complexity resulted in slow trail walking as well as slower trail tracing. The motor interference for the gross motor tasks was least for the simplest conditions and greatest for the complex conditions and was more pronounced in children with DCD. Cognitive interference was low irrespective of the motor task. Children with DCD show a different approach to allocation of cognitive resources, and have difficulties making motor skills automatic. The latter notion is consistent with impaired cerebellar function and the "automatization deficit hypothesis", suggesting that any deficit in the automatization process will appear if conscious monitoring of the motor skill is made more difficult by integrating another task requiring attentional resources. Copyright © 2016 Elsevier Ltd. All

  18. Proportional reasoning as a heuristic-based process: time constraint and dual task considerations.

    PubMed

    Gillard, Ellen; Van Dooren, Wim; Schaeken, Walter; Verschaffel, Lieven

    2009-01-01

    The present study interprets the overuse of proportional solution methods from a dual process framework. Dual process theories claim that analytic operations involve time-consuming executive processing, whereas heuristic operations are fast and automatic. In two experiments to test whether proportional reasoning is heuristic-based, the participants solved "proportional" problems, for which proportional solution methods provide correct answers, and "nonproportional" problems known to elicit incorrect answers based on the assumption of proportionality. In Experiment 1, the available solution time was restricted. In Experiment 2, the executive resources were burdened with a secondary task. Both manipulations induced an increase in proportional answers and a decrease in correct answers to nonproportional problems. These results support the hypothesis that the choice for proportional methods is heuristic-based.

  19. Interference effects of vocalization on dual task performance

    NASA Astrophysics Data System (ADS)

    Owens, J. M.; Goodman, L. S.; Pianka, M. J.

    1984-09-01

    Voice command and control systems have been proposed as a potential means of off-loading the typically overburdened visual information processing system. However, prior to introducing novel human-machine interfacing technologies in high workload environments, consideration must be given to the integration of the new technologists within existing task structures to ensure that no new sources of workload or interference are systematically introduced. This study examined the use of voice interactive systems technology in the joint performance of two cognitive information processing tasks requiring continuous memory and choice reaction wherein a basis for intertask interference might be expected. Stimuli for the continuous memory task were presented aurally and either voice or keyboard responding was required in the choice reaction task. Performance was significantly degraded in each task when voice responding was required in the choice reaction time task. Performance degradation was evident in higher error scores for both the choice reaction and continuous memory tasks. Performance decrements observed under conditions of high intertask stimulus similarity were not statistically significant. The results signal the need to consider further the task requirements for verbal short-term memory when applying speech technology in multitask environments.

  20. Effects of visual and verbal interference tasks on olfactory memory: the role of task complexity.

    PubMed

    Annett, J M; Leslie, J C

    1996-08-01

    Recent studies have demonstrated that visual and verbal suppression tasks interfere with olfactory memory in a manner which is partially consistent with a dual coding interpretation. However, it has been suggested that total task complexity rather than modality specificity of the suppression tasks might account for the observed pattern of results. This study addressed the issue of whether or not the level of difficulty and complexity of suppression tasks could explain the apparent modality effects noted in earlier experiments. A total of 608 participants were each allocated to one of 19 experimental conditions involving interference tasks which varied suppression type (visual or verbal), nature of complexity (single, double or mixed) and level of difficulty (easy, optimal or difficult) and presented with 13 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Both recognition and recall performance showed an overall effect for suppression nature, suppression level and time of testing with no effect for suppression type. The results lend only limited support to Paivio's (1986) dual coding theory, but have a number of characteristics which suggest that an adequate account of olfactory memory may be broadly similar to current theories of face and object recognition. All of these phenomena might be dealt with by an appropriately modified version of dual coding theory.

  1. An electrophysiological study of task demands on concreteness effects: evidence for dual coding theory.

    PubMed

    Welcome, Suzanne E; Paivio, Allan; McRae, Ken; Joanisse, Marc F

    2011-07-01

    We examined ERP responses during the generation of word associates or mental images in response to concrete and abstract concepts. Of interest were the predictions of dual coding theory (DCT), which proposes that processing lexical concepts depends on functionally independent but interconnected verbal and nonverbal systems. ERP responses were time-locked to either stimulus onset or response to compensate for potential latency differences across conditions. During word associate generation, but not mental imagery, concrete items elicited a greater N400 than abstract items. A concreteness effect emerged at a later time point during the mental imagery task. Data were also analyzed using time-frequency analysis that investigated synchronization of neuronal populations over time during processing. Concrete words elicited an enhanced late going desynchronization of theta-band power (723-938 ms post stimulus onset) during associate generation. During mental imagery, abstract items elicited greater delta-band power from 800 to 1,000 ms following stimulus onset, theta-band power from 350 to 205 ms before response, and alpha-band power from 900 to 800 ms before response. Overall, the findings support DCT in suggesting that lexical concepts are not amodal and that concreteness effects are modulated by tasks that focus participants on verbal versus nonverbal, imagery-based knowledge.

  2. The neural substrates associated with attentional resources and difficulty of concurrent processing of the two verbal tasks.

    PubMed

    Mizuno, Kei; Tanaka, Masaaki; Tanabe, Hiroki C; Sadato, Norihiro; Watanabe, Yasuyoshi

    2012-07-01

    The kana pick-out test has been widely used in Japan to evaluate the ability to divide attention in both adult and pediatric patients. However, the neural substrates underlying the ability to divide attention using the kana pick-out test, which requires participants to pick out individual letters (vowels) in a story while also reading for comprehension, thus requiring simultaneous allocation of attention to both activities, are still unclear. Moreover, outside of the clinical area, neuroimaging studies focused on the mechanisms of divided attention during complex story comprehension are rare. Thus, the purpose of the present study, to clarify the neural substrates of kana pick-out test, improves our current understanding of the basic neural mechanisms of dual task performance in verbal memory function. We compared patterns of activation in the brain obtained during performance of the individual tasks of vowel identification and story comprehension, to levels of activation when participants performed the two tasks simultaneously during the kana pick-out test. We found that activations of the left dorsal inferior frontal gyrus and superior parietal lobule increase in functional connectivity to a greater extent during the dual task condition compared to the two single task conditions. In contrast, activations of the left fusiform gyrus and middle temporal gyrus, which are significantly involved in picking out letters and complex sentences during story comprehension, respectively, were reduced in the dual task condition compared to during the two single task conditions. These results suggest that increased activations of the dorsal inferior frontal gyrus and superior parietal lobule during dual task performance may be associated with the capacity for attentional resources, and reduced activations of the left fusiform gyrus and middle temporal gyrus may reflect the difficulty of concurrent processing of the two tasks. In addition, the increase in synchronization between

  3. Assessing the Relationship between Vitamin D Status and Impairments in Cognitive and Physical Performance in Older Adults Using a Dual Task Physical Performance Test.

    PubMed

    Lopez, J; Campa, A; Lewis, J E; Huffman, F G; Liuzzi, J P; Li, T; Martinez, A H; Ferris, S M; Rasul, A; Farooqi, A; Lopez Medrano, A M; Atlas, S E; Tiozzo, E; Konefal, J; Woolger, J M

    2017-01-01

    Vitamin D deficiency has been associated with an increased risk of falls in older adults. Several studies have demonstrated an association between vitamin D deficiency and gait and cognitive impairments, which are two risk factors for falls in the elderly. There is lack of research about the role of vitamin D in cognitive function in the context of mobility. The purpose of this study was to evaluate the association between vitamin D status with the age-related changes in mobility through higher order cognitive function using a dual task physical performance test. Cross-sectional. Community-dwelling older adult population located in Miami, Fl. Healthy participants over the age of 55 (n=97) who participated in the parent interventional study. Participants completed assessments that included serum levels of vitamin D, surveys, and dual task physical performance tests. Spearman's correlations, independent t-tests, repeated measures ANOVAs and multiple logistic regressions were used to examine the relationship between vitamin D insufficiency (25-hydroxyvitamin D <30 ng/ml) and sufficiency (≥30 ng/ml) and dual task physical performance variables. The significance level was set at α=0.05. There were no significant associations between vitamin D insufficiency and gait velocity during either task. Using Spearman correlations, slower single (P=0.011) and dual task counting rates (P=0.006) were significantly associated with vitamin D insufficiency. Independent t-tests showed dual and single task counting rates were significantly lower in the vitamin D insufficient group compared to the sufficient group (P=0.018 and P=0.028, respectively). The results for the ANOVAs indicated that velocities and counting rates were not significantly different by vitamin D status (Wilk's Lambda =0.999; F (1, 95) =.11, P=.740) (Wilk's Lambda =.999, F(1,95)=.13, P=.718). Vitamin D status was not significantly associated with dual task physical performance (defined as the difference in dual and

  4. A 9-Week Jaques-Dalcroze Eurhythmics Intervention Improves Single and Dual-Task Gait Speed in Community-Dwelling Older People.

    PubMed

    Ferguson-Stegall, Lisa; Vang, Mandy; Wolfe, Anthony S; Thomsen, Kathy M

    2017-09-01

    Falls are a major public health concern among older adults, and most occur while walking, especially under dualtask conditions. Jaques-Dalcroze eurhythmics (JDE) is a music-based movement training program that emphasizes multitask coordinated movement. A previous 6-mo JDE study in older people demonstrated improved gait and balance; however, the effects of short-term JDE interventions on fall risk-related outcomes are largely unknown. We conducted a preliminary investigation on whether a 9-week JDE intervention improved gait and stability in a community-dwelling older cohort, hypothesizing that improvements would occur in all outcome measures. Nine participants (78.9 ± 12.3 y) completed the supervised JDE intervention (once/week for 60 min). Gait speed was determined by the 6-m timed walk test (6MTW); dual-task gait speed was determined by another 6MTW while counting backward from 50 aloud; and coordinated stability was assessed using a Swaymeter-like device. Gait speed (0.92 ± 0.11 vs 1.04 ± 0.12 m/sec, P = .04) and dual-task gait speed (0.77 ± 0.09 vs 0.92 ± 0.11 m/sec, P = .0005) significantly improved. This novel intervention is an effective short-term physical activity option for those that plan physical activity or fall-risk reduction programs for the older people.

  5. Dual Frequency Head Maps: A New Method for Indexing Mental Workload Continuously during Execution of Cognitive Tasks

    PubMed Central

    Radüntz, Thea

    2017-01-01

    One goal of advanced information and communication technology is to simplify work. However, there is growing consensus regarding the negative consequences of inappropriate workload on employee's health and the safety of persons. In order to develop a method for continuous mental workload monitoring, we implemented a task battery consisting of cognitive tasks with diverse levels of complexity and difficulty. We conducted experiments and registered the electroencephalogram (EEG), performance data, and the NASA-TLX questionnaire from 54 people. Analysis of the EEG spectra demonstrates an increase of the frontal theta band power and a decrease of the parietal alpha band power, both under increasing task difficulty level. Based on these findings we implemented a new method for monitoring mental workload, the so-called Dual Frequency Head Maps (DFHM) that are classified by support vectors machines (SVMs) in three different workload levels. The results are in accordance with the expected difficulty levels arising from the requirements of the tasks on the executive functions. Furthermore, this article includes an empirical validation of the new method on a secondary subset with new subjects and one additional new task without any adjustment of the classifiers. Hence, the main advantage of the proposed method compared with the existing solutions is that it provides an automatic, continuous classification of the mental workload state without any need for retraining the classifier—neither for new subjects nor for new tasks. The continuous workload monitoring can help ensure good working conditions, maintain a good level of performance, and simultaneously preserve a good state of health. PMID:29276490

  6. Dual-task interference in visual working memory: A limitation in storage capacity but not in encoding or retrieval

    PubMed Central

    Fougnie, Daryl; Marois, René

    2009-01-01

    The concurrent maintenance of two visual working memory (VWM) arrays can lead to profound interference. It is unclear, however, whether these costs arise from limitations in VWM storage capacity (Fougnie & Marois, 2006), or from interference between the storage of one visual array and encoding or retrieval of another visual array (Cowan & Morey, 2007). Here, we show that encoding a VWM array does not interfere with maintenance of another VWM array unless the two displays exceed maintenance capacity (Experiments 1 and 2). Moreover, manipulating the extent to which encoding and maintenance can interfere with one another had no discernable effect on dual-task performance (Experiment 2). Finally, maintenance of a VWM array was not affected by retrieval of information from another VWM array (Experiment 3). Taken together, these findings demonstrate that dual-task interference between two concurrent VWM tasks is due to a capacity-limited store that is independent from encoding and retrieval processes. PMID:19933566

  7. Cognitive-motor dual-task interference: A systematic review of neural correlates.

    PubMed

    Leone, Carmela; Feys, Peter; Moumdjian, Lousin; D'Amico, Emanuele; Zappia, Mario; Patti, Francesco

    2017-04-01

    Cognitive-motor interference refers to dual-tasking (DT) interference (DTi) occurring when the simultaneous performance of a cognitive and a motor task leads to a percentage change in one or both tasks. Several theories exist to explain DTi in humans: the capacity-sharing, the bottleneck and the cross-talk theories. Numerous studies investigating whether a specific brain locus is associated with cognitive-motor DTi have been conducted, but not systematically reviewed. We aimed to review the evidences on brain activity associated with the cognitive-motor DT, in order to better understand the neurological basis of the CMi. Results were reported according to the technique used to assess brain activity. Twenty-three articles met the inclusion criteria. Out of them, nine studies used functional magnetic resonance imaging to show an additive, under-additive, over- additive, or a mixed activation pattern of the brain. Seven studies used near-infrared spectroscopy, and seven neurophysiological instruments. Yet a specific DT locus in the brain cannot be concluded from the overall current literature. Future studies are warranted to overcome the shortcomings identified. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Development of a German reading span test with dual task design for application in cognitive hearing research.

    PubMed

    Carroll, Rebecca; Meis, Markus; Schulte, Michael; Vormann, Matthias; Kießling, Jürgen; Meister, Hartmut

    2015-02-01

    To report the development of a standardized German version of a reading span test (RST) with a dual task design. Special attention was paid to psycholinguistic control of the test items and time-sensitive scoring. We aim to establish our RST version to use for determining an individual's working memory in the framework of hearing research in German contexts. RST stimuli were controlled and pretested for psycholinguistic factors. The RST task was to read sentences, quickly determine their plausibility, and later recall certain words to determine a listener's individual reading span. RST results were correlated with outcomes of additional sentence-in-noise tests measured in an aided and an unaided listening condition, each at two reception thresholds. Item plausibility was pre-determined by 28 native German participants. An additional 62 listeners (45-86 years, M = 69.8) with mild-to-moderate hearing loss were tested for speech intelligibility and reading span in a multicenter study. The reading span test significantly correlated with speech intelligibility at both speech reception thresholds in the aided listening condition. Our German RST is standardized with respect to psycholinguistic construction principles of the stimuli, and is a cognitive correlate of intelligibility in a German matrix speech-in-noise test.

  9. Metacognition of Multi-Tasking: How Well Do We Predict the Costs of Divided Attention?

    PubMed Central

    Finley, Jason R.; Benjamin, Aaron S.; McCarley, Jason S.

    2014-01-01

    Risky multi-tasking, such as texting while driving, may occur because people misestimate the costs of divided attention. In two experiments, participants performed a computerized visual-manual tracking task in which they attempted to keep a mouse cursor within a small target that moved erratically around a circular track. They then separately performed an auditory n-back task. After practicing both tasks separately, participants received feedback on their single-task tracking performance and predicted their dual-task tracking performance before finally performing the two tasks simultaneously. Most participants correctly predicted reductions in tracking performance under dual-task conditions, with a majority overestimating the costs of dual-tasking. However, the between-subjects correlation between predicted and actual performance decrements was near zero. This combination of results suggests that people do anticipate costs of multi-tasking, but have little metacognitive insight on the extent to which they are personally vulnerable to the risks of divided attention, relative to other people. PMID:24490818

  10. Executive Function Is Necessary for Perspective Selection, Not Level-1 Visual Perspective Calculation: Evidence from a Dual-Task Study of Adults

    ERIC Educational Resources Information Center

    Qureshi, Adam W.; Apperly, Ian A.; Samson, Dana

    2010-01-01

    Previous research suggests that perspective-taking and other "theory of mind" processes may be cognitively demanding for adult participants, and may be disrupted by concurrent performance of a secondary task. In the current study, a Level-1 visual perspective task was administered to 32 adults using a dual-task paradigm in which the secondary task…

  11. The Influence of a Cognitive Task on the Postural Phase of Gait Initiation in Parkinson's Disease: An Electromyographic-Based Analysis.

    PubMed

    Fernandes, Ângela; Sousa, Andreia S P; Rocha, Nuno; Tavares, João Manuel R S

    2017-07-01

    The aim of this study was to compare postural control strategies during gait initiation in single- and dual-task conditions in individuals in early stages of Parkinson's Disease (PD). The activation timing of tibialis anterior occurred significantly later in the individuals with PD than in the controls (p = .05), and a significant interaction between the groups, conditions and limbs was found (p = .027). Differences between the single- and dual-task conditions were observed for the activation timing of the tibialis anterior (p = .042) and for the magnitude of soleus (p = .007), with lower values for the dual-task condition. Furthermore, not all the individuals followed the previously reported pattern of soleus inhibition followed by tibialis anterior activation. The duration of the mediolateral displacement of the center of pressure was longer in the individuals with PD than in the controls (p = .019). The anticipatory postural adjustments during gait initiation are impaired in PD and are expressed by an activation failure of tibialis anterior in both single- and dual-task conditions. Hence, it is important that during rehabilitation, intervention should concentrate on the tibialis anterior TA.

  12. Brief time course of trait anxiety-related attentional bias to fear-conditioned stimuli: Evidence from the dual-RSVP task.

    PubMed

    Booth, Robert W

    2017-03-01

    Attentional bias to threat is a much-studied feature of anxiety; it is typically assessed using response time (RT) tasks such as the dot probe. Findings regarding the time course of attentional bias have been inconsistent, possibly because RT tasks are sensitive to processes downstream of attention. Attentional bias was assessed using an accuracy-based task in which participants detected a single digit in two simultaneous rapid serial visual presentation (RSVP) streams of letters. Before the target, two coloured shapes were presented simultaneously, one in each RSVP stream; one shape had previously been associated with threat through Pavlovian fear conditioning. Attentional bias was indicated wherever participants identified targets in the threat's RSVP stream more accurately than targets in the other RSVP stream. In 87 unselected undergraduates, trait anxiety only predicted attentional bias when the target was presented immediately following the shapes, i.e. 160 ms later; by 320 ms the bias had disappeared. This suggests attentional bias in anxiety can be extremely brief and transitory. This initial study utilised an analogue sample, and was unable to physiologically verify the efficacy of the conditioning. The next steps will be to verify these results in a sample of diagnosed anxious patients, and to use alternative threat stimuli. The results of studies using response time to assess the time course of attentional bias may partially reflect later processes such as decision making and response preparation. This may limit the efficacy of therapies aiming to retrain attentional biases using response time tasks. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Short Term Auditory Pacing Changes Dual Motor Task Coordination in Children with and without Dyslexia

    ERIC Educational Resources Information Center

    Getchell, Nancy; Mackenzie, Samuel J.; Marmon, Adam R.

    2010-01-01

    This study examined the effect of short-term auditory pacing practice on dual motor task performance in children with and without dyslexia. Groups included dyslexic with Movement Assessment Battery for Children (MABC) scores greater than 15th percentile (D_HIGH, n = 18; mean age 9.89 [plus or minus] 2.0 years), dyslexic with MABC [less than or…

  14. Multi-Tasking and Choice of Training Data Influencing Parietal ERP Expression and Single-Trial Detection-Relevance for Neuroscience and Clinical Applications.

