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Sample records for dual task conditions

  1. 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

  2. Attention and dual-task conditions: physical therapy implications for individuals with acquired brain injury.

    PubMed

    McCulloch, Karen

    2007-09-01

    The aim of this article is to consider how impairments in attention may affect the performance of two tasks during balance or walking in individuals recovering from acquired brain injury (ABI). Guidelines from the experimental dual-task paradigm from cognitive psychology are reviewed. In this paper, dual-task conditions are described as the use of two tasks performed simultaneously, but not necessarily following all the experimental guidelines of the dual-task paradigm. How and why dual-task costs may emerge are discussed as well as considerations for task selection. Review of literature that describes dual-task performance problems in older adults is summarized briefly as a foundation for considering how similar conditions may affect individuals with ABI. Studies of individuals with ABI of dual-task performance in balance or walking are reviewed in detail. Examination approaches including observational measures of attention as well as clinical measures of dual-task performance during walking are reviewed. Intervention concepts and approaches are described by review of intervention designs used with older adults and individuals with ABI that describe task selection and use of instructional set for dual-task training. Two intervention strategies described in the literature for treating attention problems are contrasted: (1) an explicit focus on cognitive impairments with the expectation that function will improve as a result and (2) an implicit focus on functional tasks through errorless learning with the expectation that cognition (and attention) will improve. An illustration of the use of both of these strategies in a complementary fashion to improve attention in a patient with ABI is reviewed. Current literature is limited in clearly directing assessment and intervention to improve attention after ABI, but strategies are presented and areas for future research are identified.

  3. Age- and practice-related influences on dual-task costs and compensation mechanisms under optimal conditions of dual-task performance.

    PubMed

    Strobach, Tilo; Frensch, Peter; Müller, Hermann; 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, practice effects under these conditions in older adults are unknown. Further, it is open, how changed task scheduling and/ or the acquisition of task coordination skills affect the temporal overlap of two tasks in different age groups; this overlap indicate the involvement of these practice-related mechanisms to compensate for impaired dual-task performance. In a dual-task situation of Schumacher et al. (2001 , Psychological Science, 12, 230) including optimal conditions for dual-task performance, both younger and older adults were able to achieve an improvement in dual-task performance with 8 practice sessions to the same degree. The temporal task overlap changed similarly in both age groups during these sessions demonstrating a similar degree of the involvement of compensation mechanisms in younger and older adults. At the end of practice, however, we showed that older adults do not achieve the same optimized dual-task performance level of younger adults.

  4. Age-related changes of arm movements in dual task condition when walking on different surfaces.

    PubMed

    Hsieh, Yao-Jen; Cho, Chiung-Yu

    2012-02-01

    The purpose of this study was to investigate whether the dual task paradigm would influence arm movements during walking. Furthermore, we examined the effects of different walking surfaces on arm movements while performing dual tasks. The effects of age and gender were also investigated. Fifteen young adults and 15 older adults were included in this study. Subjects were asked to perform the walking task alone (single-task trial) and walking in combination with a cognitive task (dual-task trial). Four walking conditions (1 single task and 3 dual task trials)×two walking surfaces were encountered. Both age groups had greater elbow and trunk movement in the sagittal plane under the dual task trials as compared to the single task trial (p<.05). Subjects had greater upper extremity and upper body movement on the soft floor than on the hard floor (p<.05). Subjects had greater movement amplitude when confronting a challenging environment, especially in the contralateral side. Among gender, there was a group-gender interaction: the older females had smaller upper extremity movement than the older males (p<.05) but the opposite was true for the young adults. The results suggest that different age groups of males and females use different balance control strategy to deal with the challenging conditions.

  5. Healthy older adults balance pattern under dual task conditions: exploring the strategy and trend

    PubMed Central

    Zeynalzadeh Ghoochani, Bahareh; Hosseini, Seyed Ali; Talebian, Saeed; Biglarian, Akbar; Zeinalzadeh, Afsaneh; Nazary-Moghadam, Salman; Derakhshanrad, Seyed Alireza

    2016-01-01

    Background: In line with health promotion plans, early intervention and fall prevention in geriatric population, it is important to study healthy individuals balance mechanisms. The aim of this research was to investigate the effect of adding and removing visual input and dual task on elderly balance. Methods: Twenty healthy elderly recruited from four different senior citizen health club centers and from the University of Social Welfare and Rehabilitation Sciences (USWR) participated in this analytic cross-sectional study. At USWR’s Motor Control Laboratory, the participants’ postural sway were assessed using force plate in 4 distinct double leg standing conditions with and without presence of visual input and Stroop dual task. Postural and Stroop variables were compared. Results: Findings indicated that when the elderly encountered with either dual task or absence of visual input, they can still manage the situation in a way that changes in sway parameter would not become significant. But, when these two conditions occurred simultaneously, the participant’s balance strategy fluctuated. Therefore, the mean velocity showed a significant difference between the “single quiet standing” condition and the condition of standing with eyes closed while the participants were answering Stroop dual task (Mean difference = -0.007, 95% CI = -0.012, -0.002). Conclusion: It appears that velocity parameter is sensitive to small changes, so it is recommended that researchers include this parameter in their future analyses. Balance in elderly can be manipulated by dual task and visual input deprivation. PMID:27766239

  6. 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.

  7. The relation between the Type A behavior pattern, pacing, and subjective workload under single- and dual-task conditions

    NASA Technical Reports Server (NTRS)

    Damos, D.

    1985-01-01

    Twenty Type A and 20 Type B subjects performed two discrete tasks alone and together. Half of the subjects performed paced versions of both tasks; half, unpaced versions. Workload ratings were obtained for all subjects under single- and dual-task conditions using eight bipolar adjective scales. Under single-task conditions there was a significant interaction between behavior pattern and pacing on one of the tasks. This interaction indicated that Type A subjects responded more rapidly under unpaced conditions than did Type B subjects, although there was little difference between the groups under paced conditions. Under dual-task conditions, Type A subjects responded more rapidly than did Type B subjects regardless of pacing. There was one significant interaction between behavior pattern and task on one of the workload scales.

  8. Sonification of in-vehicle interface reduces gaze movements under dual-task condition.

    PubMed

    Tardieu, Julien; Misdariis, Nicolas; Langlois, Sabine; Gaillard, Pascal; Lemercier, Céline

    2015-09-01

    In-car infotainment systems (ICIS) often degrade driving performances since they divert the driver's gaze from the driving scene. Sonification of hierarchical menus (such as those found in most ICIS) is examined in this paper as one possible solution to reduce gaze movements towards the visual display. In a dual-task experiment in the laboratory, 46 participants were requested to prioritize a primary task (a continuous target detection task) and to simultaneously navigate in a realistic mock-up of an ICIS, either sonified or not. Results indicated that sonification significantly increased the time spent looking at the primary task, and significantly decreased the number and the duration of gaze saccades towards the ICIS. In other words, the sonified ICIS could be used nearly exclusively by ear. On the other hand, the reaction times in the primary task were increased in both silent and sonified conditions. This study suggests that sonification of secondary tasks while driving could improve the driver's visual attention of the driving scene.

  9. Attentional focus influences postural control and reaction time performances only during challenging dual-task conditions in healthy young adults.

    PubMed

    Remaud, Anthony; Boyas, Sébastien; Lajoie, Yves; Bilodeau, Martin

    2013-11-01

    The dual-task paradigm has previously been used to investigate the attentional demands associated with postural control. Previous studies have identified both the focus of attention and the difficulty of a postural task as potential factors influencing dual-task performance. The aim of this study was to examine how the instructed focus of attention influences dual-task performance during quiet standing tasks of various levels of difficulty. Thirteen young adults participated in two testing sessions consisting of standing as still as possible on a force platform in different postural conditions, while simultaneously performing a simple reaction time (RT) task. Postural task difficulty was manipulated by various combinations of three bases of support (feet together, tandem and single leg) and two visual conditions (eyes opened and closed). Participants were instructed to focus on either their balance or their RT performance, depending on the testing session. When comparing postural control with respect to session focus, anterior-posterior sway velocity decreased with the addition of the simple RT task when the focus was on balance, but only during the more difficult dual-task conditions. In contrast, sway area and medial-lateral sway velocity did not change between the two instructed focus sessions. Participants responded faster in all dual-task conditions when focusing on RT performance than on balance. The modified attention allocation index indicated that participants' ability to modulate their allocation of attentional resources to respond positively to instruction was more pronounced in the most challenging postural condition. The present findings could have important implications for the interpretation of dual-task performance in both clinical and research settings.

  10. Quality of standing balance in community-dwelling elderly: Age-related differences in single and dual task conditions.

    PubMed

    Coelho, Tiago; Fernandes, Ângela; Santos, Rubim; Paúl, Constança; Fernandes, Lia

    2016-01-01

    To examine the relationship between age and quality of standing balance in single and dual task conditions. A cross-sectional study was conducted using a sample of 243 community-dwellers aged ≥65 years. Quality of standing balance was assessed by measuring the center of pressure (COP) sway with a pressure platform. Measurements were performed under single task (orthostatic position) and dual task (orthostatic position while performing a verbal fluency task) conditions. The mean age of the participants was 79.1(±7.3)years and 76.1% were women. Older age was associated with an increased COP sway, mainly in the medial/lateral (ML) direction. Most COP sway parameters were higher under dual task conditions than under single task. After controlling for the effect of the number of words enunciated in dual task conditions, only the differences in COP sway parameters in the ML direction remained significant. There was no significant interaction between age group (65-79; ≥80 years) and condition, which indicates that differences in COP sway caused by performing a secondary task were similar for younger and for older participants. Age did not seem to influence significantly the decline in the quality of standing balance triggered by performing a concurrent cognitive task. However, older age was consistently associated with poorer standing balance, both in single and in dual task conditions. Therefore, performing a secondary task may lead older individuals to reach their postural stability limits and, consequently, to fall. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Effect of exercise on dual-task and balance on elderly in multiple disease conditions.

    PubMed

    Zanotto, Tobia; Bergamin, Marco; Roman, Fausto; Sieverdes, John C; Gobbo, Stefano; Zaccaria, Marco; Ermolao, Andrea

    2014-01-01

    Investigations on how exercise and physical activity affect dual-task (DT) performance in the elderly are growing rapidly due to the fact that DT activities are commonplace with activities of daily living. Preliminary evidence has shown the benefit in exercise on DT balance, though it is unclear to what extent the effect exercise has on DT performance in elderly subjects with disease conditions, including subjects with a high risk of falls. Hence, the objective of this study was to critically review the existing evidence of a potential relationship between exercise and improvement of static and dynamic balance during DT conditions as well as secondary outcomes in elderly subjects with different disease conditions. A systematic search using online databases was performed to source documents. Inclusion criteria sourced articles classified as randomized controlled trials (RCT), controlled trials (CT) and uncontrolled trials (UT). Moreover, the studies had to administrate an exercise or physical activity protocol in the intervention. Seventeen studies met the eligibility criteria and were comprised of 12 RCTs, 3 CTs, and 2 UTs. Overall, 13 studies supported exercise being effective to improve parameters of static and dynamic balance during single or DT conditions. Despite the heterogeneity of pathologic conditions, exercise showed similar benefits to improve function in two main areas: neurological conditions and frailty conditions. The lack of a common method to assess DT performance limited the ability to compare different interventions directly. Future research is warranted to study the optimal dose and exercise modalities to best reduce the risk of falls in the elderly with multiple disease conditions.

  12. 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

    2017-04-03

    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.

  13. 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.

  14. Stress and gender effects on prefrontal cortex oxygenation levels assessed during single and dual-task walking conditions.

    PubMed

    Holtzer, Roee; Schoen, Chelsea; Demetriou, Eleni; Mahoney, Jeannette R; Izzetoglu, Meltem; Wang, Cuiling; Verghese, Joe

    2017-03-01

    The ability to walk is critical for functional independence and wellbeing. The pre-frontal cortex (PFC) plays a key role in cognitive control of locomotion, notably under attention-demanding conditions. Factors that influence brain responses to cognitive demands of locomotion, however, are poorly understood. Herein, we evaluated the individual and combined effects of gender and perceived stress on stride velocity and PFC Oxygenated Hemoglobin (HbO2 ) assessed during single and dual-task walking conditions. The experimental paradigm included Normal Walk (NW); Cognitive Interference (Alpha); and Walk-While-Talk (WWT) tasks. An instrumented walkway was used to assess stride velocity in NW and WWT conditions. Functional Near-Infrared-Spectroscopy (fNIRS) was used to quantify PFC HbO2 levels during NW, Alpha and WWT. Perceived task-related stress was evaluated with a single 11-point scale item. Participants were community residing older adults (age = 76.8 ± 6.7 years; %female = 56). Results revealed that higher perceived stress was associated with greater decline in stride velocity from single to dual-task conditions among men. Three-way interactions revealed that gender moderated the effect of perceived stress on changes in HbO2 levels comparing WWT to NW and Alpha. Attenuation in the increase in HbO2 levels, in high compared to low perceived stress levels, from the two single task conditions to WWT was observed only in men. Thus, older men may be more vulnerable to the effect of perceived stress on the change in PFC oxygenation levels across walking conditions that vary in terms of cognitive demands. These findings confer important implications for assessment and treatment of individuals at risk of mobility impairments. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  15. Effect of single dose methylphenidate on walking and postural stability under single- and dual-task conditions in older adults--a double-blind randomized control trial.

    PubMed

    Shorer, Zamir; Bachner, Yaakov; Guy, Tal; Melzer, Itshak

    2013-10-01

    Methylphenidate (MPH) action may improve executive function and motor function. Effects of MPH on balance function in older adults were investigated. A randomized controlled double-blind study examined the effects of a single dose of MPH on gait and postural stability in 30 healthy older adults (mean age = 74.9 ± 5.6) in four task conditions: (a) single task, standing still; (b) dual task, standing still performing a memory task; (c) single task, narrow base walking; and (d) dual task, narrow base walking, performing concurrent cognitive tasks. A single dose of MPH improved narrow base walking by reducing the number of step errors and step error rate in both single and dual tasks, with no equivalent improvement in postural stability. A single dose of MPH was able to improve gait function in older adults, especially in complex dual tasks that require higher executive control. This could largely account for the effects of MPH on a sustained attention dual task, but direct effects on the motor system may have also played a role.

  16. The effect of a cognitive-motor intervention on voluntary step execution under single and dual task conditions in older adults: a randomized controlled pilot study

    PubMed Central

    Pichierri, Giuseppe; Coppe, Amos; Lorenzetti, Silvio; Murer, Kurt; de Bruin, Eling D

    2012-01-01

    Background This randomized controlled pilot study aimed to explore whether a cognitive-motor exercise program that combines traditional physical exercise with dance video gaming can improve the voluntary stepping responses of older adults under attention demanding dual task conditions. Methods Elderly subjects received twice weekly cognitive-motor exercise that included progressive strength and balance training supplemented by dance video gaming for 12 weeks (intervention group). The control group received no specific intervention. Voluntary step execution under single and dual task conditions was recorded at baseline and post intervention (Week 12). Results After intervention between-group comparison revealed significant differences for initiation time of forward steps under dual task conditions (U = 9, P = 0.034, r = 0.55) and backward steps under dual task conditions (U = 10, P = 0.045, r = 0.52) in favor of the intervention group, showing altered stepping levels in the intervention group compared to the control group. Conclusion A cognitive-motor intervention based on strength and balance exercises with additional dance video gaming is able to improve voluntary step execution under both single and dual task conditions in older adults. PMID:22865999

  17. Performance in Dual Tasks.

    DTIC Science & Technology

    1984-02-29

    Continue on reverse aide it neceeay and identify by block nualtber) Problem solving, attention , computer simulation, choice reaction time ...construct a single theoretical framework for the analysis of problem solving and real time 4attention and performance’ behavior. Such a model has been...the "production system * approach. The program has been used to simulate results from choice reaction time , stimulus repetition, dual channel

  18. 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.

  19. 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

  20. 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)

  1. Dual task interference in psychogenic tremor.

    PubMed

    Kumru, Hatice; Begeman, Maaike; Tolosa, Eduardo; Valls-Sole, Josep

    2007-10-31

    Psychogenic tremor (PT) is visually indistinguishable from voluntarily mimicked tremor. Healthy volunteers have difficulties with carrying out simultaneously two tasks due to the phenomenon known as dual task interference. Therefore, performing voluntary rhythmic movements would be a burden for carrying out fast ballistic movements with the contralateral hand. We hypothesized that, similarly to healthy volunteers performing rhythmic movements, patients with PT should show the effects of dual task interference, and this may distinguish them from patients with other types of tremor. We studied 6 patients with PT, 9 with Parkinson's disease (PD) and predominantly unilateral tremor, 11 with essential tremor (ET), and 10 normal volunteers (NV) mimicking tremor. They were requested to perform a unilateral simple reaction time task (SRT) to a visual imperative signal in two different conditions: at rest (rSRT) and during contralateral hand tremor (tSRT). Reaction time was significantly longer in tSRT than in rSRT in PT and in NV groups (P < 0.01 for both groups). However, no significant differences were observed between rSRT and tSRT in PD and ET. The delay of unilateral tSRT with respect to rSRT suggests an effect of tremorlike oscillatory movements on reaction time that is consistent with the concept of dual-task interference in NV or PT patients but not in PD or ET. These observations may be useful in the evaluation of psychogenic movement disorders.

  2. 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

  3. 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.

  4. Dual-task practice enhances motor learning: a preliminary investigation.

    PubMed

    Goh, Hui-Ting; Sullivan, Katherine J; Gordon, James; Wulf, Gabriele; Winstein, Carolee J

    2012-10-01

    Practicing a motor task under dual-task conditions can be beneficial to motor learning when the secondary task is difficult (Roche et al. in Percept Psychophys 69(4):513-522, 2007) or when it engages similar processes as the primary motor task (Hemond et al. in J Neurosci 30(2):650-654, 2010). The purpose of this pilot study was to determine which factor, difficulty level or engaged processes, of a secondary task is more critical in determining dual-task benefit. Participants practiced a discrete arm task in conjunction with an audio-vocal reaction time (RT) task. We presented two different RT tasks that differed in difficulty, simple versus choice (i.e., more difficult), at two different arm task phases that differed in engaged processes, preparation versus execution, resulting in four dual-task conditions. A simple RT task is thought to predominantly engage motor execution processes, therefore would engage similar processes as the arm movement task when it is presented during the execution phase, while a choice RT task is thought to engage planning processes and therefore would engage similar processes too when it is presented during the preparation phase. Enhanced motor learning was found in those who engaged similar process as the primary task during dual-tasking (i.e., choice RT presented during preparation and simple RT presented during execution). Moreover, those who showed enhanced learning also demonstrated high dual-task cost (poor RT task performance) during practice, indicating that both tasks were taxing the same resource pool possibly due to engaging similar cognitive processes. To further test the relation between dual-task cost and enhanced learning, we delayed the presentation timing of the choice RT task during the preparation phase and the simple RT task during the execution phase in two control experiments. Dual-task cost was reduced in these delayed timing conditions, and the enhanced learning effect was attenuated. Together, our preliminary

  5. 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 Central

    2012-01-01

    Background 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. Methods 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. Results 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. Conclusions 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. Trial registration

  6. Dual tasking in Parkinson's disease: Cognitive consequences while walking.

    PubMed

    Salazar, Robert D; Ren, Xiaolin; Ellis, Terry D; Toraif, Noor; Barthelemy, Olivier J; Neargarder, Sandy; Cronin-Golomb, Alice

    2017-09-01

    Cognitive deficits are common in Parkinson's disease (PD) and exacerbate the functional limitations imposed by PD's hallmark motor symptoms, including impairments in walking. Though much research has addressed the effect of dual cognitive-locomotor tasks on walking, less is known about their effect on cognition. The purpose of this study was to investigate the relation between gait and executive function, with the hypothesis that dual tasking would exacerbate cognitive vulnerabilities in PD as well as being associated with gait disturbances. Nineteen individuals with mild-moderate PD without dementia and 13 age- and education-matched normal control adults (NC) participated. Executive function (set-shifting) and walking were assessed singly and during dual tasking. Dual tasking had a significant effect on cognition (reduced set-shifting) and on walking (speed, stride length) for both PD and NC, and also on stride frequency for PD only. The impact of dual tasking on walking speed and stride frequency was significantly greater for PD than NC. Though the group by condition interaction was not significant, PD had fewer set-shifts than NC on dual task. Further, relative to NC, PD showed significantly greater variability in cognitive performance under dual tasking, whereas variability in motor performance remained unaffected by dual tasking. Dual tasking had a significantly greater effect in PD than in NC on cognition as well as on walking. The results suggest that assessment and treatment of PD should consider the cognitive as well as the gait components of PD-related deficits under dual-task conditions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Response selection in dual task paradigms: observations from random generation tasks.

    PubMed

    Dirnberger, Georg; Jahanshahi, Marjan

    2010-03-01

    Performance of attention-demanding tasks is worse if two tasks are carried out simultaneously than if each of the tasks is performed alone. Our aim was to determine whether these 'dual task costs' can be attributed to mechanisms on a supra-trial level such as switching of limited resources between trials or concurrent breakdown of supervisory functions, or to mechanisms effective within each trial such as demands of response selection. Twenty healthy volunteers performed verbal random number generation (RNG) and random movement generation (RMG) at three different rates. For each rate, both tasks were examined once in a single task condition and once in a dual task condition. Results showed that performance (quality of randomness) in each random generation task (RNG/RMG) was reduced at faster rates and impaired by concurrent performance of a secondary random generation task. In the dual task condition, transient increase or decrease of bias in one random generation task during any short interval was not associated with concurrent increase or decrease of bias in the other task. In conclusion, the fact that during dual task performance transient bias in one task was not associated with concurrent improvement of performance in the other task indicates that alternation of supervisory control or attentional resources from one to the other task does not mediate the observed dual task costs. Resources of the central executive are not re-allocated or 'switched' from one to the other task. Dual task costs may result from mechanisms effective within each trial such as the demands of response selection.

  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.

  9. Modulation of executive control in dual tasks with transcranial direct current stimulation (tDCS).

    PubMed

    Strobach, Tilo; Soutschek, Alexander; Antonenko, Daria; Flöel, Agnes; Schubert, Torsten

    2015-02-01

    Executive processing in dual tasks is primarily associated with activation of the lateral prefrontal cortex (lPFC), which is demonstrated in functional imaging studies (e.g., Szameitat et al., 2006). However, a causal relation between lPFC activity and executive functions in dual tasks has not been demonstrated so far. Here, we used anodal transcranial direct current stimulation (atDCS [1 mA, 20 min] vs. sham stimulation [1 mA, 30s]) over the left inferior frontal junction under conditions of random and fixed task order in dual tasks as well as in single tasks in healthy young individuals (Experiment 1). We found that atDCS, if administered simultaneously to the task, improved performance in random-order dual tasks, but not in fixed-order dual tasks and single tasks. Moreover, dual-task performance under random-order conditions did not improve if atDCS was applied prior to the task performance. The identical procedure in Experiment 2 showed no difference in dual-task performance under random-task order conditions when we compared cathodal tDCS (ctDCS) with sham stimulation. Our findings suggest that dual-task performance is causally related to lPFC activation under conditions that require task-order decisions and high demands on executive functioning. Subsequent studies may now explore if atDCS leads to sustained improvements parallel to the training of dual tasks.

  10. Loss attention in a dual-task setting.

    PubMed

    Yechiam, Eldad; Hochman, Guy

    2014-02-01

    The positive effect of losses on performance has been explained as stemming from the increased weighting of losses relative to gains. We examine an alternative possibility whereby this effect is mediated by attentional processes. Using the dual-task paradigm, we expected that positive effects of losses on performance would emerge under attentional scarcity and diffuse to a concurrently presented task. In Study 1, decision performance was compared for a task that involved either gains or losses and was performed either alone or as a secondary task. The results showed a significant 40% improvement in performance in the loss condition, but only under conditions of resource scarcity, when the task was a secondary one. In Study 2, the same task was presented as a primary task. Again, losses were associated with improved performance in the secondary task. Given that this secondary task did not include losses, these findings demonstrate an attentional spillover effect.