    PubMed

    Kirchner, Elsa A; Kim, Su Kyoung

    2018-01-01

    Event-related potentials (ERPs) are often used in brain-computer interfaces (BCIs) for communication or system control for enhancing or regaining control for motor-disabled persons. Especially results from single-trial EEG classification approaches for BCIs support correlations between single-trial ERP detection performance and ERP expression. Hence, BCIs can be considered as a paradigm shift contributing to new methods with strong influence on both neuroscience and clinical applications. Here, we investigate the relevance of the choice of training data and classifier transfer for the interpretability of results from single-trial ERP detection. In our experiments, subjects performed a visual-motor oddball task with motor-task relevant infrequent ( targets ), motor-task irrelevant infrequent ( deviants ), and motor-task irrelevant frequent ( standards ) stimuli. Under dual-task condition, a secondary senso-motor task was performed, compared to the simple-task condition. For evaluation, average ERP analysis and single-trial detection analysis with different numbers of electrodes were performed. Further, classifier transfer was investigated between simple and dual task. Parietal positive ERPs evoked by target stimuli (but not by deviants) were expressed stronger under dual-task condition, which is discussed as an increase of task emphasis and brain processes involved in task coordination and change of task set. Highest classification performance was found for targets irrespective whether all 62, 6 or 2 parietal electrodes were used. Further, higher detection performance of targets compared to standards was achieved under dual-task compared to simple-task condition in case of training on data from 2 parietal electrodes corresponding to results of ERP average analysis. Classifier transfer between tasks improves classification performance in case that training took place on more varying examples (from dual task). In summary, we showed that P300 and overlaying parietal

  15. Multi-Tasking and Choice of Training Data Influencing Parietal ERP Expression and Single-Trial Detection—Relevance for Neuroscience and Clinical Applications

    PubMed Central

    Kirchner, Elsa A.; Kim, Su Kyoung

    2018-01-01

    Event-related potentials (ERPs) are often used in brain-computer interfaces (BCIs) for communication or system control for enhancing or regaining control for motor-disabled persons. Especially results from single-trial EEG classification approaches for BCIs support correlations between single-trial ERP detection performance and ERP expression. Hence, BCIs can be considered as a paradigm shift contributing to new methods with strong influence on both neuroscience and clinical applications. Here, we investigate the relevance of the choice of training data and classifier transfer for the interpretability of results from single-trial ERP detection. In our experiments, subjects performed a visual-motor oddball task with motor-task relevant infrequent (targets), motor-task irrelevant infrequent (deviants), and motor-task irrelevant frequent (standards) stimuli. Under dual-task condition, a secondary senso-motor task was performed, compared to the simple-task condition. For evaluation, average ERP analysis and single-trial detection analysis with different numbers of electrodes were performed. Further, classifier transfer was investigated between simple and dual task. Parietal positive ERPs evoked by target stimuli (but not by deviants) were expressed stronger under dual-task condition, which is discussed as an increase of task emphasis and brain processes involved in task coordination and change of task set. Highest classification performance was found for targets irrespective whether all 62, 6 or 2 parietal electrodes were used. Further, higher detection performance of targets compared to standards was achieved under dual-task compared to simple-task condition in case of training on data from 2 parietal electrodes corresponding to results of ERP average analysis. Classifier transfer between tasks improves classification performance in case that training took place on more varying examples (from dual task). In summary, we showed that P300 and overlaying parietal positive

  16. The planetary water drama: Dual task of feeding humanity and curbing climate change

    NASA Astrophysics Data System (ADS)

    Rockström, J.; Falkenmark, M.; Lannerstad, M.; Karlberg, L.

    2012-08-01

    This paper analyses the potential conflict between resilience of the Earth system and global freshwater requirements for the dual task of carbon sequestration to reduce CO2 in the atmosphere, and food production to feed humanity by 2050. It makes an attempt to assess the order of magnitude of the increased consumptive water use involved and analyses the implications as seen from two parallel perspectives; the global perspective of human development within a “safe operating space” with regard to the definition of the Planetary Boundary for freshwater; and the social-ecological implications at the regional river basin scale in terms of sharpening water shortages and threats to aquatic ecosystems. The paper shows that the consumptive water use involved in the dual task would both transgress the proposed planetary boundary range for global consumptive freshwater use and would further exacerbate already severe river depletion, causing societal problems related to water shortage and water allocation. Thus, strategies to rely on sequestration of CO2 as a mitigation strategy must recognize the high freshwater costs involved, implying that the key climate mitigation strategy must be to reduce emissions. The paper finally highlights the need to analyze both water and carbon tradeoffs from anticipated large scale biofuel production climate change mitigation strategy, to reveal gains and impact of this in contrast to carbon sequestration strategies.

  17. Factors Contributing to Single- and Dual-Task Timed "Up & Go" Test Performance in Middle-Aged and Older Adults Who Are Active and Dwell in the Community.

    PubMed

    Chen, Hui-Ya; Tang, Pei-Fang

    2016-03-01

    Dual-task Timed "Up & Go" (TUG) tests are likely to have applications different from those of a single-task TUG test and may have different contributing factors. The purpose of this study was to compare factors contributing to performance on single- and dual-task TUG tests. This investigation was a cross-sectional study. Sixty-four adults who were more than 50 years of age and dwelled in the community were recruited. Interviews and physical examinations were performed to identify potential contributors to TUG test performance. The time to complete the single-task TUG test (TUGsingle) or the dual-task TUG test, which consisted of completing the TUG test while performing a serial subtraction task (TUGcognitive) or while carrying water (TUGmanual), was measured. Age, hip extensor strength, walking speed, general mental function, and Stroop scores for word and color were significantly associated with performance on all TUG tests. Hierarchical multiple regression models, without the input of walking speed, revealed different independent factors contributing to TUGsingle performance (Mini-Mental Status Examination score, β=-0.32), TUGmanual performance (age, β=0.35), and TUGcognitive performance (Stroop word score, β=-0.40; Mini-Mental Status Examination score, β=-0.31). At least 40% of the variance in the performance on the 3 TUG tests was not explained by common clinical measures, even when the factor of walking speed was considered. However, this study successfully identified some important factors contributing to performance on different TUG tests, and other studies have reported similar findings for single-task TUG test and dual-task gait performance. Although the TUGsingle and the TUGcognitive shared general mental function as a common factor, the TUGmanual was uniquely influenced by age and the TUGcognitive was uniquely influenced by focused attention. These results suggest that both common and unique factors contribute to performance on single- and dual-task

  18. Interference between a fast-paced spatial puzzle task and verbal memory demands.

    PubMed

    Epling, Samantha L; Blakely, Megan J; Russell, Paul N; Helton, William S

    2017-06-01

    Research continues to provide evidence that people are poor multi-taskers. Cognitive resource theory is a common explanation for the inability to efficiently perform multiple tasks at the same time. This theory proposes that one's limited supply of cognitive resources can be utilized faster than it is replenished, which results in a performance decline, particularly when these limited resources must be allocated among multiple tasks. Researchers have proposed both domain-specific, for example, spatial versus verbal processing resources, and domain general cognitive resources. In the present research, we investigated whether a spatial puzzle task performed simultaneously with a verbal recall task would impair performance in either task or both tasks, compared to performance on the tasks individually. As hypothesized, a reduction in word recall was found when dual-tasking, though performance on the puzzle task did not significantly differ between the single- and dual-task conditions. This is consistent, in part, with both a general resource theory and a Multiple Resource Theory, but further work is required to better understand the cognitive processing system. The employment of the recall task in the dual-task paradigm with a variety of secondary tasks will help to continue mapping out the specificity (or lack thereof) of cognitive resources utilized in various mental and physical tasks.

  19. The effects of aging on postural control and selective attention when stepping down while performing a concurrent auditory response task.

    PubMed

    Tsang, William W N; Lam, Nazca K Y; Lau, Kit N L; Leung, Harry C H; Tsang, Crystal M S; Lu, Xi

    2013-12-01

    To investigate the effects of aging on postural control and cognitive performance in single- and dual-tasking. A cross-sectional comparative design was conducted in a university motion analysis laboratory. Young adults (n = 30; age 21.9 ± 2.4 years) and older adults (n = 30; age 71.9 ± 6.4 years) were recruited. Postural control after stepping down was measured with and without performing a concurrent auditory response task. Measurement included: (1) reaction time and (2) error rate in performing the cognitive task; (3) total sway path and (4) total sway area after stepping down. Our findings showed that the older adults had significantly longer reaction times and higher error rates than the younger subjects in both the single-tasking and dual-tasking conditions. The older adults had significantly longer reaction times and higher error rates when dual-tasking compared with single-tasking, but the younger adults did not. The older adults demonstrated significantly less total sway path, but larger total sway area in single-leg stance after stepping down than the young adults. The older adults showed no significant change in total sway path and area between the dual-tasking and when compared with single-tasking conditions, while the younger adults showed significant decreases in sway. Older adults prioritize postural control by sacrificing cognitive performance when faced with dual-tasking.

  20. Cortical Thickness Changes and Their Relationship to Dual-Task Performance following Mild Traumatic Brain Injury in Youth.

    PubMed

    Urban, Karolina J; Riggs, Lily; Wells, Greg D; Keightley, Michelle; Chen, Jen-Kai; Ptito, Alain; Fait, Philippe; Taha, Tim; Sinopoli, Katia J

    2017-02-15

    Mild traumatic brain injury (mTBI) is common in youth, especially in those who participate in sport. Recent investigations from our group have shown that asymptomatic children and adolescents with mTBI continue to exhibit alterations in neural activity and cognitive performance compared with those without a history of mTBI. This is an intriguing finding, given that current return-to-learn and return-to-play protocols rely predominately on subjective symptom reports, which may not be sensitive enough to detect subtle injury-related changes. As a result, youth may be at greater risk for re-injury and long-term consequences if they are cleared for activity while their brains continue to be compromised. It is currently unknown whether mTBI also affects brain microstructure in the developing brain, particularly cortical thickness, and whether such changes are also related to cognitive performance. The present study examined cortical thickness in 13 asymptomatic youth (10-14 years old) who had sustained an mTBI 3-8 months prior to testing compared with 14 age-matched typically developing controls. Cortical thickness was also examined in relation to working memory performance during single and dual task paradigms. The results show that youth who had sustained an mTBI had thinner cortices in the left dorsolateral prefrontal region and right anterior and posterior inferior parietal lobes. Additionally, cortical thinning was associated with slower reaction time during the dual-task condition in the injured youth only. The results also point to a possible relationship between functional and structural alterations as a result of mTBI in youth, and lend evidence for neural changes beyond symptom resolution.

  1. Mental rotation impairs attention shifting and short-term memory encoding: neurophysiological evidence against the response-selection bottleneck model of dual-task performance.

    PubMed

    Pannebakker, Merel M; Jolicœur, Pierre; van Dam, Wessel O; Band, Guido P H; Ridderinkhof, K Richard; Hommel, Bernhard

    2011-09-01

    Dual tasks and their associated delays have often been used to examine the boundaries of processing in the brain. We used the dual-task procedure and recorded event-related potentials (ERPs) to investigate how mental rotation of a first stimulus (S1) influences the shifting of visual-spatial attention to a second stimulus (S2). Visual-spatial attention was monitored by using the N2pc component of the ERP. In addition, we examined the sustained posterior contralateral negativity (SPCN) believed to index the retention of information in visual short-term memory. We found modulations of both the N2pc and the SPCN, suggesting that engaging mechanisms of mental rotation impairs the deployment of visual-spatial attention and delays the passage of a representation of S2 into visual short-term memory. Both results suggest interactions between mental rotation and visual-spatial attention in capacity-limited processing mechanisms indicating that response selection is not pivotal in dual-task delays and all three processes are likely to share a common resource like executive control. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Dual Dynamically Orthogonal approximation of incompressible Navier Stokes equations with random boundary conditions

    NASA Astrophysics Data System (ADS)

    Musharbash, Eleonora; Nobile, Fabio

    2018-02-01

    In this paper we propose a method for the strong imposition of random Dirichlet boundary conditions in the Dynamical Low Rank (DLR) approximation of parabolic PDEs and, in particular, incompressible Navier Stokes equations. We show that the DLR variational principle can be set in the constrained manifold of all S rank random fields with a prescribed value on the boundary, expressed in low rank format, with rank smaller then S. We characterize the tangent space to the constrained manifold by means of a Dual Dynamically Orthogonal (Dual DO) formulation, in which the stochastic modes are kept orthonormal and the deterministic modes satisfy suitable boundary conditions, consistent with the original problem. The Dual DO formulation is also convenient to include the incompressibility constraint, when dealing with incompressible Navier Stokes equations. We show the performance of the proposed Dual DO approximation on two numerical test cases: the classical benchmark of a laminar flow around a cylinder with random inflow velocity, and a biomedical application for simulating blood flow in realistic carotid artery reconstructed from MRI data with random inflow conditions coming from Doppler measurements.

  3. Effects of spatial congruency on saccade and visual discrimination performance in a dual-task paradigm.

    PubMed

    Moehler, Tobias; Fiehler, Katja

    2014-12-01

    The present study investigated the coupling of selection-for-perception and selection-for-action during saccadic eye movement planning in three dual-task experiments. We focused on the effects of spatial congruency of saccade target (ST) location and discrimination target (DT) location and the time between ST-cue and Go-signal (SOA) on saccadic eye movement performance. In two experiments, participants performed a visual discrimination task at a cued location while programming a saccadic eye movement to a cued location. In the third experiment, the discrimination task was not cued and appeared at a random location. Spatial congruency of ST-location and DT-location resulted in enhanced perceptual performance irrespective of SOA. Perceptual performance in spatially incongruent trials was above chance, but only when the DT-location was cued. Saccade accuracy and precision were also affected by spatial congruency showing superior performance when the ST- and DT-location coincided. Saccade latency was only affected by spatial congruency when the DT-cue was predictive of the ST-location. Moreover, saccades consistently curved away from the incongruent DT-locations. Importantly, the effects of spatial congruency on saccade parameters only occurred when the DT-location was cued; therefore, results from experiments 1 and 2 are due to the endogenous allocation of attention to the DT-location and not caused by the salience of the probe. The SOA affected saccade latency showing decreasing latencies with increasing SOA. In conclusion, our results demonstrate that visuospatial attention can be voluntarily distributed upon spatially distinct perceptual and motor goals in dual-task situations, resulting in a decline of visual discrimination and saccade performance.

  4. The effects of concurrent cognitive tasks on postural sway in healthy subjects.

    PubMed

    Mujdeci, Banu; Turkyilmaz, Didem; Yagcioglu, Suha; Aksoy, Songul

    2016-01-01

    Keeping balance of the upright stance is a highly practiced daily task for healthy adults and is effectively performed without overt attentional control in most. The purpose of this study was to examine the influence of concurrent cognitive tasks on postural sway in healthy participants. This was a prospective study. 20 healthy volunteer subjects were included. The cognitive and balance tasks were performed separately and then, concurrently. Postural control task consisted of 6 conditions (C) of the Sensory Organization Test. The cognitive task consisted of digit rehearsal task of varying presentation and varying levels of difficulty. A statistically significant difference was noted between dual task and no task for C1, C2, C3 and C4 Sensory Organization Test scores (p<0.05). There was no statistically significant difference between dual task versus non-task for C5, C6 and combined Sensory Organization Test scores (p>0.05). During dual task, increase has been determined in postural sway for C1, C2, C3 and C4 for all presentation modes and difficulty levels of the cognitive tasks. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  5. Lateralized dual task interference in left-handers: initial value differences do not affect the outcome.

    PubMed

    McBride, D M; Cherry, B J; Kee, D W; Neale, P L

    1995-07-01

    The study was conducted to clarify factors involved in dual-task finger-tapping interference. Left-handers, as assessed by hand-writing preference and left-hand baseline tapping advantage, tapped both alone and while solving anagrams. Even though the left-hand baseline tapping advantage was experimentally removed on some (adjusted) trials, greater left- than right-hand tapping interference was observed during concurrent task performance. This result coupled with previous findings for right-handed subjects [Kee and Cherry, Neuropsychologia, Vol. 28, pp. 313-316, 1990] indicates that lateralized interference effects are not merely due to initial baseline tapping differences as proposed by Willis and Goodwin [Neuropsychologia, Vol. 25, pp. 719-724, 1987].

  6. Engine performance analysis and optimization of a dual-mode scramjet with varied inlet conditions

    NASA Astrophysics Data System (ADS)

    Tian, Lu; Chen, Li-Hong; Chen, Qiang; Zhong, Feng-Quan; Chang, Xin-Yu

    2016-02-01

    A dual-mode scramjet can operate in a wide range of flight conditions. Higher thrust can be generated by adopting suitable combustion modes. Based on the net thrust, an analysis and preliminary optimal design of a kerosene-fueled parameterized dual-mode scramjet at a crucial flight Mach number of 6 were investigated by using a modified quasi-one-dimensional method and simulated annealing strategy. Engine structure and heat release distributions, affecting the engine thrust, were chosen as analytical parameters for varied inlet conditions (isolator entrance Mach number: 1.5-3.5). Results show that different optimal heat release distributions and structural conditions can be obtained at five different inlet conditions. The highest net thrust of the parameterized dual-mode engine can be achieved by a subsonic combustion mode at an isolator entrance Mach number of 2.5. Additionally, the effects of heat release and scramjet structure on net thrust have been discussed. The present results and the developed analytical method can provide guidance for the design and optimization of high-performance dual-mode scramjets.

  7. Auditory temporal preparation induced by rhythmic cues during concurrent auditory working memory tasks.

    PubMed

    Cutanda, Diana; Correa, Ángel; Sanabria, Daniel

    2015-06-01

    The present study investigated whether participants can develop temporal preparation driven by auditory isochronous rhythms when concurrently performing an auditory working memory (WM) task. In Experiment 1, participants had to respond to an auditory target presented after a regular or an irregular sequence of auditory stimuli while concurrently performing a Sternberg-type WM task. Results showed that participants responded faster after regular compared with irregular rhythms and that this effect was not affected by WM load; however, the lack of a significant main effect of WM load made it difficult to draw any conclusion regarding the influence of the dual-task manipulation in Experiment 1. In order to enhance dual-task interference, Experiment 2 combined the auditory rhythm procedure with an auditory N-Back task, which required WM updating (monitoring and coding of the information) and was presumably more demanding than the mere rehearsal of the WM task used in Experiment 1. Results now clearly showed dual-task interference effects (slower reaction times [RTs] in the high- vs. the low-load condition). However, such interference did not affect temporal preparation induced by rhythms, with faster RTs after regular than after irregular sequences in the high-load and low-load conditions. These results revealed that secondary tasks demanding memory updating, relative to tasks just demanding rehearsal, produced larger interference effects on overall RTs in the auditory rhythm task. Nevertheless, rhythm regularity exerted a strong temporal preparation effect that survived the interference of the WM task even when both tasks competed for processing resources within the auditory modality. (c) 2015 APA, all rights reserved).

  8. The exercise and affect relationship: evidence for the dual-mode model and a modified opponent process theory.

    PubMed

    Markowitz, Sarah M; Arent, Shawn M

    2010-10-01

    This study examined the relationship between exertion level and affect using the framework of opponent-process theory and the dual-mode model, with the Activation-Deactivation Adjective Checklist and the State Anxiety Inventory among 14 active and 14 sedentary participants doing 20 min of treadmill exercise at speeds of 5% below, 5% above, and at lactate threshold (LT). We found a significant effect of time, condition, Time × Condition, and Time × Group, but no group, Group × Condition, or Time × Group × Condition effects, such that the 5% above LT condition produced a worsening of affect in-task compared with all other conditions whereas, across conditions, participants experienced in-task increases in energy and tension, and in-task decreases in tiredness and calmness relative to baseline. Posttask, participants experienced mood improvement (decreased tension, anxiety, and increased calmness) across conditions, with a 30-min delay in the above LT condition. These results partially support the dual-mode model and a modified opponent-process theory.

  9. Heating, Ventilation, and Air Conditioning Series. Duty Task List.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This task list is intended for use in planning and/or evaluating a competency-based course in heating, ventilation, and air conditioning. The guide outlines the tasks entailed in eight different duties typically required of employees in the following occupations: residential installer, domestic refrigeration technician, air conditioning and…

  10. The relationship between dual-task and cognitive performance among elderly participants who exercise regularly

    PubMed Central

    Lima, Luciana C. A.; Ansai, Juliana H.; Andrade, Larissa P.; Takahashi, Anielle C. M.

    2015-01-01

    BACKGROUND: The dual-task performance is associated with the functionality of the elderly and it becomes more complex with age. OBJECTIVE: To investigate the relationship between the Timed Up and Go dual task (TUG-DT) and cognitive tests among elderly participants who exercise regularly. METHOD: This study examined 98 non-institutionalized people over 60 years old who exercised regularly. Participants were assessed using the TUG-DT (i.e. doing the TUG while listing the days of the week in reverse order), the Montreal Cognitive Assessment (MoCA), the Clock Drawing Test (CDT), and the Mini Mental State Examination (MMSE). The motor (i.e. time and number of steps) and cognitive (i.e. number of correct words) data were collected from TUG-DT . We used a significance level of α=0.05 and SPSS 17.0 for all data analyses. RESULTS: This current elderly sample featured a predominance of women (69.4%) who were highly educated (median=10 years of education) compared to Brazilian population and mostly non-fallers (86.7%). The volunteers showed a good performance on the TUG-DT and the other cognitive tests, except the MoCA, with scores below the cutoff of 26 points. Significant and weak correlations were observed between the TUG-DT (time) and the visuo-spatial/executive domain of the MoCA and the MMSE. The cognitive component of the TUG-DT showed strong correlations between the total MoCA performance score and its visuo-spatial/executive domain. CONCLUSIONS: The use of the TUG-DT to assess cognition is promising; however, the use of more challenging cognitive tasks should be considered when the study population has a high level of education. PMID:25993629

  11. Examining the stability of dual-task posture and reaction time measures in older adults over five sessions: a pilot study.

    PubMed

    Jehu, Deborah A; Paquet, Nicole; Lajoie, Yves

    2016-12-01

    Improved performance may be inherent due to repeated exposure to a testing protocol. However, limited research has examined this phenomenon in postural control. The aim was to determine the influence of repeated administration of a dual-task testing protocol once per week for 5 weeks on postural sway and reaction time. Ten healthy older adults (67.0 ± 6.9 years) stood on a force plate for 30 s in feet apart and semi-tandem positions while completing simple reaction time (SRT) and choice reaction time (CRT) tasks. They were instructed to stand as still as possible while verbally responding as fast as possible to the stimuli. No significant differences in postural sway were shown over time (p > 0.05). A plateau in average CRT emerged as the time effect revealed longer CRT during session 1 compared to sessions 3-5 (p < 0.05). Furthermore, the time effect for within-subject variability of CRT uncovered no plateaus as it was less variable in session 5 than sessions 1-4 (p < 0.05). The lack of a plateau in variability of CRT may have emerged as older adults may require longer to reach optimal performance potential in a dual-task context. Postural sway and SRT were stable over the 5 testing sessions, but variability of CRT continued to improve over time. These findings form a basis for future studies to examine performance-related improvements due to repeated exposure to a testing protocol in a dual-task setting.

  12. Spatial and temporal EEG dynamics of dual-task driving performance

    PubMed Central

    2011-01-01

    Background Driver distraction is a significant cause of traffic accidents. The aim of this study is to investigate Electroencephalography (EEG) dynamics in relation to distraction during driving. To study human cognition under a specific driving task, simulated real driving using virtual reality (VR)-based simulation and designed dual-task events are built, which include unexpected car deviations and mathematics questions. Methods We designed five cases with different stimulus onset asynchrony (SOA) to investigate the distraction effects between the deviations and equations. The EEG channel signals are first converted into separated brain sources by independent component analysis (ICA). Then, event-related spectral perturbation (ERSP) changes of the EEG power spectrum are used to evaluate brain dynamics in time-frequency domains. Results Power increases in the theta and beta bands are observed in relation with distraction effects in the frontal cortex. In the motor area, alpha and beta power suppressions are also observed. All of the above results are consistently observed across 15 subjects. Additionally, further analysis demonstrates that response time and multiple cortical EEG power both changed significantly with different SOA. Conclusions This study suggests that theta power increases in the frontal area is related to driver distraction and represents the strength of distraction in real-life situations. PMID:21332977

  13. Singing numbers…in cognitive space--a dual-task study of the link between pitch, space, and numbers.

    PubMed

    Fischer, Martin H; Riello, Marianna; Giordano, Bruno L; Rusconi, Elena

    2013-04-01

    We assessed the automaticity of spatial-numerical and spatial-musical associations by testing their intentionality and load sensitivity in a dual-task paradigm. In separate sessions, 16 healthy adults performed magnitude and pitch comparisons on sung numbers with variable pitch. Stimuli and response alternatives were identical, but the relevant stimulus attribute (pitch or number) differed between tasks. Concomitant tasks required retention of either color or location information. Results show that spatial associations of both magnitude and pitch are load sensitive and that the spatial association for pitch is more powerful than that for magnitude. These findings argue against the automaticity of spatial mappings in either stimulus dimension. Copyright © 2013 Cognitive Science Society, Inc.

  14. Reduced mental capacity and behavior of a rider of a bicycle simulator under alcohol stress or under dual task load

    NASA Technical Reports Server (NTRS)

    Soede, M.

    1977-01-01

    Experiments were carried out on a bicycle simulator with alcohol administration and a binary choice task in separate sessions, intending to reduce the subject's mental capacity. Before and after such sessions a visual evoked response measurement was done. The subject's performance was analyzed with describing function techniques. The results indicate that the alcohol affects the course-following task as well as the balancing task. The binary choice task is more specifically influencing the course-following task. The dual task shows a more pronounced effect on the recovery of the evoked response. The alcohol is delaying the recovery curve of the evoked response. A tentative explanation can be given which agrees with the performance data.

  15. Exploring the cognitive load of negative thinking: a novel dual-task experiment.

    PubMed

    Takano, Keisuke; Iijima, Yudai; Sakamoto, Shinji; Tanno, Yoshihiko

    2014-12-01

    Females are more likely to engage in the preoccupation of past negative experiences than males, which might contribute to their greater tendency toward depression. However, there is limited understanding regarding the cognitive basis for the negative autobiographical information processing of females. In the present study, we assessed the cognitive resources required for negative thinking, by using a novel dual-task paradigm that combined think-aloud and time-estimation tasks. Fifty-three Japanese undergraduate students were asked to think aloud about personal past or future emotional episodes for a particular duration. In addition, they were asked to estimate the duration of their speech. Their estimates were compared to the actual time taken, and the errors were used as indices of cognitive burden during the speech task. As compared to males, females exhibited greater judgment errors, particularly when thinking about their past negative experiences. This suggests that females allocate more attentional resources toward thinking about the past. Participants could rehearse the task during the time reproduction phase, and the quality of the rehearsal and their memory capacity might have influenced the accuracy of their duration judgment. Females tend to allocate more attentional resources than males to thinking about past negative episodes, which in turn might be associated with reduced availability of resources for central cognitive control processes such as inhibition of and switching away from processing of negative autobiographical information. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Dual-Task Processing as a Measure of Executive Function: A Comparison between Adults with Williams and Down Syndromes

    ERIC Educational Resources Information Center

    Kittler, Phyllis M.; Krinsky-McHale, Sharon J.; Devenny, Darlynne A.

    2008-01-01

    Behavioral phenotypes of individuals with Williams syndrome and individuals with Down syndrome have been contrasted in relation to short-term memory. People with Down syndrome are stronger visuospatially and those with Williams syndrome are stronger verbally. We examined short-term memory, then explored whether dual-task processing further…

  17. Effect of a dual-task net-step exercise on cognitive and gait function in older adults.

    PubMed

    Kitazawa, Kazutoshi; Showa, Satoko; Hiraoka, Akira; Fushiki, Yasuhiro; Sakauchi, Humio; Mori, Mitsuru

    2015-01-01

    Participation in generally recommended aerobics or strength exercises may be challenging for older adults. Therefore, it is necessary to consider the types and levels of physical activities suited for them to improve their cognitive and gait function and adherence to exercise programs. This has prompted efforts to identify exercises that require less physical strength and frequency of performance, while still offering cognitive and health benefits. Here, we aimed to assess the effect of a novel dual-task net-step exercise (NSE) performed once a week for 8 consecutive weeks on improvements in cognitive performance and gait function in an older population. In this pretest/posttest experimental case control study, 60 healthy older adults (mean age 76.4 years) were recruited from community-dwelling people and separated randomly into 2 groups: a dual-task NSE group and a control group. The NSE group was asked to walk across a net without stepping on the ropes or being caught in the net. Two computer panel-type cognitive functional assessments, the Touch-M and Touch Panel-Type Dementia Assessment Scale, were administered at baseline and after 8 weeks of intervention to determine the effects of NSE. Improvements in gait function were also evaluated using Timed Up and Go test scores. Mixed-effect models with repeated measures (group × time) (analysis of variance, F test) were used to test the effects of NSE. Adjustments were made for covariates including age and sex (analysis of covariance). The NSE group showed significant improvement in cognitive performance (6.8% change; total Touch-M score 5.4 points; P = .04) and gait performance (11.5% change; Timed Up and Go time -0.98 second; P < .001) over the 8-week period. In the control group, there was no significant improvement. This study shows that dual-task NSE is capable of improving cognitive and gait performance in healthy older adults. Our results indicate that NSE offers an option for a large segment of the older

  18. Dual-task interference effects on cross-modal numerical order and sound intensity judgments: the more the louder?

    PubMed

    Alards-Tomalin, Doug; Walker, Alexander C; Nepon, Hillary; Leboe-McGowan, Launa C

    2017-09-01

    In the current study, cross-task interactions between number order and sound intensity judgments were assessed using a dual-task paradigm. Participants first categorized numerical sequences composed of Arabic digits as either ordered (ascending, descending) or non-ordered. Following each number sequence, participants then had to judge the intensity level of a target sound. Experiment 1 emphasized processing the two tasks independently (serial processing), while Experiments 2 and 3 emphasized processing the two tasks simultaneously (parallel processing). Cross-task interference occurred only when the task required parallel processing and was specific to ascending numerical sequences, which led to a higher proportion of louder sound intensity judgments. In Experiment 4 we examined whether this unidirectional interaction was the result of participants misattributing enhanced processing fluency experienced on ascending sequences as indicating a louder target sound. The unidirectional finding could not be entirely attributed to misattributed processing fluency, and may also be connected to experientially derived conceptual associations between ascending number sequences and greater magnitude, consistent with conceptual mapping theory.

  19. Allocation of Attentional Resources toward a Secondary Cognitive Task Leads to Compromised Ankle Proprioceptive Performance in Healthy Young Adults

    PubMed Central

    Yasuda, Kazuhiro; Iimura, Naoyuki; Iwata, Hiroyasu

    2014-01-01

    The objective of the present study was to determine whether increased attentional demands influence the assessment of ankle joint proprioceptive ability in young adults. We used a dual-task condition, in which participants performed an ankle ipsilateral position-matching task with and without a secondary serial auditory subtraction task during target angle encoding. Two experiments were performed with two different cohorts: one in which the auditory subtraction task was easy (experiment 1a) and one in which it was difficult (experiment 1b). The results showed that, compared with the single-task condition, participants had higher absolute error under dual-task conditions in experiment 1b. The reduction in position-matching accuracy with an attentionally demanding cognitive task suggests that allocation of attentional resources toward a difficult second task can lead to compromised ankle proprioceptive performance. Therefore, these findings indicate that the difficulty level of the cognitive task might be the possible critical factor that decreased accuracy of position-matching task. We conclude that increased attentional demand with difficult cognitive task does influence the assessment of ankle joint proprioceptive ability in young adults when measured using an ankle ipsilateral position-matching task. PMID:24523966

  20. A dual-loop model of the human controller in single-axis tracking tasks

    NASA Technical Reports Server (NTRS)

    Hess, R. A.

    1977-01-01

    A dual loop model of the human controller in single axis compensatory tracking tasks is introduced. This model possesses an inner-loop closure which involves feeding back that portion of the controlled element output rate which is due to control activity. The sensory inputs to the human controller are assumed to be system error and control force. The former is assumed to be sensed via visual, aural, or tactile displays while the latter is assumed to be sensed in kinesthetic fashion. A nonlinear form of the model is briefly discussed. This model is then linearized and parameterized. A set of general adaptive characteristics for the parameterized model is hypothesized. These characteristics describe the manner in which the parameters in the linearized model will vary with such things as display quality. It is demonstrated that the parameterized model can produce controller describing functions which closely approximate those measured in laboratory tracking tasks for a wide variety of controlled elements.

  1. Motivation to comply with task rules and multitasking performance: The role of need for cognitive closure and goal importance.

    PubMed

    Szumowska, Ewa; Kossowska, Małgorzata; Roets, Arne

    2018-01-01

    In three studies, we examined the role task rules play in multitasking performance. We postulated that rules should be especially important for individuals highly motivated to have structure and clear answers, i.e., those high on need for cognitive closure (NFC). High NFC should thus be related to greater compliance with task rules. Specifically, given high goal importance, NFC should be more strongly related to a multitasking strategy when multitasking is imposed by the rules, and to a mono-tasking strategy when monotasking is imposed by the rules. This should translate into better multitasking or mono-tasking performance, depending on condition. Overall, the results were supportive as NFC was related to a more mono-tasking strategy in the mono-tasking condition (Studies 1 and 2 only) and more dual-tasking strategy in the dual-tasking condition (Studies 1-3). This translated into respective differences in performance. The effects were significant only when goal importance was high (Study 1) and held when cognitive ability was controlled for (Study 2).

  2. Hysteresis in Mental Workload and Task Performance: The Influence of Demand Transitions and Task Prioritization.

    PubMed

    Jansen, Reinier J; Sawyer, Ben D; van Egmond, René; de Ridder, Huib; Hancock, Peter A

    2016-12-01

    We examine how transitions in task demand are manifested in mental workload and performance in a dual-task setting. Hysteresis has been defined as the ongoing influence of demand levels prior to a demand transition. Authors of previous studies predominantly examined hysteretic effects in terms of performance. However, little is known about the temporal development of hysteresis in mental workload. A simulated driving task was combined with an auditory memory task. Participants were instructed to prioritize driving or to prioritize both tasks equally. Three experimental conditions with low, high, and low task demands were constructed by manipulating the frequency of lane changing. Multiple measures of subjective mental workload were taken during experimental conditions. Contrary to our prediction, no hysteretic effects were found after the high- to low-demand transition. However, a hysteretic effect in mental workload was found within the high-demand condition, which degraded toward the end of the high condition. Priority instructions were not reflected in performance. Online assessment of both performance and mental workload demonstrates the transient nature of hysteretic effects. An explanation for the observed hysteretic effect in mental workload is offered in terms of effort regulation. An informed arrival at the scene is important in safety operations, but peaks in mental workload should be avoided to prevent buildup of fatigue. Therefore, communication technologies should incorporate the historical profile of task demand. © 2016, Human Factors and Ergonomics Society.

  3. Dual Task Costs of Oral Reading for Young versus Older Adults

    PubMed Central

    Kemper, Susan; Bontempo, Daniel; Schmalzried, RaLynn; McKedy, Whitney; Tagliaferri, Bruno; Kieweg, Doug

    2013-01-01

    A digital pursuit rotor was used to monitor oral reading costs by time-locking tracking performance to the auditory wave form produced as young and older adults were reading out short paragraphs. Multilevel modeling was used to determine how paragraph-level predictors of length, grammatical complexity, and readability and person-level predictors such as speaker age or working memory capacity predicted reading and tracking performance. In addition, sentence-by-sentence variation in tracking performance was examined during the production of individual sentences and during the pauses before upcoming sentences. The results suggest that dual tasking has a greater impact on older adults’ reading comprehension and tracking performance. At the level of individual sentences, young and older adults adopt different strategies to deal with grammatically complex and propositionally dense sentences. PMID:23463405

  4. Influence of dual task and frailty on gait parameters of older community-dwelling individuals

    PubMed Central

    Guedes, Rita C.; Dias, Rosângela C.; Pereira, Leani S. M.; Silva, Sílvia L. A.; Lustosa, Lygia P.; Dias, João M. D.

    2014-01-01

    Background: Gait parameters such as gait speed (GS) are important indicators of functional capacity. Frailty Syndrome is closely related to GS and is also capable of predicting adverse outcomes. The cognitive demand of gait control is usually explored with dual-task (DT) methodology. Objective: To investigate the effect of DT and frailty on the spatio-temporal parameters of gait in older people and identify which variables relate to GS. Method: The presence of frailty was verified by Fried's Frailty Criteria. Cognitive function was evaluated with the Mini-Mental State Exam (MMSE) and gait parameters were analyzed through the GAITRite(r) system in the single-task and DT conditions. The Kolmogorov-Smirnov, ANOVA, and Pearson's Correlation tests were administered. Results: The participants were assigned to the groups frail (FG), pre-frail (PFG), and non-frail (NFG). During the DT, the three groups showed a decrease in GS, cadence, and stride length and an increase in stride time (p<0.001). The reduction in the GS of the FG during the DT showed a positive correlation with the MMSE scores (r=730; p=0.001) and with grip strength (r=681; p=0.001). Conclusions: Gait parameters are more affected by the DT, especially in the frail older subjects. The reduction in GS in the FG is associated with lower grip strength and lower scores in the MMSE. The GS was able to discriminate the older adults in the three levels of frailty, being an important measure of the functional capacity in this population. PMID:25372007

  5. The Effect of Writing Task and Task Conditions on Colombian EFL Learners' Language Use

    ERIC Educational Resources Information Center

    McDonough, Kim; Fuentes, César García

    2015-01-01

    This classroom study examines whether English L2 writers' language use differs depending on the writing task (operationalized as paragraph type), and task conditions (operationalized as individual or collaborative writing). The texts written by English L2 university students in Colombia (N = 26) in response to problem/solution and cause/effect…

  6. Can tutoring improve performance on a reasoning task under deadline conditions?

    PubMed

    Osman, Magda

    2007-03-01

    The present study examined the effectiveness of a tutoring technique that has been used to identify and address participants' misunderstandings in Wason's selection task. In particular, the study investigated whether the technique would lead to improvements in performance when the task was presented in a deadline format (a condition in which time restrictions are imposed). In Experiment 1, the effects of tutoring on performance were compared in free time (conditions in which no time restrictions are imposed) and deadline task formats. In Experiment 2, improvements in performance were studied in deadline task formats, in which the tutoring and test phases were separated by an interval of 1 day. The results suggested that tutoring improved performance on the selection task under deadline and in free time conditions. Additionally, the study showed that participants made errors because they had misinterpreted the task. With tutoring, they were able to modify their initial misunderstandings.

  7. Deficits in Interval Timing Measured by the Dual-Task Paradigm among Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Hwang, Shoou-Lian; Gau, Susan Shur-Fen; Hsu, Wen-Yau; Wu, Yu-Yu

    2010-01-01

    Background: The underlying mechanism of time perception deficit in long time intervals in attention-deficit/hyperactivity disorder (ADHD) is still unclear. This study used the time reproduction dual task to explore the role of the attentional resource in time perception deficits among children and adolescents with ADHD. Methods: Participants…

  8. Task Interference in Time-Based, Event-Based, and Dual Intention Prospective Memory Conditions

    ERIC Educational Resources Information Center

    Hicks, Jason L.; Marsh, Richard L.; Cook, Gabriel I.

    2005-01-01

    Forming the intention to complete an activity later is the standard definition of a prospective memory task. Recently, a debate has arisen concerning the degree to which near-term intentions usurp resources away from other ongoing activities. In four experiments the authors tested how much interference was caused by holding a variety of different…

  9. Does extending the dual-task functional exercises workout improve postural balance in individuals with ID?

    PubMed

    Mikolajczyk, Edyta; Jankowicz-Szymanska, Agnieszka

    2015-03-01

    Maintaining postural balance, overcoming visual and motor coordination disorders and experiencing problems with low general fitness - typical of intellectually disabled individuals - adversely affect the performance quality of their activities of daily living (ADLs). Physical fitness and postural balance can be improved by taking part in special intervention programs. Our study was designed to test whether extending the dual-task intervention program (combining ADLs with balance exercises on unstable surfaces) from 12 to 24 weeks additionally improved postural balance in individuals with intellectual disability (ID). We also attempted to assess whether the effects of the above intervention program were still noticeable after 8 weeks of holidays, in which participants did not take any rehabilitation exercises. A total of 34 adolescents, aged 14-16 years (15.06±0.9), with moderate ID took part in our study. The experimental group (E) consisted of 17 individuals, who continued the intervention program originated 3 months earlier, and the control group (C) comprised the same number of participants. Postural balance was assessed on a stabilometric platform Alfa. Having extended the workout period by another 12 weeks, we noticed that the path length of the center of pressure (COP) covered by participants on tests with their eyes open and closed significantly shortened. After a lapse of 8 weeks from the completion of the program, the experimental group revealed a statistically significant decrease in the velocity along the medio-lateral (M/L) and anterior-posterior (A/P) axes. The remaining variables stayed at the same level and the control group did not demonstrate any statistically significant changes. Dual-task exercises, in which enhancing functional tasks of daily living is combined with a parallel stimulation of balance reactions, may improve static balance in persons with ID. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Less head motion during MRI under task than resting-state conditions.

    PubMed

    Huijbers, Willem; Van Dijk, Koene R A; Boenniger, Meta M; Stirnberg, Rüdiger; Breteler, Monique M B

    2017-02-15

    Head motion reduces data quality of neuroimaging data. In three functional magnetic resonance imaging (MRI) experiments we demonstrate that people make less head movements under task than resting-state conditions. In Experiment 1, we observed less head motion during a memory encoding task than during the resting-state condition. In Experiment 2, using publicly shared data from the UCLA Consortium for Neuropsychiatric Phenomics LA5c Study, we again found less head motion during several active task conditions than during a resting-state condition, although some task conditions also showed comparable motion. In the healthy controls, we found more head motion in men than in women and more motion with increasing age. When comparing clinical groups, we found that patients with a clinical diagnosis of bipolar disorder, or schizophrenia, move more compared to healthy controls or patients with ADHD. Both these experiments had a fixed acquisition order across participants, and we could not rule out that a first or last scan during a session might be particularly prone to more head motion. Therefore, we conducted Experiment 3, in which we collected several task and resting-state fMRI runs with an acquisition order counter-balanced. The results of Experiment 3 show again less head motion during several task conditions than during rest. Together these experiments demonstrate that small head motions occur during MRI even with careful instruction to remain still and fixation with foam pillows, but that head motion is lower when participants are engaged in a cognitive task. These finding may inform the choice of functional runs when studying difficult-to-scan populations, such as children or certain patient populations. Our findings also indicate that differences in head motion complicate direct comparisons of measures of functional neuronal networks between task and resting-state fMRI because of potential differences in data quality. In practice, a task to reduce head motion

  11. The effect of cognitive-motor dual-task training on cognitive function and plasma amyloid β peptide 42/40 ratio in healthy elderly persons: a randomized controlled trial.