  11. 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

  12. Reduction of Dual-task Costs by Noninvasive Modulation of Prefrontal Activity in Healthy Elders

    PubMed Central

    Manor, Brad; Zhou, Junhong; Jor'dan, Azizah; Zhang, Jue; Fang, Jing; Pascual-Leone, Alvaro

    2016-01-01

    Dual tasking (e.g., walking or standing while performing a cognitive task) disrupts performance in one or both tasks, and such dual-task costs increase with aging into senescence. Dual tasking activates a network of brain regions including pFC. We therefore hypothesized that facilitation of prefrontal cortical activity via transcranial direct current stimulation (tDCS) would reduce dual-task costs in older adults. Thirty-seven healthy older adults completed two visits during which dual tasking was assessed before and after 20 min of real or sham tDCS targeting the left pFC. Trials of single-task standing, walking, and verbalized serial subtractions were completed, along with dual-task trials of standing or walking while performing serial subtractions. Dual-task costs were calculated as the percent change in markers of gait and postural control and serial subtraction performance, from single to dual tasking. Significant dual-task costs to standing, walking, and serial subtraction performance were observed before tDCS (p < .01). These dual-task costs were less after real tDCS as compared with sham tDCS as well as compared with either pre-tDCS condition (p < .03). Further analyses indicated that tDCS did not alter single task performance but instead improved performance solely within dual-task conditions (p < .02). These results demonstrate that dual tasking can be improved by modulating prefrontal activity, thus indicating that dual-task decrements are modifiable and may not necessarily reflect an obligatory consequence of aging. Moreover, tDCS may ultimately serve as a novel approach to preserving dual-task capacity into senescence. PMID:26488591

  13. Task Dependent Differences and Individual Differences in Dual Task Performance

    DTIC Science & Technology

    1980-10-01

    conversation with the flight instructor, with the skilled pilot who can easily excercise flight control, and converse in par- allel. A difference...The subjects tested were 35 twelve-year olds , who performed tasks singly first then two dual task pairs and then each singly again. McQueen’s results...conducted by Sverko (1977) on adults in an effort to find evidence for a general factor of time-sharing skill. This study was conducted in order to

  14. Effect of motor practice on dual-task performance in older adults.

    PubMed

    Voelcker-Rehage, Claudia; Alberts, Jay L

    2007-05-01

    The aim of this study was to determine the effects of motor practice on cognitive and motor performance in older adults under single- and dual-task conditions. Fourteen younger (19-28 years) and 12 older adults (67-75 years) performed a precision grip sine wave force-tracking and a working memory task under single- and dual-task conditions. Participants performed a pretest, 100 motor practice trials, and a post-test. In the force-tracking and cognitive task, young outperformed older adults. Motor practice improved force-tracking under single- and dual-task conditions for both groups. However, practice did not prevent a decline in motor performance for older adults when they moved from single- to dual-task conditions. After practice, older adults improved cognitive performance in dual-task conditions. Advances in age appear to be associated with a decrease in the ability to manage and coordinate multiple tasks, which remains after extended practice.

  15. Single-Task and Dual-Task Gait Among Collegiate Athletes of Different Sport Classifications: Implications for Concussion Management.

    PubMed

    Howell, David R; Oldham, Jessie R; DiFabio, Melissa; Vallabhajosula, Srikant; Hall, Eric E; Ketcham, Caroline J; Meehan, William P; Buckley, Thomas A

    2017-02-01

    Gait impairments have been documented following sport-related concussion. Whether preexisting gait pattern differences exist among athletes who participate in different sport classifications, however, remains unclear. Dual-task gait examinations probe the simultaneous performance of everyday tasks (ie, walking and thinking), and can quantify gait performance using inertial sensors. The purpose of this study was to compare the single-task and dual-task gait performance of collision/contact and noncontact athletes. A group of collegiate athletes (n = 265) were tested before their season at 3 institutions (mean age= 19.1 ± 1.1 years). All participants stood still (single-task standing) and walked while simultaneously completing a cognitive test (dual-task gait), and completed walking trials without the cognitive test (single-task gait). Spatial-temporal gait parameters were compared between collision/contact and noncontact athletes using MANCOVAs; cognitive task performance was compared using ANCOVAs. No significant single-task or dual-task gait differences were found between collision/contact and noncontact athletes. Noncontact athletes demonstrated higher cognitive task accuracy during single-task standing (P = .001) and dual-task gait conditions (P = .02) than collision/contact athletes. These data demonstrate the utility of a dual-task gait assessment outside of a laboratory and suggest that preinjury cognitive task performance during dual-tasks may differ between athletes of different sport classifications.

  16. Attentional modulation of word recognition by children in a dual-task paradigm.

    PubMed

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

    2008-08-01

    This study investigated an account of limited short-term memory capacity for children's speech perception in noise using a dual-task paradigm. 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 rehearsing sets of 3 or 5 digits for subsequent serial recall. Half of the children were told to allocate their primary attention to word repetition and the other half to remembering digits. Dual-task performance was compared to single-task performance. Limitations in short-term memory demands required for the primary task were measured by dual-task decrements in nonprimary tasks. Results revealed that (a) regardless of task priority, no dual-task decrements were found for word recognition, but significant dual-task decrements were found for digit recall; (b) most children did not show the ability to allocate attention preferentially to primary tasks; and (c) younger children (7- to 10-year-olds) demonstrated improved word recognition in the dual-task conditions relative to their single-task performance. Seven- to 8-year-old children showed the greatest improvement in word recognition at the expense of the greatest decrement in digit recall during dual tasks. Several possibilities for improved word recognition in the dual-task conditions are discussed.

  17. 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.

  18. Discourse coherence and cognition after stroke: A dual task study

    PubMed Central

    Rogalski, Yvonne; Altmann, Lori J.P.; Plummer-D’Amato, Prudence; Behrman, Andrea L.; Marsiske, Michael

    2010-01-01

    Several researchers have suggested that the maintenance of global coherence (topic maintenance) and local coherence (maintenance between utterances) in discourse requires cognitive resources. This study directly tests this hypothesis by examining the relationship between cognitive variables and coherence in narrative discourse produced by mobility-impaired stroke survivors under single (talking) and dual (talking and walking) task conditions. Although there were no effects of the dual task on coherence, global coherence was significantly disrupted regardless of the single or dual task condition. Moreover, global coherence strongly correlated with cognitive function measures, whereas local coherence did not. Findings are consistent with two interpretations: (1) that global and local coherence may be subserved by different cognitive processes or (2) that maintaining global coherence is a more difficult task and thus will show effects of cognitive impairment before local coherence is impaired. These are both testable hypotheses for future research. Learning outcomes After reading the manuscript, the reader will be able to: (1) understand and differentiate between local and global measures of coherence; (2) discuss the effects of a dual task, walking and talking, on global coherence in a gait-impaired group of stroke survivors; (3) understand why the maintenance of global coherence in discourse might be more cognitively demanding than the maintenance of local coherence. PMID:20219209

  19. The Effect of Dual Task Demands and Proficiency on Second Language Speech Production

    ERIC Educational Resources Information Center

    Declerck, Mathieu; Kormos, Judit

    2012-01-01

    In this study we examined how the introduction of a parallel finger-tapping task influences second language (L2) speech encoding mechanisms and monitoring processes, and how the level of proficiency impacts the efficiency and accuracy of L2 performance under single and dual task conditions. The results indicate that imposing dual task demands had…

  20. The Effect of Dual Task Demands and Proficiency on Second Language Speech Production

    ERIC Educational Resources Information Center

    Declerck, Mathieu; Kormos, Judit

    2012-01-01

    In this study we examined how the introduction of a parallel finger-tapping task influences second language (L2) speech encoding mechanisms and monitoring processes, and how the level of proficiency impacts the efficiency and accuracy of L2 performance under single and dual task conditions. The results indicate that imposing dual task demands had…

  1. Balance Performance With a Cognitive Task: A Continuation of the Dual-Task Testing Paradigm

    PubMed Central

    Resch, Jacob E.; May, Bryson; Tomporowski, Phillip D.; Ferrara, Michael S.

    2011-01-01

    Abstract Context: To ensure that concussed athletes return to play safely, we need better methods of measuring concussion severity and monitoring concussion resolution. Objective: To develop a dual-task model that assesses postural stability and cognitive processing in concussed athletes. Design: Repeated measures study. Setting: University laboratory. Patients or Other Participants: Twenty healthy, college-aged students (10 men, 10 women; age  =  20 ± 1.86 years, height  =  173 ± 4.10 cm, mass  =  71.83 + 35.77 kg). Intervention(s): Participants were tested individually in 2 sessions separated by 2 days. In one session, a balance task and a cognitive task were performed separately. In the other session, the balance and cognitive tasks were performed concurrently. The balance task consisted of 6 conditions of the Sensory Organization Test performed on the NeuroCom Smart Balance Master. The cognitive task consisted of an auditory switch task (3 trials per condition, 60 seconds per trial). Main Outcome Measure(s): For the balance test, scores for each Sensory Organization Test condition; the visual, vestibular, somatosensory, and visual-conflict subscores; and the composite balance score were calculated. For the cognitive task, response time and accuracy were measured. Results: Balance improved during 2 dual-task conditions: fixed support and fixed visual reference (t18  =  −2.34, P < .05) and fixed support and sway visual reference (t18  =  −2.72, P  =  .014). Participants' response times were longer (F1,18  =  67.77, P < .001, η2  =  0.79) and choice errors were more numerous under dual-task conditions than under single-task conditions (F1,18  =  5.58, P  =  .03, η2  =  0.24). However, differences were observed only during category-switch trials. Conclusions: Balance was either maintained or improved under dual-task conditions. Thus, postural control took priority over cognitive processing when the tasks were

  2. 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.

  3. The effects of instructions on dual-task walking and cognitive task performance in people with Parkinson's disease.

    PubMed

    Kelly, Valerie E; Eusterbrock, Alexis J; Shumway-Cook, Anne

    2012-01-01

    Gait impairments are prevalent among people with Parkinson's disease (PD). Instructions to focus on walking can improve walking in PD, but the use of such a cognitive strategy may be limited under dual-task walking conditions, when walking is performed simultaneously with concurrent cognitive or motor tasks. This study examined how dual-task performance of walking and a concurrent cognitive task was affected by instructions in people with PD compared to healthy young and older individuals. Dual-task walking and cognitive task performance was characterized under two sets of instructions as follows: (1) focus on walking and (2) focus on the cognitive task. People with PD and healthy adults walked faster when instructed to focus on walking. However, when focused on walking, people with PD and young adults demonstrated declines in the cognitive task. This suggests that dual-task performance is flexible and can be modified by instructions in people with PD, but walking improvements may come at a cost to cognitive task performance. The ability to modify dual-task performance in response to instructions or other task and environmental factors is critical to mobility in daily life. Future research should continue to examine factors that influence dual-task performance among people with PD.

  4. 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

  5. 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.

  6. 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…

  7. 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…

  8. Increased Brain Activation for Dual Tasking with 70-Days Head-Down Bed Rest

    PubMed Central

    Yuan, Peng; Koppelmans, Vincent; Reuter-Lorenz, Patricia A.; De Dios, Yiri E.; Gadd, Nichole E.; Wood, Scott J.; Riascos, Roy; Kofman, Igor S.; Bloomberg, Jacob J.; Mulavara, Ajitkumar P.; Seidler, Rachael D.

    2016-01-01

    Head-down tilt bed rest (HDBR) has been used as a spaceflight analog to simulate the effects of microgravity exposure on human physiology, sensorimotor function, and cognition on Earth. Previous studies have reported that concurrent performance of motor and cognitive tasks can be impaired during space missions. Understanding the consequences of HDBR for neural control of dual tasking may possibly provide insight into neural efficiency during spaceflight. In the current study, we evaluated how dual task performance and the underlying brain activation changed as a function of HDBR. Eighteen healthy men participated in this study. They remained continuously in the 6° head-down tilt position for 70 days. Functional MRI for bimanual finger tapping was acquired during both single task and dual task conditions, and repeated at 7 time points pre-, during- and post-HDBR. Another 12 healthy males participated as controls who did not undergo HDBR. A widely distributed network involving the frontal, parietal, cingulate, temporal, and occipital cortices exhibited increased activation for dual tasking and increased activation differences between dual and single task conditions during HDBR relative to pre- or post-HDBR. This HDBR-related brain activation increase for dual tasking implies that more neurocognitive control is needed for dual task execution during HDBR compared to pre- and post-HDBR. We observed a positive correlation between pre-to-post HDBR changes in dual-task cost of reaction time and pre-to-post HDBR change in dual-task cost of brain activation in several cerebral and cerebellar regions. These findings could be predictive of changes in dual task processing during spaceflight. PMID:27601982

  9. 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

  10. 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.

  11. Cerebral lateralization of music perception in the dual task paradigm: unfamiliar melody recognition in sinistrals.

    PubMed

    LaBarba, R C; Kingsberg, S A; Martin, P A; Pellegrin, K

    1989-01-01

    A dual task study of unfamiliar music perception during concurrent right and left hand finger tapping was conducted with a group of left-handed non-musicians. A pattern of symmetrical, bilateral suppression of finger tapping was observed during a concurrent music task of unfamiliar melody recognition. There was no evidence of trade-off effects in the dual task inasmuch as no interference in melody recognition was observed. The absence of attentional shifts strongly suggests that the bilateral symmetry in motor performance in the dual task condition reflects bilateralized cerebral organization among sinistrals for processing unfamiliar music.

  12. Brain atrophy and trunk stability during dual-task walking among older adults.

    PubMed

    Doi, Takehiko; Makizako, Hyuma; Shimada, Hiroyuki; Yoshida, Daisuke; Ito, Kengo; Kato, Takashi; Ando, Hiroshi; Suzuki, Takao

    2012-06-01

    Dual-task walking is believed to be more cognitively demanding than normal walking and alters trunk movement among older adults. However, the possible association between brain atrophy and spatiotemporal gait parameters, particularly during dual-task walking, is poorly understood. In this study, we examined the relationship between dual-task walking and brain atrophy. One hundred ten elderly adults (aged 65-94 years, women n = 55) underwent magnetic resonance imaging scanning and gait experiments under normal and dual-task walking conditions. Linear accelerations of the trunk were measured in vertical, anteroposterior, and mediolateral directions using a triaxial accelerometer attached to the lower trunk. Gait speed, stride length, and cadence were recorded. The harmonic ratio, a measure of trunk stability, was computed separately in each direction to evaluate the smoothness of trunk movement during walking. Brain atrophy was quantitatively assessed using magnetic resonance image data. Gait speed, stride length, cadence, and harmonic ratio in all directions were lower in dual-task walking than in normal walking (p < .05). The dual-task-related changes in harmonic ratio were independently correlated with brain atrophy adjusted for subject characteristics only in the vertical direction (p < .05). Our findings support the hypothesis that dual-task walking is more cognitively demanding than normal walking. Decreased trunk stability during dual-task walking is associated with brain atrophy. Additional studies are necessary to elucidate the effects of regional brain atrophy on the control of walking.

  13. Neural correlates of dual-task practice benefit on motor learning: a repetitive transcranial magnetic stimulation study.

    PubMed

    Goh, Hui-Ting; Lee, Ya-Yun; Fisher, Beth E

    2013-06-01

    Dual-task practice has been previously shown to enhance motor learning when both primary and secondary tasks engage similar cognitive processes. In the present study, participants practiced a finger sequence task with the non-dominant hand under a single-task condition (i.e. without a probe task) or a dual-task condition in which a probe choice reaction time (CRT) task was presented during the preparation phase (before movement onset) of the finger task. It was hypothesised that by engaging similar 'planning' processes, the dual-task condition may facilitate the activation of shared 'planning' circuitry that includes dorsal premotor cortex (dPM), an important neural substrate for CRT task performance and movement preparation. Repetitive transcranial magnetic stimulation (rTMS; 1 Hz) was applied to the contralateral dPM immediately following practice. Motor learning was assessed by a retention test conducted ~ 24 h after practice. Consistent with our previous results, the dual-task condition enhanced learning compared with the single-task condition. rTMS applied to dPM attenuated the dual-task practice benefit on motor learning. In contrast, rTMS to M1 did not attenuate the dual-task practice benefit, suggesting the rTMS effect was specific to dPM. Our findings suggest a unique role of dPM in mediating the dual-task practice effect on motor learning. © 2013 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  14. Cerebral lateralization of familiar and unfamiliar music perception in nonmusicians: a dual task approach.

    PubMed

    LaBarba, R C; Kingsberg, S A

    1990-12-01

    In a dual task procedure that controls for attentional trade-off effects, asymmetrical interference effects were observed in dual task conditions of finger tapping and concurrent processing of familiar and unfamiliar music. Laterality effects suggested that perception of orchestral presentations is largely lateralized to the left hemisphere in both males and females. In a second dual task condition of vocalization and music processing, both males and females displayed interference in speech production during concurrent music processing. Males showed greater left hemispheric interference effects during simultaneous vocalization and music processing.

  15. 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…

  16. 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…

  17. 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

  18. 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

  19. Different effects of dual task demands on the speech of young and older adults

    PubMed Central

    Herman, Ruth E.; Nartowicz, Jennifer

    2005-01-01

    Young and older adults provided language samples in response to elicitation questions while concurrently performing 3 different tasks. The language samples were scored on three dimensions: fluency, grammatical complexity, and content. Previous research had suggested the hypothesis that the restricted speech register of older adults is buffered from the costs of dual task demands. This hypothesis was tested by comparing language samples collected during a baseline condition with those produced while the participants were performing the concurrent tasks. The results indicate that young and older adults adopt different strategies when confronted with dual task demands. Young adults shift to a restricted speech register when confronted with dual task demands. Older adults, who were already using a restricted speech register, became less fluent although the grammatical complexity and informational content of their speech was preserved. Hence, some but not all aspects of older adults' speech are buffered from dual task demands. PMID:16557294

  20. Physiological Synchronization in a Vigilance Dual Task.

    PubMed

    Guastello, Stephen J

    2016-01-01

    The synchronization of autonomic arousal levels and other physio-logical responses between people is a potentially important component of work team performance, client-therapist relationships, and other types of human interaction. This study addressed several problems: What statistical models are viable for identifying synchronization for loosely coupled human systems? How is the level of synchronization related to psychosocial variables such as empathy, subjective ratings of workload, and actual performance? Participants were 70 undergraduates who worked in pairs on a vigilance dual task in which they watched a virtual reality security camera, rang a bell when they saw the target intruder, and completed a jig-saw puzzle. Event rates either increased or decreased during the 90 min work period. The average R2 values for each person were .66, .66, .62, and .53 for the linear autoregressive model, linear autoregressive model with a synchronization component, the nonlinear autoregressive model, and the nonlinear autoregressive model with a synchronization component, respectively. All models were more accurate at a lag of 20 sec compared to 50 sec or customized lag lengths. Although the linear models were more accurate overall, the nonlinear synchronization parameters were more often related to psychological variables and performance. In particular, greater synchronization was observed with the nonlinear model when the target event rate increased, compared to when it decreased, which was expected from the general theory of synchronization. Nonlinear models were also more effective for uncovering inhibitory or dampening relationships between the co-workers as well as mutually excitatory relationships. Future research should explore the comparative model results for tasks that induce higher levels of synchronization and involve different types of internal group coordination.

  1. Motor Dual-Task Effect on Gait and Task of Upper Limbs in Older Adults under Specific Task Prioritization: Pilot Study

    PubMed Central

    Oh-Park, Mooyeon; Holtzer, Roee; Mahoney, Jeannette; Wang, Cuiling; Raghavan, Preeti; Verghese, Joe

    2014-01-01

    Background and Aims Performing multiple tasks simultaneously may result in reduced performance of subtasks (dual-task cost) particularly among old individuals. Subtask performance during dual-tasking is also known to be affected by task prioritization. However, it has not been well studied how the performance of subtasks is affected during motor dual-task in old adults compared to young when instructed to prioritize one task over the other. This study aims to investigate the dual-task effect on subtasks during motor dual-tasking under specific instruction of task prioritization in old compared to young adults. Methods Sixteen independent old and 18 young adults performed two single tasks (usual walking, holding a tray as steady as possible while standing) and two dual-tasks (walking while holding a tray focusing attention on keeping tray as steady as possible-WTAT, and walking while holding tray focusing attention on walking -WTAW). Gait parameters [velocity and variability (coefficient of variation; CV) of stride length] and the pitch (forward-backward) and roll (side-to-side) angles of the tray were measured during the four conditions. Results During the WTAT compared to single tasks, both young and old groups showed reduced gait velocity (β = -14.0 for old, -34.3 for young), increased gait variability (β = 0.19 for old, 0.51 for young), and increased tray tilt (β =9.4 for old, 7.9 for young in pitch; β =8.8 for old, 5.9 for young in roll). Higher proportion of older individuals showed higher dual-task effect on tray stability, but lower dual-task effect on gait compared to young individuals. During WTAW, there was no difference in dual-task effect between age groups in tray stability or gait performance. Conclusions Compared to young, older adults tend to compromise the task involving upper limbs during motor dual-tasking even when instructed to prioritize this task over gait. These findings may have ramifications on developing training strategies to learn

  2. Dual-tasking postural control in patients with right brain damage.

    PubMed

    Bourlon, Clémence; Lehenaff, Laurent; Batifoulier, Cécile; Bordier, Aurélie; Chatenet, Aurélia; Desailly, Eric; Fouchard, Christian; Marsal, Muriel; Martinez, Marianne; Rastelli, Federica; Thierry, Anaïs; Bartolomeo, Paolo; Duret, Christophe

    2014-01-01

    The control of dual-tasking effects is a daily challenge in stroke neurorehabilitation. It maybe one of the reasons why there is poor functional prognosis after a stroke in the right hemisphere, which plays a dominant role in posture control. The purpose of this study was to explore cognitive motor interference in right brain-lesioned and healthy subjects maintaining a standing position while performing three different tasks: a control task, a simple attentional task and a complex attentional task. We measured the sway area of the subjects on a force platform, including the center of pressure and its displacements. Results showed that stroke patients presented a reduced postural sway compared to healthy subjects, who were able to maintain their posture while performing a concomitant attentional task in the same dual-tasking conditions. Moreover, in both groups, the postural sway decreased with the increase in attentional load from cognitive tasks. We also noticed that the stability of stroke patients in dual-tasking conditions increased together with the weight-bearing rightward deviation, especially when the attentional load of the cognitive tasks and lower limb motor impairments were high. These results suggest that stroke patients and healthy subjects adopt a similar postural regulation pattern aimed at maintaining stability in dual-tasking conditions involving a static standing position and different attention-related cognitive tasks. Our results indicate that attention processes might facilitate static postural control.

  3. An Investigation of Response and Stimulus Modality Transfer Effects after Dual-Task Training in Younger and Older

    PubMed Central

    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. PMID:22629239

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. The role of dual-task and task-switch in prospective memory: behavioural data and neural correlates.

    PubMed

    Bisiacchi, Patrizia S; Schiff, Sami; Ciccola, Alessia; Kliegel, Matthias

    2009-04-01

    Event-based prospective memory (PM) requires remembering the delayed execution of an intended action in response to a pre-specified PM cue while being actively engaged in an ongoing task in which the cue is embedded. To date, experimental paradigms vary as to whether or not they require participants immediately to stop working on the ongoing task whenever they encounter a PM event (cue) and directly switch to the prospective action (task-switch approach). Alternatively, several other paradigms used in the literature encourage participants to continue working on the ongoing task item after the cue, and only then, perform the prospective action (dual-task approach). The present study explores the possible behavioural and electrophysiological effects that both approaches may have on PM performance. Seventeen young adults performed both versions of a standard PM task in a counterbalanced order during which behavioural data and electroencephalogram (EEG) were recorded. Behavioural data showed a decrement in PM performance in the task-switch compared to the dual-task condition. In addition, EEG data revealed differences between the dual-task and task-switch approach in event-related potential (ERP) components associated with response inhibition and with post-retrieval monitoring (i.e. late positive complex). No differences between the two tasks were found with regard to the PM event detection processes (i.e. N300) and the retrieval of the intended action from long-term memory. In sum, findings demonstrate that it does make a difference which task approach is applied and suggest that dual-task and task-switch paradigms may result in different processing and neurophysiological dynamics particularly concerning attentional resources and cognitive control.