    PubMed

    Yokoyama, Hisayo; Okazaki, Kazunobu; Imai, Daiki; Yamashina, Yoshihiro; Takeda, Ryosuke; Naghavi, Nooshin; Ota, Akemi; Hirasawa, Yoshikazu; Miyagawa, Toshiaki

    2015-05-28

    Physical activity reduces the incidence and progression of cognitive impairment. Cognitive-motor dual-task training, which requires dividing attention between cognitive tasks and exercise, may improve various cognitive domains; therefore, we examined the effect of dual-task training on the executive functions and on plasma amyloid β peptide (Aβ) 42/40 ratio, a potent biomarker of Alzheimer's disease, in healthy elderly people. Twenty-seven sedentary elderly people participated in a 12-week randomized, controlled trial. The subjects assigned to the dual-task training (DT) group underwent a specific cognitive-motor dual-task training, and then the clinical outcomes, including cognitive functions by the Modified Mini-Mental State (3MS) examination and the Trail-Making Test (TMT), and the plasma Aβ 42/40 ratio following the intervention were compared with those of the control single-task training (ST) group by unpaired t-test. Among 27 participants, 25 completed the study. The total scores in the 3MS examination as well as the muscular strength of quadriceps were equally improved in both groups after the training. The specific cognitive domains, "registration & recall", "attention", "verbal fluency & understanding", and "visuospatial skills" were significantly improved only in the DT group. Higher scores in "attention", "verbal fluency & understanding", and "similarities" were found in the DT group than in the ST group at post-intervention. The absolute changes in the total (8.5 ± 1.6 vs 2.4 ± 0.9, p = 0.004, 95 % confidence interval (CI) 0.75-3.39) and in the scores of "attention" (1.9 ± 0.5 vs -0.2 ± 0.4, p = 0.004, 95 % CI 2.25-9.98) were greater in the DT group than in the ST group. We found no changes in the TMT results in either group. Plasma Aβ 42/40 ratio decreased in both groups following the training (ST group: 0.63 ± 0.13 to 0.16 ± 0.03, p = 0.001; DT group: 0.60 ± 0.12 to 0.25 ± 0.06, p = 0.044), although the pre- and post-intervention values

  12. Who is talking in backward crosstalk? Disentangling response- from goal-conflict in dual-task performance.

    PubMed

    Janczyk, Markus; Pfister, Roland; Hommel, Bernhard; Kunde, Wilfried

    2014-07-01

    Responses in the second of two subsequently performed tasks can speed up compatible responses in the temporally preceding first task. Such backward crosstalk effects (BCEs) represent a challenge to the assumption of serial processing in stage models of human information processing, because they indicate that certain features of the second response have to be represented before the first response is emitted. Which of these features are actually relevant for BCEs is an open question, even though identifying these features is important for understanding the nature of parallel and serial response selection processes in dual-task performance. Motivated by effect-based models of action control, we show in three experiments that the BCE to a considerable degree reflects features of intended action effects, although features of the response proper (or response-associated kinesthetic feedback) also seem to play a role. These findings suggest that the codes of action effects (or action goals) can become activated simultaneously rather than serially, thereby creating BCEs. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Task switching and response correspondence in the psychological refractory period paradigm

    NASA Technical Reports Server (NTRS)

    Lien, Mei-Ching; Schweickert, Richard; Proctor, Robert W.

    2003-01-01

    Three experiments examined the effects of task switching and response correspondence in a psychological refractory period paradigm. A letter task (vowel-consonant) and a digit task (odd-even) were combined to form 4 possible dual-task pairs in each trial: letter-letter, letter-digit, digit-digit, and digit-letter. Foreknowledge of task transition (repeat or switch) and task identity (letter or digit) was varied across experiments: no foreknowledge in Experiment 1, partial foreknowledge (task transition only) in Experiment 2, and full foreknowledge in Experiment 3. For all experiments, the switch cost for Task 2 was additive with stimulus onset asynchrony, and the response-correspondence effect for Task 2 was numerically smaller in the switch condition than in the repeat condition. These outcomes suggest that reconfiguration for Task 2 takes place after the central processing of Task 1 and that the crosstalk correspondence effect is due to response activation by way of stimulus-response associations.

  14. What Phonological Facilitation Tells about Semantic Interference: A Dual-Task Study

    PubMed Central

    Ayora, Pauline; Peressotti, Francesca; Alario, F.-Xavier; Mulatti, Claudio; Pluchino, Patrick; Job, Remo; Dell'Acqua, Roberto

    2011-01-01

    Despite increasing interest in the topic, the extent to which linguistic processing demands attentional resources remains poorly understood. We report an empirical re-examination of claims about lexical processing made on the basis of the picture–word interference task when merged in a dual-task psychological refractory period (PRP) paradigm. Two experiments were conducted in which participants were presented with a tone followed, at varying stimulus onset asynchronies (SOAs), by a picture–word stimulus. In Experiment 1, the phonological relatedness between pictures and words was manipulated. Begin- and end-related words decreased picture naming latencies relative to unrelated words. This effect was additive with SOA effects. In Experiment 2, both the semantic and the phonological relatedness between pictures and words were manipulated. Replicating Experiment 1, effects arising from the phonological manipulation were additive with SOA effects on picture naming latencies. In contrast, effects arising from the semantic manipulation were under additive with SOA effects on picture naming latencies, that is, semantic interference decreased as SOA was decreased. Such contrastive pattern suggests that semantic and phonological effects on picture naming latencies are characterized by distinguishable sources, the former prior to the PRP bottleneck and the latter at the PRP bottleneck or after. The present findings are discussed in relation to current models of language production. PMID:21716584

  15. Performance under dichoptic versus binocular viewing conditions - Effects of attention and task requirements

    NASA Technical Reports Server (NTRS)

    Kimchi, Ruth; Gopher, Daniel; Rubin, Yifat; Raij, David

    1993-01-01

    Three experiments investigated subjects' ability to allocate attention and cope with task requirements under dichoptic versus binocular viewing conditions. Experiments 1 and 2 employed a target detection task in compound and noncompound stimuli, and Experiment 3 employed a relative-proximity judgment task. The tasks were performed in a focused attention condition in which subjects had to attend to the stimulus presented to one eye or field (under dichoptic and binocular viewing conditions, respectively) while ignoring the stimulus presented to the other eye or field, and in a divided attention condition in which subjects had to attend to the stimuli presented to both eyes or fields. Subjects' performance was affected by the interaction of attention conditions with task requirements, but it was generally the same under dichoptic and binocular viewing conditions. The more dependent the task was on finer discrimination, the more performance was impaired by divided attention. These results suggest that at least with discrete tasks and relatively short exposure durations, performance when each eye is presented with a separate stimulus is the same as when the entire field of stimulation is viewed by both eyes.

  16. Age-related effects on postural control under multi-task conditions.

    PubMed

    Granacher, Urs; Bridenbaugh, Stephanie A; Muehlbauer, Thomas; Wehrle, Anja; Kressig, Reto W

    2011-01-01

    Changes in postural sway and gait patterns due to simultaneously performed cognitive (CI) and/or motor interference (MI) tasks have previously been reported and are associated with an increased risk of falling in older adults. The objectives of this study were to investigate the effects of a CI and/or MI task on static and dynamic postural control in young and elderly subjects, and to find out whether there is an association between measures of static and dynamic postural control while concurrently performing the CI and/or MI task. A total of 36 healthy young (n = 18; age: 22.3 ± 3.0 years; BMI: 21.0 ± 1.6 kg/m(2)) and elderly adults (n = 18; age: 73.5 ± 5.5 years; BMI: 24.2 ± 2.9 kg/m(2)) participated in this study. Static postural control was measured during bipedal stance, and dynamic postural control was obtained while walking on an instrumented walkway. Irrespective of the task condition, i.e. single-task or multiple tasks, elderly participants showed larger center-of-pressure displacements and greater stride-to-stride variability than younger participants. Associations between measures of static and dynamic postural control were found only under the single-task condition in the elderly. Age-related deficits in the postural control system seem to be primarily responsible for the observed results. The weak correlations detected between static and dynamic measures could indicate that fall-risk assessment should incorporate dynamic measures under multi-task conditions, and that skills like erect standing and walking are independent of each other and may have to be trained complementarily. Copyright © 2010 S. Karger AG, Basel.

  17. Diffusion models of the flanker task: Discrete versus gradual attentional selection

    PubMed Central

    White, Corey N.; Ratcliff, Roger; Starns, Jeffrey S.

    2011-01-01

    The present study tested diffusion models of processing in the flanker task, in which participants identify a target that is flanked by items that indicate the same (congruent) or opposite response (incongruent). Single- and dual-process flanker models were implemented in a diffusion-model framework and tested against data from experiments that manipulated response bias, speed/accuracy tradeoffs, attentional focus, and stimulus configuration. There was strong mimcry among the models, and each captured the main trends in the data for the standard conditions. However, when more complex conditions were used, a single-process spotlight model captured qualitative and quantitative patterns that the dual-process models could not. Since the single-process model provided the best balance of fit quality and parsimony, the results indicate that processing in the simple versions of the flanker task is better described by gradual rather than discrete narrowing of attention. PMID:21964663

  18. Influence of Sequential vs. Simultaneous Dual-Task Exercise Training on Cognitive Function in Older Adults.

    PubMed

    Tait, Jamie L; Duckham, Rachel L; Milte, Catherine M; Main, Luana C; Daly, Robin M

    2017-01-01

    Emerging research indicates that exercise combined with cognitive training may improve cognitive function in older adults. Typically these programs have incorporated sequential training, where exercise and cognitive training are undertaken separately. However, simultaneous or dual-task training, where cognitive and/or motor training are performed simultaneously with exercise, may offer greater benefits. This review summary provides an overview of the effects of combined simultaneous vs. sequential training on cognitive function in older adults. Based on the available evidence, there are inconsistent findings with regard to the cognitive benefits of sequential training in comparison to cognitive or exercise training alone. In contrast, simultaneous training interventions, particularly multimodal exercise programs in combination with secondary tasks regulated by sensory cues, have significantly improved cognition in both healthy older and clinical populations. However, further research is needed to determine the optimal characteristics of a successful simultaneous training program for optimizing cognitive function in older people.

  19. Individual Differences in Dual Task Performance.

    DTIC Science & Technology

    1981-06-10

    SJCURITY CLASSIFICATION OF THIS PAGE("en Data Entered) second experimental series, we compared ability to detect visual and audi- tory targets in single...used performance on a simple secondary task executed during an easy primary task to predict performance on a more diffi- cult’version of the same...process concepts developed b’j cognitive ps:choloqists°’ In this laborators, we adapted a number of experimental tasks to 4ield individual measures of the

  20. Psychophysiological response to cognitive workload during symmetrical, asymmetrical and dual-task walking.

    PubMed

    Knaepen, Kristel; Marusic, Uros; Crea, Simona; Rodríguez Guerrero, Carlos D; Vitiello, Nicola; Pattyn, Nathalie; Mairesse, Olivier; Lefeber, Dirk; Meeusen, Romain

    2015-04-01

    Walking with a lower limb prosthesis comes at a high cognitive workload for amputees, possibly affecting their mobility, safety and independency. A biocooperative prosthesis which is able to reduce the cognitive workload of walking could offer a solution. Therefore, we wanted to investigate whether different levels of cognitive workload can be assessed during symmetrical, asymmetrical and dual-task walking and to identify which parameters are the most sensitive. Twenty-four healthy subjects participated in this study. Cognitive workload was assessed through psychophysiological responses, physical and cognitive performance and subjective ratings. The results showed that breathing frequency and heart rate significantly increased, and heart rate variability significantly decreased with increasing cognitive workload during walking (p<.05). Performance measures (e.g., cadence) only changed under high cognitive workload. As a result, psychophysiological measures are the most sensitive to identify changes in cognitive workload during walking. These parameters reflect the cognitive effort necessary to maintain performance during complex walking and can easily be assessed regardless of the task. This makes them excellent candidates to feed to the control loop of a biocooperative prosthesis in order to detect the cognitive workload. This information can then be used to adapt the robotic assistance to the patient's cognitive abilities. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Effects of a cognitive dual task on variability and local dynamic stability in sustained repetitive arm movements using principal component analysis: a pilot study.

    PubMed

    Longo, Alessia; Federolf, Peter; Haid, Thomas; Meulenbroek, Ruud

    2018-06-01

    In many daily jobs, repetitive arm movements are performed for extended periods of time under continuous cognitive demands. Even highly monotonous tasks exhibit an inherent motor variability and subtle fluctuations in movement stability. Variability and stability are different aspects of system dynamics, whose magnitude may be further affected by a cognitive load. Thus, the aim of the study was to explore and compare the effects of a cognitive dual task on the variability and local dynamic stability in a repetitive bimanual task. Thirteen healthy volunteers performed the repetitive motor task with and without a concurrent cognitive task of counting aloud backwards in multiples of three. Upper-body 3D kinematics were collected and postural reconfigurations-the variability related to the volunteer's postural change-were determined through a principal component analysis-based procedure. Subsequently, the most salient component was selected for the analysis of (1) cycle-to-cycle spatial and temporal variability, and (2) local dynamic stability as reflected by the largest Lyapunov exponent. Finally, end-point variability was evaluated as a control measure. The dual cognitive task proved to increase the temporal variability and reduce the local dynamic stability, marginally decrease endpoint variability, and substantially lower the incidence of postural reconfigurations. Particularly, the latter effect is considered to be relevant for the prevention of work-related musculoskeletal disorders since reduced variability in sustained repetitive tasks might increase the risk of overuse injuries.

  2. Single-task fMRI overlap predicts concurrent multitasking interference.

    PubMed

    Nijboer, Menno; Borst, Jelmer; van Rijn, Hedderik; Taatgen, Niels

    2014-10-15

    There is no consensus regarding the origin of behavioral interference that occurs during concurrent multitasking. Some evidence points toward a multitasking locus in the brain, while other results imply that interference is the consequence of task interactions in several brain regions. To investigate this issue, we conducted a functional MRI (fMRI) study consisting of three component tasks, which were performed both separately and in combination. The results indicated that no specific multitasking area exists. Instead, different patterns of activation across conditions could be explained by assuming that the interference is a result of task interactions. Additionally, similarity in single-task activation patterns correlated with a decrease in accuracy during dual-task conditions. Taken together, these results support the view that multitasking interference is not due to a bottleneck in a single "multitasking" brain region, but is a result of interactions between concurrently running processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Cognitive and Physical Fatigue Tasks Enhance Pain, Cognitive Fatigue and Physical Fatigue in People with Fibromyalgia

    PubMed Central

    Dailey, Dana L; Keffala, Valerie J; Sluka, Kathleen A

    2014-01-01

    Objective Fibromyalgia is a condition characterized by chronic widespread muscle pain and fatigue. The primary objective of this study was to determine if pain, perceived cognitive fatigue, and perceived physical fatigue were enhanced in participants with fibromyalgia compared to healthy controls during a cognitive fatigue task, a physical fatigue task and a dual fatigue task. Methods Twenty four people with fibromyalgia and 33 healthy controls completed pain, fatigue and function measures. A cognitive fatigue task (Controlled Oral Word Association Test) and physical fatigue task (Valpar peg test) were done individually and combined for a dual fatigue task. Resting pain, perceived cognitive fatigue and perceived physical fatigue were assessed during each task using visual analogue scales. Function was assessed with shoulder range of motion and grip. Results People with fibromyalgia had significantly higher increases in pain, cognitive fatigue and physical fatigue when compared to healthy controls after completion of a cognitive fatigue task, a physical fatigue task, or a dual fatigue task (p<0.01). People with fibromyalgia performed equivalently on measures of physical performance and cognitive performance on the physical and cognitive fatigue tasks, respectively. Conclusions These data show that people with fibromyalgia show larger increases in pain, perceived cognitive fatigue and perceived physical fatigue to both cognitive and physical fatigue tasks compared to healthy controls. The increases in pain and fatigue during cognitive and physical fatigue tasks could influence subject participation in daily activities and rehabilitation. PMID:25074583

  4. Interference with olfactory memory by visual and verbal tasks.

    PubMed

    Annett, J M; Cook, N M; Leslie, J C

    1995-06-01

    It has been claimed that olfactory memory is distinct from memory in other modalities. This study investigated the effectiveness of visual and verbal tasks in interfering with olfactory memory and included methodological changes from other recent studies. Subjects were allocated to one of four experimental conditions involving interference tasks [no interference task; visual task; verbal task; visual-plus-verbal task] and presented 15 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Recognition and recall performance both showed effects of interference of visual and verbal tasks but there was no effect for time of testing. While the results may be accommodated within a dual coding framework, further work is indicated to resolve theoretical issues relating to task complexity.

  5. Influence of Sequential vs. Simultaneous Dual-Task Exercise Training on Cognitive Function in Older Adults

    PubMed Central

    Tait, Jamie L.; Duckham, Rachel L.; Milte, Catherine M.; Main, Luana C.; Daly, Robin M.

    2017-01-01

    Emerging research indicates that exercise combined with cognitive training may improve cognitive function in older adults. Typically these programs have incorporated sequential training, where exercise and cognitive training are undertaken separately. However, simultaneous or dual-task training, where cognitive and/or motor training are performed simultaneously with exercise, may offer greater benefits. This review summary provides an overview of the effects of combined simultaneous vs. sequential training on cognitive function in older adults. Based on the available evidence, there are inconsistent findings with regard to the cognitive benefits of sequential training in comparison to cognitive or exercise training alone. In contrast, simultaneous training interventions, particularly multimodal exercise programs in combination with secondary tasks regulated by sensory cues, have significantly improved cognition in both healthy older and clinical populations. However, further research is needed to determine the optimal characteristics of a successful simultaneous training program for optimizing cognitive function in older people. PMID:29163146

  6. Increased integrity of white matter pathways after dual n-back training.

    PubMed

    Salminen, Tiina; Mårtensson, Johan; Schubert, Torsten; Kühn, Simone

    2016-06-01

    Dual n-back WM training has been shown to produce broad transfer effects to different untrained cognitive functions. The task is demanding to the cognitive system because it includes a bi-modal (auditory and visual) dual-task component. A previous WM training study showed increased white matter integrity in the parietal lobe as well as the anterior part of the corpus callosum after visual n-back training. We investigated dual n-back training-related changes in white matter pathways. We anticipated dual n-back training to increase white matter integrity in pathways that connect brain regions related to WM processes. Additionally, we hypothesized that dual n-back training would produce more brain-wide white matter changes than single n-back training because of the involvement of two modalities and the additional dual-task coordination component of the task. The dual n-back training group showed increased white matter integrity (reflected as increased fractional anisotropy, FA) after training. The effects were mostly left lateralized as compared with changes from pretest to posttest in the passive and active control groups. Additionally, significant effects were observed in the anterior part of the corpus callosum, when the training group was compared with the passive control group. There were no changes in pretest to posttest FA changes between the passive and active control groups. The results therefore show that dual n-back training produces increased integrity in white matter pathways connecting different brain regions. The results are discussed in reference to the bi-modal dual-task component of the training task. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Strategic Adaptation to Task Characteristics, Incentives, and Individual Differences in Dual-Tasking

    PubMed Central

    Janssen, Christian P.; Brumby, Duncan P.

    2015-01-01

    We investigate how good people are at multitasking by comparing behavior to a prediction of the optimal strategy for dividing attention between two concurrent tasks. In our experiment, 24 participants had to interleave entering digits on a keyboard with controlling a randomly moving cursor with a joystick. The difficulty of the tracking task was systematically varied as a within-subjects factor. Participants were also exposed to different explicit reward functions that varied the relative importance of the tracking task relative to the typing task (between-subjects). Results demonstrate that these changes in task characteristics and monetary incentives, together with individual differences in typing ability, influenced how participants choose to interleave tasks. This change in strategy then affected their performance on each task. A computational cognitive model was used to predict performance for a wide set of alternative strategies for how participants might have possibly interleaved tasks. This allowed for predictions of optimal performance to be derived, given the constraints placed on performance by the task and cognition. A comparison of human behavior with the predicted optimal strategy shows that participants behaved near optimally. Our findings have implications for the design and evaluation of technology for multitasking situations, as consideration should be given to the characteristics of the task, but also to how different users might use technology depending on their individual characteristics and their priorities. PMID:26161851

  8. The JFK BIG study: the impact of LSVT BIG® on dual task walking and mobility in persons with Parkinson's disease.

    PubMed

    Isaacson, Sara; O'Brien, Ashley; Lazaro, Jennifer D; Ray, Arlen; Fluet, Gerard

    2018-04-01

    [Purpose] The aim of this study was to test the hypothesis that Lee Silverman Voice Treatment-BIG decreases the negative impact of hypokinesia on dual task performance in persons with Parkinson's disease. [Subjects and Methods] The records of 114 patients with Parkinson's admitted to outpatient rehabilitation at a suburban hospital were reviewed. Demographics and data for 8 outcome measures were extracted for subjects that completed 14 of 16 sessions of BIG. 93 of these subjects had records of pre and post-test Timed Up and Go, Timed Up and Go Motor, and Timed Up and Go Cognitive scores. Average age was 68.4 years (SD=10.6) and average disease duration was 4.9 years (SD=5.3). [Results] Subjects demonstrated statistically significant improvements for Timed Up and Go (3.3 SD=4.5), Timed Up and Go Motor (4.4 SD=5.8) and Timed Up and Go Cognitive (4.7 SD=5.4). Concurrent motor and cognitive performance remained stable. Dual task cost decreased at a statistically significant level for Timed Up and Go Cognitive (7% SD=31%) but not Motor (4% SD=32%). [Conclusion] These findings suggest that cueing strategies associated with LSVT BIG become internalized and decrease the negative impact of hypokinesia on mobility and cognitive performance while performing two tasks simultaneously in persons with Parkinson's.

  9. Combined Dual-Task Gait Training and Aerobic Exercise to Improve Cognition, Mobility, and Vascular Health in Community-Dwelling Older Adults at Risk for Future Cognitive Decline1.