  9. Effects of extensive dual-task practice on processing stages in simultaneous choice tasks.

    PubMed

    Strobach, Tilo; Liepelt, Roman; Pashler, Harold; Frensch, Peter A; Schubert, Torsten

    2013-07-01

    Schumacher et al. Psychological Science 12:101-108, (2001) demonstrated the elimination of most dual-task costs ("perfect time-sharing") after extensive dual-task practice of a visual and an auditory task in combination. For the present research, we used a transfer methodology to examine this practice effect in more detail, asking what task-processing stages were sped up by this dual-task practice. Such research will be essential to specify mechanisms associated with the practice-related elimination of dual-task costs. In three experiments, we introduced postpractice transfer probes focusing on the perception, central response-selection, and final motor-response stages. The results indicated that the major change achieved by dual-task practice was a speed-up in the central response-selection stages of both tasks. Additionally, perceptual-stage shortening of the auditory task was found to contribute to the improvements in time-sharing. For a better understanding of such time-sharing, we discuss the contributions of the present findings in relation to models of practiced dual-task performance.

  10. Measuring the cost of cognitive-motor dual tasking during walking in multiple sclerosis.

    PubMed

    Leone, Carmela; Patti, Francesco; Feys, Peter

    2015-02-01

    Purposeful, safe locomotion requires higher-level cortical processes, to meet the real-life demands of walking while performing concurrent cognitive tasks (e.g. recalling a shopping list or attending to a conversation). The assessment of walking and a secondary cognitive task under these 'dual tasking' conditions may represent a more valid outcome measure in multiple sclerosis (MS), by examining the occurrence and magnitude of the cognitive-motor interference of walking. This topical review provides a state-of-the-art overview of research into dual-tasking during walking in persons with MS, based on 14 recent papers. Studies consistently demonstrate a slowing of ambulation under dual tasking, regardless of the cognitive task demand, the stage of the disease and the disability level. The reciprocal effect of walking on the cognitive tasks was rarely assessed. We present our main findings, highlight the different factors contributing to dual-task deficits, identify methodological shortcomings and offer recommendations for constructing dual-tasking paradigms useful in clinical practice and research.

  11. 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

  12. TRANSFER EFFECTS IN TASK-SET COST AND DUAL-TASK COST AFTER DUAL-TASK TRAINING IN OLDER AND YOUNGER ADULTS: FURTHER EVIDENCE FOR COGNITIVE PLASTICITY IN ATTENTIONAL CONTROL IN LATE ADULTHOOD

    PubMed Central

    Bherer, Louis; Kramer, Arthur F.; Peterson, Matthew S.; Colcombe, Stanley; Erickson, Kirk; Becic, Ensar

    2010-01-01

    Older adults’ difficulties in performing two tasks concurrently have been well documented (Kramer & Madden, 2008). It has been observed that the age-related differences in dual-task performance are larger when the two tasks require similar motor responses (Hartley, 2001) and that in some conditions older adults also show greater susceptibility than younger adults to input interference (Hein & Schubert, 2004). The authors recently observed that even when the two tasks require motor responses, both older and younger adults can learn to perform a visual discrimination task and an auditory discrimination task faster and more accurately (Bherer et al., 2005). In the present study, the authors extended this finding to a dual-task condition that involves two visual tasks requiring two motor responses. Older and younger adults completed a dual-task training program in which continuous individualized adaptive feedback was provided to enhance performance. The results indicate that, even with similar motor responses and two visual stimuli, both older and younger adults showed substantial gains in performance after training and that the improvement generalized to new task combinations involving new stimuli. These results suggest that dual-task skills can be substantially improved in older adults and that cognitive plasticity in attentional control is still possible in old age. PMID:18568979

  13. Aging-related decrements during specific phases of the dual-task Timed Up-and-Go test.

    PubMed

    Porciuncula, Franchino S; Rao, Ashwini K; McIsaac, Tara L

    2016-02-01

    It is unclear how young and older adults modulate dual-task mobility under changing postural challenges. To examine age-related changes in dual-task processing during specific phases of dual-task Timed Up-and-Go (TUGdual-task). Healthy young and older adults performed the Timed Up-and-Go (TUG) with the following dual-task conditions: (1) serial-three subtractions, (2) carrying cup of water, (3) combined subtraction and carrying water, and (4) dialing cell phone. The primary outcome was the dual-task cost on performance of TUG (percent change from single- to dual-task) based on duration and peak trunk velocity of each phase: (a) straight-walk, (b) sit-to-stand, (c) turn, (d) turn-to-sit. Mixed-design univariate analysis of variance was performed for each type of task. Older adults had more pronounced mobility decrements than young adults during straight-ahead walking and turns when the secondary task engaged both cognitive and manual modalities. Simple cognitive or manual tasks during TUGdual-task did not differentiate young from older participants. Subtraction performance during simple and complex cognitive conditions differed by phase of the TUG. Manual task performance of carrying water did not vary by phase or age. Our findings suggest that dual-task processing is dynamic across phases of TUGdual-task. Aging-related dual-task decrements are demonstrated during straight-ahead walking and turning, particularly when the secondary task is more complex. Older adults are susceptible to reduced dual-task mobility during straight-ahead walking and turning particularly when attentional loading was increased.

  14. Effects of Single-Task Interference on Dual-Task Interference

    NASA Technical Reports Server (NTRS)

    Johnson, James C.; Ruthruff, Eric; VanSelst, Mark; Remington, Roger W.

    1998-01-01

    Van Sergi, Ruthruff and Johnston found that dual-task practice can markedly reduce interference in the Psychological Refractory Period paradigm. Their results are consistent with a bottleneck model in which practice serves primarily to reduce stage durations. This model predicts that single-task practice on Task 1 alone should produce marked reductions in interference, whereas single-task practice on Task 2 should not. New experiments test these predictions. Alternative theoretical accounts are also considered.

  15. 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

  16. 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.

  17. Dual task interference during walking: The effects of texting on situational awareness and gait stability.

    PubMed

    Lim, Jongil; Amado, Avelino; Sheehan, Leo; Van Emmerik, Richard E A

    2015-10-01

    Dual-task interference caused by mobile phone use while walking increases safety risks by increasing attentional and cognitive demands. Situational awareness, important for control of walking and safety, has been examined previously but measured only by the awareness of visually noteworthy objects in the environment or the number of times the person looked up from the phone. This study systematically investigated the effects of texting on situational awareness to different environments and its consequent impact on gait kinematics. Twenty healthy volunteers walked on a treadmill while texting and attending to visual tasks simultaneously. Gait parameters and situational awareness examined under dual-task conditions (walk and text or walk, text, and visual task) were compared with those of single-task conditions (text, walk or visual task only). The size of the visual field, display duration of the visual cue, and visual acuity demand were varied across the visual task conditions. About half of the visual cues provided during walking and texting were not perceived (48.3%) as compared to the visual task only condition. The magnitude of this loss of situational awareness was dependent upon the nature of visual information provided. While gait parameters were not different among visual task conditions, greater total medial-lateral excursion of the pelvis was observed in the walk and text condition compared to the walk only condition, showing the dual-task effects of texting on gait kinematics. The study provides further evidence of dual-task effects of texting on situational awareness as well as gait kinematics.

  18. 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.

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

    PubMed Central

    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. PMID:25132818

  20. Evidence for the acquisition of dual-task coordination skills in older adults.

    PubMed

    Strobach, Tilo; Frensch, Peter; Müller, Hermann; Schubert, Torsten

    2015-09-01

    Practicing two simultaneously presented tasks in dual-task situations results in improved dual-task performance, in both younger and older adults. Recent findings with younger adults demonstrated that this improvement is attributable in part to improved task coordination skills acquired through practice. However, it is unclear whether practice also improves older adults' skills at dual-task coordination. To clarify this, the present study examined the acquisition of task coordination skills, reflecting one specific mechanism of practice-dependent improvement in dual-task performance for this particular age group. This examination was based on two assumptions, namely, that (1) these skills are acquired during practice of the tasks presented simultaneously (dual-task situations), but not during the separate practice of the two tasks (single-task situations), and (2), rather than being dependent on the specific properties of practiced tasks, these skills are transferable to new dual-task situations. In the context of dual-task situations with well-structured reaction-time tasks, the results indeed revealed improved dual-task performance following dual-task practice, as compared to single-task practice, in both the practiced dual-task and new dual-task (transfer) situations. These findings are consistent with the notion that, similar to younger adults, acquired task coordination skills represent one practice-related mechanism that contributes to improved dual-task performance in the age group of older adults.

  1. Imaging "brain strain" in youth athletes with mild traumatic brain injury during dual-task performance.

    PubMed

    Sinopoli, Katia J; Chen, Jen-Kai; Wells, Greg; Fait, Philippe; Ptito, Alain; Taha, Tim; Keightley, Michelle

    2014-11-15

    Mild traumatic brain injury (mTBI) is a common cause of injury in youth athletes. Much of what is known about the sequelae of mTBI is yielded from the adult literature, and it appears that it is mainly those with persistent post-injury symptoms who have ongoing cognitive and neural abnormalities. However, most studies have employed single-task paradigms, which may not be challenging enough to uncover subtle deficits. We sought to examine the neural correlates of dual-task performance in male athletes aged 9-15 years using a functional neuroimaging protocol. Participants included 13 youths with a history of mTBI three to six months prior to testing and 14 typically-developing controls. All participants completed a working memory task in isolation (single-task) and while completing a concurrent motor task (dual-task); neural activity during performance was then compared between groups. Although working memory performance was similar during the single-task condition, increased working memory load resulted in an altered pattern of neural activation in key working memory areas (i.e., dorsolateral prefrontal and parietal cortices) in youth with mTBI relative to controls. During the dual-task condition, accuracy was similar between groups but injured youth performed slower than typically-developing controls, suggesting a speed-accuracy tradeoff in the mTBI group only. The injured youths also exhibited abnormal recruitment of brain structures involved in both working memory and dual-tasking. These data show that the dual-task paradigm can uncover functional impairments in youth with mTBI who are not highly symptomatic and who do not exhibit neuropsychological dysfunction. Moreover, neural recruitment abnormalities were noted in both task conditions, which we argue suggests mTBI-related disruptions in achieving efficient cognitive control and allocation of processing resources.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Neural Correlates of Dual-Task Walking: Effects of Cognitive versus Motor Interference in Young Adults.

    PubMed

    Beurskens, Rainer; Steinberg, Fabian; Antoniewicz, Franziska; Wolff, Wanja; Granacher, Urs

    2016-01-01

    Walking while concurrently performing cognitive and/or motor interference tasks is the norm rather than the exception during everyday life and there is evidence from behavioral studies that it negatively affects human locomotion. However, there is hardly any information available regarding the underlying neural correlates of single- and dual-task walking. We had 12 young adults (23.8 ± 2.8 years) walk while concurrently performing a cognitive interference (CI) or a motor interference (MI) task. Simultaneously, neural activation in frontal, central, and parietal brain areas was registered using a mobile EEG system. Results showed that the MI task but not the CI task affected walking performance in terms of significantly decreased gait velocity and stride length and significantly increased stride time and tempo-spatial variability. Average activity in alpha and beta frequencies was significantly modulated during both CI and MI walking conditions in frontal and central brain regions, indicating an increased cognitive load during dual-task walking. Our results suggest that impaired motor performance during dual-task walking is mirrored in neural activation patterns of the brain. This finding is in line with established cognitive theories arguing that dual-task situations overstrain cognitive capabilities resulting in motor performance decrements.

  7. Building a framework for a dual task taxonomy.

    PubMed

    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.

  8. 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

  9. 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.

  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. 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

    2016-03-09

    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.

  12. Texting and walking: effect of environmental setting and task prioritization on dual-task interference in healthy young adults.

    PubMed

    Plummer, Prudence; Apple, Sarah; Dowd, Colleen; Keith, Eliza

    2015-01-01

    Recent studies have shown that young adults significantly reduce their gait speed and weave more when texting while walking. Previous research has not examined the simultaneous dual-task effects on texting performance, therefore, the attention prioritization strategy used by young adults while texting and walking is not currently known. Moreover, it is not known whether laboratory-based studies accurately reflect texting and walking performance in the real world. This study compared dual-task interference during texting and walking between laboratory and real-world settings, and examined the ability of young adults to flexibly prioritize their attention between the two tasks in each environment. Texting and walking were assessed in single-task and three dual-task conditions (no-priority, gait-priority, texting-priority) in the lab and a University Student Center, in 32 healthy young adults. Dual-task effects on gait speed, texting speed, and texting accuracy were significant, but did not significantly differ between the two environments. Young adults were able to flexibly prioritize their attention between texting and walking, according to specific instruction, and this ability was not influenced by environmental setting. In the absence of instructions, young adults prioritized the texting task in the low-distraction environment, but displayed more equal focus between tasks in the real world. The finding that young adults do not significantly modify their texting and walking behavior in high-distraction environments lends weight to growing concerns about cell phone use and pedestrian safety. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. 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

  14. 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.

  15. 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.

  16. Sleep quality is associated with walking under dual-task, but not single-task performance.

    PubMed

    Agmon, Maayan; Shochat, Tamar; Kizony, Rachel

    2016-09-01

    The objective of this study was to assess the relationship between sleep behavior and gait performance under single-task (ST) and dual-task (DT) walking conditions in community- dwelling older adults. Walking under ST and DT conditions was evaluated in 34 community-dwelling older adults, 64.7% women, mean age 71.5 (SD±5.8). Gait-speed and gait-variability data were collected using the OPAL wearable sensors of the Mobility Lab. Sleep behavior (sleep efficiency [SE] and sleep latency [SL]) was assessed using actigraphy, over 5 consecutive nights. Lower SE was associated with decreased gait speed and increased stride-length variability during DT (rs=0.35; p=0.04; rs=-0.36; p=0.03, respectively), whereas longer SL was associated with increased stride-length variability during DT (rs=0.38; p=.03). After controlling for age and cognition, SE accounted for 24% and 33% of the variability in stride length and stride time. No associations were found between sleep and gait measures under ST walking. Lower SE is associated with decreased gait speed and increased gait variability under DT conditions that are indicative of an increased risk for falls in older adults. Our findings support clinical recommendations to incorporate the evaluation of sleep quality in the context of risk assessment for falls. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. 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

  18. Measuring listening effort: driving simulator versus simple dual-task paradigm.

    PubMed

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

    2014-01-01

    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. 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 omnidirectional 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. 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 listening effort was not

  19. Dual-task performance under acute stress in female adolescents with borderline personality disorder.

    PubMed

    Kaess, Michael; Parzer, Peter; Koenig, Julian; Resch, Franz; Brunner, Romuald

    2016-09-01

    Research to elucidate early alterations of higher cognitive processes in adolescents with BPD is rare. This study investigated differences in dual-task performance in adolescents with BPD during stress and non-stress conditions. The study sample comprised 30 female adolescents with BPD and 34 healthy controls. The impact of stress on dual-task performance was measured using a standardized stressor. Self-reports of distress and measures of heart rate (HR) were obtained to measure stress reactivity. There were no group differences in task performance. Under stress conditions, the performance on the auditory task decreased in both groups but without significant group differences. Healthy controls showed an increase of mean HR after stress induction compared to no change in the BPD group. The finding of attenuated HR response to acute stress in adolescent patients with BPD may contradict current theories that the affective hyperresponsivity in BPD is based on a biologically determined mechanism.

  20. Gait in Very Preterm School-Aged Children in Dual-Task Paradigms

    PubMed Central

    Hagmann-von Arx, Priska; Manicolo, Olivia; Perkinson-Gloor, Nadine; Weber, Peter; Grob, Alexander; Lemola, Sakari

    2015-01-01

    Objective The control of gait requires executive and attentional functions. As preterm children show executive and attentional deficits compared to full-term children, performing concurrent tasks that impose additional cognitive load may lead to poorer walking performance in preterm compared to full-term children. Knowledge regarding gait in preterm children after early childhood is scarce. We examined straight walking and if it is more affected in very preterm than in full-term children in dual-task paradigms. Study design Twenty preterm children with very low birth-weight (≤ 1500 g), 24 preterm children with birth-weight > 1500 g, and 44 full-term children, born between 2001 and 2006, were investigated. Gait was assessed using an electronic walkway system (GAITRite) while walking without a concurrent task (single-task) and while performing one concurrent (dual-task) or two concurrent (triple-task) tasks. Spatio-temporal gait parameters (gait velocity, cadence, stride length, single support time, double support time), normalized gait parameters (normalized velocity, normalized cadence, normalized stride length) and gait variability parameters (stride velocity variability, stride length variability) were analyzed. Results In dual- and triple-task conditions children showed decreased gait velocity, cadence, stride length, as well as increased single support time, double support time and gait variability compared to single-task walking. Further, results showed systematic decreases in stride velocity variability from preterm children with very low birth weight (≤ 1500 g) to preterm children with birth weight > 1500 g to full-term children. There were no significant interactions between walking conditions and prematurity status. Conclusions Dual and triple tasking affects gait of preterm and full-term children, confirming previous results that walking requires executive and attentional functions. Birth-weight dependent systematic changes in stride velocity

  1. Gait in Very Preterm School-Aged Children in Dual-Task Paradigms.

    PubMed

    Hagmann-von Arx, Priska; Manicolo, Olivia; Perkinson-Gloor, Nadine; Weber, Peter; Grob, Alexander; Lemola, Sakari

    2015-01-01

    The control of gait requires executive and attentional functions. As preterm children show executive and attentional deficits compared to full-term children, performing concurrent tasks that impose additional cognitive load may lead to poorer walking performance in preterm compared to full-term children. Knowledge regarding gait in preterm children after early childhood is scarce. We examined straight walking and if it is more affected in very preterm than in full-term children in dual-task paradigms. Twenty preterm children with very low birth-weight (≤ 1500 g), 24 preterm children with birth-weight > 1500 g, and 44 full-term children, born between 2001 and 2006, were investigated. Gait was assessed using an electronic walkway system (GAITRite) while walking without a concurrent task (single-task) and while performing one concurrent (dual-task) or two concurrent (triple-task) tasks. Spatio-temporal gait parameters (gait velocity, cadence, stride length, single support time, double support time), normalized gait parameters (normalized velocity, normalized cadence, normalized stride length) and gait variability parameters (stride velocity variability, stride length variability) were analyzed. In dual- and triple-task conditions children showed decreased gait velocity, cadence, stride length, as well as increased single support time, double support time and gait variability compared to single-task walking. Further, results showed systematic decreases in stride velocity variability from preterm children with very low birth weight (≤ 1500 g) to preterm children with birth weight > 1500 g to full-term children. There were no significant interactions between walking conditions and prematurity status. Dual and triple tasking affects gait of preterm and full-term children, confirming previous results that walking requires executive and attentional functions. Birth-weight dependent systematic changes in stride velocity variability indicate poorer walking performance in

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Age-related deficits of dual-task walking: the role of foot vision.

    PubMed

    Bock, Otmar; Beurskens, Rainer

    2011-02-01

    Previous studies found that age-related deficits of dual-task walking emerge with secondary tasks that require substantial visual processing, but are absent with tasks that require little or no visual processing. We evaluated whether this is so because visual tasks typically interfere with foot vision, on which older persons depend more heavily than young ones. Young (25±3 years) and older (69±5 years) subjects walked along a straight path and checked boxes on a handheld panel, separately or concurrently. The panel was either transparent or opaque, thus allowing or blocking vision of the feet, respectively. We quantified subjects' performance by spatial and temporal gait measures, and as the speed of checking. An analysis of variance revealed significant effects of age and of condition (single, dual) for several gait measures, as well as for checking speed. The dual-task costs (ǀdual-singleǀ/single) averaged 0.04±0.14 in younger and 0.33±0.30 in older subjects; this age difference was significant in a t-test (p<0.01). Most importantly, performance measures obtained with the transparent and with the opaque panel were not significantly different. In conclusion, our study confirms previous findings about age-related deficits of walking with a concurrent visual task, documents for the first time that these deficits influence the entire spatio-temporal gait structure, but provides no support for the notion that they reflect an increased dependence on foot vision.

  8. Is dual-task performance necessarily impaired in space?

    PubMed

    Fowler, B; Bock, O; Comfort, D

    2000-01-01

    Recent single-subject experiments in space have reported impaired dual-task performance that could result from either a direct effect of microgravity on the central nervous system or from the multistressor environment. We sought to distinguish between these hypotheses using 6 astronauts in the 16-day NASA Neurolab mission, testing them at intervals with a dual task consisting of primary pursuit tracking without vision of the hand and secondary reaction time (RT). The participants were highly trained, instructed to maintain a fixed attention strategy, and restrained in the apparatus. The results showed that absolute and variable tracking error, as well as correct RT and the standard deviation of RT, were unimpaired. However, RT errors became more variable, an effect attributed to a decrease in strategic control. We conclude that the impairments observed in previous dual-task space experiments can be attributed to stressors rather than to microgravity and that performance deficits are probably not a necessary concomitant of space flight if attention is paid to task design and astronaut training.

  9. Using dual-task methodology to dissociate automatic from nonautomatic processes involved in artificial grammar learning.

    PubMed

    Hendricks, Michelle A; Conway, Christopher M; Kellogg, Ronald T

    2013-09-01

    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 intentional grammar- and fragment-based knowledge in AGL at both acquisition and at test. Both experiments used a balanced chunk strength grammar to assure an equal proportion of fragment cues (i.e., chunks) in grammatical and nongrammatical test items. In Experiment 1, participants engaged in a working memory dual-task either during acquisition, test, or both acquisition and test. The results showed that participants performing the dual-task during acquisition learned the artificial grammar as well as the single-task group, presumably by relying on automatic learning mechanisms. A working memory dual-task at test resulted in attenuated grammar performance, suggesting a role for intentional processes for the expression of grammatical learning at test. Experiment 2 explored the importance of perceptual cues by changing letters between the acquisition and test phase; unlike Experiment 1, there was no significant learning of grammatical information for participants under dual-task conditions in Experiment 2, suggesting that intentional processing is necessary for successful acquisition and expression of grammar-based knowledge under transfer conditions. In sum, it appears that some aspects of learning in AGL are indeed relatively automatic, although the expression of grammatical information and the learning of grammatical patterns when perceptual similarity is eliminated both appear to require explicit resources.

  10. 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.

  11. Deep thinking increases task-set shielding and reduces shifting flexibility in dual-task performance.

    PubMed

    Fischer, Rico; Hommel, Bernhard

    2012-05-01

    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 thinking-which were suspected to induce a holistic, flexible task processing mode, or convergent thinking-which were assumed to induce a systematic, focused processing mode. Participants showed reduced cross-talk between tasks and increased task-component switching costs (dual-task costs) for the convergent-thinking group compared to both, a divergent-thinking group and a neutral control group. The results suggest that the cognitive-control style people engage in prior to the task predicts their multitasking performance. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. The association between media multitasking, task-switching, and dual-task performance.

    PubMed

    Alzahabi, Reem; Becker, Mark W

    2013-10-01

    The recent rise in media use has prompted researchers to investigate its influence on users' basic cognitive processes, such as attention and cognitive control. However, most of these investigations have failed to consider that the rise in media use has been accompanied by an even more dramatic rise in media multitasking (engaging with multiple forms of media simultaneously). Here we investigate how one's ability to switch between 2 tasks and to perform 2 tasks simultaneously is associated with media multitasking experience. Participants saw displays comprised of a number-letter pair and classified the number as odd or even and/or the letter as a consonant or vowel. In task-switching blocks, a cue indicated which classification to perform on each trial. In dual-task blocks, participants performed both classifications. Heavy and light media multitaskers showed comparable performance in the dual-task. Across 2 experiments, heavy media multitaskers were better able to switch between tasks in the task-switching paradigm. Thus, while media multitasking was not associated with increased ability to process 2 tasks in parallel, it was associated with an increased ability to shift between discrete tasks. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  13. 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.

  14. Effects of dual tasking on the postural performance of people with and without multiple sclerosis: a pilot study.

    PubMed

    Jacobs, Jesse V; Kasser, Susan L

    2012-06-01

    People with multiple sclerosis (MS) exhibit both cognitive and postural impairments. This study examined the effects of MS and of dual tasking on postural performance, and explored associations among dual-task postural performance, cognitive capacity, fear of falling, and fatigue. Thirteen subjects with MS (Expanded Disability Status Scale: 0-4.5) and 13 matched subjects without MS performed three tasks of standing postural control, with and without dual tasking amid an auditory Stroop task: (1) step initiation, (2) forward leaning to the limits of stability, and (3) postural responses to rotations of the support surface. Two-factor general linear models were used to evaluate differences between the groups (with or without MS) and two conditions (single or dual tasking) for each postural task. During step initiation, dual tasking significantly delayed the onset of the anticipatory postural adjustment (APA) more for the subjects with MS than for those without MS, and step lengths increased for the subjects with MS but decreased for those without MS. No other significant group-by-condition interactions were evident on the recorded variables of stepping, leaning, postural responses, or Stroop-response accuracies and latencies. The scores for the subjects with MS on the Modified Fatigue Impact Scale significantly associated with the change between single-task to dual-task conditions in APA onset and foot-lift onset during step initiation as well as in lean position variability and lean onset times during forward leaning. The results suggest dual-task effects were more evident during step initiation and are associated with levels of fatigue for subjects with MS.

  15. 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.

  16. 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

  17. Dual task interference on postural sway, postural transitions and gait in people with Parkinson's disease and freezing of gait.

    PubMed

    de Souza Fortaleza, Ana Claudia; Mancini, Martina; Carlson-Kuhta, Patty; King, Laurie A; Nutt, John G; Chagas, Eliane Ferrari; Freitas, Ismael Forte; Horak, Fay B

    2017-07-01

    Freezing of gait (FoG) is associated with less automatic gait and more impaired cognition, balance and postural transitions compared to people with PD who do not have FoG. However, it is unknown whether dual-task cost during postural sway, postural transitions (such as gait initiation and turning), and gait are more in subjects with Parkinson's disease (PD) who have freezing of gait (FoG+) compared to those who do not have FoG (FoG-). Here, we hypothesized that the effects of a cognitive dual task on postural sway, postural transitions and gait would be larger in FoG+ than FoG-. Thirty FoG- and 24 FoG+ performed an Instrumented Stand and Walk test in OFF medication state, with and without a secondary cognitive task (serial subtraction by 3s). Measures of postural sway, gait initiation, turning, and walking were extracted using body-worn inertial sensors. FoG+ showed significantly larger dual task cost than FoG- for several gait metrics, but not during postural sway or postural transitions. During walking, FoG+ exhibited a larger dual task cost than FoG- resulting in shorter stride length and slower stride velocity. During standing, FoG+ showed a larger postural sway compared to FoG- and during gait initiation, FoG+, but not FoG-, showed a longer first step duration during the dual-task condition compared to single-task condition (interaction effect, p=0.04). During turning, both groups showed a slower turn peak speed in the dual-task condition compared to single task condition. These findings partly support our hypothesis that dual task cost on walking is greater in FoG+ than FoG-. Copyright © 2017. Published by Elsevier B.V.

  18. Motor-Cognitive Dual-Task Training in Neurologic Disorders: A Systematic Review

    PubMed Central

    Fritz, NE; Cheek, FM; Nichols-Larsen, DS

    2015-01-01

    Background and Purpose Deficits in motor-cognitive dual-tasks (e.g., walking while talking) are common in individuals with neurological conditions. This review was conducted to determine the effectiveness of motor-cognitive dual-task training (DTT) compared to usual care on mobility and cognition in individuals with neurologic disorders. Methods Databases searched were Biosis, CINAHL, ERIC, PsychInfo, EBSCO Psychological & Behavioral, PubMed, Scopus, and Web of Knowledge. Eligibility criteria were studies of adults with neurologic disorders that included DTT and outcomes of gait or balance were included. Fourteen studies met inclusion criteria. Participants were individuals with brain injury, Parkinson’s disease (PD) and Alzheimer’s disease (AD). Intervention protocols included cued walking, cognitive tasks paired with gait, balance, and strength training and virtual reality or gaming. Quality of the included trials was evaluated with a standardized rating scale of clinical relevance. Results Results show that DTT improves single-task gait velocity and stride length in PD and AD, dual-task gait velocity and stride length in PD, AD and brain injury, and may improve balance and cognition in PD and AD. The inclusion criteria limited the diagnostic groups included. Discussion and Conclusions The range of training protocols and outcome assessments in available studies limited comparison of the results across studies. Improvement of dual-task ability in individuals with neurologic disorders holds potential for improving gait, balance and cognition. Motor-cognitive dual-task deficits in individuals with neurologic disorders may be amenable to training. Video Abstract available for additional insights from the authors (See Supplemental Digital Content). PMID:26079569

  19. 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

  20. 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.

  1. The effect of dual-task difficulty on the inhibition of the motor cortex.

    PubMed

    Corp, Daniel T; Rogers, Mark A; Youssef, George J; Pearce, Alan J

    2016-02-01

    Dual-tasking is intrinsic to many daily activities, including walking and driving. However, the activity of the primary motor cortex (M1) in response to dual-tasks (DT) is still not well characterised. A recent meta-analysis (Corp in Neurosci Biobehav Rev 43:74-87, 2014) demonstrated a reduction in M1 inhibition during dual-tasking, yet responses were not consistent between studies. It was suggested that DT difficulty might account for some of this between-study variability. The aim of this study was to investigate whether corticospinal excitability and M1 inhibition differed between an easier and more difficult dual-task. Transcranial magnetic stimulation (TMS) was applied to participants' abductor pollicis brevis muscle representation during a concurrent pincer grip task and stationary bike-riding. The margin of error in which to maintain pincer grip force was reduced to increase task difficulty. Compared to ST conditions, significantly increased M1 inhibition was demonstrated for the easier, but not more difficult, DT. However, there was no significant difference in M1 inhibition between easy and difficult DTs. The difference in difficulty between the two tasks may not have been wide enough to result in significant differences in M1 inhibition. Increased M1 inhibition for the easy DT condition was in opposition to the reduction in M1 inhibition found in our meta-analysis (Corp in Neurosci Biobehav Rev 43:74-87, 2014). We propose that this may be partially explained by differences in the timing of the TMS pulse between DT studies.

  2. The Effects of Age and Hearing Loss on Dual-Task Balance and Listening.

    PubMed

    Bruce, Halina; Aponte, Daniel; St-Onge, Nancy; Phillips, Natalie; Gagné, Jean-Pierre; Li, Karen Z H

    2017-05-09

    Among older adults (OA), hearing loss is associated with an increased risk for falls. The aim of the present study was to experimentally investigate the cognitive compensation hypothesis, wherein decreased auditory and motor functioning are compensated by the recruitment of cognitive resources. Twenty-nine younger adults (YA), 26 OA, and 32 OA with age-related hearing loss (ARHL) completed a dual-task paradigm consisting of cognitive and balance recovery tasks performed singly and concurrently. The auditory stimuli were presented with or without background noise. Both older adult groups performed significantly worse than YA on the cognitive task in noisy conditions and ARHL also demonstrated disproportionate negative effects of dual-tasking and noise. The kinematic data indicated that OA and ARHL demonstrated greater plantarflexion when compared with YA. Conversely, YA showed greater hip extension in response to dual-tasking. The cognitive and balance results suggest that YA were able to flexibly allocate their attention between tasks, whereas ARHL exhibited prioritization of posture over cognitive performance.

  3. 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.

  4. Dual task performance in Parkinson's disease: a sensitive predictor of impairment and disability.

    PubMed

    Fuller, Rebecca L; Van Winkle, Elizabeth P; Anderson, Karen E; Gruber-Baldini, Ann L; Hill, Terra; Zampieri, Cris; Weiner, William J; Shulman, Lisa M

    2013-03-01

    Dual task (DT) performance assesses the ability to perform two tasks simultaneously. Difficulty with DT performance may be a sensitive indicator of early Parkinson's disease (PD) impairment. The objective of this study was to assess what elements of a DT performance (cognition or gait) are most associated with impairment and disability in PD. Performance in single and DT conditions was examined in 154 PD patients. The single task assessments included the time required to walk 50 feet (gait speed) and the number of words generated in a verbal fluency task (word generation). The DT comprised simultaneous performance of the single tasks. Impairment and disability were measured with the Unified Parkinson's Disease Rating Scale, Hoehn &Yahr, Berg Balance Scale, and Older Americans Resource and Services Scale. Age, education, and gender were control variables. Standardized residuals from regressions of DT upon single task performance were computed separately for word and gait, indicating the extent that the individual performed proportionally better/worse than predicted in DT considering their single task performance. Multiple regressions revealed that individuals who performed worse than expected in DT-word had greater impairment and disability. Dual task-gait was not significant in any model. Verbal fluency during DT performance is more closely associated with PD-related impairment and disability than gait speed during DT. This suggests that subjects prioritize gait performance at the expense of cognitive performance, and that DT word generation may be a sensitive indicator of early PD impairment and disability. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. 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.

  6. 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.

  7. Effect of dual-attention task on attack and defensive actions in fencing.

    PubMed

    Gutiérrez-Davila, Marcos; Rojas, F Javier; Gutiérrez-Cruz, Carmen; Navarro, Enrique

    2017-09-01

    The objectives of this study were to investigate the effect that the presence of two stimuli that require two different responses (dual-attention) has both, on offensive reaction-response time to a light stimulus, and on defensive response time when the stimulus is a real fencing attack. Twenty-five elite fencers and a fencing master were included in the study. The equipment included four force plates adapted to a scaffold that served as a fencing piste. Two force plates were placed, at the start position, under the fencer's feet and another two plates were placed under the master's feet. The results demonstrate that choice reaction time to visual stimuli increases in dual-task conditions with respect to simple reaction time, whereas the mean horizontal force tends to decrease in dual-task. However, when the stimulus was an opponent's movement, dual-task conditions did not have any effect on the time required to initiate a defensive action. The changes in reaction time when real movements were used as stimuli challenge the validity of the reaction time to visual stimuli paradigm as a predictor of performance in fencing. Also, the results obtained demonstrate that perceptual and attentional processes play a major role in fencer performance in real competition.

  8. Effect of practice and span length on the dual-task coordination executive test.

    PubMed

    Sylwan, R P; Rosin, F M; Galera, C

    1999-10-01

    The measure "mu", proposed as an index of the ability to coordinate concurrent box-crossing (BC) and digit-span (DS) tasks in the dual task (DT), should reflect the capacity of the executive component of the working memory system. We investigated the effect of practice in BC and of a change in the digit span on mu by adding previous practice trials in BC and diminishing, maintaining or increasing the digit sequence length. The mu behavior was evaluated throughout three trials of the test. Reported strategies in digit tasks were also analyzed. Subjects with diminished span showed the best performance in DT due to a stable performance in DS and BC in the single- and dual-task conditions. These subjects also showed a more stable performance throughout trials. Subjects with diminished span tended to employ effortless strategies, whereas subjects with increased span employed effort-requiring strategies and showed the lowest means of mu. Subjects with initial practice trials showed the best performance in BC and the most differentiated performance between the single- and dual-task conditions in BC. The correlation coefficient between the mu values obtained in the first and second trials was 0.814 for subjects with diminished span and practice trials in BC. It seems that the within-session practice in BC and the performance variability in DS affect the reliability of the index mu. To control these factors we propose the introduction of previous practice trials in BC and a modification of the current method to determine the digit sequence length. This proposal should contribute to the development of a more reliable method to evaluate the executive capacity of coordination in the dual-task paradigm.

  9. 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.

  10. Test-retest reliability of stride time variability while dual tasking in healthy and demented adults with frontotemporal degeneration

    PubMed Central

    2011-01-01

    Background Although test-retest reliability of mean values of spatio-temporal gait parameters has been assessed for reliability while walking alone (i.e., single tasking), little is known about the test-retest reliability of stride time variability (STV) while performing an attention demanding-task (i.e., dual tasking). The objective of this study was to examine immediate test-retest reliability of STV while single and dual tasking in cognitively healthy older individuals (CHI) and in demented patients with frontotemporal degeneration (FTD). Methods Based on a cross-sectional design, 69 community-dwelling CHI (mean age 75.5 ± 4.3; 43.5% women) and 14 demented patients with FTD (mean age 65.7 ± 9.8 years; 6.7% women) walked alone (without performing an additional task; i.e., single tasking) and while counting backward (CB) aloud starting from 50 (i.e., dual tasking). Each subject completed two trials for all the testing conditions. The mean value and the coefficient of variation (CoV) of stride time while walking alone and while CB at self-selected walking speed were measured using GAITRite® and SMTEC® footswitch systems. Results ICC of mean value in CHI under both walking conditions were higher than ICC of demented patients with FTD and indicated perfect reliability (ICC > 0.80). Reliability of mean value was better while single tasking than dual tasking in CHI (ICC = 0.96 under single-task and ICC = 0.86 under dual-task), whereas it was the opposite in demented patients (ICC = 0.65 under single-task and ICC = 0.81 under dual-task). ICC of CoV was slight to poor whatever the group of participants and the walking condition (ICC < 0.20), except while dual tasking in demented patients where it was fair (ICC = 0.34). Conclusions The immediate test-retest reliability of the mean value of stride time in single and dual tasking was good in older CHI as well as in demented patients with FTD. In contrast, the variability of stride time was low in both groups of

  11. Neural mechanisms of dual-task interference and cognitive capacity limitation in the prefrontal cortex.

    PubMed

    Watanabe, Kei; Funahashi, Shintaro

    2014-04-01

    Simultaneous performance of two tasks often leads to performance deficits in the component tasks. This effect, known as dual-task interference, is thought to be a proof of capacity limitation in cognition, and the lateral prefrontal cortex (LPFC) has been highlighted as its putative neural substrate. Here we recorded single-neuron activities in LPFC while monkeys performed dual tasks that required the simultaneous performance of a varying-load spatial attention task and a spatial memory task. We found that the performance of the monkeys exhibited dual-task interference, and prefrontal neuron activities showed a decreased ability to represent task-relevant information to a degree proportional to the increased demand of the concurrent counterpart task. The locus of the interference was shown to originate in the simultaneous, overloaded recruitment of the same LPFC neural population by the two tasks. These results provide direct neurophysiological evidence for, and constraints to, psychological models of dual-task interference and capacity limitation.

  12. Dual task-related gait changes in patients with mild cognitive impairment

    PubMed Central

    Nascimbeni, Alberto; Caruso, Shiva; Salatino, Adriana; Carenza, Marinella; Rigano, Marta; Raviolo, Andrea; Ricci, Raffaella

    2015-01-01

    Summary Mild cognitive impairment (MCI) entails a high risk of developing Alzheimer’s dementia. In MCI patients gait impairment, which increases the risk of falls and institutionalization, is an early motor sign. A dual-task (DT) paradigm might improve the observation of this phenomenon. The aim of this study was to investigate motor-cognitive interference in a sample of MCI patients and a group of matched healthy controls submitted to DT conditions. To this end, three different cognitive tasks were used: counting backwards, short story recall and a phonemic fluency task. Overall, the patients, compared with the healthy participants, performed worse on the cognitive tasks and showed some degree of gait impairment. In the DT conditions, both groups showed significant gait disruption independently of the concomitant cognitive task. As regards cognitive performance, counting backwards worsened during dual tasking, while short story recall improved in both groups. Overall, our results suggest that the use of a DT paradigm does not improve the early detection of MCI. Our findings of enhanced story recall during walking might have interesting implications for rehabilitation of memory function. PMID:26214028

  13. The impact of depression on dual tasking among patients with high fall risk.

    PubMed

    Wright, Sara L; Kay, Rachel E; Avery, Erich T; Giordani, Bruno; Alexander, Neil B

    2011-09-01

    Depression predicts fall risk among older adults, and this relationship may be partially explained by depression-associated executive dysfunction, relevant to navigating demanding environments. This pilot study examined timed stepping accuracy under simple and complex dual-task conditions, using an instrumented walkway based on the Trail Making Test. Participants were balance-impaired older adults, either with (n = 8; major depressive disorder [MDD]) or without (n = 8; nondepressed [ND]) MDD. After accounting for comfortable gait speed and age, the MDD group was significantly slower than the ND group on the walkway with the highest cognitive demand and demonstrated greater dual-task cost, both of which were correlated with performance on traditional measures of executive functioning. No group differences were observed on the walkway with the least cognitive demand. Balance-impaired older adults with MDD demonstrate increased stepping accuracy time under cognitively demanding conditions, reflecting executive dysfunction and an additional contribution to increased fall risk.

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

    PubMed Central

    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). PMID:27992586

  15. 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).

  16. 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.

  17. Dynamic Changes in Brain Functional Connectivity during Concurrent Dual-Task Performance

    PubMed Central

    Cocchi, Luca; Zalesky, Andrew; Toepel, Ulrike; Whitford, Thomas J.; De-Lucia, Marzia; Murray, Micah M.; Carter, Olivia

    2011-01-01

    This study investigated the spatial, spectral, temporal and functional proprieties of functional brain connections involved in the concurrent execution of unrelated visual perception and working memory tasks. Electroencephalography data was analysed using a novel data-driven approach assessing source coherence at the whole-brain level. Three connections in the beta-band (18–24 Hz) and one in the gamma-band (30–40 Hz) were modulated by dual-task performance. Beta-coherence increased within two dorsofrontal-occipital connections in dual-task conditions compared to the single-task condition, with the highest coherence seen during low working memory load trials. In contrast, beta-coherence in a prefrontal-occipital functional connection and gamma-coherence in an inferior frontal-occipitoparietal connection was not affected by the addition of the second task and only showed elevated coherence under high working memory load. Analysis of coherence as a function of time suggested that the dorsofrontal-occipital beta-connections were relevant to working memory maintenance, while the prefrontal-occipital beta-connection and the inferior frontal-occipitoparietal gamma-connection were involved in top-down control of concurrent visual processing. The fact that increased coherence in the gamma-connection, from low to high working memory load, was negatively correlated with faster reaction time on the perception task supports this interpretation. Together, these results demonstrate that dual-task demands trigger non-linear changes in functional interactions between frontal-executive and occipitoparietal-perceptual cortices. PMID:22140572

  18. Task switching: the effect of task recency with dual- and single-affordance stimuli.

    PubMed

    Sumner, Petroc; Ahmed, Lubna

    2006-07-01

    When we switch to a new task, performance is transiently relatively poor, but improves dramatically after one trial. Such a "switch cost" may result from the preceding task being highly primed while the new task is not yet primed. This predicts that it should become more difficult to switch back to Task A when more trials of Task B have intervened. Such a lag effect has been found in some but not in most previous experiments, and to resolve this discrepancy we examined the effects of task lag with different stimuli. We found that when stimuli uniquely and clearly cued the task--minimizing the need for control--switch reaction time increased with task lag. However, when the need for control was increased by using similar or identical stimuli in the two tasks, this lag effect was abolished or reversed. Thus only when control processes are minimized can priming explain the difficulty of switching back from Task B to Task A. Second, we asked how the impact of control is mediated in conditions where it is not minimized. If it is mediated through altering the relative activation states of competing tasks, then as it becomes easier to do one task--the relative task-set activation state is tipped in that task's favour--it should always become harder to do the other task. On the other hand, if control bias affects switch performance directly, this relationship need not hold. We found that as it becomes easier to perform one task it can become easier, not harder, to switch to the competing task. Thus control bias must act directly on switch performance, rather than only through its influence on relative task-set activation.

  19. 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.

  20. Modulation of hyperactive error signals in obsessive-compulsive disorder by dual-task demands.

    PubMed

    Klawohn, Julia; Endrass, Tanja; Preuss, Julia; Riesel, Anja; Kathmann, Norbert

    2016-02-01

    Brain correlates of performance-monitoring have been shown to be hyperactive in patients with obsessive-compulsive disorder (OCD), indexed by enhanced amplitudes of the error-related negativity (ERN) in the event-related potential (ERP). This hyperactivity was found to be temporally stable, independent of symptom remission, and could not be further increased by punishing committed errors. The current study examined whether the ERN in OCD is generally insensitive to modulatory influences or can be decreased by manipulation of task demands. Twenty-two OCD patients and 22 control participants performed a flanker task alone or with a concurrent n-back task to manipulate attentional resource allocation. Response-related ERP data were examined. OCD patients showed enhanced ERN-amplitudes in the standard flanker (ηp2 = .13). In both groups a significant decrease in ERN was found under dual-task conditions (ηp2 = .72) that was larger in the OCD group (ηp2 = .14), resulting in a nonsignificant ERN group difference in dual-task conditions. The current study replicated enhanced performance-monitoring in OCD as indexed by higher ERN-amplitudes. Importantly, it further showed a larger ERN-reduction with dual-task demands in patients compared to healthy participants. These results suggest that overactive performance-monitoring was normalized in patients with OCD by experimental conditions. Changing the attentional focus appears to be an effective strategy in modifying hyperactive error-signals in OCD and might be a target for innovative interventions.

  1. 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

  2. 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…

  3. Single and dual task gait training in people with Parkinson's Disease: A protocol for a randomised controlled trial

    PubMed Central

    2011-01-01

    Background Difficulty performing more than one task at a time (dual tasking) is a common and disabling problem experienced by people with Parkinson disease (PD). If asked to perform another task when walking, people with PD often take shorter steps or walk more slowly. Currently there is uncertainty about whether clinicians should teach people with PD to avoid dual tasking or whether they should encourage them to practice dual tasking with the hope that practice will lead to enhanced performance. This study will address this issue by comparing single to dual task gait training. Methods and design A prospective randomised clinical trial is being conducted. Sixty participants with idiopathic PD will be recruited, provided they score I-IV on the modified Hoehn and Yahr (1967) scale, and fulfil other inclusion criteria. Participants will be randomly allocated to either a single or dual task gait training group. Both groups will receive 12 hours of walking training over 4 weeks. The single task group will undertake gait training with cueing strategies to increase step length. The dual task group will train to improve step length when walking and performing a variety of added tasks. Both groups will receive a tailored home program for 6 months. Blinded assessors will conduct four assessments: two baseline assessments, one post intervention and one at 6 months follow-up. The primary outcome measure will be step length when dual tasking over 8 m. Secondary outcome measures include: spatiotemporal gait parameters when walking under single and dual task conditions, measures of executive function, the timed up and go test, measures of community mobility, and quality of life. All analyses will be based on intention to treat principle. Discussion This trial will examine the immediate and longer term effect of dual task walking training as compared to single task training in people with idiopathic PD, at the impairment, activity, and participation levels. It has the potential to

  4. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:25963755

  6. 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.

  7. 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; F2,58 = 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.

  8. 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

  9. 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

  10. Characterisation of foot clearance during gait in people with early Parkinson׳s disease: Deficits associated with a dual task.

    PubMed

    Alcock, Lisa; Galna, Brook; Lord, Sue; Rochester, Lynn

    2016-09-06

    Tripping is a common cause of falls in older adults and people with Parkinson׳s disease (PD). Foot clearance during gait may be impaired when distracted by a dual task and thus inform trip risk. This study aimed to evaluate whether foot clearance is impaired in PD and is adversely affected by a dual task. 81 older adults and 76 PD walked at a comfortable pace for two minutes under single and dual task conditions (digit recall). Temporal spatial gait was measured using an instrumented walkway. Heel and toe trajectories were obtained bilaterally using 3-dimensional motion capture. Foot clearance was reduced in PD (p<.001) and under dual task (p<.027). The take-off (toe) gradient was reduced under dual task irrespective of group and the landing (heel) gradient was reduced in PD irrespective of task (p<.001). An increased proportion of unimodal toe distributions were observed for PD, particularly under dual task. Group differences were retained when controlling for step length (landing gradient and peak toe clearance in late swing) and gait velocity (landing gradient). Distinct differences in foot clearance were observed even in the early clinical stages of PD. Dual tasking may increase trip risk due to insufficient toe clearance (early swing) for both older adults and PD. Inadequate heel clearance (late swing) may increase falls risk in PD. Clearance deficits in PD are partially related to a reduced gait velocity and step length which may be targeted in tailored therapies. Further work is necessary to understand the mechanisms underlying this pathology-associated deficit.