    PubMed

    Gregory, Michael A; Boa Sorte Silva, Narlon C; Gill, Dawn P; McGowan, Cheri L; Liu-Ambrose, Teresa; Shoemaker, J Kevin; Hachinski, Vladimir; Holmes, Jeff; Petrella, Robert J

    2017-01-01

    This 6-month experimental case series study investigated the effects of a dual-task gait training and aerobic exercise intervention on cognition, mobility, and cardiovascular health in community-dwelling older adults without dementia. Participants exercised 40 min/day, 3 days/week for 26 weeks on a Biodex GaitTrainer2 treadmill. Participants were assessed at baseline (V0), interim (V1: 12-weeks), intervention endpoint (V2: 26-weeks), and study endpoint (V3: 52-weeks). The study outcomes included: cognition [executive function (EF), processing speed, verbal fluency, and memory]; mobility: usual & dual-task gait (speed, step length, and stride time variability); and vascular health: ambulatory blood pressure, carotid arterial compliance, and intima-media thickness (cIMT). Fifty-six participants [age: 70(6) years; 61% female] were included in this study. Significant improvements following the exercise program (V2) were observed in cognition: EF (p = 0.002), processing speed (p < 0.001), verbal fluency [digit symbol coding (p < 0.001), phonemic verbal fluency (p < 0.001)], and memory [immediate recall (p < 0.001) and delayed recall (p < 0.001)]; mobility: usual & dual-task gait speed (p = 0.002 and p < 0.001, respectively) and step length (p = 0.001 and p = 0.003, respectively); and vascular health: cIMT (p = 0.002). No changes were seen in the remaining outcomes. In conclusion, 26 weeks of dual-task gait training and aerobic exercise improved performance on a number of cognitive outcomes, while increasing usual & dual-task gait speed and step length in a sample of older adults without dementia.

  10. Functional mobility in a divided attention task in older adults with cognitive impairment.

    PubMed

    Borges, Sheila de Melo; Radanovic, Márcia; Forlenza, Orestes Vicente

    2015-01-01

    Motor disorders may occur in mild cognitive impairment (MCI) and at early stages of Alzheimer's disease (AD), particularly under divided attention conditions. We examined functional mobility in 104 older adults (42 with MCI, 26 with mild AD, and 36 cognitively healthy) using the Timed Up and Go test (TUG) under 4 experimental conditions: TUG single task, TUG plus a cognitive task, TUG plus a manual task, and TUG plus a cognitive and a manual task. Statistically significant differences in mean time of execution were found in all four experimental conditions when comparing MCI and controls (p < .001), and when comparing MCI and AD patients (p < .05). Receiver-operating characteristic curve analyses showed that all four testing conditions could differentiate the three groups (area under the curve > .8, p < .001 for MCI vs. controls; area under the curve > .7, p < .001 for MCI vs. AD). The authors conclude that functional motor deficits occurring in MCI can be assessed by the TUG test, in single or dual task modality.

  11. The significance of task significance: Job performance effects, relational mechanisms, and boundary conditions.

    PubMed

    Grant, Adam M

    2008-01-01

    Does task significance increase job performance? Correlational designs and confounded manipulations have prevented researchers from assessing the causal impact of task significance on job performance. To address this gap, 3 field experiments examined the performance effects, relational mechanisms, and boundary conditions of task significance. In Experiment 1, fundraising callers who received a task significance intervention increased their levels of job performance relative to callers in 2 other conditions and to their own prior performance. In Experiment 2, task significance increased the job dedication and helping behavior of lifeguards, and these effects were mediated by increases in perceptions of social impact and social worth. In Experiment 3, conscientiousness and prosocial values moderated the effects of task significance on the performance of new fundraising callers. The results provide fresh insights into the effects, relational mechanisms, and boundary conditions of task significance, offering noteworthy implications for theory, research, and practice on job design, social information processing, and work motivation and performance. 2008 APA

  12. Dual-Arm Generalized Compliant Motion With Shared Control

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.

    1994-01-01

    Dual-Arm Generalized Compliant Motion (DAGCM) primitive computer program implementing improved unified control scheme for two manipulator arms cooperating in task in which both grasp same object. Provides capabilities for autonomous, teleoperation, and shared control of two robot arms. Unifies cooperative dual-arm control with multi-sensor-based task control and makes complete task-control capability available to higher-level task-planning computer system via large set of input parameters used to describe desired force and position trajectories followed by manipulator arms. Some concepts discussed in "A Generalized-Compliant-Motion Primitive" (NPO-18134).

  13. Strength-balance supplemented with computerized cognitive training to improve dual task gait and divided attention in older adults: a multicenter randomized-controlled trial.

    PubMed

    van het Reve, Eva; de Bruin, Eling D

    2014-12-15

    Exercise interventions often do not combine physical and cognitive training. However, this combination is assumed to be more beneficial in improving walking and cognitive functioning compared to isolated cognitive or physical training. A multicenter parallel randomized controlled trial was conducted to compare a motor to a cognitive-motor exercise program. A total of 182 eligible residents of homes-for-the-aged (n = 159) or elderly living in the vicinity of the homes (n = 23) were randomly assigned to either strength-balance (SB) or strength-balance-cognitive (SBC) training. Both groups conducted similar strength-balance training during 12 weeks. SBC additionally absolved computerized cognitive training. Outcomes were dual task costs of walking, physical performance, simple reaction time, executive functions, divided attention, fear of falling and fall rate. Participants were analysed with an intention to treat approach. The 182 participants (mean age ± SD: 81.5 ± 7.3 years) were allocated to either SB (n = 98) or SBC (n = 84). The attrition rate was 14.3%. Interaction effects were observed for dual task costs of step length (preferred walking speed: F(1,174) = 4.94, p = 0.028, η2 = 0.027, fast walking speed: F(1,166) = 6.14, p = 0.009, η2 = 0.040) and dual task costs of the standard deviation of step length (F(1,166) = 6.14, p = 0.014, η2 = 0.036), in favor of SBC. Significant interactions in favor of SBC revealed for in gait initiation (F(1,166) = 9.16, p = 0.003, η2 = 0.052), 'reaction time' (F(1,180) = 5.243, p = 0.023, η² = 0.028) & 'missed answers' (F(1,180) = 11.839, p = 0.001, η² = 0.062) as part of the test for divided attention. Within-group comparison revealed significant improvements in dual task costs of walking (preferred speed; velocity (p = 0.002), step time (p = 0.018), step length (p = 0.028), fast speed; velocity (p < 0

  14. Evaluating the Effort Expended to Understand Speech in Noise Using a Dual-Task Paradigm: The Effects of Providing Visual Speech Cues

    ERIC Educational Resources Information Center

    Fraser, Sarah; Gagne, Jean-Pierre; Alepins, Majolaine; Dubois, Pascale

    2010-01-01

    Purpose: Using a dual-task paradigm, 2 experiments (Experiments 1 and 2) were conducted to assess differences in the amount of listening effort expended to understand speech in noise in audiovisual (AV) and audio-only (A-only) modalities. Experiment 1 had equivalent noise levels in both modalities, and Experiment 2 equated speech recognition…

  15. Tracking reading: dual task costs of oral reading for young versus older adults.

    PubMed

    Kemper, Susan; Bontempo, Daniel; Schmalzried, RaLynn; McKedy, Whitney; Tagliaferri, Bruno; Kieweg, Doug

    2014-02-01

    A digital pursuit rotor was used to monitor oral reading costs by time-locking tracking performance to the auditory wave form produced as young and older adults were reading out short paragraphs. Multilevel modeling was used to determine how paragraph-level predictors of length, grammatical complexity, and readability and person-level predictors such as speaker age or working memory capacity predicted reading and tracking performance. In addition, sentence-by-sentence variation in tracking performance was examined during the production of individual sentences and during the pauses before upcoming sentences. The results suggest that dual tasking has a greater impact on older adults' reading comprehension and tracking performance. At the level of individual sentences, young and older adults adopt different strategies to deal with grammatically complex and propositionally dense sentences.

  16. Dual Coding and Bilingual Memory.

    ERIC Educational Resources Information Center

    Paivio, Allan; Lambert, Wallace

    1981-01-01

    Describes study which tested a dual coding approach to bilingual memory using tasks that permit comparison of the effects of bilingual encoding with verbal-nonverbal dual encoding items. Results provide strong support for a version of the independent or separate stories view of bilingual memory. (Author/BK)

  17. Transfer after Dual n-Back Training Depends on Striatal Activation Change.

    PubMed

    Salminen, Tiina; Kühn, Simone; Frensch, Peter A; Schubert, Torsten

    2016-09-28

    The dual n-back working memory (WM) training paradigm (comprising auditory and visual stimuli) has gained much attention since studies have shown widespread transfer effects. By including a multimodal dual-task component, the task is demanding to the human cognitive system. We investigated whether dual n-back training improves general cognitive resources or a task-specific WM updating process in participants. We expected: (1) widespread transfer effects and the recruitment of a common neuronal network by the training and the transfer tasks and (2) narrower transfer results and that a common activation network alone would not produce transfer, but instead an activation focus on the striatum, which is associated with WM updating processes. The training group showed transfer to an untrained dual-modality WM updating task, but not to single-task versions of the training or the transfer task. They also showed diminished neuronal overlap between the training and the transfer task from pretest to posttest and an increase in striatal activation in both tasks. Furthermore, we found an association between the striatal activation increase and behavioral improvement. The control groups showed no transfer and no change in the amount of activation overlap or in striatal activation from pretest to posttest. We conclude that, instead of improving general cognitive resources (which would have required a transfer effect to all transfer tasks and that a frontal activation overlap between the tasks produced transfer), dual n-back training improved a task-specific process: WM updating of stimuli from two modalities. The current study allows for a better understanding of the cognitive and neural effects of working memory (WM) training and transfer. It shows that dual n-back training mainly improves specific processes of WM updating, and this improvement leads to narrow transfer effects to tasks involving the same processes. On a neuronal level this is accompanied by increased neural

  18. The JFK BIG study: the impact of LSVT BIG® on dual task walking and mobility in persons with Parkinson’s disease

    PubMed Central

    Isaacson, Sara; O’Brien, Ashley; Lazaro, Jennifer D.; Ray, Arlen; Fluet, Gerard

    2018-01-01

    [Purpose] The aim of this study was to test the hypothesis that Lee Silverman Voice Treatment-BIG decreases the negative impact of hypokinesia on dual task performance in persons with Parkinson’s disease. [Subjects and Methods] The records of 114 patients with Parkinson’s admitted to outpatient rehabilitation at a suburban hospital were reviewed. Demographics and data for 8 outcome measures were extracted for subjects that completed 14 of 16 sessions of BIG. 93 of these subjects had records of pre and post-test Timed Up and Go, Timed Up and Go Motor, and Timed Up and Go Cognitive scores. Average age was 68.4 years (SD=10.6) and average disease duration was 4.9 years (SD=5.3). [Results] Subjects demonstrated statistically significant improvements for Timed Up and Go (3.3 SD=4.5), Timed Up and Go Motor (4.4 SD=5.8) and Timed Up and Go Cognitive (4.7 SD=5.4). Concurrent motor and cognitive performance remained stable. Dual task cost decreased at a statistically significant level for Timed Up and Go Cognitive (7% SD=31%) but not Motor (4% SD=32%). [Conclusion] These findings suggest that cueing strategies associated with LSVT BIG become internalized and decrease the negative impact of hypokinesia on mobility and cognitive performance while performing two tasks simultaneously in persons with Parkinson’s. PMID:29706722

  19. A mixed Rasch model of dual-process conditional reasoning.

    PubMed

    Bonnefon, Jean-François; Eid, Michael; Vautier, Stéphane; Jmel, Saïd

    2008-05-01

    A fine-grained dual-process approach to conditional reasoning is advocated: Responses to conditional syllogisms are reached through the operation of either one of two systems, each of which can rely on two different mechanisms. System1 relies either on pragmatic implicatures or on the retrieval of information from semantic memory; System2 operates first through inhibition of System1, then (but not always) through activation of analytical processes. It follows that reasoners will fall into one of four groups of increasing reasoning ability, each group being uniquely characterized by (a) the modal pattern of individual answers to blocks of affirming the consequent (AC), denying the antecedent (DA), and modus tollens (MT) syllogisms featuring the same conditional; and (b) the average rate of determinate answers to AC, DA, and MT. This account receives indirect support from the extant literature and direct support from a mixed Rasch model of responses given to 18 syllogisms by 486 adult reasoners.

  20. Planning and task management in Parkinson's disease: differential emphasis in dual-task performance.

    PubMed

    Bialystok, Ellen; Craik, Fergus I M; Stefurak, Taresa

    2008-03-01

    Seventeen patients diagnosed with Parkinson's disease completed a complex computer-based task that involved planning and management while also performing an attention-demanding secondary task. The tasks were performed concurrently, but it was necessary to switch from one to the other. Performance was compared to a group of healthy age-matched control participants and a group of young participants. Parkinson's patients performed better than the age-matched controls on almost all measures and as well as the young controls in many cases. However, the Parkinson's patients achieved this by paying relatively less attention to the secondary task and focusing attention more on the primary task. Thus, Parkinson's patients can apparently improve their performance on some aspects of a multidimensional task by simplifying task demands. This benefit may occur as a consequence of their inflexible exaggerated attention to some aspects of a complex task to the relative neglect of other aspects.

  1. Memory-driven attentional capture reveals the waxing and waning of working memory activation due to dual-task interference.

    PubMed

    Sasin, Edyta; Nieuwenstein, Mark

    2016-12-01

    Previous studies have shown that information held in working memory (WM) actively or as a residue of previous processing can lead to attentional capture by corresponding stimuli in the environment. Here, we compared attentional capture by goal-driven and residual WM activation and examined how these effects are affected by dual-task interference. In two experiments, participants performed an animacy judgment task for a word that they did or did not have to remember for a later recognition test. The word was followed in half of the trials by an arithmetic task that served to disrupt the WM activation of the previously processed word. Subsequently, WM-driven capture was assessed by having participants perform a single-target rapid serial visual presentation task in which a line drawing corresponding to the word was presented shortly before a target. The results showed that the line drawing captured attention irrespective of the presence of the arithmetic task when the word had to be remembered. In comparison, the animacy judgment alone resulted in capture only when the arithmetic task was absent, and this effect was equally strong as the capture effect caused by a to-be-remembered word. Taken together, these findings show that although residual and goal-driven WM activation may be equally potent in guiding attentional selection, these two forms of WM activation differ in that residual activation is overwritten by an attention-demanding task, whereas goal-driven WM activation can lead to the reinstatement of a stimulus after performing such a task.

  2. WHY DOES OLDER ADULTS' BALANCE BECOME LESS STABLE WHEN WALKING AND PERFORMING A SECONDARY TASK? EXAMINATION OF ATTENTIONAL SWITCHING ABILITIES

    PubMed Central

    Hawkes, Teresa D; Siu, Ka-Chun; Silsupadol, Patima; Woollacott, Marjorie H.

    2011-01-01

    Previous research using dual-task paradigms indicates balance-impaired older adults (BIOA) are less able to flexibly shift attentional focus between a cognitive and motor task than healthy older adults (HOA). Shifting attention is a component of executive function. Task switch tests assess executive attention function. This multivariate study asked if BIOAs demonstrate greater task switching deficits than HOAs. A group of 39 HOA (65–80 yrs) and BIOA (65–87 yrs) subjects performed a visuo-spatial task switch. A sub-group of subjects performed a dual-task obstacle avoidance paradigm. All participants completed the Berg Balance Scale (BBS) and Timed Up and Go (TUG). We assessed differences by group for: 1) visuo-spatial task switch reaction times (switch/no-switch), and performance on the BBS and TUG. Our balance groups differed significantly on BBS score (p < .001) and switch reaction time (p = .032), but not the TUG. This confirmed our hypothesis that neuromuscular and executive attention function differs between these two groups. For our BIOA sub-group, gait velocity correlated negatively with performance on the switch condition (p=.036). This suggests that BIOA efficiency of attentional allocation in dual task settings should be further explored. PMID:21964051

  3. Associations between Tactile Sensory Threshold and Postural Performance and Effects of Healthy Aging and Subthreshold Vibrotactile Stimulation on Postural Outcomes in a Simple Dual Task

    PubMed Central

    Dettmer, Marius; Pourmoghaddam, Amir; Lee, Beom-Chan; Layne, Charles S.

    2016-01-01

    Specific activities that require concurrent processing of postural and cognitive tasks may increase the risk for falls in older adults. We investigated whether peripheral receptor sensitivity was associated with postural performance in a dual-task and whether an intervention in form of subthreshold vibration could affect performance. Ten younger (age: 20–35 years) and ten older adults (70–85 years) performed repeated auditory-verbal 1-back tasks while standing quietly on a force platform. Foot sole vibration was randomly added during several trials. Several postural control and performance measures were assessed and statistically analyzed (significance set to α-levels of .05). There were moderate correlations between peripheral sensitivity and several postural performance and control measures (r = .45 to .59). Several postural performance measures differed significantly between older and younger adults (p < 0.05); addition of vibration did not affect outcome measures. Aging affects healthy older adults' performance in dual-tasks, and peripheral sensitivity may be a contributor to the observed differences. A vibration intervention may only be useful when there are more severe impairments of the sensorimotor system. Hence, future research regarding the efficacy of sensorimotor interventions in the form of vibrotactile stimulation should focus on older adults whose balance is significantly affected. PMID:27143967

  4. Non-visual spatial tasks reveal increased interactions with stance postural control.

    PubMed

    Woollacott, Marjorie; Vander Velde, Timothy

    2008-05-07

    The current investigation aimed to contrast the level and quality of dual-task interactions resulting from the combined performance of a challenging primary postural task and three specific, yet categorically dissociated, secondary central executive tasks. Experiments determined the extent to which modality (visual vs. auditory) and code (non-spatial vs. spatial) specific cognitive resources contributed to postural interference in young adults (n=9) in a dual-task setting. We hypothesized that the different forms of executive n-back task processing employed (visual-object, auditory-object and auditory-spatial) would display contrasting levels of interactions with tandem Romberg stance postural control, and that interactions within the spatial domain would be revealed as most vulnerable to dual-task interactions. Across all cognitive tasks employed, including auditory-object (aOBJ), auditory-spatial (aSPA), and visual-object (vOBJ) tasks, increasing n-back task complexity produced correlated increases in verbal reaction time measures. Increasing cognitive task complexity also resulted in consistent decreases in judgment accuracy. Postural performance was significantly influenced by the type of cognitive loading delivered. At comparable levels of cognitive task difficulty (n-back demands and accuracy judgments) the performance of challenging auditory-spatial tasks produced significantly greater levels of postural sway than either the auditory-object or visual-object based tasks. These results suggest that it is the employment of limited non-visual spatially based coding resources that may underlie previously observed visual dual-task interference effects with stance postural control in healthy young adults.

  5. The development of a novel high-precision major depressive disorder screening system using transient autonomic responses induced by dual mental tasks.

    PubMed

    Matsui, Takemi; Shinba, Toshikazu; Sun, Guanghao

    2018-02-01

    12.6% of major depressive disorder (MDD) patients have suicide intent, while it has been reported that 43% of patients did not consult their doctors for MDD, automated MDD screening is eagerly anticipated. Recently, in order to achieve automated screening of MDD, biomarkers such as multiplex DNA methylation profiles or physiological method using near infra-red spectroscopy (NIRS) have been studied, however, they require inspection using 96-well DNA ELIZA kit after blood sampling or significant cost. Using a single-lead electrocardiography (ECG), we developed a high-precision MDD screening system using transient autonomic responses induced by dual mental tasks. We developed a novel high precision MDD screening system which is composed of a single-lead ECG monitor, analogue to digital (AD) converter and a personal computer with measurement and analysis program written by LabView programming language. The system discriminates MDD patients from normal subjects using heat rate variability (HRV)-derived transient autonomic responses induced by dual mental tasks, i.e. verbal fluency task and random number generation task, via linear discriminant analysis (LDA) adopting HRV-related predictor variables (hear rate (HR), high frequency (HF), low frequency (LF)/HF). The proposed system was tested for 12 MDD patients (32 ± 15 years) under antidepressant treatment from Shizuoka Saiseikai General Hospital outpatient unit and 30 normal volunteers (37 ± 17 years) from Tokyo Metropolitan University. The proposed system achieved 100% sensitivity and 100% specificity in classifying 42 examinees into 12 MDD patients and 30 normal subjects. The proposed system appears promising for future HRV-based high-precision and low-cost screening of MDDs using only single-lead ECG.

  6. The role of attention during retrieval in working-memory span: a dual-task study.

    PubMed

    Healey, M Karl; Miyake, Akira

    2009-04-01

    We tested the hypothesis that retrieving target words in operation span (OSpan) involves attention-demanding processes. Participants completed the standard OSpan task and a modified version in which all equations preceded all target words. Recall took place under either full attention or easy versus hard divided-attention conditions. Recall suffered under divided attention with the recall decrement being greater for the hard secondary task. Moreover, secondary-task performance was disrupted more by the standard OSpan task than by the modified version with the hard secondary task showing the larger decrement. Finally, the time taken to start recalling the first word was considerably longer for the standard version than for the modified version. These results are consistent with the proposal that successful OSpan task performance in part involves the attention-demanding retrieval of targets from long-term memory.

  7. Individual differences in working memory capacity determine the effects of oculomotor task load on concurrent word recall performance.