  11. 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

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

    PubMed

    Ehlers, Diane K; 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).

  13. Individual differences in oscillatory brain activity in response to varying attentional demands during a word recall and oculomotor dual task

    PubMed Central

    Kwon, Gusang; Lim, Sanghyun; Kim, Min-Young; Kwon, Hyukchan; Lee, Yong-Ho; Kim, Kiwoong; Lee, Eun-Ju; Suh, Minah

    2015-01-01

    Every day, we face situations that involve multi-tasking. How our brain utilizes cortical resources during multi-tasking is one of many interesting research topics. In this study, we tested whether a dual-task can be differentiated in the neural and behavioral responses of healthy subjects with varying degree of working memory capacity (WMC). We combined word recall and oculomotor tasks because they incorporate common neural networks including the fronto-parietal (FP) network. Three different types of oculomotor tasks (eye fixation, Fix-EM; predictive and random smooth pursuit eye movement, P-SPEM and R-SPEM) were combined with two memory load levels (low-load: five words, high-load: 10 words) for a word recall task. Each of those dual-task combinations was supposed to create varying cognitive loads on the FP network. We hypothesize that each dual-task requires different cognitive strategies for allocating the brain’s limited cortical resources and affects brain oscillation of the FP network. In addition, we hypothesized that groups with different WMC will show differential neural and behavioral responses. We measured oscillatory brain activity with simultaneous MEG and EEG recordings and behavioral performance by word recall. Prominent frontal midline (FM) theta (4–6 Hz) synchronization emerged in the EEG of the high-WMC group experiencing R-SPEM with high-load conditions during the early phase of the word maintenance period. Conversely, significant parietal upper alpha (10–12 Hz) desynchronization was observed in the EEG and MEG of the low-WMC group experiencing P-SPEM under high-load conditions during the same period. Different brain oscillatory patterns seem to depend on each individual’s WMC and varying attentional demands from different dual-task combinations. These findings suggest that specific brain oscillations may reflect different strategies for allocating cortical resources during combined word recall and oculomotor dual-tasks. PMID:26175681

  14. Gait in Children with Attention-Deficit Hyperactivity Disorder in a Dual-Task Paradigm

    PubMed Central

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

    2017-01-01

    The aim was to examine gait in school-aged children with attention-deficit hyperactivity disorder (ADHD) and typically developing controls in a dual-task paradigm. Thirty children with ADHD (without or off medication) aged 7–13 years and 28 controls walked without an additional task (single-task walking) and while performing a concurrent cognitive or motor task (dual-task walking). Gait was assessed using GAITRite recordings of spatiotemporal and variability gait parameters. Compared to single-task walking, dual-tasking significantly altered walking performance of children with and without ADHD, whereby dual-task effects on gait were not different between the two groups. For both children with ADHD and controls the motor concurrent task had a stronger effect on gait than the cognitive concurrent task. Gait in children with and without ADHD is affected in a dual-task paradigm indicating that walking requires executive functions. Future investigations of children's dual-task walking should account for the type of concurrent tasks. PMID:28154547

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

    PubMed

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

    2015-01-01

    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.

  16. The Effects of Aging and Dual Task Demands on Language Production

    PubMed Central

    Kemper, Susan; Schmalzried, RaLynn; Herman, Ruth; Leedahl, Skye; Mohankumar, Deepthi

    2008-01-01

    A digital pursuit rotor task was used to measure dual task costs of language production by young and older adults. After training on the pursuit rotor, participants were asked to track the moving target while providing a language sample. When simultaneously engaged, young adults experienced greater dual task costs to tracking, fluency, and grammatical complexity than older adults. Older adults were able to preserve their tracking performance by speaking more slowly. Individual differences in working memory, processing speed, and Stroop interference affected vulnerability to dual task costs. These results demonstrate the utility of using a digital pursuit rotor to study the effects of aging and dual task demands on language production and confirm prior findings that young and older adults use different strategies to accommodate to dual task demands. PMID:18982506

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

    PubMed

    Little, C Elaine; Woollacott, Marjorie

    2015-01-01

    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 = 06) 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.

  18. Dual-task study of cognitive and postural interference: a preliminary investigation of the automatization deficit hypothesis of developmental co-ordination disorder.

    PubMed

    Tsai, C-L; Pan, C-Y; Cherng, R-J; Wu, S-K

    2009-07-01

    The purpose of this study was to investigate whether children with developmental co-ordination disorder and balance problem (DCD-BP) had greater problems than controls in performing a primary balance task while concurrently completing different cognitive tasks varying in oral or listening cognitive complexity, as well as to investigate the automatization deficit hypothesis of DCD-BP. Children with DCD-BP (n= 39), along with age-matched control counterparts (n= 39), were placed on automatic processing situation under dual-task conditions. All children were required to perform a primary task, five dual-task paradigms (oral counting task, auditory-verbal reaction task, auditory-choice reaction task, auditory-memory task and articulation alone) and an eyes-closed balancing task. In the primary task condition, the differences were not statistically significant (P= 0.393) between children with and without DCD-BP. However, children with DCD-BP were significantly more impaired on three of five dual-task conditions (oral counting task: P= 0.003; auditory-verbal reaction task: P= 0.011; auditory-memory task: P= 0.041) compared with the single-task situation, with the exception of the auditory-choice reaction task (P= 0.471) and articulation alone (P= 0.067). These results suggest that children with DCD-BP were more cognitively dependant and may have an automatization deficit.

  19. Working Memory in Down Syndrome: Is There a Dual Task Deficit?

    ERIC Educational Resources Information Center

    Lanfranchi, S.; Baddeley, A.; Gathercole, S.; Vianello, R.

    2012-01-01

    Background: Recent studies have shown that individuals with Down syndrome (DS) are poorer than controls in performing verbal and visuospatial dual tasks. The present study aims at better investigating the dual task deficit in working memory in individuals with DS. Method: Forty-five individuals with DS and 45 typically developing children matched…

  20. 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…

  1. Working Memory in Down Syndrome: Is There a Dual Task Deficit?

    ERIC Educational Resources Information Center

    Lanfranchi, S.; Baddeley, A.; Gathercole, S.; Vianello, R.

    2012-01-01

    Background: Recent studies have shown that individuals with Down syndrome (DS) are poorer than controls in performing verbal and visuospatial dual tasks. The present study aims at better investigating the dual task deficit in working memory in individuals with DS. Method: Forty-five individuals with DS and 45 typically developing children matched…

  2. Dual-Tasking Effects on Dynamic Postural Stability in Athletes With and Without Anterior Cruciate Ligament Reconstruction.

    PubMed

    Mohammadi-Rad, Shahrzad; Salavati, Mahyar; Ebrahimi-Takamjani, Ismail; Akhbari, Behnam; Sherafat, Shiva; Negahban, Hossein; Lali, Pezhman; Mazaheri, Masood

    2016-12-01

    To compare the effect of dual tasking on postural stability between patients with anterior cruciate ligament reconstruction (ACL-R) and healthy controls. Single-limb postural stability was assessed in 17 athletes with ACL-R and 17 healthy matched athletes while standing on a Biodex Balance System platform in 4 conditions: stability level of 8 (ie, more-stable support surface) with eyes open, stability level of 8 with eyes closed, stability level of 6 (ie, less-stable support surface) with eyes open, and stability level of 6 with eyes closed. Postural-stability tasks were performed with and without auditory Stroop task. The anteroposterior stability index (APSI), mediolateral stability index (MLSI), and overall stability index (OSI) as measures of postural performance, as well as reaction time and error ratio as measures of cognitive performance, were recorded. Dual-tasking effect on postural stability was not significantly different between the groups in 3 postural conditions. Only in level 6 with eyes open, for APSI and OSI, patients with ACL-R showed lower postural stability under the dual-task condition. However, patients showed poorer performance on both reaction time and error ratio in all postural conditions. The patients with ACL-R appeared to sacrifice their cognitive performance to optimize their performance on postural stability. This posture-first strategy was reflected by a more pronounced effect of dual tasking on the auditory Stroop task than the postural-stability task. In situations where maintenance of posture is challenging, giving priority to the postural task at the expense of cognitive performance can ensure safety from balance loss.

  3. Attention deficits and dual task demands after mild traumatic brain injury.

    PubMed

    Cicerone, K D

    1996-02-01

    Attention deficits are a prominent aspect of cognitive dysfunction after mild traumatic brain injury (MTBI). Patients frequently complain of distractibility and difficulty attending to more than one thing at a time, and several neuropsychological studies have found evidence for a specific attention deficit without general neuropsychological impairment. The present study examined the nature of attentional disturbance after MTBI using an extended version of the 2 and 7 Test, which introduced two conditions reflecting patients' subjective complaints: the ability to perform with background 'noise', and while simultaneously attending to a secondary task. The dual task demands produced a significant slowing in processing speed for both the MTBI patients and control subjects. However, the relative decline in processing speed appeared much greater for the patients with MTBI, and they differed from control subjects only in this condition. The results are consistent with findings that patients with MTBI exhibit relatively subtle cognitive deficits which are apparent primarily under conditions which require effortful or controlled cognitive processing and exceed their available cognitive resources. Thus, the attentional deficits apparent during dual task demands may represent decreased cognitive, and perhaps neural, efficiency which reflects MTBI patients' subjective complaints and functional impairments.

  4. 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

  5. Effects of white matter lesions on trunk stability during dual-task walking among older adults with mild cognitive impairment.

    PubMed

    Doi, Takehiko; Shimada, Hiroyuki; Makizako, Hyuma; Tsutsumimoto, Kota; Hotta, Ryo; Nakakubo, Sho; Suzuki, Takao

    2015-12-01

    The linkage between gait and cognition has been shown in cases of white matter lesion (WML) that affect gait in older adults. Dual-task walking is believed to be cognitively demanding and to alter trunk movement, and gait impairment in people with mild cognitive impairment (MCI) is highlighted under this condition. However, the association between dual-task walking and structural changes in the brain, particularly with WML, in people with MCI is still unclear. The aim of this study was to examine the association between trunk stability during dual-task walking and WML in 560 older adults with MCI. We measured magnetic resonance imaging (MRI) and gait variables. Gait variables included harmonic ratio in vertical, mediolateral, and anteroposterior directions, analyzed using a tri-axial accelerometer attached to the lower trunk. Walking conditions were normal walking and dual-task walking (counting backwards while walking) conditions. Demographical data and brain atrophy were measured as covariates. Subjects were classified into non-severe WML (n = 451, mean age = 73.2 years) and severe WML (n = 109, mean age = 75.9 years) groups. Linear mixed-effects model analysis controlled for covariates showed dual-task-related changes in all harmonic ratios associated with WML (p < 0.05). Even after adjustment for executive function, harmonic ratio in the mediolateral direction was significantly associated with WML (p < 0.05). Our findings revealed that WMLs were associated with trunk stability in dual-task walking. Further studies are required to investigate the neural basis for deficits in gait ability among MCI subjects.

  6. Inhibitory processes relate differently to balance/reaction time dual tasks in young and older adults.

    PubMed

    Mendelson, David N; Redfern, Mark S; Nebes, Robert D; Richard Jennings, J

    2010-01-01

    Inhibitory processes have been suggested to be involved in maintaining balance in older adults, specifically in the integration of sensory information. This study investigated the association between inhibition and the ability to shift attention between auditory and visual modalities during a balance challenge. Young (21-35 years; n = 24) and older (70-85 years; n = 22) healthy subjects completed tasks assessing perceptual inhibition and motor inhibition. Subjects then performed dual-task paradigms pairing auditory and visual choice reaction time tasks with different postural conditions. Sensory channel switch cost was quantified as the difference between visual and auditory reaction times. Results showed that better perceptual and motor inhibition capabilities were associated with less sensory switch cost in the old (perceptual inhibition: r = .51; motor inhibition: r = .48). In the young, neither perceptual nor motor inhibition was associated with sensory switch cost. Inhibitory skills appear particularly important in the elderly for processing events from multiple sensory channels while maintaining balance.

  7. Working memory in nonsymbolic approximate arithmetic processing: a dual-task study with preschoolers.

    PubMed

    Xenidou-Dervou, Iro; van Lieshout, Ernest C D M; van der Schoot, Menno

    2014-01-01

    Preschool children have been proven to possess nonsymbolic approximate arithmetic skills before learning how to manipulate symbolic math and thus before any formal math instruction. It has been assumed that nonsymbolic approximate math tasks necessitate the allocation of Working Memory (WM) resources. WM has been consistently shown to be an important predictor of children's math development and achievement. The aim of our study was to uncover the specific role of WM in nonsymbolic approximate math. For this purpose, we conducted a dual-task study with preschoolers with active phonological, visual, spatial, and central executive interference during the completion of a nonsymbolic approximate addition dot task. With regard to the role of WM, we found a clear performance breakdown in the central executive interference condition. Our findings provide insight into the underlying cognitive processes involved in storing and manipulating nonsymbolic approximate numerosities during early arithmetic. Copyright © 2013 Cognitive Science Society, Inc.

  8. 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

  9. 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.

  10. The cerebellum in dual-task performance in Parkinson’s disease

    PubMed Central

    Gao, Linlin; Zhang, Jiarong; Hou, Yanan; Hallett, Mark; Chan, Piu; Wu, Tao

    2017-01-01

    Parkinson’s disease (PD) patients have difficulty in performing a dual-task. It has been suggested that the cerebellum is important in dual-tasking. We used functional MRI to investigate the role of the cerebellum in performing a dual motor and cognitive task in PD patients. We have examined whether there are any areas additionally activated for dual-task performance, and compared the neural activity and functional connectivity pattern in the cerebellum between PD patients and healthy controls. We found that the right cerebellar vermis and left lobule V of cerebellar anterior lobe were additionally activated for dual-task performance in healthy controls and for motor task in PD patients. We didn’t find any cerebellar regions additionally activated while performing dual-task in PD patients. In addition, the right cerebellar vermis had enhanced connectivity with motor and cognitive associated networks in PD patients. PD patients have limited cerebellar resources that are already utilized for single tasks and, for dual tasks, cannot augment as necessary in order to integrate motor and cognitive networks. PMID:28358358

  11. The Effect of Dual-Task Training on Balance and Cognition in Patients With Subacute Post-Stroke

    PubMed Central

    Choi, Jun Hwan; Han, Eun Young; Kim, Sun Mi

    2015-01-01

    Objective To investigate the effect of dual-task training on the recovery of balance ability and cognitive function in patients with subacute stroke. Methods Twenty patients (12 males and eight females; average age, 59.70 years) with subacute stroke were enrolled in this study. All participants were randomly assigned to one of two groups, the dual-task group (n=10) or the control group (n=10). The dual task was simultaneous balance and cognitive training using the BioRescue. All patients were evaluated with posturographic parameters and the Berg Balance Scale for balance ability, a computerized neuropsychological test and the Korean version of the Mini-Mental State Examination for cognitive function, the Fugl-Meyer Assessment for motor function, and the Korean-Modified Barthel Index for activities of daily living (ADL) function before and after 4 weeks of rehabilitation. Results The dual-task group showed significant improvements in the pressure of the weight distribution index (WDI), surface area, and length of the stability index during the eyes-open condition; surface area of the limit of stability (LOS) on the hemiparetic and intact sides, and the auditory continuous performance test and backward visual span test after rehabilitation. Although no significant difference was observed for the changes in balance ability or cognitive, motor, and ADL functions between the groups, changes in the WDI pressure during the eyes-open condition and in the area ratio of LOS (hemiparetic/intact) showed a tendency to improve in the dual-task group. Conclusion Our findings suggest that dual-task training could be as effective as conventional balance training for improving balance and cognition in subacute post-stroke patients. PMID:25750876

  12. Development of a clinical measure of dual-task performance in walking: reliability and preliminary validity of the Walking and Remembering Test.

    PubMed

    McCulloch, Karen L; Mercer, Vicki; Giuliani, Carol; Marshall, Steve

    2009-01-01

    (1) To examine the reliability of a new clinical measure of simultaneous walking with performance of a working memory task, the Walking and Remembering Test (WART). (2) To compare older adult to younger adult WART performance to illustrate preliminary validity. Convenience sample of 25 young adults (ages 22-35) and 25 older adults (ages 65-86) performed the WART twice. Subjects walked 6.1 meters at their fastest safe speed along a path requiring a narrowed base of support in both single and dual-task (with simultaneous digit span task) conditions. Reductions in walking and cognitive performance were examined in the dual-task condition for older adults as compared to younger adults. Walking time, step accuracy, digit span memory accuracy, and dual-task costs for walking and cognitive tasks. Inter-rater reliability ICC (2,1) values were > or = .97 for walking time and digit span accuracy. Rater agreement of steps off the path was excellent (93%) for young adults and good (76%) for older adults. Test-retest reliability ICC (2,1) values for walking time were > or = .79. Older adults were slower and remembered shorter digit spans, and demonstrated greater dual-task costs for digit span accuracy and steps off the path than younger adults, but relative dual-task costs for walking time were not significantly different between groups. The WART is a reliable clinical measure of dual-task memory and walking that can be administered safely with community-dwelling older adults. Expected greater dual-task costs for older adults were observed, but not as strongly as anticipated in this group of very active subjects. The WART provides information that may be useful in targeting patients for intervention to reduce risk of falls in dual-task conditions, but needs validation with older adults across a greater range of walking ability.

  13. The Effect of Two Different Cognitive Tests on Gait Parameters during Dual Tasks in Healthy Postmenopausal Women

    PubMed Central

    Kałużny, Krystian; Hagner, Wojciech; Kałużna, Anna; Kochański, Bartosz; Borkowska, Alina; Budzyński, Jacek

    2016-01-01

    Introduction. The paper aims to evaluate the influence of two different demanding cognitive tasks on gait parameters using BTS SMART system analysis. Patients and Methods. The study comprised 53 postmenopausal women aged 64.5 ± 6.7 years (range: 47–79). For every subject, gait analysis using a BTS SMART system was performed in a dual-task study design under three conditions: (I) while walking only (single task), (II) walking while performing a simultaneous simple cognitive task (SCT) (dual task), and (III) walking while performing a simultaneous complex cognitive task (CCT) (dual task). Time-space parameters of gait pertaining to the length of a single support phase, double support phase, gait speed, step length, step width, and leg swing speed were analyzed. Results. Performance of cognitive tests during gait resulted in a statistically significant prolongation of the left (by 7%) and right (by 7%) foot gait cycle, shortening of the length of steps made with the right extremity (by 4%), reduction of speed of swings made with the left (by 11%) and right (by 8%) extremity, and reduction in gait speed (by 6%). Conclusions. Performance of cognitive tests during gait changes its individual pattern in relation to the level of the difficulty of the task. PMID:27022602

  14. Impaired dual tasking in Parkinson's disease is associated with reduced focusing of cortico-striatal activity.

    PubMed

    Nieuwhof, Freek; Bloem, Bastiaan R; Reelick, Miriam F; Aarts, Esther; Maidan, Inbal; Mirelman, Anat; Hausdorff, Jeffrey M; Toni, Ivan; Helmich, Rick C

    2017-03-17

    Impaired dual tasking, namely the inability to concurrently perform a cognitive and a motor task (e.g. 'stops walking while talking'), is a largely unexplained and frequent symptom of Parkinson's disease. Here we consider two circuit-level accounts of how striatal dopamine depletion might lead to impaired dual tasking in patients with Parkinson's disease. First, the loss of segregation between striatal territories induced by dopamine depletion may lead to dysfunctional overlaps between the motor and cognitive processes usually implemented in parallel cortico-striatal circuits. Second, the known dorso-posterior to ventro-anterior gradient of dopamine depletion in patients with Parkinson's disease may cause a funnelling of motor and cognitive processes into the relatively spared ventro-anterior putamen, causing a neural bottleneck. Using functional magnetic resonance imaging, we measured brain activity in 19 patients with Parkinson's disease and 26 control subjects during performance of a motor task (auditory-cued ankle movements), a cognitive task (implementing a switch-stay rule), and both tasks simultaneously (dual task). The distribution of task-related activity respected the known segregation between motor and cognitive territories of the putamen in both groups, with motor-related responses in the dorso-posterior putamen and task switch-related responses in the ventro-anterior putamen. During dual task performance, patients made more motor and cognitive errors than control subjects. They recruited a striatal territory (ventro-posterior putamen) not engaged during either the cognitive or the motor task, nor used by controls. Relatively higher ventro-posterior putamen activity in controls was associated with worse dual task performance. These observations suggest that dual task impairments in Parkinson's disease are related to reduced spatial focusing of striatal activity. This pattern of striatal activity may be explained by a loss of functional segregation

  15. 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)…

  16. 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)…

  17. 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 (F1, 36=11.33, p=0.002) and dual-Timed Up-and-Go (F1, 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.

  18. 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).

  19. Recalibration of inhibitory control systems during walking-related dual-task interference: a mobile brain-body imaging (MOBI) study.

    PubMed

    De Sanctis, Pierfilippo; Butler, John S; Malcolm, Brenda R; Foxe, John J

    2014-07-01

    Walking while simultaneously performing cognitively demanding tasks such as talking or texting are typical complex behaviors in our daily routines. Little is known about neural mechanisms underlying cortical resource allocation during such mobile actions, largely due to portability limitations of conventional neuroimaging technologies. We applied an EEG-based Mobile Brain-Body Imaging (MOBI) system that integrates high-density event-related potential (ERP) recordings with simultaneously acquired foot-force sensor data to monitor gait patterns and brain activity. We compared behavioral and ERP measures associated with performing a Go/NoGo response-inhibition task under conditions where participants (N=18) sat in a stationary way, walked deliberately or walked briskly. This allowed for assessment of effects of increasing dual-task load (i.e. walking speed) on neural indices of inhibitory control. Stride time and variability were also measured during inhibitory task performance and compared to stride parameters without task performance, thereby assessing reciprocal dual-task effects on gait parameters. There were no task performance differences between sitting and either walking condition, indicating that participants could perform both tasks simultaneously without suffering dual-task costs. However, participants took longer strides under dual-task load, likely indicating an adaptive mechanism to reduce inter-task competition for cortical resources. We found robust differences in amplitude, latency and topography of ERP components (N2 and P3) associated with inhibitory control between the sitting and walking conditions. Considering that participants showed no dual-task performance costs, we suggest that observed neural alterations under increasing task-load represent adaptive recalibration of the inhibitory network towards a more controlled and effortful processing mode, thereby optimizing performance under dual-task situations.

  20. Recalibration of Inhibitory Control Systems during Walking-Related Dual-Task Interference: A Mobile Brain-Body Imaging (MOBI) Study

    PubMed Central

    De Sanctis, Pierfilippo; Butler, John S.; Malcolm, Brenda; Foxe, John J.

    2014-01-01

    Walking while simultaneously performing cognitively demanding tasks such as talking or texting are typical complex behaviors in our daily routines. Little is known about neural mechanisms underlying cortical resource allocation during such mobile actions, largely due to portability limitations of conventional neuroimaging technologies. We applied an EEG-based Mobile Brain-Body Imaging (MOBI) system that integrates high-density event-related potential (ERP) recordings with simultaneously acquired foot-force sensor data to monitor gait patterns and brain activity. We compared behavioral and ERP measures associated with performing a Go/NoGo response-inhibition task under conditions where participants (N=18) sat stationary, walked deliberately or walked briskly. This allowed for assessment of effects of increasing dual-task load (i.e. walking speed) on neural indices of inhibitory control. Stride time and variability were also measured during inhibitory task performance and compared to stride parameters without task performance, thereby assessing reciprocal dual-task effects on gait parameters. There were no task performance differences between sitting and either walking condition, indicating that participants could perform both tasks simultaneously without suffering dual-task costs. However, participants took longer strides under dual-task load, likely indicating an adaptive mechanism to reduce inter-task competition for cortical resources. We found robust differences in amplitude, latency and topography of ERP components (N2 and P3) associated with inhibitory control between the sitting and walking conditions. Considering that participants showed no dual-task performance costs, we suggest that observed neural alterations under increasing task-load represent adaptive recalibration of the inhibitory network towards a more controlled and effortful processing mode, thereby optimizing performance under dual-task situations. PMID:24642283

  1. 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.

  2. 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.

  3. A dual-task paradigm for behavioral and neurobiological studies in nonhuman primates.

    PubMed

    Watanabe, Kei; Funahashi, Shintaro

    2015-05-15

    The dual-task paradigm is a procedure in which subjects are asked to perform two behavioral tasks concurrently, each of which involves a distinct goal with a unique stimulus-response association. Due to the heavy demand on subject's cognitive abilities, human studies using this paradigm have provided detailed insights regarding how the components of cognitive systems are functionally organized and implemented. Although dual-task paradigms are widely used in human studies, they are seldom used in nonhuman animal studies. We propose a novel dual-task paradigm for monkeys that requires the simultaneous performance of two cognitively demanding component tasks, each of which uses an independent effector for behavioral responses (hand and eyes). We provide a detailed description of an optimal training protocol for this paradigm, which has been lacking in the existing literature. An analysis of behavioral performance showed that the proposed dual-task paradigm (1) was quickly learned by monkeys (less than 40 sessions) with step-by-step training protocols, (2) produced specific behavioral effects, known as dual-task interference in human studies, and (3) achieved rigid and independent control of the effectors for behavioral responses throughout the trial. The proposed dual-task paradigm has a scalable task structure, in that each of the two component tasks can be easily replaced by other tasks, while preserving the overall structure of the paradigm. This paradigm should be useful for investigating executive control that underlies dual-task performance at both the behavioral and neuronal levels. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Dynamic coupling of complex brain networks and dual-task behavior.

    PubMed

    Alavash, Mohsen; Thiel, Christiane M; Gießing, Carsten

    2016-04-01

    Multi-tasking is a familiar situation where behavioral performance is often challenged. To date, fMRI studies investigating the neural underpinning of dual-task interference have mostly relied on local brain activation maps or static brain connectivity networks. Here, based on task fMRI we explored how fluctuations in behavior during concurrent performance of a visuospatial and a speech task relate to alternations in the topology of dynamic brain connectivity networks. We combined a time-resolved functional connectivity and complex network analysis with a sliding window approach applied to the trial by trial behavioral responses to investigate the coupling between dynamic brain networks and dual-task behavior at close temporal proximity. Participants showed fluctuations in their dual-task behavior over time, with the accuracy in the component tasks being statistically independent from one another. On the global level of brain networks we found that dynamic changes of network topology were differentially coupled with the behavior in each component task during the course of dual-tasking. While momentary decrease in the global efficiency of dynamic brain networks correlated with subsequent increase in visuospatial accuracy, better speech performance was preceded by higher global network efficiency and was followed by an increase in between-module connectivity over time. Additionally, dynamic alternations in the modular organization of brain networks at the posterior cingulate cortex were differentially predictive for the visuospatial as compared to the speech accuracy over time. Our results provide the first evidence that, during the course of dual-tasking, each component task is supported by a distinct topological configuration of brain connectivity networks. This finding suggests that the failure of functional brain connectivity networks to adapt to an optimal topology supporting the performance in both component tasks at the same time contributes to the moment to

  5. Influence of dual-task on sit-to-stand-to-sit postural control in Parkinson's disease.

    PubMed

    Fernandes, Ângela; Sousa, Andreia S P; Couras, Joana; Rocha, Nuno; Tavares, João Manuel R S

    2015-11-01

    Postural control deficits are the most disabling aspects of Parkinson's disease (PD), resulting in decreased mobility and functional independence. The aim of this study was to assess the postural control stability, revealed by variables based on the centre of pressure (CoP), in individuals with PD while performing a sit-to-stand-to-sit sequence under single- and dual-task conditions. An observational, analytical and cross-sectional study was performed. The sample consisted of 9 individuals with PD and 9 healthy controls. A force platform was used to measure the CoP displacement and velocity during the sit-to-stand-to-sit sequence. The results were statistically analysed. Individuals with PD required greater durations for the sit-to-stand-to-sit sequence than the controls (p < 0.05). The anteroposterior and mediolateral CoP displacement were higher in the individuals with PD (p < 0.05). However, only the anteroposterior CoP velocity in the stand-to-sit phase (p = 0.006) was lower in the same individuals. Comparing the single- and dual-task conditions in both groups, the duration, the anteroposterior CoP displacement and velocity were higher in the dual-task condition (p < 0.05). The individuals with PD presented reduced postural control stability during the sit-to-stand-to-sit sequence, especially when under the dual-task condition. These individuals have deficits not only in motor performance, but also in cognitive performance when performing the sit-to-stand-to-sit sequence in their daily life tasks. Moreover, both deficits tend to be intensified when two tasks are performed simultaneously.

  6. 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

    2017-03-02

    This review examines the effect of a dual-task on the gait parameters of older adults with a mean gait speed of 1.0m/s or greater, and the effect of type and complexity of task. A systematic review of Web of Science, PubMed, SCOPUS, Embase and psychINFO was performed in July 2016. Twenty-three studies (twenty-eight 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.

  7. Task-oriented dual-arm manipulability and its application to configuration optimization

    NASA Technical Reports Server (NTRS)

    Lee, Sukhan; Lee, Jang M.

    1988-01-01

    A measure of static manipulability is derived for a dual-redundant-arm (DRA) system engaged in cooperative task execution. Considering the kinematic interaction between the two cooperating arms, the dual-arm (DA) manipulability is defined as the intersection between the two manipulability ellipsoids from individual arms. A task-oriented DA manipulability measure is defined as the measure of geometrical similarity between the desired and the actual DA manipulability ellipsoids at the selected task points. Mathematical formulas are developed to define task-oriented DRA static manipulability, and their application to the optimization of DRA joint and grasp configurations is demonstrated.

  8. A demonstration of dual-task performance without interference in some older adults.

    PubMed

    Hartley, Alan A; Maquestiaux, François; Butts, Nicole Silverman

    2011-03-01

    Highly efficient dual-task processing is demonstrated when reaction time to each of two tasks does not differ between the dual-task situation and the single-task situation. This has been demonstrated reliably in younger adults; nevertheless, the two extant studies of extensive dual-task training did not find evidence for it in any elderly adult. The origins of age-related differences after training were explored in a study in which the stimuli for the two tasks were perfectly redundant although two distinct responses were required. The dual-task situation thus greatly reduced the demands of stimulus categorization while still requiring two response selections and two response executions. After only limited training 8 of 8 younger adults and 5 of 8 older adults showed performance consistent with highly efficient processing. Three older adults failed to show this even after 12 training sessions. The results implicate stimulus categorization more than response selection as an important locus of inefficient dual-task processing, particularly for older adults. (c) 2011 APA, all rights reserved.

  9. Dual task performance after focal cerebral lesions and closed head injuries.

    PubMed

    Vilkki, J; Virtanen, S; Surma-Aho, O; Servo, A

    1996-11-01

    The aim of this study was to demonstrate that focal frontal lobe lesions and closed head injuries cause a deficit in the deliberate minimizing of dual task decrements that follow when two separate tasks should be done concurrently. In single tasks, subjects counted backwards and cancelled visual targets as quickly and accurately as possible on separate 1 min trials. In the dual task, they were required to do both tasks simultaneously, taking care that performance on neither task would be notably more impaired than on the other, as only the performance showing a larger percentage decrement from the corresponding single task performance was taken into account as the result of the test. Patients with acute closed head injury displayed more pronounced dual task decrement than the controls. This deficit was not secondary to inefficiency on the single tasks but was related to the depth of coma at admission, the acuteness of injury and age. Contrary to expectation, patients with focal frontal lobe lesions or patients with subacute closed head injury did not demonstrate abnormal dual task decrement.

  10. The Assessment of Military Multitasking Performance: Validation of a Dual-Task and Multitask Protocol

    DTIC Science & Technology

    2014-08-01

    1 AD_________________ Award Number: Contract W81XWH-12-2-0070 TITLE: Annual Report: The Assessment of Military Multitasking ...Performance: Validation of a Dual-Task and Multitask Protocol (Contract W81XWH-12-2-0070) PRINCIPAL INVESTIGATOR: Margaret M. Weightman PT...Assessment of Military Multitasking Performance: Validation of a Dual-Task and Multitask Protocol 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  11. Parkinson's Disease and Cognitive-Motor Dual-Task: Is Motor Prioritization Possible in the Early Stages of the Disease?

    PubMed

    Fernandes, Ângela; Sousa, Andreia S P; Rocha, Nuno; Tavares, João Manuel R S

    2016-01-01

    The authors aimed to compare the postural phase of gait initiation under single-task (gait initiation) and dual-task (gait initiation plus Stroop test) conditions in healthy subjects and in subjects with Parkinson's disease (PD) in the early stages (Hoehn and Yahr scale < 3). The postural phase of gait initiation was assessed through the centre of pressure in single and dual task in 10 healthy subjects and 9 with PD. The analysis indicated that in the early stages of PD, an additional cognitive task did not affect the displacement of the gait initiation. No significant effects occurred between the groups and within-subjects (p > .05). Also, no interaction was found between the groups and the conditions (single- and dual-task). Differences were found in the duration of the mediolateral postural phase (p = .003), which was higher in PD subjects than in healthy subjects. The findings suggest that subjects in the early stages of PD prioritize gait initiation, as their motor performance was similar to that of healthy subjects.

  12. Test-Retest Reliability of Individual Differences in Dual-Task Performance.

    DTIC Science & Technology

    1978-07-01

    separate and combined performances of a one-dimensional tracking and a digit - processing, reaction-time task. FINDINGS The data from this study indicate...represented by tracking and digit processing. Furthermore, separate K task performances were generally unrelated to the subsequent decrement scores in dual...discrete, digit -processing, reaction-time task. Furthermore, there were low and nonreliable correlations between single-task performances, and generally low

  13. The immediate effect of attentional, auditory, and a combined cue strategy on gait during single and dual tasks in Parkinson's disease.

    PubMed

    Baker, Katherine; Rochester, Lynn; Nieuwboer, Alice

    2007-12-01

    To compare the effect of rhythmic auditory and attentional cues, and a combination of both cues on gait, in people with Parkinson's disease (PD) during single and dual tasks. A repeated-measures study requiring participants to perform single and dual-motor tasks under different cueing conditions. Human movement analysis laboratory. Fifteen participants with idiopathic PD and a comparison group of 12 healthy participants. Three cueing strategies were compared: a rhythmic auditory cue (walking in time to a metronome beat), an attentional strategy (asked to focus on taking big step), and a combination cue (asked to walk in time to a metronome beat while taking big steps). Walking speed, step amplitude, and step frequency. Walking speed of PD participants improved significantly compared with noncued walking in the single- and dual-task condition with the attentional (P<.001, P=.037) and combination cue strategies (P=.013, P=.028). Step amplitude also increased significantly with the attentional and combination cue strategies in single- (P<.001, P<.001) and dual-task (P<.001, P<.001) conditions. Step frequency was reduced significantly with the attentional strategy (P=.042) in the single and dual tasks (P<.001) and combination cue strategy (P=.009) in the dual task. The rhythmic auditory cue alone did not alter significantly any parameter of gait in the single or dual tasks. The attentional strategy and the combination of a rhythmic auditory cue with an attentional strategy were equally effective, and improved walking speed and step amplitude significantly during both single and dual tasks. The combination cue, however, may still be a useful alternative in situations of increased attentional demand, or where problems exist with executive function.

  14. 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.

  15. Visual Scanning Training for Neglect after Stroke with and without a Computerized Lane Tracking Dual Task

    PubMed Central

    van Kessel, M. E.; Geurts, A. C. H.; Brouwer, W. H.; Fasotti, L.

    2013-01-01

    Neglect patients typically fail to explore the contralesional half-space. During visual scanning training, these patients learn to consciously pay attention to contralesional target stimuli. It has been suggested that combining scanning training with methods addressing non-spatial attention might enhance training results. In the present study, a dual task training component was added to a visual scanning training (i.e., Training di Scanning Visuospaziale – TSVS; Pizzamiglio et al., 1990). Twenty-nine subacute right hemisphere stroke patients were semi-randomly assigned to an experimental (N = 14) or a control group (N = 15). Patients received 30 training sessions during 6 weeks. TSVS consisted of four standardized tasks (digit detection, reading/copying, copying drawings, and figure description). Moreover, a driving simulator task was integrated in the training procedure. Control patients practiced a single lane tracking task for 2 days a week during 6 weeks. The experimental group was administered the same training schedule, but in weeks 4–6 of the training, the TSVS digit detection task was combined with lane tracking on the same projection screen, so as to create a dual task (computerized visual reaction time task designed for training). Various neglect tests and driving simulator tasks were administered before and after training. No significant group and interaction effects were found that might reflect additional positive effects of dual task training. Significant improvements after training were observed in both groups taken together on most assessment tasks. Ameliorations were generally not correlated to post-onset time, but spontaneous recovery, test–retest variability, and learning effects could not be ruled out completely, since these were not controlled for. Future research might focus on increasing the amount of dual task training, the implementation of progressive difficulty levels in driving simulator tasks, and further exploration

  16. Visual Scanning Training for Neglect after Stroke with and without a Computerized Lane Tracking Dual Task.

    PubMed

    van Kessel, M E; Geurts, A C H; Brouwer, W H; Fasotti, L

    2013-01-01

    Neglect patients typically fail to explore the contralesional half-space. During visual scanning training, these patients learn to consciously pay attention to contralesional target stimuli. It has been suggested that combining scanning training with methods addressing non-spatial attention might enhance training results. In the present study, a dual task training component was added to a visual scanning training (i.e., Training di Scanning Visuospaziale - TSVS; Pizzamiglio et al., 1990). Twenty-nine subacute right hemisphere stroke patients were semi-randomly assigned to an experimental (N = 14) or a control group (N = 15). Patients received 30 training sessions during 6 weeks. TSVS consisted of four standardized tasks (digit detection, reading/copying, copying drawings, and figure description). Moreover, a driving simulator task was integrated in the training procedure. Control patients practiced a single lane tracking task for 2 days a week during 6 weeks. The experimental group was administered the same training schedule, but in weeks 4-6 of the training, the TSVS digit detection task was combined with lane tracking on the same projection screen, so as to create a dual task (computerized visual reaction time task designed for training). Various neglect tests and driving simulator tasks were administered before and after training. No significant group and interaction effects were found that might reflect additional positive effects of dual task training. Significant improvements after training were observed in both groups taken together on most assessment tasks. Ameliorations were generally not correlated to post-onset time, but spontaneous recovery, test-retest variability, and learning effects could not be ruled out completely, since these were not controlled for. Future research might focus on increasing the amount of dual task training, the implementation of progressive difficulty levels in driving simulator tasks, and further exploration of

  17. Analysis of dual-task elderly gait in fallers and non-fallers using wearable sensors.

    PubMed

    Howcroft, Jennifer; Kofman, Jonathan; Lemaire, Edward D; McIlroy, William E

    2016-05-03

    Dual-task (DT) gait involves walking while simultaneously performing an attention-demanding task and can be used to identify impaired gait or executive function in older adults. Advancment is needed in techniques that quantify the influence of dual tasking to improve predictive and diagnostic potential. This study investigated the viability of wearable sensor measures to identify DT gait changes in older adults and distinguish between elderly fallers and non-fallers. A convenience sample of 100 older individuals (75.5±6.7 years; 76 non-fallers, 24 fallers based on 6 month retrospective fall occurrence) walked 7.62m under single-task (ST) and DT conditions while wearing pressure-sensing insoles and tri-axial accelerometers at the head, pelvis, and left and right shanks. Differences between ST and DT gait were identified for temporal measures, acceleration descriptive statistics, Fast Fourier Transform (FFT) quartiles, ratio of even to odd harmonics, center of pressure (CoP) stance path coefficient of variation, and deviations to expected CoP stance path. Increased posterior CoP stance path deviations, increased coefficient of variation, decreased FFT quartiles, and decreased ratio of even to odd harmonics suggested increased DT gait variability. Decreased gait velocity and decreased acceleration standard deviations (SD) at the pelvis and shanks could represent compensatory gait strategies that maintain stability. Differences in acceleration between fallers and non-fallers in head posterior SD and pelvis AP ratio of even to odd harmonics during ST, and pelvis vertical maximum Lyapunov exponent during DT gait were identified. Wearable-sensor-based DT gait assessments could be used in point-of-care environments to identify gait deficits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Novel challenges to gait in Parkinson's disease: the effect of concurrent music in single- and dual-task contexts.

    PubMed

    Brown, Lesley A; de Bruin, Natalie; Doan, Jon B; Suchowersky, Oksana; Hu, Bin

    2009-09-01

    To investigate the effect of concurrent music on parkinsonian gait in single- and dual-task contexts. A counterbalanced repeated-measure design. A university balance research laboratory. People with idiopathic Parkinson's disease (PD) (n=10) (67+/-7 y) and healthy age-matched (65+/-6 y) control subjects (n=10). Subjects walked at a self-selected pace along an unobstructed walkway in 4 differing test conditions. Test conditions were differentiated by the presence of music accompaniment (no music/music) and the presence of a secondary cognitive task (single/dual). Single- and dual-task conditions were randomized; trials were blocked by the presence of music and counterbalanced between subjects. Music was self-selected by subjects. The cognitive task consisted of serial subtractions (3's). Subjects were not instructed to attend to the music nor were they provided with instructions regarding task prioritization. Mean gait velocity, stride length, and the percentage of the gait cycle spent in double-limb support. Gait among the PD patients was adversely affected by concurrent music. In contrast, gait performance in the control subjects showed no significant difference between no music and music conditions. The added requirement of a cognitive task differentially influenced gait performance in PD patients and control subjects, with PD patients displaying a further decrease in spatiotemporal parameters of gait and control subjects displaying a marginal improvement. Gait impairments associated with PD are exacerbated in the presence of concurrent music, an effect that is further exaggerated by the addition of a cognitive task. These results have implications for patient safety in multitasking situations.

  19. Dual task interference during gait in patients with unilateral vestibular disorders

    PubMed Central

    2010-01-01

    Background Vestibular patients show slower and unsteady gait; they have also been shown to need greater cognitive resources when carrying out balance and cognitive dual tasks (DT). This study investigated DT interference during gait in a middle-aged group of subjects with dizziness and unsteadiness after unilateral vestibular neuronitis and in a healthy control group. Methods Fourteen individuals with subacute unilateral vestibular impairment after neuronitis and seventeen healthy subjects performed gait and cognitive tasks in single and DT conditions. A statistical gait analysis system was used and spatio-temporal parameters were considered. The cognitive task, consisting of backward counting by three, was tape recorded and the number of right figures was then calculated. Results Both patients and controls showed a more conservative gait during DT and between groups significant differences were not found. A significant decrease in cognitive performance during DT was found only in the vestibular group. Conclusions Results suggest that less attentional resources are available during gait in vestibular patients compared to controls, and that a priority is given in keeping up the motor task to the detriment of a decrease of the cognitive performance during DT. PMID:20854671

  20. 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.

  1. Relationship between balance and dual task walking in the very elderly.

    PubMed

    Ansai, Juliana Hotta; Aurichio, Thais Rabiatti; Rebelatto, José Rubens

    2016-01-01

    To investigate the relationship between balance and dual task performance in adults aged over 80 years, and to analyze possible differences between fallers and non-fallers in dual task performance. An observational cross-sectional study was carried out at the Federal University of São Carlos (Brazil). We assessed 67 community-dwelling older adults aged over 80 years who were able to walk. The volunteers were divided into groups of fallers and non-fallers. The one-leg standing and tandem tests were used to assess balance. Dual task was assessed by the Timed Up and Go test, associated with a motor task (TUGT-motor) and a cognitive task (TUGT-cognitive). Statistical analyses were carried out, and the significance level was set at α = 5%. Significant correlations were found between balance and dual task variables. Fallers took significantly more time and steps on both the TUGT-motor and the TUGT-cognitive, with no significant differences on balance tests between groups. Recognizing the influence of dual task walking on balance and fall risk could help health professionals to prevent falls in older adults, as well as optimize assessment and intervention planning. © 2015 Japan Geriatrics Society.

  2. Share or compete? Load-dependent recruitment of prefrontal cortex during dual-task performance

    PubMed Central

    Low, Kathy A.; Leaver, Echo E.; Kramer, Arthur F.; Fabiani, Monica; Gratton, Gabriele

    2009-01-01

    Dual-task performance requires flexible attention allocation to two or more streams of information. Dorsolateral prefrontal cortex (DLPFC) is considered important for executive function and recent modeling work proposes that attention control may arise from selective activation and inhibition of different processing units within this region. Here we used a tone discrimination task and a visual letter memory task to examine whether this type of competition could be measurable using a neuroimaging technique, the event-related optical signal, with high spatial and temporal resolution. Left and right DLPFC structures were differentially affected by task priority and load, with the left middle frontal gyrus (MFG) being preferentially recruited by the visual memory task, whereas the two tasks competed for recruitment, in a spatially segregated manner, in right MFG. The data provide support for a competition view of dual-task processing. PMID:19572909

  3. 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…

  4. 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…

  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. 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.

  7. Dual-Task Interference during Initial Learning of a New Motor Task Results from Competition for the Same Brain Areas

    ERIC Educational Resources Information Center

    Remy, Florence; Wenderoth, Nicole; Lipkens, Karen; Swinnen, Stephan P.

    2010-01-01

    Cerebral patterns of activity elicited by dual-task performance throughout the learning of a complex bimanual coordination pattern were addressed. Subjects (N = 12) were trained on the coordination pattern and scanned using fMRI at early (PRE) and late (POST) learning stages. During scanning, the coordination pattern was performed either as a…

  8. Dual-Task Interference during Initial Learning of a New Motor Task Results from Competition for the Same Brain Areas

    ERIC Educational Resources Information Center

    Remy, Florence; Wenderoth, Nicole; Lipkens, Karen; Swinnen, Stephan P.

    2010-01-01

    Cerebral patterns of activity elicited by dual-task performance throughout the learning of a complex bimanual coordination pattern were addressed. Subjects (N = 12) were trained on the coordination pattern and scanned using fMRI at early (PRE) and late (POST) learning stages. During scanning, the coordination pattern was performed either as a…

  9. Age-related differences in performance and stimulus processing in dual task situation.

    PubMed

    Hahn, Melanie; Wild-Wall, Nele; Falkenstein, Michael

    2011-09-26

    Competition for limited processing resources is most critical in dual-tasks which incorporate cognitive and motor demands. Performance is usually diminished with increasing age in such tasks. This decline is relevant for activities in real life like driving. In the present study we aim to examine if there are age-related differences in stimulus processing in a dual-task and if these differences have an impact on performance of a driving-like tracking task. Young and older participants performed a dual-task consisting of a tracking task and a visual attention task. Alongside, the EEG was recorded for calculating the P300 (P3) of the event-related potential as a reflection of controlled stimulus processing. In the visual attention task older vs. young participants showed more misses and false alarms. For young participants the P3 shows an expected pattern of higher amplitudes for relevant compared to irrelevant stimuli. This was not found for the older participants. A general age-related decline in tracking performance was relatively more pronounced if a secondary motor response was required in the visual attention task and also after irrelevant stimuli. The results suggest that older compared to young participants had greater difficulties to differentiate between relevant and irrelevant stimuli in a dual-task situation as they probably apply comparable attentional resources to all stimuli. This may also explain the higher error rates. These results have important implications for the understanding of age-related stimulus processing in dual and multi task situations in real life as for instance driving.

  10. 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

  11. Childcare Task Division and Shared Parenting Attitudes in Dual-Earner Families with Young Children.

    ERIC Educational Resources Information Center

    Ehrenberg, Marion F.; Gearing-Small, Margaret; Hunter, Michael A.; Small, Brent J.

    2001-01-01

    Evaluates shared parenting (SP), marital satisfaction, and division of child-care tasks in dual-earner families (N=116). Results show that psychological and relational SP dimensions predicted marital satisfaction, parental competence, and closeness to their children, but division of child-care tasks did not. Findings are interpreted to highlight…

  12. 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…

  13. 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…

  14. 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…

  15. 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.