    PubMed

    Lee, Eun-Ju; Kwon, Gusang; Lee, Aekyoung; Ghajar, Jamshid; Suh, Minah

    2011-07-05

    In this study, the interaction between individual differences in working memory capacity, which were assessed by the Korean version of the California Verbal Learning Test (K-CVLT), and the effects of oculomotor task load on word recall performance are examined in a dual-task experiment. We hypothesized that varying levels of oculomotor task load should result in different demands on cognitive resources. The verbal working memory task used in this study involved a brief exposure to seven words to be remembered, followed by a 30-second delay during which the subject carried out an oculomotor task. Then, memory performance was assessed by having the subjects recall as many words as possible. Forty healthy normal subjects with no vision-related problems carried out four separate dual-tasks over four consecutive days of participation, wherein word recall performances were tested under unpredictable random SPEM (smooth pursuit eye movement), predictive SPEM, fixation, and eyes-closed conditions. The word recall performance of subjects with low K-CVLT scores was significantly enhanced under predictive SPEM conditions as opposed to the fixation and eyes-closed conditions, but performance was reduced under the random SPEM condition, thus reflecting an inverted-U relationship between the oculomotor task load and word recall performance. Subjects with high K-CVLT scores evidenced steady word recall performances, regardless of the type of oculomotor task performed. The concurrent oculomotor performance measured by velocity error did not differ significantly among the K-CVLT groups. However, the high-scoring subjects evidenced smaller phase errors under predictive SPEM conditions than did the low-scoring subjects; this suggests that different resource allocation strategies may be adopted, depending on individuals' working memory capacity. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. The influence of an auditory-memory attention-demanding task on postural control in blind persons.

    PubMed

    Melzer, Itshak; Damry, Elad; Landau, Anat; Yagev, Ronit

    2011-05-01

    In order to evaluate the effect of an auditory-memory attention-demanding task on balance control, nine blind adults were compared to nine age-gender-matched sighted controls. This issue is particularly relevant for the blind population in which functional assessment of postural control has to be revealed through "real life" motor and cognitive function. The study aimed to explore whether an auditory-memory attention-demanding cognitive task would influence postural control in blind persons and compare this with blindfolded sighted persons. Subjects were instructed to minimize body sway during narrow base upright standing on a single force platform under two conditions: 1) standing still (single task); 2) as in 1) while performing an auditory-memory attention-demanding cognitive task (dual task). Subjects in both groups were required to stand blindfolded with their eyes closed. Center of Pressure displacement data were collected and analyzed using summary statistics and stabilogram-diffusion analysis. Blind and sighted subjects had similar postural sway in eyes closed condition. However, for dual compared to single task, sighted subjects show significant decrease in postural sway while blind subjects did not. The auditory-memory attention-demanding cognitive task had no interference effect on balance control on blind subjects. It seems that sighted individuals used auditory cues to compensate for momentary loss of vision, whereas blind subjects did not. This may suggest that blind and sighted people use different sensorimotor strategies to achieve stability. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Dual tasking and balance in those with central and peripheral vision loss.

    PubMed

    Kotecha, Aachal; Chopra, Reena; Fahy, Rachel T A; Rubin, Gary S

    2013-08-09

    To investigate the effects of a secondary task on standing balance in patients with glaucoma or AMD compared with age-similar control subjects. Twelve AMD, 12 glaucoma, and 12 control participants underwent posturography under two standing conditions (eyes open on a firm or foam-rubber surface) and two tasks: quiet standing and undertaking a mental arithmetic task. Center of foot-pressure average displacement (root mean square [RMS]; in millimeters) was calculated. The mean (SD) age of the participants in each group was as follows: controls 66.2 (6.4) years, glaucoma 69.2 (4.3) years, and AMD 72.2 (5.3) years. There were significant differences in RMS between controls and AMD patients when undertaking the mental arithmetic task standing on the firm surface (mean difference [SE]: 2.8 [0.8] mm, P = 0.005). There were significant differences between controls and AMD patients when undertaking the mental arithmetic task on the foam surface, with the difference between controls and glaucoma patients approaching significance (mean difference [SE]: control versus AMD = 3.1 [0.9] mm, P = 0.005; control versus glaucoma = 2.2 [0.9] mm, P = 0.06). Postural instability increases with the addition of a secondary task in older persons, which may put them at greater risk of falls. Patients with central losses exhibit greater instability with the addition of a secondary task, particularly during somatosensory perturbations. The negative effects of secondary tasks on balance control in those with peripheral visual losses become more apparent under somatosensory perturbations.

  10. Executive function is necessary for perspective selection, not Level-1 visual perspective calculation: evidence from a dual-task study of adults.

    PubMed

    Qureshi, Adam W; Apperly, Ian A; Samson, Dana

    2010-11-01

    Previous research suggests that perspective-taking and other "theory of mind" processes may be cognitively demanding for adult participants, and may be disrupted by concurrent performance of a secondary task. In the current study, a Level-1 visual perspective task was administered to 32 adults using a dual-task paradigm in which the secondary task tapped executive function. Results suggested that the secondary task did not affect the calculation of perspective, but did affect the selection of the relevant (Self or Other) perspective for a given trial. This is the first direct evidence of a cognitively efficient process for "theory of mind" in adults that operates independently of executive function. The contrast between this and previous findings points to a distinction between simple perspective-taking and the more complex and cognitively demanding abilities more typically examined in studies of "theory of mind". It is suggested that these findings may provide a parsimonious explanation of the success of infants on 'indirect' measures of perspective-taking that do not explicitly require selection of the relevant perspective. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Common mechanisms of spatial attention in memory and perception: a tactile dual-task study.

    PubMed

    Katus, Tobias; Andersen, Søren K; Müller, Matthias M

    2014-03-01

    Orienting attention to locations in mnemonic representations engages processes that functionally and anatomically overlap the neural circuitry guiding prospective shifts of spatial attention. The attention-based rehearsal account predicts that the requirement to withdraw attention from a memorized location impairs memory accuracy. In a dual-task study, we simultaneously presented retro-cues and pre-cues to guide spatial attention in short-term memory (STM) and perception, respectively. The spatial direction of each cue was independent of the other. The locations indicated by the combined cues could be compatible (same hand) or incompatible (opposite hands). Incompatible directional cues decreased lateralized activity in brain potentials evoked by visual cues, indicating interference in the generation of prospective attention shifts. The detection of external stimuli at the prospectively cued location was impaired when the memorized location was part of the perceptually ignored hand. The disruption of attention-based rehearsal by means of incompatible pre-cues reduced memory accuracy and affected encoding of tactile test stimuli at the retrospectively cued hand. These findings highlight the functional significance of spatial attention for spatial STM. The bidirectional interactions between both tasks demonstrate that spatial attention is a shared neural resource of a capacity-limited system that regulates information processing in internal and external stimulus representations.

  12. Context Influences Holistic Processing of Non-face Objects in the Composite Task

    PubMed Central

    Richler, Jennifer J.; Bukach, Cindy M.; Gauthier, Isabel

    2013-01-01

    We explore whether holistic-like effects can be observed for non-face objects in novices as a result of the task context. We measure contextually-induced congruency effects for novel objects (Greebles) in a sequential matching selective attention task (composite task). When format at study was blocked, congruency effects were observed for study-misaligned, but not study-aligned, conditions (Experiment 1). However, congruency effects were observed in all conditions when study formats were randomized (Experiment 2), revealing that the presence of certain trial types (study-misaligned) in an experiment can induce congruency effects. In a dual task, a congruency effect for Greebles was induced in trials where a face was first encoded, only if it was aligned (Experiment 3). Thus, congruency effects can be induced by context that operates at the scale of the entire experiment or within a single trial. Implications for using the composite task to measure holistic processing are discussed. PMID:19304644

  13. Rethinking of the heuristic-analytic dual process theory: a comment on Wada and Nittono (2004) and the reasoning process in the Wason selection task.

    PubMed

    Cardaci, Maurizio; Misuraca, Raffaella

    2005-08-01

    This paper raises some methodological problems in the dual process explanation provided by Wada and Nittono for their 2004 results using the Wason selection task. We maintain that the Nittono rethinking approach is weak and that it should be refined to grasp better the evidence of analytic processes.

  14. Measuring cognitive load during simulation-based psychomotor skills training: sensitivity of secondary-task performance and subjective ratings.

    PubMed

    Haji, Faizal A; Khan, Rabia; Regehr, Glenn; Drake, James; de Ribaupierre, Sandrine; Dubrowski, Adam

    2015-12-01

    As interest in applying cognitive load theory (CLT) to the study and design of pedagogic and technological approaches in healthcare simulation grows, suitable measures of cognitive load (CL) are needed. Here, we report a two-phased study investigating the sensitivity of subjective ratings of mental effort (SRME) and secondary-task performance (signal detection rate, SDR and recognition reaction time, RRT) as measures of CL. In phase 1 of the study, novice learners and expert surgeons attempted a visual-monitoring task under two conditions: single-task (monitoring a virtual patient's heart-rate) and dual-task (tying surgical knots on a bench-top simulator while monitoring the virtual patient's heart-rate). Novices demonstrated higher mental effort and inferior secondary-task performance on the dual-task compared to experts (RRT 1.76 vs. 0.73, p = 0.012; SDR 0.27 vs. 0.97, p < 0.001; SRME 7.75 vs. 2.80, p < 0.001). Similarly, secondary task performance deteriorated from baseline to dual-task among novices (RRT 0.63 vs. 1.76 s, p < 0.006 and SDR 1.00 vs. 0.27, p < 0.001), but not experts (RRT 0.63 vs. 0.73 s, p = 0.124 and SDR 1.00 vs. 0.97, p = 0.178). In phase 2, novices practiced surgical knot-tying on the bench top simulator during consecutive dual-task trials. A significant increase in SDR (F(9,63) = 6.63, p < 0.001, f = 0.97) and decrease in SRME (F(9,63) = 9.39, p < 0.001, f = 1.04) was observed during simulation training, while RRT did not change significantly (F(9,63) = 1.18, p < 0.32, f = 0.41). The results suggest subjective ratings and dual-task performance can be used to track changes in CL among novices, particularly in early phases of simulation-based skills training. The implications for measuring CL in simulation instructional design research are discussed.

  15. The influence of dimensional overlap on location-related priming in the Simon task.

    PubMed

    Lehle, Carola; Stürmer, Birgit; Sommer, Werner

    2013-01-01

    Choice reaction times are shorter when stimulus and response locations are compatible than when they are incompatible as in the Simon effect. Recent studies revealed that Simon effects are strongly attenuated when there is temporal overlap with a different high-priority task, accompanied by a decrease of early location-related response priming as reflected in the lateralized readiness potential (LRP). The latter result was obtained in a study excluding overlap of stimulus location with any other dimension in the tasks. Independent evidence suggests that location-related priming might be present in conditions with dimensional overlap. Here we tested this prediction in a dual-task experiment supplemented with recording LRPs. The secondary task was either a standard Simon task where irrelevant stimulus location overlapped with dimensions of the primary task or a Stroop-like Simon task including additional overlap of irrelevant and relevant stimulus attributes. At high temporal overlap, there was no Simon effect nor was there stimulus-related response priming in either condition. Therefore stimulus-triggered response priming seems to be abolished in conditions of limited capacity even if the likelihood of an S-R compatibility effect is maximized.

  16. A dual-task home-based rehabilitation programme for improving balance control in patients with acquired brain injury: a single-blind, randomized controlled pilot study.

    PubMed

    Peirone, Eliana; Goria, Paolo Filiberto; Anselmino, Arianna

    2014-04-01

    To evaluate the safety, feasibility and effectiveness of a dual-task home-based rehabilitation programme on balance impairments among adult patients with acquired brain injury. Single-blind, randomized controlled pilot study. Single rehabilitation centre. Sixteen participants between 12 and 18 months post-acquired brain injury with balance impairments and a score <10 seconds on the One-Leg Stance Test (eyes open). All participants received 50-minutes individualised traditional physiotherapy sessions three times a week for seven weeks. In addition, the intervention group (N = 8) performed an individualised dual-task home-based programme six days a week for seven weeks. The primary outcome measure was the Balance Evaluation System Test; secondary measures were the Activities-specific Balance Confidence Scale and Goal Attainment Scaling. At the end of the pilot study, the intervention group showed significantly greater improvement in Balance Evaluation System Test scores (17.87, SD 6.05) vs. the control group (5.5, SD 3.53; P = 0.008, r = 0.63). There was no significant difference in improvement in Activities-specific Balance Confidence Scale scores between the intervention group (25.25, SD 25.51) and the control group (7.00, SD 14.73; P = 0.11, r = 0.63). There was no significant improvement in Goal Attainment Scaling scores in the intervention (19.37, SD 9.03) vs. the control group (16.28, SD 6.58; P = 0.093, r = 0.63). This pilot study shows the safety, feasibility and short-term benefit of a dual-task home-based rehabilitation programme to improve balance control in patients with acquired brain injury. A sample size of 26 participants is required for a definitive study.

  17. Task stressfulness moderates the effects of verbal person centeredness on cardiovascular reactivity: a dual-process account of the reactivity hypothesis.

    PubMed

    Bodie, Graham D

    2012-01-01

    This study sought to investigate the impact of person-centered comfort on cardiovascular reactivity and to test a recently developed dual-process theory of supportive message outcomes proposing that the impact of supportive communication is moderated by the motivation and ability to attend to message content. Participants (n = 179) completed a public speaking task that served to experimentally manipulate stress. During the preparation period, instant messages containing either low or high person-centered messages or containing no imbedded supportive message were sent. Results indicated that, in line with theoretical predictions, message content did influence mean arterial pressure and heart rate for participants exposed to moderate but not to low or high stress. Results are discussed in terms of the dual-process theory of supportive message outcomes, and the discussion offers both theoretical and practical implications of the research.

  18. Executive Resources and Item-Context Binding: Exploring the Influence of Concurrent Inhibition, Updating, and Shifting Tasks on Context Memory

    PubMed Central

    Nieznański, Marek; Obidziński, Michał; Zyskowska, Emilia; Niedziałkowska, Daria

    2015-01-01

    Previous research has demonstrated that context memory performance decreases as a result of cognitive load. However, the role of specific executive resources availability has not been specified yet. In a dual-task experiment, participants performed three kinds of concurrent task engaging: inhibition, updating, or shifting operations. In comparison with a no-load single-task condition, a significant decrease in item and context memory was observed, regardless of the kind of executive task. When executive load conditions were compared with non-specific cognitive load conditions, a significant interference effect was observed in the case of the inhibition task. The inhibition process appears to be an aspect of executive control, which relies on the same resource as item-context binding does, especially when binding refers to associations retrieved from long-term memory. PMID:26435761

  19. Single- and dual-task performance during on-the-road driving at a low and moderate dose of alcohol: A comparison between young novice and more experienced drivers.

    PubMed

    Jongen, Stefan; van der Sluiszen, Nick N J J M; Brown, Dennis; Vuurman, Eric F P M

    2018-05-01

    Driving experience and alcohol are two factors associated with a higher risk of crash involvement in young novice drivers. Driving a car is a complex task involving multiple tasks leading to dividing attention. The aim of this study was to compare the single and combined effects of a low and moderate dose of alcohol on single- and dual-task performance between young novice and more experienced young drivers during actual driving. Nine healthy novice drivers were compared with 9 more experienced drivers in a three-way, placebo-controlled, cross-over study design. Driving performance was measured in actual traffic, with standard deviation of lateral position as the primary outcome variable. Secondary task performance was measured with an auditory word learning test during driving. Results showed that standard deviation of lateral position increased dose-dependently at a blood alcohol concentration (BAC) of 0.2 and 0.5 g/L in both novice and experienced drivers. Secondary task performance was impaired in both groups at a BAC of 0.5 g/L. Furthermore, it was found that driving performance in novice drivers was already impaired at a BAC of 0.2 g/L during dual-task performance. The findings suggest that young inexperienced drivers are especially vulnerable to increased mental load while under the influence of alcohol. © 2018 The Authors Human Psychopharmacology: Clinical and Experimental Published by John Wiley & Sons Ltd.

  20. Facial and semantic emotional interference: A pilot study on the behavioral and cortical responses to the dual valence association task

    PubMed Central

    2011-01-01

    Background Integration of compatible or incompatible emotional valence and semantic information is an essential aspect of complex social interactions. A modified version of the Implicit Association Test (IAT) called Dual Valence Association Task (DVAT) was designed in order to measure conflict resolution processing from compatibility/incompatibly of semantic and facial valence. The DVAT involves two emotional valence evaluative tasks which elicits two forms of emotional compatible/incompatible associations (facial and semantic). Methods Behavioural measures and Event Related Potentials were recorded while participants performed the DVAT. Results Behavioural data showed a robust effect that distinguished compatible/incompatible tasks. The effects of valence and contextual association (between facial and semantic stimuli) showed early discrimination in N170 of faces. The LPP component was modulated by the compatibility of the DVAT. Conclusions Results suggest that DVAT is a robust paradigm for studying the emotional interference effect in the processing of simultaneous information from semantic and facial stimuli. PMID:21489277

  1. Walking and cognition, but not symptoms, correlate with dual task cost of walking in multiple sclerosis.

    PubMed

    Motl, Robert W; Sosnoff, Jacob J; Dlugonski, Deirdre; Pilutti, Lara A; Klaren, Rachel; Sandroff, Brian M

    2014-03-01

    Performing a cognitive task while walking results in a reduction of walking performance among persons with MS. To date, very little is known about correlates of this dual task cost (DTC) of walking in MS. We examined walking performance, cognitive processing speed, and symptoms of fatigue, depression, anxiety, and pain as correlates of DTC of walking in MS. 82 persons with MS undertook a 6-min walk test (6MWT) and completed the Symbol Digit Modalities Test (SDMT), Fatigue Severity Scale (FSS), Short-form of the McGill Pain Questionnaire (SF-MPQ), Hospital Anxiety and Depression Scale (HADS), and self-reported Expanded Disability Status Scale (SR-EDSS). The participants completed 4 trials of walking at a self-selected pace on an electronic walkway that recorded spatiotemporal parameters of gait. The first 2 trials were performed without a cognitive task, whereas the second 2 trials were completed while performing a modified Word List Generation task. There were significant and large declines in gait performance with the addition of a cognitive task for velocity (p<.001, η2=.52), cadence (p<.001, η2=.49), and step length (p<.001, η2=.23). 6MWT and SDMT scores correlated with DTC for velocity (r=-.41, p<.001 and r=-.32, p<.001, respectively) and step length (r=-.45, p<.001 and r=-.37, p<.001, respectively); there were no significant associations between FSS, SF-MPQ, and HADS scores with the DTC of walking. Regression analyses indicated that 6MW, but not SDMT, explained variance in DTC for velocity (ΔR2=.11, p<.001) and step length (ΔR2=.13, p<.001), after controlling for SR-EDSS scores. Walking performance might be a target of interventions for reducing the DTC of walking in MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Effects of age, task, and frequency on variability of finger tapping.

    PubMed

    Sommervoll, Yngve; Ettema, Gertjan; Vereijken, Beatrix

    2011-10-01

    The goal was to assess whether prior studies might have overestimated performance variability in older adults in dual task conditions by relying on primary motor tasks that are not constant with aging. 30 younger and 31 older adults performed a bimanual tapping task at four different frequencies in isolation or concurrently with a secondary task. Results showed that performance of younger and older adults was not significantly different in performing the tapping task at all frequencies and with either secondary task, as indicated by mean tapping performance and low number of errors in the secondary tasks. Both groups showed increased variability as tapping frequency increased and with the presence of a secondary task. Tapping concurrently while reading words increased tapping variability more than tapping concurrently while naming colours. Although older participants' performances were overall more variable, no interaction effects with age were found and at the highest frequencies of tapping, younger and older participants did not differ in performance.

  3. Task-set switching under cue-based versus memory-based switching conditions in younger and older adults.

    PubMed

    Kray, Jutta

    2006-08-11

    Adult age differences in task switching and advance preparation were examined by comparing cue-based and memory-based switching conditions. Task switching was assessed by determining two types of costs that occur at the general (mixing costs) and specific (switching costs) level of switching. Advance preparation was investigated by varying the time interval until the next task (short, middle, very long). Results indicated that the implementation of task sets was different for cue-based switching with random task sequences and memory-based switching with predictable task sequences. Switching costs were strongly reduced under cue-based switching conditions, indicating that task-set cues facilitate the retrieval of the next task. Age differences were found for mixing costs and for switching costs only under cue-based conditions in which older adults showed smaller switching costs than younger adults. It is suggested that older adults adopt a less extreme bias between two tasks than younger adults in situations associated with uncertainty. For cue-based switching with random task sequences, older adults are less engaged in a complete reconfiguration of task sets because of the probability of a further task change. Furthermore, the reduction of switching costs was more pronounced for cue- than memory-based switching for short preparation intervals, whereas the reduction of switch costs was more pronounced for memory- than cue-based switching for longer preparation intervals at least for older adults. Together these findings suggest that the implementation of task sets is functionally different for the two types of task-switching conditions.

  4. Is Semantic Processing During Sentence Reading Autonomous or Controlled? Evidence from the N400 Component in a Dual Task Paradigm

    PubMed Central

    Hohlfeld, Annette; Martín-Loeches, Manuel; Sommer, Werner

    2015-01-01

    The present study contributes to the discussion on the automaticity of semantic processing. Whereas most previous research investigated semantic processing at word level, the present study addressed semantic processing during sentence reading. A dual task paradigm was combined with the recording of event-related brain potentials. Previous research at word level processing reported different patterns of interference with the N400 by additional tasks: attenuation of amplitude or delay of latency. In the present study, we presented Spanish sentences that were semantically correct or contained a semantic violation in a critical word. At different intervals preceding the critical word a tone was presented that required a high-priority choice response. At short intervals/high temporal overlap between the tasks mean amplitude of the N400 was reduced relative to long intervals/low temporal overlap, but there were no shifts of peak latency. We propose that processing at sentence level exerts a protective effect against the additional task. This is in accord with the attentional sensitization model (Kiefer & Martens, 2010), which suggests that semantic processing is an automatic process that can be enhanced by the currently activated task set. The present experimental sentences also induced a P600, which is taken as an index of integrative processing. Additional task effects are comparable to those in the N400 time window and are briefly discussed. PMID:26203312

  5. Impact of cognitive task on the posture of elderly subjects with Alzheimer's disease compared to healthy elderly subjects.