  16. 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…

  17. Free-Throw Shooting during Dual-Task Performance: Implications for Attentional Demand and Performance

    ERIC Educational Resources Information Center

    Price, Jayme; Gill, Diane L.; Etnier, Jennifer; Kornatz, Kurt

    2009-01-01

    In this study, the dual-task paradigm was used to determine peak attentional demand during the free-throw process. Thirty participants completed 40 free-throw trials. The free throw was the primary task, but participants also verbally responded to a tone administered at one of four probe positions (PP). Repeated measures analysis of variance…

  18. Preparing coordinated eye and hand movements: dual-task costs are not attentional.

    PubMed

    Jonikaitis, Donatas; Schubert, Torsten; Deubel, Heiner

    2010-12-20

    Dual-task costs are observed when people perform two tasks at the same time. It has been suggested that these costs arise from limitations of movement goal selection when multiple goal-directed movements are made simultaneously. To investigate this, we asked participants to reach and look at different locations while we varied the time between the cues to start the eye and the hand movement between 150 ms and 900 ms. In Experiment 1, participants executed the reach first, and the saccade second, in Experiment 2 the order of the movements was reversed. We observed dual-task costs-participants were slower to start the eye or hand movement if they were planning another movement at that time. In Experiment 3, we investigated whether these dual-task costs were due to limited attentional resources needed to select saccade and reach goal locations. We found that the discrimination of a probe improved at both saccade and reach locations, indicating that attention shifted to both movement goals. Importantly, while we again observed the expected dual-task costs as reflected in movement latencies, there was no apparent delay of the associated attention shifts. Our results rule out attentional goal selection as the causal factor leading to the dual-task costs occurring in eye-hand movements.

  19. A new quantitative method for evaluating freezing of gait and dual-attention task deficits in Parkinson's disease.

    PubMed

    Chomiak, Taylor; Pereira, Fernando Vieira; Meyer, Nicole; de Bruin, Natalie; Derwent, Lorelei; Luan, Kailie; Cihal, Alexandra; Brown, Lesley A; Hu, Bin

    2015-11-01

    People with Parkinson's disease (PD) can exhibit disabling gait symptoms such as freezing of gait especially when distracted by a secondary task. Quantitative measurement method of this type of cognitive-motor abnormality, however, remains poorly developed. Here we examined whether stepping-in-place (SIP) with a concurrent mental task (e.g., subtraction) can be used as a simple method for evaluating cognitive-motor deficits in PD. We used a 4th generation iPod Touch sensor system to capture hip flexion data and obtain step height (SH) measurements (z axis). The accuracy of the method was compared to and validated by kinematic video analysis software. We found a general trend of reduced SH for PD subjects relative to controls under all conditions. However, the SH of PD freezers was significantly worse than PD non-freezers and controls during concurrent serial 7 subtraction and SIP tasking. During serial 7 subtraction, SH was significantly associated with whether or not a PD patient was a self-reported freezer even when controlling for disease severity. Given that this SIP-based dual-task paradigm is not limited by space requirements and can be quantified using a mobile tracking device that delivers specifically designed auditory task instructions, the method reported here may be used to standardize clinical assessment of cognitive-motor deficits under a variety of dual-task conditions in PD.

  20. Capacity limitations of a classic M-power measure: a modified dual-task approach.

    PubMed

    Foley, E J; Berch, D B

    1997-08-01

    A modified dual-task approach was employed with 7- to 9-year-olds in an effort to determine whether one of the classic M-power measures, the digit placement task, is indeed capacity-limited. To this end, a computerized version of a three-item digit placement task was administered in addition to three other computerized tasks: a four-item digit placement task, simple reaction time (RT) to a tone presented alone, and reaction time to a tone occurring during the performance of another three-item digit placement task. Careful examination of the data revealed that several critical assumptions concerning the use of the dual-task procedure were successfully met. This permitted a test of the extent to which dual-task RTs were predictive of accuracy in the harder, four-item digit placement task. Not only was this relationship significant, but after partialling out other possible sources of variance, a significant correlation remained, indicating that the digit placement task is indeed capacity-limited.

  1. Dual-task performance in dysexecutive and nondysexecutive patients with a frontal lesion.

    PubMed

    Baddeley, A; Della Sala, S; Papagno, C; Spinnler, H

    1997-04-01

    Patients with defined frontal lobe lesions were assigned to 1 of 2 groups based on whether they showed a behaviorally assessed dysexecutive syndrome or were behaviorally normal. All participants were tested on dual-task performance and on 2 tasks assumed to measure frontal lobe function, the Wisconsin Card Sorting Test and verbal fluency. The dysexecutive group differed significantly from the nondysexecutive in showing impaired capacity for dual-task coordination, but there were no significant differences on the Wisconsin Card Sorting Test and verbal fluency. Results are interpreted in terms of a multicomponent central executive, whose function is linked to, but not coterminous with, the operation of the frontal lobes.

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

    PubMed Central

    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. PMID:26903862

  3. Deficits in interval timing measured by the dual-task paradigm among children and adolescents with attention-deficit/hyperactivity disorder.

    PubMed

    Hwang, Shoou-Lian; Gau, Susan Shur-Fen; Hsu, Wen-Yau; Wu, Yu-Yu

    2010-03-01

    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. Participants included 168 children and adolescents with DSM-IV ADHD and 90 control children and adolescents without ADHD, aged 10 to 17 years, in Taipei. The DSM-IV diagnoses of ADHD and other psychiatric comorbid conditions were made by clinical assessments and confirmed by the psychiatric interviews of both parents and participants using the Chinese Kiddie Epidemiologic version of the Schedule for Affective Disorders and Schizophrenia. The participants were also assessed by using the Wechsler Intelligence Scale for Children-3(rd) edition (WISC-III), and time reproduction tasks (the single task and the simple and difficult versions of the dual tasks) at 5-second, 12-second, and 17-second intervals. The linear mixed model was used for data analysis. Children and adolescents with ADHD had less precise time reproduction than the controls in all three tasks except the 5-second interval of the single task. There were significant interactions between group and interval (12-second vs. 5-second, p = .030; 17-second vs. 5-second, p < .001), and between group and task (simple dual task vs. single task, p = .016; difficult dual task vs. single task, p < .001) after controlling for FSIQ, comorbidity, sex, age, use of methylphenidate, and the performance of the non-temporal tasks in dual tasks, if relevant. Significantly increased estimation errors in ADHD with increased task difficulties suggest that impaired timing processing in children and adolescents with ADHD during long time intervals may be accounted for by the limited attentional capacity rather than a primary problem in timing per se. This finding does not apply to rapid time intervals, in which cerebellar

  4. Dual Tasking for the Differentiation between Depression and Mild Cognitive Impairment

    PubMed Central

    Metzger, Florian G.; Hobert, Markus A.; Ehlis, Ann-Christine; Hasmann, Sandra E.; Hahn, Tim; Eschweiler, Gerhard W.; Berg, Daniela; Fallgatter, Andreas J.; Maetzler, Walter

    2016-01-01

    Differentiation of mild cognitive impairment from depression in elderly adults is a clinically relevant issue which is not sufficiently solved. Gait and dual task (DT) parameters may have the potential to complement current diagnostic work-up, as both dementia and depression are associated with changes of gait and DT parameters. Methods: Seven hundred and four participants of the TREND study (Tübinger evaluation of Risk factors for Early detection of NeuroDegeneration) aged 50–80 years were assessed using the Consortium to Establish a Registry for Alzheimer's Disease Plus test battery for testing cognition and Beck's Depression Inventory for evaluation of depression. Based on these results, four groups were defined: acute depressed (N = 53), cognitively mildly impaired (N = 97), acute depressed, and cognitively mildly impaired (N = 15), and controls (N = 536). Participants underwent a 20 m walk and checking boxes task under single (ST) and DT conditions. ST and DT performance and dual task costs (DTC) were calculated. Due to the typical age of increasing incidence of depressive and also cognitive symptoms, the 7th decade was calculated separately. Results: ST speeds of gait and checking boxes, DT walking speed, and walking DTC were significantly different between groups. Healthy controls were the fastest in all paradigms and cognitively mildly impaired had higher DTC than depressed individuals. Additionally, we constructed a multivariate predictive model differentiating the groups on a single-subject level. Conclusion: DT parameters are simply and comfortably measureable, and DTC can easily be determined. The combination of these parameters allows a differentiation of depressed and cognitively mildly impaired elderly adults. PMID:27790136

  5. Postural Control in Dual-Task Situations: Does Whole-Body Fatigue Matter?

    PubMed Central

    Beurskens, Rainer; Haeger, Matthias; Kliegl, Reinhold; Roecker, Kai; Granacher, Urs

    2016-01-01

    Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single- (ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 ± 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2–21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9–2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3–4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9–3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment. PMID:26796320

  6. A Task that Elicits Reasoning: A Dual Analysis

    ERIC Educational Resources Information Center

    Yankelewitz, Dina; Mueller, Mary; Maher, Carolyn A.

    2010-01-01

    This paper reports on the forms of reasoning elicited as fourth grade students in a suburban district and sixth grade students in an urban district worked on similar tasks involving reasoning with the use of Cuisenaire rods. Analysis of the two data sets shows similarities in the reasoning used by both groups of students on specific tasks, and the…

  7. A Task that Elicits Reasoning: A Dual Analysis

    ERIC Educational Resources Information Center

    Yankelewitz, Dina; Mueller, Mary; Maher, Carolyn A.

    2010-01-01

    This paper reports on the forms of reasoning elicited as fourth grade students in a suburban district and sixth grade students in an urban district worked on similar tasks involving reasoning with the use of Cuisenaire rods. Analysis of the two data sets shows similarities in the reasoning used by both groups of students on specific tasks, and the…

  8. Step initiation interferes with working memory in nondisabled patients with the earliest multiple sclerosis-A dual-task study.

    PubMed

    Brecl Jakob, G; Remšak, T; Šega Jazbec, S; Horvat Ledinek, A; Rot, U

    2017-01-01

    Balance and cognition are affected by multiple sclerosis (MS). Cognitive-motor interference (CMI) is important for balance impairment in MS, however little is known about CMI at the earliest stages of the disease. Step initiation (SI) with anticipatory postural adjustments (APAs) has been linked to postural instability and falls in subjects with MS, therefore we aimed to assess CMI between SI and the two storage systems of working memory in patients with clinically isolated syndrome (presented as optic neuritis-ON) suggestive of MS. Twenty patients with normal/near normal visual acuity and 20 age-, weight-, height-, sex- and education-matched control subjects were included. APAs were studied using center of pressure measures in three conditions: SI alone, SI+Brooks' spatial- and SI+2-back verbal working memory task. Decrements (% change) in performance on cognitive tasks and in APA parameters were calculated. CMI was assessed combining the two decrements scores. Performance on both cognitive tasks was more affected by dual-tasking in patients compared to healthy subjects. In both groups APA parameters were not influenced by dual-tasking. CMI was higher in patients compared to healthy subjects. Our results suggest that the disease affects CMI in its earliest stages. Since both cognitive tasks were similarly affected by dual-tasking in patients and controls central executive seems to play the major role in CMI between SI and working memory. Patients prioritizing motor over cognitive task for balance maintenance suggests reduced divided attention capacity as a cause of increased CMI in the earliest MS.

  9. A novel eye-tracking method to assess attention allocation in individuals with and without aphasia using a dual-task paradigm.

    PubMed

    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. Readers will be able to: (1) summarize the nature of dual-task paradigms, (2) identify shortcomings of existing dual-task measures of attention allocation for application to people with aphasia, (3) describe how eye-tracking measures may be recorded and analyzed to reflect differences in attention allocation across conditions, and (4) summarize potential clinical applications for eye-tracking measures of attention allocation. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. 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.

  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. 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.

  13. NEQ and task in dual-energy imaging: from cascaded systems analysis to human observer performance

    NASA Astrophysics Data System (ADS)

    Richard, Samuel; Siewerdsen, Jeffrey H.; Tward, Daniel J.

    2008-03-01

    The relationship between theoretical descriptions of imaging performance (Fourier-based cascaded systems analysis) and the performance of real human observers was investigated for various detection and discrimination tasks. Dual-energy (DE) imaging provided a useful basis for investigating this relationship, because it presents a host of acquisition and processing parameters that can significantly affect signal and noise transfer characteristics and, correspondingly, human observer performance. The detectability index was computed theoretically using: 1) cascaded systems analysis of the modulation transfer function (MTF), and noise-power spectrum (NPS) for DE imaging; 2) a Fourier description of imaging task; and 3.) integration of MTF, NPS, and task function according to various observer models, including Fisher-Hotelling and non-prewhitening with and without an eye filter and internal noise. Three idealized tasks were considered: sphere detection, shape discrimination (sphere vs. disk), and texture discrimination (uniform vs. textured disk). Using images of phantoms acquired on a prototype DE imaging system, human observer performance was assessed in multiple-alternative forced choice (MAFC) tests, giving an estimate of area under the ROC curve (A Ζ). The degree to which the theoretical detectability index correlated with human observer performance was investigated, and results agreed well over a broad range of imaging conditions, depending on the choice of observer model. Results demonstrated that optimal DE image acquisition and decomposition parameters depend significantly on the imaging task. These studies provide important initial validation that the detectability index derived theoretically by Fourier-based cascaded systems analysis correlates well with actual human observer performance and represents a meaningful metric for system optimization.

  14. Corticospinal activity during dual tasking: a systematic review and meta-analysis of TMS literature from 1995 to 2013.

    PubMed

    Corp, Daniel T; Lum, Jarrad A G; Tooley, Gregory A; Pearce, Alan J

    2014-06-01

    This systematic review and meta-analysis was conducted across studies using transcranial magnetic stimulation to investigate corticospinal excitability and inhibition in response to a dual task (DT). Quantitative analysis was performed on eleven controlled studies that had included healthy participants over the age of 18 years. Results showed a small effect size for increased corticospinal excitability for DT conditions (SMD=0.207; p=.217, and a small effect size (SMD=-0.253) demonstrating a significant decrease in corticospinal inhibition for DT conditions (p=.019). Meta-regression demonstrated that neither age, task type, or task prioritisation accounted for the high variability in effect sizes between studies. A number of possible sources of within study bias are identified, which reduced the level of evidence for study findings. The results show overall changes in corticospinal responses between ST and DT conditions; however further research is necessary to investigate variables that could account for differences in corticospinal responses between studies.

  15. 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

  16. 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.

  17. 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

  18. 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)…

  19. 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)…

  20. 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

  1. The impact of free-order and sequential-order instructions on task-order regulation in dual tasks.

    PubMed

    Kübler, Sebastian; Reimer, Christina B; Strobach, Tilo; Schubert, Torsten

    2017-08-30

    Dual tasks (DTs) are characterized by the requirement for additional mechanisms that coordinate the processing order of two temporally overlapping tasks. These mechanisms are indicated by two types of costs that occur when comparing DT blocks with fixed and random orders of the component tasks. On a block level, task-order control costs are reflected in increased reaction times (RTs) in random-order compared to fixed-order blocks, indicating global, monitoring-based, coordination mechanisms. On a trial level, within random-order blocks, order-switch costs are indicated by increased RTs on order switch compared to order repetition trials, reflecting memory-based mechanisms that guide task-order in DTs. To test the nature of these mechanisms in two experiments, participants performed DTs in fixed- and random-order blocks. In random-order blocks, participants were either instructed to respond to both tasks according to the order of task presentation (sequential-order instruction) or instructed to freely decide in which order to perform both tasks (free-order instruction). As a result of both experiments, we demonstrated that task-order control costs were reduced under the free-order compared to the sequential-order instruction, whereas order-switch costs were not affected by our instruction manipulation. This pattern of results suggests that the task-order control costs reflect global processes of task-order regulation such as engaging monitoring processes that are sensitive to changes in order instructions, while order-switch costs reflect rather local memory-based mechanisms that occur irrespective of any effort to coordinate task-order.

  2. 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

  3. Attentional requirements of postural control in people with spinal cord injury: the effect of dual task.

    PubMed

    Tse, C M; Carpenter, M G; Liu-Ambrose, T; Chisholm, A E; Lam, T

    2017-05-16

    Cross-sectional study. To investigate the attentional requirements for maintaining standing balance in people with spinal cord injury (SCI) using a dual-task paradigm and to compare standing balance performance between SCI and able-bodied (AB) controls. LaboratoryMethods:Nine adults with incomplete SCI, who were able to stand unassisted were recruited, along with eight AB controls. Subjects performed a dual task involving counting backwards by 3 s out loud while standing with eyes open or closed. The primary outcome measures were the differences between SCI and control groups for movement reinvestment and the change in performance between single task and dual task for: (i) maximum standing time (STime); (ii) error ratio and total number of words uttered; and (iii) center of pressure measures. Perceptual measures included perceived mental workload, fear and confidence. SCI subjects stood for shorter duration during dual task (stand and count) than single task (stand) compared with controls during eyes closed. Significant differences between groups were observed for movement reinvestment, center of pressure, perceived mental effort, fear and confidence. No significant effects were observed for math-task performance. Total STime during eyes closed is adversely affected by the addition of a math task for SCI subjects. Perceptual measures appear to correspond to increases in postural sway and conscious control of standing in subjects with SCI. Individuals who can stand for >60 s with eyes closed do not appear to be significantly affected by the addition of a concurrent secondary task of minimal mental workload.Spinal Cord advance online publication, 16 May 2017; doi:10.1038/sc.2017.42.

  4. Walking & Talking: Dual-Task Effects on Street Crossing Behavior in Older Adults

    PubMed Central

    Neider, Mark B.; Gaspar, John G.; McCarley, Jason S.; Crowell, James A.; Kaczmarski, Henry; Kramer, Arthur F.

    2013-01-01

    The ability to perform multiple tasks simultaneously has become increasingly important as technologies such as cell phones and portable music players have become more common. In the current study, we examined dual-task costs in older and younger adults using a simulated street crossing task constructed in an immersive virtual environment with an integrated treadmill so that participants could walk as they would in the real world. Participants were asked to cross simulated streets of varying difficulty while either undistracted, listening to music, or conversing on a cell phone. Older adults were more vulnerable to dual-task impairments than younger adults when the crossing task was difficult; dual-task costs were largely absent in the younger adult group. Performance costs in older adults were primarily reflected in timeout rates. When conversing on a cell phone older adults were less likely to complete their crossing compared to when listening to music or undistracted. Analysis of time spent next to the street prior to each crossing, where participants were presumably analyzing traffic patterns and making decisions regarding when to cross, revealed that older adults took longer than younger adults to initiate their crossing, and that this difference was exacerbated during cell phone conversation, suggesting impairments in cognitive planning processes. Our data suggest that multi-tasking costs may be particularly dangerous for older adults even during everyday activities such as crossing the street. PMID:21401262

  5. Dual-task interference in right- and left-handers: typical laterality patterns are obtained despite reversal of baseline asymmetries.

    PubMed

    Caroselli, Jerome S; Hiscock, Merrill; Bullock, Ryan

    2006-01-01

    Lateralized interference between concurrent cognitive and manual activities is used to infer cerebral hemisphere specialization for the cognitive activity. However, some evidence indicates that lateralized interference depends largely on manual asymmetry in the single-task (baseline) condition. To test the competing explanations, we asked 40 right-handed (RH) and 40 left-handed (LH) adults to key press and calculate concurrently. Baseline manual asymmetries were manipulated by increasing the complexity of the task performed by the dominant hand. Nevertheless, in the dual-task conditions, RHs showed more overall interference when performing with the right hand and LHs showed a nonsignificant tendency in the opposite direction. The results indicate that differential interference patterns, similar to those previously reported for right- and left-handers, may be obtained even when the usual baseline manual asymmetries are reversed.

  6. 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.

  7. 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

    2017-08-31

    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.

  8. 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…

  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. 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.

  11. Bilateral coordination of gait and Parkinson's disease: the effects of dual tasking.

    PubMed

    Plotnik, M; Giladi, N; Hausdorff, J M

    2009-03-01

    The aetiology of gait disturbances in Parkinson's disease (PD) is not fully understood. Recently, it was shown that in patients with PD, bilateral coordination of gait is impaired and that walking while being simultaneously engaged in a cognitive task is detrimental to their gait. To assess whether cognitive function influences the bilateral coordination of gait in PD, this study quantified left-right stepping coordination using a phase coordination index (PCI) that evaluates both the variability and inaccuracy of the left-right stepping phase (phi) generation (where the ideal phi value between left and right stepping is 180 degrees ). This report calculated PCI values from data obtained from force sensitive insoles embedded in subjects' shoes during 2 min of walking in a group of patients with PD (n = 21) and in an age matched control group (n = 13). All subjects walked under two walking conditions: usual walking and dual tasking (DT) (ie, cognitive loading) condition. For patients with PD, PCI values were significantly higher (ie, poorer coordination) during the DT walking condition compared with usual walking (p<0.001). In contrast, DT did not significantly affect the PCI of the healthy controls (p = 0.29). PCI changes caused by DT were significantly correlated with changes in gait variability but not with changes in gait asymmetry that resulted from the DT condition. These changes were also associated with performance on a test of executive function. The present findings suggest that in patients with PD, cognitive resources are used in order to maintain consistent and accurate alternations in left-right stepping.

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

    PubMed

    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

  13. 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

  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. Strategic Adaptation to Task Characteristics, Incentives, and Individual Differences in Dual-Tasking.

    PubMed

    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.

  16. Dual-tasking alleviated sleep deprivation disruption in visuomotor tracking: An fMRI study

    PubMed Central

    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-hr 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 target and non-matches were non-targets. Tracking error means were binned time-locked to stimulus onset of the detection task in order to observe changes associated with dual-responding by comparing the error during targets and non-targets. Similar comparison was made with fMRI data. Our result showed that despite a significant increase in the overall tracking error post SD, from 20 pixels pre SD to 45 pixels post SD, error decreased to a minimum of about 25 pixels 0 to 6 s after dual-response. Despite an overall reduced activation post SD, greater activation difference between targets and non-targets was found post SD in task-related regions, such as the left cerebellum, the left somatosensory cortex, the left extrastriate cortex, bilateral precuneus, the left middle frontal gyrus, and the left motor cortex. Our results suggest that dual-response helps to alleviate performance impairment usually associated with SD. The duration of the alleviation effect was on the order of seconds after dual-responding. PMID:22305924

  17. Walking and talking: dual-task effects on street crossing behavior in older adults.

    PubMed

    Neider, Mark B; Gaspar, John G; McCarley, Jason S; Crowell, James A; Kaczmarski, Henry; Kramer, Arthur F

    2011-06-01

    The ability to perform multiple tasks simultaneously has become increasingly important as technologies such as cell phones and portable music players have become more common. In the current study, we examined dual-task costs in older and younger adults using a simulated street crossing task constructed in an immersive virtual environment with an integrated treadmill so that participants could walk as they would in the real world. Participants were asked to cross simulated streets of varying difficulty while either undistracted, listening to music, or conversing on a cell phone. Older adults were more vulnerable to dual-task impairments than younger adults when the crossing task was difficult; dual-task costs were largely absent in the younger adult group. Performance costs in older adults were primarily reflected in timeout rates. When conversing on a cell phone, older adults were less likely to complete their crossing compared with when listening to music or undistracted. Analysis of time spent next to the street prior to each crossing, where participants were presumably analyzing traffic patterns and making decisions regarding when to cross, revealed that older adults took longer than younger adults to initiate their crossing, and that this difference was exacerbated during cell phone conversation, suggesting impairments in cognitive planning processes. Our data suggest that multitasking costs may be particularly dangerous for older adults even during everyday activities such as crossing the street.