    PubMed

    Manckoundia, Patrick; Pfitzenmeyer, Pierre; d'Athis, Philippe; Dubost, Véronique; Mourey, France

    2006-02-01

    The aims of this study were to analyze the effects of cognitive task on static posture in Alzheimer's disease (AD) and in healthy elderly (HE) subjects and to evaluate whether those effects were greater in AD subjects than in HE subjects. We performed a posturographic analysis on 13 subjects with mild AD (mean age, 79.7+/-5.1 years, Mini-Mental State Examination scores between 18 and 23) and on 17 HE subjects (mean age, 78.5+/-4.4 years). After watching a video sequence, the subjects were asked to maintain a stable upright posture while standing on a force platform. Then, the postural sway was measured during the following two conditions: (1) quiet standing and (2) both standing and answering questions about the video sequence. We were interested in the center of pressure (CoP) area and path. For each group, the single task was compared to the dual task for the CoP area and path. We also compared the variability of both CoP area (variation of the CoP area between the single and the dual task) and path (variation of the CoP path between the single and the dual task) between the two groups. We showed that there was no significant difference between the single and the dual task in HE subjects concerning the CoP area and path, in contrast to the AD group, and that variability of both the CoP area and path were significantly greater in the AD subjects than in the HE subjects. This finding may contribute to the risk of falls in AD patients. Copyright (c) 2005 Movement Disorder Society.

  6. Reversible second-order conditional sequences in incidental sequence learning tasks.

    PubMed

    Pasquali, Antoine; Cleeremans, Axel; Gaillard, Vinciane

    2018-06-01

    In sequence learning tasks, participants' sensitivity to the sequential structure of a series of events often overshoots their ability to express relevant knowledge intentionally, as in generation tasks that require participants to produce either the next element of a sequence (inclusion) or a different element (exclusion). Comparing generation performance under inclusion and exclusion conditions makes it possible to assess the respective influences of conscious and unconscious learning. Recently, two main concerns have been expressed concerning such tasks. First, it is often difficult to design control sequences in such a way that they enable clear comparisons with the training material. Second, it is challenging to ask participants to perform appropriately under exclusion instructions, for the requirement to exclude familiar responses often leads them to adopt degenerate strategies (e.g., pushing on the same key all the time), which then need to be specifically singled out as invalid. To overcome both concerns, we introduce reversible second-order conditional (RSOC) sequences and show (a) that they elicit particularly strong transfer effects, (b) that dissociation of implicit and explicit influences becomes possible thanks to the removal of salient transitions in RSOCs, and (c) that exclusion instructions can be greatly simplified without losing sensitivity.

  7. Local dynamic stability and gait variability during attentional tasks in young adults.

    PubMed

    Magnani, Rina Márcia; Lehnen, Georgia Cristina; Rodrigues, Fábio Barbosa; de Sá E Souza, Gustavo Souto; de Oliveira Andrade, Adriano; Vieira, Marcus Fraga

    2017-06-01

    Cell phone use while walking may be a cognitive distraction and reduce visual and motor attention. Thus, the aim of this study was to verify the effects of attentional dual-tasks while using a cell phone in different conditions. Stability, regularity, and linear variability of trunk kinematics, and gait spatiotemporal parameters in young adults were measured. Twenty young subjects of both genders were asked to walk on a treadmill for 4min under the following conditions: (a) looking forward at a fixed target 2.5m away (walking); (b) talking on a cell phone with unilateral handling (talking); (c) texting messages on a cell phone with unilateral handling (texting); and (d) looking forward at the aforementioned target while listening to music without handling the phone (listening). Local dynamic stability measured in terms of the largest Lyapunov exponent decreased while handling a cell phone (talking and texting). Gait variability and regularity increased when talking on a cell phone, but no variable changed in the listening condition. Under all dual-task conditions, there were significant increases in stride width and its variability. We conclude that young adults who use a cell phone when walking adapt their gait pattern conservatively, which can be because of increased attentional demand during cell phone use. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. The dual reading of general conditionals: The influence of abstract versus concrete contexts.

    PubMed

    Wang, Moyun; Yao, Xinyun

    2018-04-01

    A current main issue on conditionals is whether the meaning of general conditionals (e.g., If a card is red, then it is round) is deterministic (exceptionless) or probabilistic (exception-tolerating). In order to resolve the issue, two experiments examined the influence of conditional contexts (with vs. without frequency information of truth table cases) on the reading of general conditionals. Experiment 1 examined the direct reading of general conditionals in the possibility judgment task. Experiment 2 examined the indirect reading of general conditionals in the truth judgment task. It was found that both the direct and indirect reading of general conditionals exhibited the duality: the predominant deterministic semantic reading of conditionals without frequency information, and the predominant probabilistic pragmatic reading of conditionals with frequency information. The context of general conditionals determined the predominant reading of general conditionals. There were obvious individual differences in reading general conditionals with frequency information. The meaning of general conditionals is relative, depending on conditional contexts. The reading of general conditionals is flexible and complex so that no simple deterministic and probabilistic accounts are able to explain it. The present findings are beyond the extant deterministic and probabilistic accounts of conditionals.

  9. Cascaded systems analysis of noise and detectability in dual-energy cone-beam CT

    PubMed Central

    Gang, Grace J.; Zbijewski, Wojciech; Webster Stayman, J.; Siewerdsen, Jeffrey H.

    2012-01-01

    imaging conditions. Optimization results suggest a lower fraction of total dose imparted by the low-energy acquisition, a finding consistent with previous literature. The selection of optimal kVp pair reveals the combined effect of both quantum noise and contrast in the kidney stone discrimination and soft-tissue tumor detection tasks, whereas the K-edge effect of iodine was the dominant factor in determining kVp pairs in the iodine vs bone task. The soft-tissue tumor task illustrated the benefit of dual-energy imaging in eliminating anatomical background noise and improving detectability beyond that achievable by single-energy scans. Conclusions: This work established a task-based theoretical framework that is predictive of DE image quality. The model can be utilized in optimizing a broad range of parameters in image acquisition, reconstruction, and decomposition, providing a useful tool for maximizing DE-CBCT image quality and reducing dose. PMID:22894440

  10. More insight into the interplay of response selection and visual attention in dual-tasks: masked visual search and response selection are performed in parallel.

    PubMed

    Reimer, Christina B; Schubert, Torsten

    2017-09-15

    Both response selection and visual attention are limited in capacity. According to the central bottleneck model, the response selection processes of two tasks in a dual-task situation are performed sequentially. In conjunction search, visual attention is required to select the items and to bind their features (e.g., color and form), which results in a serial search process. Search time increases as items are added to the search display (i.e., set size effect). When the search display is masked, visual attention deployment is restricted to a brief period of time and target detection decreases as a function of set size. Here, we investigated whether response selection and visual attention (i.e., feature binding) rely on a common or on distinct capacity limitations. In four dual-task experiments, participants completed an auditory Task 1 and a conjunction search Task 2 that were presented with an experimentally modulated temporal interval between them (Stimulus Onset Asynchrony, SOA). In Experiment 1, Task 1 was a two-choice discrimination task and the conjunction search display was not masked. In Experiment 2, the response selection difficulty in Task 1 was increased to a four-choice discrimination and the search task was the same as in Experiment 1. We applied the locus-of-slack method in both experiments to analyze conjunction search time, that is, we compared the set size effects across SOAs. Similar set size effects across SOAs (i.e., additive effects of SOA and set size) would indicate sequential processing of response selection and visual attention. However, a significantly smaller set size effect at short SOA compared to long SOA (i.e., underadditive interaction of SOA and set size) would indicate parallel processing of response selection and visual attention. In both experiments, we found underadditive interactions of SOA and set size. In Experiments 3 and 4, the conjunction search display in Task 2 was masked. Task 1 was the same as in Experiments 1 and 2

  11. The effect of encoding conditions on learning in the prototype distortion task.

    PubMed

    Lee, Jessica C; Livesey, Evan J

    2017-06-01

    The prototype distortion task demonstrates that it is possible to learn about a category of physically similar stimuli through mere observation. However, there have been few attempts to test whether different encoding conditions affect learning in this task. This study compared prototypicality gradients produced under incidental learning conditions in which participants performed a visual search task, with those produced under intentional learning conditions in which participants were required to memorize the stimuli. Experiment 1 showed that similar prototypicality gradients could be obtained for category endorsement and familiarity ratings, but also found (weaker) prototypicality gradients in the absence of exposure. In Experiments 2 and 3, memorization was found to strengthen prototypicality gradients in familiarity ratings in comparison to visual search, but there were no group differences in participants' ability to discriminate between novel and presented exemplars. Although the Search groups in Experiments 2 and 3 produced prototypicality gradients, they were no different in magnitude to those produced in the absence of stimulus exposure in Experiment 1, suggesting that incidental learning during visual search was not conducive to producing prototypicality gradients. This study suggests that learning in the prototype distortion task is not implicit in the sense of resulting automatically from exposure, is affected by the nature of encoding, and should be considered in light of potential learning-at-test effects.

  12. On the Choice of Adequate Randomization Ranges for Limiting the Use of Unwanted Cues in Same-Different, Dual-Pair, and Oddity Tasks

    PubMed Central

    Dai, Huanping; Micheyl, Christophe

    2010-01-01

    A major concern when designing a psychophysical experiment is that participants may use another stimulus feature (“cue”) than that intended by the experimenter. One way to avoid this involves applying random variations to the corresponding feature across stimulus presentations, to make the “unwanted” cue unreliable. An important question facing experimenters who use this randomization (“roving”) technique is: How large should the randomization range be to ensure that participants cannot achieve a certain proportion correct (PC) by using the unwanted cue, while at the same time avoiding unnecessary interference of the randomization with task performance? Previous publications have provided formulas for the selection of adequate randomization ranges in yes-no and multiple-alternative, forced-choice tasks. In this article, we provide figures and tables, which can be used to select randomization ranges that are better suited to experiments involving a same-different, dual-pair, or oddity task. PMID:20139466

  13. The effects of a concurrent task on walking in persons with transfemoral amputation compared to persons without limb loss.

    PubMed

    Morgan, Sara J; Hafner, Brian J; Kelly, Valerie E

    2016-08-01

    Many people with lower limb loss report the need to concentrate on walking. This may indicate increased reliance on cognitive resources when walking compared to individuals without limb loss. This study quantified changes in walking associated with addition of a concurrent cognitive task in persons with transfemoral amputation using microprocessor knees compared to age- and sex-matched controls. Observational, cross-sectional study. Quantitative motion analysis was used to assess walking under both single-task (walking alone) and dual-task (walking while performing a cognitive task) conditions. Primary outcomes were walking speed, step width, step time asymmetry, and cognitive task response latency and accuracy. Repeated-measures analysis of variance was used to examine the effects of task (single-task and dual-task) and group (transfemoral amputation and control) for each outcome. No significant interactions between task and group were observed (all p > 0.11) indicating that a cognitive task did not differentially affect walking between groups. However, walking was slower with wider steps and more asymmetry in people with transfemoral amputation compared to controls under both conditions. Although there were significant differences in walking between people with transfemoral amputation and matched controls, the effects of a concurrent cognitive task on walking were similar between groups. The addition of a concurrent task did not differentially affect walking outcomes in people with and without transfemoral amputation. However, compared to people without limb loss, people with transfemoral amputation adopted a conservative walking strategy. This strategy may reduce the need to concentrate on walking but also contributed to notable gait deviations. © The International Society for Prosthetics and Orthotics 2015.

  14. A modular telerobotic task execution system

    NASA Technical Reports Server (NTRS)

    Backes, Paul G.; Tso, Kam S.; Hayati, Samad; Lee, Thomas S.

    1990-01-01

    A telerobot task execution system is proposed to provide a general parametrizable task execution capability. The system includes communication with the calling system, e.g., a task planning system, and single- and dual-arm sensor-based task execution with monitoring and reflexing. A specific task is described by specifying the parameters to various available task execution modules including trajectory generation, compliance control, teleoperation, monitoring, and sensor fusion. Reflex action is achieved by finding the corresponding reflex action in a reflex table when an execution event has been detected with a monitor.

  15. Dynamic, continuous multitasking training leads to task-specific improvements but does not transfer across action selection tasks

    NASA Astrophysics Data System (ADS)

    Bender, Angela D.; Filmer, Hannah L.; Naughtin, Claire K.; Dux, Paul E.

    2017-12-01

    The ability to perform multiple tasks concurrently is an ever-increasing requirement in our information-rich world. Despite this, multitasking typically compromises performance due to the processing limitations associated with cognitive control and decision-making. While intensive dual-task training is known to improve multitasking performance, only limited evidence suggests that training-related performance benefits can transfer to untrained tasks that share overlapping processes. In the real world, however, coordinating and selecting several responses within close temporal proximity will often occur in high-interference environments. Over the last decade, there have been notable reports that training on video action games that require dynamic multitasking in a demanding environment can lead to transfer effects on aspects of cognition such as attention and working memory. Here, we asked whether continuous and dynamic multitasking training extends benefits to tasks that are theoretically related to the trained tasks. To examine this issue, we asked a group of participants to train on a combined continuous visuomotor tracking task and a perceptual discrimination task for six sessions, while an active control group practiced the component tasks in isolation. A battery of tests measuring response selection, response inhibition, and spatial attention was administered before and immediately after training to investigate transfer. Multitasking training resulted in substantial, task-specific gains in dual-task ability, but there was no evidence that these benefits generalized to other action control tasks. The findings suggest that training on a combined visuomotor tracking and discrimination task results in task-specific benefits but provides no additional value for untrained action selection tasks.

  16. A functional near-infrared spectroscopy study of lexical decision task supports the dual route model and the phonological deficit theory of dyslexia.

    PubMed

    Sela, Itamar; Izzetoglu, Meltem; Izzetoglu, Kurtulus; Onaral, Banu

    2014-01-01

    The dual route model (DRM) of reading suggests two routes of reading development: the phonological and the orthographic routes. It was proposed that although the two routes are active in the process of reading; the first is more involved at the initial stages of reading acquisition, whereas the latter needs more reading training to mature. A number of studies have shown that deficient phonological processing is a core deficit in developmental dyslexia. According to the DRM, when the Lexical Decision Task (LDT) is performed, the orthographic route should also be involved when decoding words, whereas it is clear that when decoding pseudowords the phonological route should be activated. Previous functional near-infrared spectroscopy (fNIR) studies have suggested that the upper left frontal lobe is involved in decision making in the LDT. The current study used fNIR to compare left frontal lobe activity during LDT performance among three reading-level groups: 12-year-old children, young adult dyslexic readers, and young adult typical readers. Compared to typical readers, the children demonstrated lower activity under the word condition only, whereas the dyslexic readers showed lower activity under the pseudoword condition only. The results provide evidence for upper left frontal lobe involvement in LDT and support the DRM and the phonological deficit theory of dyslexia.

  17. Attentional Demand of a Virtual Reality-Based Reaching Task in Nondisabled Older Adults.

    PubMed

    Chen, Yi-An; Chung, Yu-Chen; Proffitt, Rachel; Wade, Eric; Winstein, Carolee

    2015-12-01

    Attention during exercise is known to affect performance; however, the attentional demand inherent to virtual reality (VR)-based exercise is not well understood. We used a dual-task paradigm to compare the attentional demands of VR-based and non-VR-based (conventional, real-world) exercise: 22 non-disabled older adults performed a primary reaching task to virtual and real targets in a counterbalanced block order while verbally responding to an unanticipated auditory tone in one third of the trials. The attentional demand of the primary reaching task was inferred from the voice response time (VRT) to the auditory tone. Participants' engagement level and task experience were also obtained using questionnaires. The virtual target condition was more attention demanding (significantly longer VRT) than the real target condition. Secondary analyses revealed a significant interaction between engagement level and target condition on attentional demand. For participants who were highly engaged, attentional demand was high and independent of target condition. However, for those who were less engaged, attentional demand was low and depended on target condition (i.e., virtual > real). These findings add important knowledge to the growing body of research pertaining to the development and application of technology-enhanced exercise for elders and for rehabilitation purposes.

  18. Attentional Demand of a Virtual Reality-Based Reaching Task in Nondisabled Older Adults

    PubMed Central

    Chen, Yi-An; Chung, Yu-Chen; Proffitt, Rachel; Wade, Eric; Winstein, Carolee

    2015-01-01

    Attention during exercise is known to affect performance; however, the attentional demand inherent to virtual reality (VR)-based exercise is not well understood. We used a dual-task paradigm to compare the attentional demands of VR-based and non-VR-based (conventional, real-world) exercise: 22 non-disabled older adults performed a primary reaching task to virtual and real targets in a counterbalanced block order while verbally responding to an unanticipated auditory tone in one third of the trials. The attentional demand of the primary reaching task was inferred from the voice response time (VRT) to the auditory tone. Participants' engagement level and task experience were also obtained using questionnaires. The virtual target condition was more attention demanding (significantly longer VRT) than the real target condition. Secondary analyses revealed a significant interaction between engagement level and target condition on attentional demand. For participants who were highly engaged, attentional demand was high and independent of target condition. However, for those who were less engaged, attentional demand was low and depended on target condition (i.e., virtual > real). These findings add important knowledge to the growing body of research pertaining to the development and application of technology-enhanced exercise for elders and for rehabilitation purposes. PMID:27004233

  19. Using dual-process theory and analogical transfer to explain facilitation on a hypothetico-deductive reasoning task.

    PubMed

    Koenig, Cynthia S; Platt, Richard D; Griggs, Richard A

    2007-07-01

    Using the analogical transfer paradigm, the present study investigated the competing explanations of Girotto and Legrenzi (Psychological Research 51: 129-135, 1993) and Griggs, Platt, Newstead, and Jackson (Thinking and Reasoning 4: 1-14, 1998) for facilitation on the SARS version of the THOG problem, a hypothetico-deductive reasoning task. Girotto and Legrenzi argue that facilitation is based on logical analysis of the task [System 2 reasoning in Evans's (Trends in Cognitive Sciences 7: 454-459, 2003) dual-process account of reasoning] while Griggs et al. maintain that facilitation is due to an attentional heuristic produced by the wording of the problem (System 1 reasoning). If Girotto and Legrenzi are correct, then System 2 reasoning, which is volitional and responsible for deductive reasoning, should be elicited, and participants should comprehend the solution principle of the THOG task and exhibit analogical transfer. However, if Griggs et al. are correct, then System 1 reasoning, which is responsible for heuristic problem solving strategies such as an attentional heuristic, should occur, and participants should not abstract the solution principle and transfer should not occur. Significant facilitation (68 and 82% correct) was only observed for the two SARS source problems, but significant analogical transfer did not occur. This lack of transfer suggests that System 1 reasoning was responsible for the facilitation observed in the SARS problem, supporting Griggs et al.'s attentional heuristic explanation. The present results also underscore the explanatory value of using analogical transfer rather than facilitation as the criterion for problem understanding.

  20. Do we always prioritize balance when walking? Towards an integrated model of task prioritization.

    PubMed

    Yogev-Seligmann, Galit; Hausdorff, Jeffrey M; Giladi, Nir

    2012-05-01

    Previous studies suggest that strategies such as "posture first" are implicitly employed to regulate safety when healthy adults walk while simultaneously performing another task, whereas "posture second" may be inappropriately applied in the presence of neurological disease. However, recent understandings raise questions about the traditional resource allocation concept during walking while dual tasking. We propose a task prioritization model of walking while dual tasking that integrates motor and cognitive capabilities, focusing on postural reserve, hazard estimation, and other individual intrinsic factors. The proposed prioritization model provides a theoretical foundation for future studies and a framework for the development of interventions designed to reduce the profound negative impacts of dual tasking on gait and fall risk in patients with neurological diseases. © 2012 Movement Disorder Society. Copyright © 2012 Movement Disorder Society.

  1. A dual-learning paradigm can simultaneously train multiple characteristics of walking

    PubMed Central

    Toliver, Alexis; Bastian, Amy J.

    2016-01-01

    Impairments in human motor patterns are complex: what is often observed as a single global deficit (e.g., limping when walking) is actually the sum of several distinct abnormalities. Motor adaptation can be useful to teach patients more normal motor patterns, yet conventional training paradigms focus on individual features of a movement, leaving others unaddressed. It is known that under certain conditions, distinct movement components can be simultaneously adapted without interference. These previous “dual-learning” studies focused solely on short, planar reaching movements, yet it is unknown whether these findings can generalize to a more complex behavior like walking. Here we asked whether a dual-learning paradigm, incorporating two distinct motor adaptation tasks, can be used to simultaneously train multiple components of the walking pattern. We developed a joint-angle learning task that provided biased visual feedback of sagittal joint angles to increase peak knee or hip flexion during the swing phase of walking. Healthy, young participants performed this task independently or concurrently with another locomotor adaptation task, split-belt treadmill adaptation, where subjects adapted their step length symmetry. We found that participants were able to successfully adapt both components of the walking pattern simultaneously, without interference, and at the same rate as adapting either component independently. This leads us to the interesting possibility that combining rehabilitation modalities within a single training session could be used to help alleviate multiple deficits at once in patients with complex gait impairments. PMID:26961100

  2. Dual-Task Processing When Task 1 Is Hard and Task 2 Is Easy: Reversed Central Processing Order?

    ERIC Educational Resources Information Center

    Leonhard, Tanja; Fernandez, Susana Ruiz; Ulrich, Rolf; Miller, Jeff

    2011-01-01

    Five psychological refractory period (PRP) experiments were conducted with an especially time-consuming first task (Experiments 1, 3, and 5: mental rotation; Experiments 2 and 4: memory scanning) and with equal emphasis on the first task and on the second (left-right tone judgment). The standard design with varying stimulus onset asynchronies…

  3. Dual redundant arm system operational quality measures and their applications - Dynamic measures

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan; Kim, Sungbok

    1990-01-01

    Dual-arm dynamic operation quality measures are presented which quantify the efficiency and capability of generating Cartesian accelerations by two cooperative arms based on the analysis of dual-arm dynamic interactions. Dual-arm dynamic manipulability is defined as the efficiency of generating Cartesian accelerations under the dynamic and kinematic interactions between individual arms and an object under manipulation. The analysis of dual-arm dynamic interactions is based on the so-called Cartesian space agent model of an arm, which represents an individual arm as a force source acting upon a point mass with the effective Cartesian space arm dynamics and an environment or an object under manipulation. The Cartesian space agent model of an arm makes it possible to derive the dynamic and kinematic constraints involved in the transport, assembly and grasping modes of dual-arm cooperation. A task-oriented operational quality measure, (TOQd) is defined by evaluating dual-arm dynamic manipulability in terms of given task requirements. TOQd is used in dual-arm joint configuration optimization. Simulation results are shown. A complete set of forward dynamic equations for a dual-arm system is derived, and dual-arm dynamic operational quality measures for various modes of dual-arm cooperation allowing sliding contacts are established.

  4. Beyond a mask and against the bottleneck: retroactive dual-task interference during working memory consolidation of a masked visual target.

    PubMed

    Nieuwenstein, Mark; Wyble, Brad

    2014-06-01

    While studies on visual memory commonly assume that the consolidation of a visual stimulus into working memory is interrupted by a trailing mask, studies on dual-task interference suggest that the consolidation of a stimulus can continue for several hundred milliseconds after a mask. As a result, estimates of the time course of working memory consolidation differ more than an order of magnitude. Here, we contrasted these opposing views by examining if and for how long the processing of a masked display of visual stimuli can be disturbed by a trailing 2-alternative forced choice task (2-AFC; a color discrimination task or a visual or auditory parity judgment task). The results showed that the presence of the 2-AFC task produced a pronounced retroactive interference effect that dissipated across stimulus onset asynchronies of 250-1,000 ms, indicating that the processing elicited by the 2-AFC task interfered with the gradual consolidation of the earlier shown stimuli. Furthermore, this interference effect occurred regardless of whether the to-be-remembered stimuli comprised a string of letters or an unfamiliar complex visual shape, and it occurred regardless of whether these stimuli were masked. Conversely, the interference effect was reduced when the memory load for the 1st task was reduced, or when the 2nd task was a color detection task that did not require decision making. Taken together, these findings show that the formation of a durable and consciously accessible working memory trace for a briefly shown visual stimulus can be disturbed by a trailing 2-AFC task for up to several hundred milliseconds after the stimulus has been masked. By implication, the current findings challenge the common view that working memory consolidation involves an immutable central processing bottleneck, and they also make clear that consolidation does not stop when a stimulus is masked. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  5. Dual leadership in a hospital practice.

    PubMed

    Thude, Bettina Ravnborg; Thomsen, Svend Erik; Stenager, Egon; Hollnagel, Erik

    2017-02-06

    Purpose Despite the practice of dual leadership in many organizations, there is relatively little research on the topic. Dual leadership means two leaders share the leadership task and are held jointly accountable for the results of the unit. To better understand how dual leadership works, this study aims to analyse three different dual leadership pairs at a Danish hospital. Furthermore, this study develops a tool to characterize dual leadership teams from each other. Design/methodology/approach This is a qualitative study using semi-structured interviews. Six leaders were interviewed to clarify how dual leadership works in a hospital context. All interviews were transcribed and coded. During coding, focus was on the nine principles found in the literature and another principle was found by looking at the themes that were generic for all six interviews. Findings Results indicate that power balance, personal relations and decision processes are important factors for creating efficient dual leaderships. The study develops a categorizing tool to use for further research or for organizations, to describe and analyse dual leaderships. Originality/value The study describes dual leadership in the hospital context and develops a categorizing tool for being able to distinguish dual leadership teams from each other. It is important to reveal if there are any indicators that can be used for optimising dual leadership teams in the health-care sector and in other organisations.

  6. Context-Sensitive Adjustment of Cognitive Control in Dual-Task Performance

    ERIC Educational Resources Information Center

    Fischer, Rico; Gottschalk, Caroline; Dreisbach, Gesine

    2014-01-01

    Performing 2 highly similar tasks at the same time requires an adaptive regulation of cognitive control to shield prioritized primary task processing from between-task (cross-talk) interference caused by secondary task processing. In the present study, the authors investigated how implicitly and explicitly delivered information promotes the…

  7. Association of fall history with the Timed Up and Go test score and the dual task cost: A cross-sectional study among independent community-dwelling older adults.

    PubMed

    Asai, Tsuyoshi; Oshima, Kensuke; Fukumoto, Yoshihiro; Yonezawa, Yuri; Matsuo, Asuka; Misu, Shogo

    2018-05-21

    To investigate the associations between fall history and the Timed Up and Go (TUG) test (single-TUG test), TUG test while counting aloud backwards from 100 (dual-TUG test) and the dual-task cost (DTC) among independent community-dwelling older adults. This cross-sectional study included 537 older adults who lived independently in the community. Data on fall history in the previous year were obtained by self-administrated questionnaire. The single- and dual-TUG tests were carried out, and the DTC value was computed from these results. Associations between fall history and these TUG-related values were analyzed using multivariate logistic regression models. The participants were divided into fall risk groups using the cut-off values of those significantly associated with falling, and the odds ratios (OR) were computed. Slower single-TUG test scores and lower DTC values were significantly associated with fall history after adjusting for potential confounders (single-TUG test score: OR 1.133, 95% CI 1.029-1.249; DTC value: OR 0.984, 95% CI 0.968-0.998). Older adults with slower single-TUG test scores and lower DTC values reported a fall history more often than those in other categories (OR compared with the lower-risk single-TUG and lower-risk DTC groups: 3.474, 95% CI 1.881-6.570). Slower single-TUG test scores and lower DTC values are associated with fall history among independent community-dwelling older adults. To some extent, dual task performance might provide added value for fall assessment, compared with administering the TUG test alone. Geriatr Gerontol Int 2018; ••: ••-••. © 2018 Japan Geriatrics Society.

  8. A dual system model of preferences under risk.

    PubMed

    Mukherjee, Kanchan

    2010-01-01

    This article presents a dual system model (DSM) of decision making under risk and uncertainty according to which the value of a gamble is a combination of the values assigned to it independently by the affective and deliberative systems. On the basis of research on dual process theories and empirical research in Hsee and Rottenstreich (2004) and Rottenstreich and Hsee (2001) among others, the DSM incorporates (a) individual differences in disposition to rational versus emotional decision making, (b) the affective nature of outcomes, and (c) different task construals within its framework. The model has good descriptive validity and accounts for (a) violation of nontransparent stochastic dominance, (b) fourfold pattern of risk attitudes, (c) ambiguity aversion, (d) common consequence effect, (e) common ratio effect, (f) isolation effect, and (g) coalescing and event-splitting effects. The DSM is also used to make several novel predictions of conditions under which specific behavior patterns may or may not occur.

  9. A Framework for the Dual Language Assessment of Young Dual Language Learners in the United States. Research Report. ETS RR-17-37

    ERIC Educational Resources Information Center

    Guzman-Orth, Danielle; Lopez, Alexis A.; Tolentino, Florencia

    2017-01-01

    Dual language learners (DLLs) and the various educational programs that serve them are increasing in number across the country. This framework lays out a conceptual approach for dual language assessment tasks designed to measure the language and literacy skills of young DLLs entering kindergarten in the United States. Although our examples focus…

  10. Response Activation in Overlapping Tasks and the Response-Selection Bottleneck

    ERIC Educational Resources Information Center

    Schubert, Torsten; Fischer, Rico; Stelzel, Christine

    2008-01-01

    The authors investigated the impact of response activation on dual-task performance by presenting a subliminal prime before the stimulus in Task 2 (S2) of a psychological refractory period (PRP) task. Congruence between prime and S2 modulated the reaction times in Task 2 at short stimulus onset asynchrony despite a PRP effect. This Task 2…

  11. Dual conception of risk in the Iowa Gambling Task: effects of sleep deprivation and test-retest gap.

    PubMed

    Singh, Varsha

    2013-01-01

    Risk in the Iowa Gambling Task (IGT) is often understood in terms of intertemporal choices, i.e., preference for immediate outcomes in favor of delayed outcomes is considered risky decision making. According to behavioral economics, healthy decision makers are expected to refrain from choosing the short-sighted immediate gain because, over time (10 trials of the IGT), the immediate gains result in a long term loss (net loss). Instead decision makers are expected to maximize their gains by choosing options that, over time (10 trials), result in delayed or long term gains (net gain). However, task choices are sometimes made on the basis of the frequency of reward and punishment such that frequent rewards/infrequent punishments are favored over infrequent rewards/frequent punishments. The presence of these two attributes (intertemporality and frequency of reward) in IGT decision making may correspond to the emotion-cognition dichotomy and reflect a dual conception of risk. Decision making on the basis of the two attributes was tested under two conditions: delay in retest and sleep deprivation. An interaction between sleep deprivation and time delay was expected to attenuate the difference between the two attributes. Participants were 40 male university students. Analysis of the effects of IGT attribute type (intertemporal vs. frequency of reinforcement), sleep deprivation (sleep deprivation vs. no sleep deprivation), and test-retest gap (short vs. long delay) showed a significant within-subjects effect of IGT attribute type thus confirming the difference between the two attributes. Sleep deprivation had no effect on the attributes, but test-retest gap and the three-way interaction between attribute type, test-retest gap, and sleep deprivation were significantly different. Post-hoc tests revealed that sleep deprivation and short test-retest gap attenuated the difference between the two attributes. Furthermore, the results showed an expected trend of increase in

  12. Posture-cognitive dual-tasking: A relevant marker of depression-related psychomotor retardation. An illustration of the positive impact of repetitive transcranial magnetic stimulation in patients with major depressive disorder.

    PubMed

    Deschamps, Thibault; Sauvaget, Anne; Pichot, Anne; Valrivière, Pierre; Maroulidès, Maxime; Bois, Aurore; Bulteau, Samuel; Thomas-Ollivier, Véronique

    2016-12-01

    This study examined whether postural control variables, particularly the center-of-pressure (COP) velocity-based parameters, could be a relevant hallmark of depression-related psychomotor retardation (PMR). We first aimed at investigating the interplay between the PMR scores and the COP performance in patients with major depressive disorder (MDD), as compared to age-matched healthy controls; secondly, we focused on the impact of a repetitive transcranial magnetic stimulation (rTMS) treatment on depression, PMR scores and postural performance. 16 MDD patients, and a control group of 16 healthy adults, were asked to maintain quiet standing balance during two trials with or without vision, and while backward counting (dual task). All the position and velocity-based COP variables were computed. Before and after the rTMS session (n eligible MDD = 10), we assessed the depression level with the Montgomery-Asberg Depression Rating Scale (MADRS), the PMR scores with the French Retardation Rating Scale for Depression (ERD), and postural performance. Before the treatment, significant positive partial correlations were found between the pre-ERD scores and the velocity-based COP variables, especially in the dual-task conditions (p < 0.05). In contrast, there was no significant correlation between the post-ERD scores and any postural parameter after the treatment. The MADRS and ERD scores showed a significant decrease between before and after the rTMS intervention. For the first time, the findings clearly validated the view that the assessment of postural performance - easy to envisage in clinical settings-constitutes a reliable and objective marker of PMR in MDD patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Carotid flow pulsatility is higher in women with greater decrement in gait speed during multi-tasking.

    PubMed

    Gonzales, Joaquin U; James, C Roger; Yang, Hyung Suk; Jensen, Daniel; Atkins, Lee; Al-Khalil, Kareem; O'Boyle, Michael

    2017-05-01

    Central arterial hemodynamics is associated with cognitive impairment. Reductions in gait speed during walking while performing concurrent tasks known as dual-tasking (DT) or multi-tasking (MT) is thought to reflect the cognitive cost that exceeds neural capacity to share resources. We hypothesized that central vascular function would associate with decrements in gait speed during DT or MT. Gait speed was measured using a motion capture system in 56 women (30-80y) without mild-cognitive impairment. Dual-tasking was considered walking at a fast-pace while balancing a tray. Multi-tasking was the DT condition plus subtracting by serial 7's. Applanation tonometry was used for measurement of aortic stiffness and central pulse pressure. Doppler-ultrasound was used to measure blood flow velocity and β-stiffness index in the common carotid artery. The percent change in gait speed was larger for MT than DT (14.1±11.2 vs. 8.7±9.6%, p <0.01). Tertiles were formed based on the percent change in gait speed for each condition. No vascular parameters differed across tertiles for DT. In contrast, carotid flow pulsatility (1.85±0.43 vs. 1.47±0.42, p=0.02) and resistance (0.75±0.07 vs. 0.68±0.07, p=0.01) indices were higher in women with more decrement (third tertile) as compared to women with less decrement (first tertile) in gait speed during MT after adjusting for age, gait speed, and task error. Carotid pulse pressure and β-stiffness did not contribute to these tertile differences. Elevated carotid flow pulsatility and resistance are characteristics found in healthy women that show lower cognitive capacity to walk and perform multiple concurrent tasks. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Cognitive load and task condition in event- and time-based prospective memory: an experimental investigation.

    PubMed

    Khan, Azizuddin; Sharma, Narendra K; Dixit, Shikha

    2008-09-01

    Prospective memory is memory for the realization of delayed intention. Researchers distinguish 2 kinds of prospective memory: event- and time-based (G. O. Einstein & M. A. McDaniel, 1990). Taking that distinction into account, the present authors explored participants' comparative performance under event- and time-based tasks. In an experimental study of 80 participants, the authors investigated the roles of cognitive load and task condition in prospective memory. Cognitive load (low vs. high) and task condition (event- vs. time-based task) were the independent variables. Accuracy in prospective memory was the dependent variable. Results showed significant differential effects under event- and time-based tasks. However, the effect of cognitive load was more detrimental in time-based prospective memory. Results also revealed that time monitoring is critical in successful performance of time estimation and so in time-based prospective memory. Similarly, participants' better performance on the event-based prospective memory task showed that they acted on the basis of environment cues. Event-based prospective memory was environmentally cued; time-based prospective memory required self-initiation.

  15. Reliability of a novel serious game using dual-task gait profiles to early characterize aMCI

    PubMed Central

    Tarnanas, Ioannis; Papagiannopoulos, Sotirios; Kazis, Dimitris; Wiederhold, Mark; Widerhold, Brenda; Tsolaki, Magda

    2015-01-01

    Background: As the population of older adults is growing, the interest in a simple way to detect characterize amnestic mild cognitive impairment (aMCI), a prodromal stage of Alzheimer’s disease (AD), is becoming increasingly important. Serious game (SG) -based cognitive and motor performance profiles while performing everyday activities and dual-task walking (DTW) “motor signatures” are two very promising markers that can be detected in predementia states. We aim to compare the consistency, or conformity, of measurements made by a custom SG with DTW (NAV), a SG without DTW (DOT), neuropsychological measures and genotyping as markers for early detection of aMCI. Methods: The study population included three groups: early AD (n = 86), aMCI (n = 65), and healthy control subjects (n = 76), who completed the custom SG tasks in three separate sessions over a 3-month period. Outcome measures were neuropsychological data across-domain and within-domain intra-individual variability (IIV) and DOT and NAV latency-based and accuracy-based IIV. IIV reflects a transient, within-person change in behavioral performance, either during different cognitive domains (across-domain) or within the same domain (within-domain). Test–retest reliability of the DOT and NAV markers were assessed using an intraclass correlation (ICC) analysis. Results: Results indicated that performance data, such as the NAV latency-based and accuracy-based IIV, during the task displayed greater reliability across sessions compared to DOT. During the NAV task-engagement, the executive function, planning, and motor performance profiles exhibited moderate to good reliability (ICC = 0.6–0.8), while during DOT, executive function and spatial memory accuracy profiles exhibited fair to moderate reliability (ICC = 0.3–0.6). Additionally, reliability across tasks was more stable when three sessions were used in the ICC calculation relative to two sessions. Discussion: Our findings suggest that

  16. Memory for pictures and words as a function of level of processing: Depth or dual coding?

    PubMed

    D'Agostino, P R; O'Neill, B J; Paivio, A

    1977-03-01

    The experiment was designed to test differential predictions derived from dual-coding and depth-of-processing hypotheses. Subjects under incidental memory instructions free recalled a list of 36 test events, each presented twice. Within the list, an equal number of events were assigned to structural, phonemic, and semantic processing conditions. Separate groups of subjects were tested with a list of pictures, concrete words, or abstract words. Results indicated that retention of concrete words increased as a direct function of the processing-task variable (structural < phonemic dual-coding model.

  17. Effects of Practice on Task Architecture: Combined Evidence from Interference Experiments and Random-Walk Models of Decision Making

    ERIC Educational Resources Information Center

    Kamienkowski, Juan E.; Pashler, Harold; Dehaene, Stanislas; Sigman, Mariano

    2011-01-01

    Does extensive practice reduce or eliminate central interference in dual-task processing? We explored the reorganization of task architecture with practice by combining interference analysis (delays in dual-task experiment) and random-walk models of decision making (measuring the decision and non-decision contributions to RT). The main delay…

  18. Stroop proactive control and task conflict are modulated by concurrent working memory load.

    PubMed

    Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai; Davelaar, Eddy J; Usher, Marius

    2015-06-01

    Performance on the Stroop task reflects two types of conflict-informational (between the incongruent word and font color) and task (between the contextually relevant color-naming task and the irrelevant, but automatic, word-reading task). According to the dual mechanisms of control theory (DMC; Braver, 2012), variability in Stroop performance can result from variability in the deployment of a proactive task-demand control mechanism. Previous research has shown that when proactive control (PC) is diminished, both increased Stroop interference and a reversed Stroop facilitation (RF) are observed. Although the current DMC model accounts for the former effect, it does not predict the observed RF, which is considered to be behavioral evidence for task conflict in the Stroop task. Here we expanded the DMC model to account for Stroop RF. Assuming that a concurrent working memory (WM) task reduces PC, we predicted both increased interference and an RF. Nineteen participants performed a standard Stroop task combined with a concurrent n-back task, which was aimed at reducing available WM resources, and thus overloading PC. Although the results indicated common Stroop interference and facilitation in the low-load condition (zero-back), in the high-load condition (two-back), both increased Stroop interference and RF were observed, consistent with the model's prediction. These findings indicate that PC is modulated by concurrent WM load and serves as a common control mechanism for both informational and task Stroop conflicts.

  19. Relationships of physical job tasks and living conditions with occupational injuries in coal miners.

    PubMed

    Bhattacherjee, Ashis; Bertrand, Jean-Pierre; Meyer, Jean-Pierre; Benamghar, Lahoucine; Otero Sierra, Carmen; Michaely, Jean-Pierre; Ghosh, Apurna Kumar; d'Houtaud, Alphonse; Mur, Jean-Marie; Chau, Nearkasen

    2007-04-01

    This study assessed the relationships of job tasks and living conditions with occupational injuries among coal miners. The sample included randomly selected 516 underground workers. They completed a standardized self-administred questionnaire. The data were analyzed via logistic regression method. The rate of injuries in the past two years was 29.8%. The job tasks with significant crude relative risks were: power hammer, vibrating hand tools, pneumatic tools, bent trunk, awkward work posture, heat, standing about and walking, job tasks for trunk and upper/lower limbs, pain caused by work, and muscular tiredness. Logistic model shows a strong relationship between the number of job tasks (JT) and injuries (adjusted ORs vs. JT 0-1: 2.21, 95%CI 1.27-3.86 for JT 2-6 and 3.82, 2.14-6.82 for JT>or=7), and significant ORs>or=1.71 for face work, not-good-health-status, and psychotropic drug use. Musculoskeletal disorders and certain personality traits were also significant in univariate analysis. Therefore job tasks and living conditions strongly increase the injuries, and occupational physicians could help workers to find remedial measures.

  20. Deep Thinking Increases Task-Set Shielding and Reduces Shifting Flexibility in Dual-Task Performance

    ERIC Educational Resources Information Center

    Fischer, Rico; Hommel, Bernhard

    2012-01-01

    Performing two tasks concurrently is difficult, which has been taken to imply the existence of a structural processing bottleneck. Here we sought to assess whether and to what degree one's multitasking abilities depend on the cognitive-control style one engages in. Participants were primed with creativity tasks that either called for divergent…