  18. Multisession, dual-task psychological refractory period practice benefits older and younger adults equally.

    PubMed

    Allen, Philip A; Ruthruff, Eric; Elicker, Joelle D; Lien, Mei-Ching

    2009-10-01

    The authors tested 18 younger adults and 18 older adults on four sessions in a psychological refractory period (PRP) paradigm, to see whether older adults can benefit as much from dual-task practice as younger adults. Task 1 involved tone discrimination and Task 2 involved simultaneous letter-matching. The stimulus onset asynchrony (SOA) between the tasks was either 50, 150, 300, or 900 ms. Although older adults showed a larger PRP effect than younger adults, there were no group differences in the practice/training benefit. These results differ from Maquestiaux, Hartley, and Bertsch (2004, Psychology and Aging, 19, 649-667, Experiment 1), who found that age differences in PRP effects became progressively larger with increased practice. These findings, along with the simultaneous-presentation, dual-task work of Kramer, Larish, and Strayer (1995, Journal of Experimental Psychology: Applied, 1, 50-76) and Bherer et al. (2005, Psychology and Aging, 20, 695-709; 2006, Acta Psychologica, 123, 261-278), suggest that older adults can benefit as much as younger adults from dual-task training.

  19. 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

  20. 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

  1. Gaze shifts during dual-tasking stair descent.

    PubMed

    Miyasike-daSilva, Veronica; McIlroy, William E

    2016-11-01

    To investigate the role of vision in stair locomotion, young adults descended a seven-step staircase during unrestricted walking (CONTROL), and while performing a concurrent visual reaction time (RT) task displayed on a monitor. The monitor was located at either 3.5 m (HIGH) or 0.5 m (LOW) above ground level at the end of the stairway, which either restricted (HIGH) or facilitated (LOW) the view of the stairs in the lower field of view as participants walked downstairs. Downward gaze shifts (recorded with an eye tracker) and gait speed were significantly reduced in HIGH and LOW compared with CONTROL. Gaze and locomotor behaviour were not different between HIGH and LOW. However, inter-individual variability increased in HIGH, in which participants combined different response characteristics including slower walking, handrail use, downward gaze, and/or increasing RTs. The fastest RTs occurred in the midsteps (non-transition steps). While gait and visual task performance were not statistically different prior to the top and bottom transition steps, gaze behaviour and RT were more variable prior to transition steps in HIGH. This study demonstrated that, in the presence of a visual task, people do not look down as often when walking downstairs and require minimum adjustments provided that the view of the stairs is available in the lower field of view. The middle of the stairs seems to require less from executive function, whereas visual attention appears a requirement to detect the last transition via gaze shifts or peripheral vision.

  2. 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…

  3. 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…

  4. The On-Line Study of Sentence Comprehension: An Examination of Dual Task Paradigms

    ERIC Educational Resources Information Center

    Nicol, Janet; Swinney, David; Love, Tracy; Hald, Lea

    2006-01-01

    This paper presents three studies which examine the susceptibility of sentence comprehension to intrusion by extra-sentential probe words in two on-line dual-task techniques commonly used to study sentence processing: the cross-modal lexical priming paradigm and the unimodal all-visual lexical priming paradigm. It provides both a general review…

  5. 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…

  6. 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…

  7. 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…

  8. Attention, Gaze Shifting, and Dual-Task Interference from Phonological Encoding in Spoken Word Planning

    ERIC Educational Resources Information Center

    Roelofs, Ardi

    2008-01-01

    Controversy exists about whether dual-task interference from word planning reflects structural bottleneck or attentional control factors. Here, participants named pictures whose names could or could not be phonologically prepared, and they manually responded to arrows presented away from (Experiment 1), or superimposed onto, the pictures…

  9. 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…

  10. Dual-Task Performance with Center-Surround Auditory-Only Displays

    DTIC Science & Technology

    2009-07-15

    subjects used HRTFs built from measurements made on the Kemar manikin ( Burkhard & Sachs, 1975) in the anechoic chamber. The volunteers completed from...dual task performance. 10 REFERENCES Burkhard , M. D. & Sachs, R. M. (1975). Anthropometric manikin for acoustic research. J Acoust Soc Am, 58

  11. 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…

  12. The Role of Input and Output Modality Pairings in Dual-Task Performance: Evidence for Content-Dependent Central Interference

    ERIC Educational Resources Information Center

    Hazeltine, Eliot; Ruthruff, Eric; Remington, Roger W.

    2006-01-01

    Recent debate regarding dual-task performance has focused on whether costs result from limitations in central capacity, and whether central operations can be performed in parallel. While these questions are controversial, the dominant models of dual-task performance share the assumption that central operations are generic--that is, their…

  13. The Role of Input and Output Modality Pairings in Dual-Task Performance: Evidence for Content-Dependent Central Interference

    ERIC Educational Resources Information Center

    Hazeltine, Eliot; Ruthruff, Eric; Remington, Roger W.

    2006-01-01

    Recent debate regarding dual-task performance has focused on whether costs result from limitations in central capacity, and whether central operations can be performed in parallel. While these questions are controversial, the dominant models of dual-task performance share the assumption that central operations are generic--that is, their…

  14. A Roving Dual-Presentation Simultaneity-Judgment Task to Estimate the Point of Subjective Simultaneity.

    PubMed

    Yarrow, Kielan; Martin, Sian E; Di Costa, Steven; Solomon, Joshua A; Arnold, Derek H

    2016-01-01

    The most popular tasks with which to investigate the perception of subjective synchrony are the temporal order judgment (TOJ) and the simultaneity judgment (SJ). Here, we discuss a complementary approach-a dual-presentation (2x) SJ task-and focus on appropriate analysis methods for a theoretically desirable "roving" design. Two stimulus pairs are presented on each trial and the observer must select the most synchronous. To demonstrate this approach, in Experiment 1 we tested the 2xSJ task alongside TOJ, SJ, and simple reaction-time (RT) tasks using audiovisual stimuli. We interpret responses from each task using detection-theoretic models, which assume variable arrival times for sensory signals at critical brain structures for timing perception. All tasks provide similar estimates of the point of subjective simultaneity (PSS) on average, and PSS estimates from some tasks were correlated on an individual basis. The 2xSJ task produced lower and more stable estimates of model-based (and thus comparable) sensory/decision noise than the TOJ. In Experiment 2 we obtained similar results using RT, TOJ, ternary, and 2xSJ tasks for all combinations of auditory, visual, and tactile stimuli. In Experiment 3 we investigated attentional prior entry, using both TOJs and 2xSJs. We found that estimates of prior-entry magnitude correlated across these tasks. Overall, our study establishes the practicality of the roving dual-presentation SJ task, but also illustrates the additional complexity of the procedure. We consider ways in which this task might complement more traditional procedures, particularly when it is important to estimate both PSS and sensory/decisional noise.

  15. 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…

  16. 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…

  17. 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…

  18. Comparison of temporal and stride characteristics in myotonic dystrophies type 1 and 2 during dual-task walking.

    PubMed

    Radovanović, S; Perić, S; Savić-Pavićević, D; Dobričić, V; Pešović, J; Kostić, V; Rakočević-Stojanović, V

    2016-02-01

    We analyzed temporal and stride characteristics in patients with myotonic dystrophy type 1 (DM1) and type 2 (DM2) while performing dual mental and motor tasks, and investigated correlations between gait parameters and cognitive impairments. Dual-task walking was performed by 37 patients (20 DM1 and 17 DM2) and 48 healthy subjects divided into two groups, age- and gender-matched control group for DM1 (HC1) and age- and gender-matched control group for DM2 (HC2). The subjects performed a basic walking task, dual-motor task, dual-mental task, and combined motor and mental task. DM1 and DM2 patients differed significantly in temporal and stride characteristics compared to HC. Main differences in DM1 were slower gait and shorter stride length, while both DM1 and DM2 patients had a higher degree of variation of the swing time during dual-task gait, a parameter that reflects posture and balance. Impact of the cognitive dual task on gait pattern changes was also observed. Visuospatial ability correlated with gait changes in DM1, while executive functions had stronger influence in DM2 (p<0.01). Both patient groups had leg muscle weakness. Gait pattern was impaired in both patient groups concerning temporal and stride characteristics. Dual-task walking paradigm may discover mild initial gait changes and could provide early identification of fall risks and predict possible falls in DM patients. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. 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.

  20. OTVE turbopump condition monitoring, task E.5

    NASA Technical Reports Server (NTRS)

    Coleman, Paul T.; Collins, J. J.

    1989-01-01

    Recent work has been carried out on development of isotope wear analysis and optical and eddy current technologies to provide bearing wear measurements and real time monitoring of shaft speed, shaft axial displacement and shaft orbit of the Orbit Transfer Vehicle hydrostatic bearing tester. Results show shaft axial displacement can be optically measured (at the same time as shaft orbital motion and speed) to within 0.3 mils by two fiberoptic deflectometers. Evaluation of eddy current probes showed that, in addition to measuring shaft orbital motion, they can be used to measure shaft speed without having to machine grooves on the shaft surface as is the usual practice for turbomachinery. The interim results of this condition monitoring effort are presented.

  1. A Roving Dual-Presentation Simultaneity-Judgment Task to Estimate the Point of Subjective Simultaneity

    PubMed Central

    Yarrow, Kielan; Martin, Sian E.; Di Costa, Steven; Solomon, Joshua A.; Arnold, Derek H.

    2016-01-01

    The most popular tasks with which to investigate the perception of subjective synchrony are the temporal order judgment (TOJ) and the simultaneity judgment (SJ). Here, we discuss a complementary approach—a dual-presentation (2x) SJ task—and focus on appropriate analysis methods for a theoretically desirable “roving” design. Two stimulus pairs are presented on each trial and the observer must select the most synchronous. To demonstrate this approach, in Experiment 1 we tested the 2xSJ task alongside TOJ, SJ, and simple reaction-time (RT) tasks using audiovisual stimuli. We interpret responses from each task using detection-theoretic models, which assume variable arrival times for sensory signals at critical brain structures for timing perception. All tasks provide similar estimates of the point of subjective simultaneity (PSS) on average, and PSS estimates from some tasks were correlated on an individual basis. The 2xSJ task produced lower and more stable estimates of model-based (and thus comparable) sensory/decision noise than the TOJ. In Experiment 2 we obtained similar results using RT, TOJ, ternary, and 2xSJ tasks for all combinations of auditory, visual, and tactile stimuli. In Experiment 3 we investigated attentional prior entry, using both TOJs and 2xSJs. We found that estimates of prior-entry magnitude correlated across these tasks. Overall, our study establishes the practicality of the roving dual-presentation SJ task, but also illustrates the additional complexity of the procedure. We consider ways in which this task might complement more traditional procedures, particularly when it is important to estimate both PSS and sensory/decisional noise. PMID:27047434

  2. Computerized Dual-Task Testing of Gait and Visuospatial Cognitive Functions; Test-Retest Reliability and Validity

    PubMed Central

    Szturm, Tony J.; Sakhalkar, Vedant S.; Kanitkar, Anuprita; Nankar, Mayur

    2017-01-01

    The common occurrence of age decline in mobility and cognition does cause a decrease in the level of physical activity and an increased falls risk. Consequently, dual -task (DT) assessment that simultaneously addresses both mobility skills and cognitive functions are important because, continued difficulties and fall injuries will have a sizable impact in this population. The first objective of the present study was to assess test-retest reliability of a computerized DT treadmill walking protocol and concurrent outcome measures of gait and visuospatial executive function in a group of healthy older adults. Secondly, discriminative validity was evaluated by examining the effect of DT conditions (single task vs. dual-task) on; (a) spatiotemporal gait measures (average and coefficient of variation) and (b) visuomotor and visuospatial executive performance measures. Twenty-five community-dwelling individuals median age 65 (range 61–67) were recruited from a Fitness Facility. Participants performed a computerized visuomotor tracking task and a visuospatial executive game task in standing and while treadmill walking. Testing was conducted on two occasions, 1 week apart. Moderate to high test-retest reliability (ICC values of 0.65–0.88) were observed for spatiotemporal gait variables. No significant differences between the group means were observed between test periods in any gait variable. Moderate test-retest reliability (ICC values of 0.6–0.65) was observed for measures of visuomotor and visuospatial executive performance during treadmill walking. Significant DT effects were observed for both spatiotemporal gait variables and visuospatial executive performance measures. This study demonstrates the reliability and reproducibility of the computer-based assessment tool for dual task treadmill walking. The high to moderate ICC values and the lack of systematic errors in the measures indicate that this tool has the ability to repeatedly record reliable data from

  3. 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…

  4. 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…

  5. Effects of dual-task cognitive-gait intervention on memory and gait dynamics in older adults with a history of falls: a preliminary investigation.

    PubMed

    You, Joshua H; Shetty, Anand; Jones, Tawaih; Shields, Kimberli; Belay, Yordanos; Brown, Deborah

    2009-01-01

    The present study highlights the effects of the dual-task cognitive-gait intervention (CGI) on working memory and gait functions in older adults with a history of falls. Thirteen older adults with a history of falls were recruited from local community centers and randomly stratified into either the control (n = 5) or experimental (n = 8) group. The experimental group received the dual-task cognitive-motor intervention involving simultaneous motor (walking) and cognitive (memory recall) task whereas the control group received a placebo treatment (walking with simple music). The intervention was provided 30 minutes per session, over a 6-week period. Memory measures included a combination of word recall and arithmetic task. Gait function measures included velocity and center of pressure (COP) stability. Non-parametric tests were used at p < 0.05. The experimental group showed a greater memory performance than the control (p < 0.05). However, no significant intervention-related changes in gait velocity and stability were observed. Our findings provide the first evidence in literature to demonstrate that the long-term dual-task cognitive-motor intervention improved memory of older adults with a history of falls under the dual cognitive motor task condition.

  6. 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…

  7. 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.

  8. Effect of dual task type on gait and dynamic stability during stair negotiation at different inclinations.

    PubMed

    Madehkhaksar, Forough; Egges, Arjan

    2016-01-01

    Stair gait is a common daily activity with great potential risk for falls. Stairs have varying inclinations and people may perform other tasks concurrently with stair gait. This study investigated dual-task interference in the context of complex gait tasks, such as stair gait at different inclinations, a topic about which little is understood. We examined how secondary cognitive and manual tasks interfere with stair gait when a person concurrently performed tasks at different levels of complexity. Gait kinematic data and secondary task performance measures were obtained from fifteen healthy young males while ascending and descending a four-step staircase at three inclinations (17.7°, 29.4°, and 41.5°) as well as level walking. They performed a cognitive task, 'backward digit recall', a manual task, 'carrying a cup of water' and a combination of the two tasks. Gait performance and dynamic stability were assessed by gait speed and whole body center of mass (COM) range of motion in the medial-lateral direction, respectively. No significant effect of the gait task on the cognitive task performance was observed. In contrast, stair walking adversely affected the performance of the manual task compared to level walking. Overall, more difficult postural and secondary tasks resulted in a decrease in gait speed and variation in COM displacement within normal range. Results suggest that COM displacement and gait alterations might be adopted to enhance the stability, and optimize the secondary task performance while walking under challenging circumstances. Our findings are useful for balance and gait evaluation, and for future falls prediction. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. 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.

  10. Vestibular disorders and dual task performance: Impairment when walking a straight path

    PubMed Central

    Roberts, Jess C.; Cohen, Helen S.; Sangi-Haghpeykar, Haleh

    2013-01-01

    Locomotion is impaired in some people with vestibular disorders. Performance on cognitive tasks is also impaired in many people with vestibular disorders. The goal of this study was to determine if patients with vestibular disorders have decreased ability to complete a dual task performance involving a cognitive task, an additional motor task or both tasks, combined along a linear path. Subjects were normal, had benign paroxysmal positional vertigo, or had various vestibular disorders that caused unilateral weakness. They were asked to walk 7.62 m in a straight line with eyes open or closed, without extra tasks, and while nodding the head, naming things, and both nodding and naming. The patients walked significantly slower than controls, especially when performing the cognitive task. Patients had greater ataxia and began veering sooner than normals. The subjects’ veering increased significantly with the addition of cognitive tasks. The patient groups did not differ significantly from each other. The changes in velocity did not affect the veering. These data suggest that patients with vestibular disorders are impaired in their ability to complete a linear path when cognitive tasks are added. PMID:21558642

  11. 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

  12. Effect of Peripheral Communication Pace on Attention Allocation in a Dual-Task Situation

    NASA Astrophysics Data System (ADS)

    Gueddana, Sofiane; Roussel, Nicolas

    Peripheral displays allow continuous awareness of information while performing other activities. Monitoring such a display while performing a central task has a cognitive cost that depends on its perceptual salience and the distraction it causes, i.e. the amount of attention it attracts away from the user’s primary action. This paper considers the particular case of peripheral displays for interpersonal communication. It reports on an experiment that studied the effect of peripheral communication pace on subjects’ allocation of attention in a dual-task situation: a snapshot-based peripheral monitoring task where participants need to assess the presence of a remote person, and a central text-correcting task against the clock. Our results show that the addition of the peripheral task caused a drop in the success rate of the central task. As the pace of snapshots increased, success rate decreased on the peripheral task while on the central one, success rate remained the same but failures to reply in time occurred more frequently. These results suggest that the increase in pace of snapshots caused participants to change their strategy for the central task and allocate more attention to the peripheral one, not enough to maintain peripheral performance but also not to the point where it would affect central performance. Overall, our work suggests that peripheral communication pace subtly influences attention allocation in dual-task situations. We conclude by discussing how control over information pace could help users of communication systems to adjust their local distraction as well as the attention they draw from remote users.

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

    PubMed

    Watanabe, Kei; Funahashi, Shintaro

    2017-08-26

    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.

  14. 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

  15. 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.

  16. 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.

  17. Attention and gaze shifting in dual-task and go/no-go performance with vocal responding.

    PubMed

    Lamers, Martijn J M; Roelofs, Ardi

    2011-07-01

    Evidence from go/no-go performance on the Eriksen flanker task with manual responding suggests that individuals gaze at stimuli just as long as needed to identify them (e.g., Sanders, 1998). In contrast, evidence from dual-task performance with vocal responding suggests that gaze shifts occur after response selection (e.g., Roelofs, 2008a). This difference in results may be due to the nature of the task situation (go/no-go vs. dual task) or the response modality (manual vs. vocal). We examined this by having participants vocally respond to congruent and incongruent flanker stimuli and shift gaze to left- or right-pointing arrows. The arrows required a manual response (dual task) or determined whether the vocal response to the flanker stimuli had to be given or not (go/no-go). Vocal response and gaze shift latencies were longer on incongruent than congruent trials in both dual-task and go/no-go performance. The flanker effect was also present in the manual response latencies in dual-task performance. Ex-Gaussian analyses revealed that the flanker effect on the gaze shifts consisted of a shift of the entire latency distribution. These results suggest that gaze shifts occur after response selection in both dual-task and go/no-go performance with vocal responding. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. 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.

  19. Effects of biofeedback on trunk sway during dual tasking in the healthy young and elderly.

    PubMed

    Verhoeff, Lonneke L; Horlings, Corinne G C; Janssen, Lindy J F; Bridenbaugh, Stephanie A; Allum, John H J

    2009-07-01

    We examined the effect of biofeedback of trunk sway on balance control while walking and performing a simultaneous cognitive or motor task. Thirteen healthy elderly (mean age (+/-S.E.M.) 70.8+/-2.0 years) and 16 healthy young (mean age 21.5+/-0.7 years) subjects performed three gait tasks while wearing body-worn gyroscopes, mounted at L1-3, to measure trunk sway. The gait tasks were walking normally, walking and counting backwards in 7's, and walking while carrying a tray with cups of water. Differences in trunk sway were examined when subjects performed the gait tasks with or without a head mounted actuator system which provided subjects with vibro-tactile, auditory and visual biofeedback of trunk sway. In the young, trunk pitch (fore-aft) angles, and trunk roll (sideways) and pitch angular velocities were significantly reduced using biofeedback across all three gait tasks. In the elderly, the same angle and angular velocities were also significantly reduced while walking normally. During walking while carrying a tray, only trunk sway velocities were significantly reduced, whereas no improvements were seen for walking while counting backwards. Counting backwards ability significantly improved with feedback. Young participants were able to perform a dual task during gait and employ biofeedback to reduce trunk sway. Elderly participants were not able to reduce sway using biofeedback during the cognitive task but were able to reduce sway velocities with biofeedback during the motor task.

  20. The effects of dual-task gait training on foot pressure in elderly women.

    PubMed

    Kim, Seong-Gil; Park, Jin-Hyun

    2015-01-01

    [Purpose] The purpose of this study was to evaluate the effect of dual-task gait training on foot pressure in elderly women. [Subjects and Methods] Twenty elderly people in local communities performed dual-task gait training for 20 minutes three times per week for 8 weeks. Foot pressure was measured using an F-scan System (Tekscan, South Boston, MA, USA) before the intervention and in the 4th and 8th weeks of the intervention. [Results] Foot pressure increased significantly between the 4th and 8th weeks of the intervention in the CFF (central forefoot); between before the intervention and the 4th week, between the 4th and 8th weeks, and between before the intervention and the 8th week in the MF (midfoot); and between before the intervention and the 4th and 8th weeks in the HL (heel). [Conclusion] The results of this study indicate that dual-task gait training may improve the gait ability of elderly persons residing in the community.

  1. 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.

  2. 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

  3. Designing On-Condition Tasks for Naval Aircraft

    DTIC Science & Technology

    1980-03-01

    8217 T>i~AKE OFIONTENTS: ) INTRODUCTION - 1 - ’J’reventive Maintenance Processes, .... mHistory of the *M Condttob1aintenance Process., 5 A iparison of...FIGURE 1 MAINTENANCE TASK ALTERNATIVES HAR ON TIME CONDITION "ON-LINE NO FUNCTIONS" TASK ; FAILURE- FINDING TASK "OFF-LINE FUNCTIONS" 4i A HISTORY OF... gremlins should be dealt with. The first is lack of repeatability, the second is what quality control technicians call "type II" error. These problems

  4. Association between dual task-related decrease in walking speed and real versus imagined Timed Up and Go test performance.

    PubMed

    Bridenbaugh, Stephanie A; Beauchet, Olivier; Annweiler, Cédric; Allali, Gilles; Herrmann, François; Kressig, Reto W

    2013-06-01

    To examine whether older people with markedly dual task-related decreases in walking speed - a marker of disturbed higher-level gait control and falls - have a larger discrepancy between real and imagined Timed Up and Go (TUG) test times than those with less dual task-related decreases in walking speed. Based on a prospective cross-sectional study, 193 older adults (mean age 77.4 ± 5.9 years; 44.0 % women) referred to and consecutively assessed at a Swiss university clinic for a gait analysis to assess either gait disorders, fall risk or memory disorders were included. For all participants, walking speed was measured using a GAITRite(®) electronic walkway system during usual walking at self-selected pace and while dual tasking (i.e., usual walking and simultaneously counting backwards out loud). In addition, real Timed Up and Go (TUGr) and imagined Timed Up and Go (TUGi) (i.e., the time needed to imagine performing the TUGr) times were measured with a stopwatch. Differences between both walking conditions for walking speed (delta of walking speed) and both TUG conditions (delta of TUG time) were calculated. Age, gender, height, total number drugs taken per day, daily use of psychoactive drugs, use of walking aid, history of falls, Mini-Mental State Examination score, near vision and education level were used as covariables in this analysis. Participants were categorized into two groups based on being in the lowest tertian (i.e., <33 %: group A corresponding to participants undisturbed by dual task) or not (i.e., ≥33 %: group B corresponding to participants disturbed by dual task) of the delta of walking speed. In both groups, TUGr and TUGi times were similar (P = .169 and P = .839). In both groups, TUGi was faster than TUGr (P < .001). Delta of TUG time was significantly greater in group B compared to group A (P < .001). After adjustment for all covariables, only the delta of walking speed was significantly associated with the delta of TUG

  5. 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

  6. The effect of performing a dual-task on postural control and selective attention of older adults when stepping backward

    PubMed Central

    Tsang, William Wai-Nam; Chan, Vito Wai-Lok; Wong, Henry Hei; Yip, Tony Wai-Cheong; Lu, Xi

    2016-01-01

    [Purpose] The purpose of the study was to investigate the postural control and cognitive performance of older adults when stepping backward with and without a concurrent cognitive task. [Subjects and Methods] Thirty young adults and twenty-eight older adults (mean age=21.3 ± 1.2 and 72.2 ± 5.7 years, respectively) were recruited. Participants were asked to step backward and then maintain a single-leg stance for 10 seconds with and without a concurrent auditory response task. The reaction time and error rate while performing the cognitive task were recorded. Postural stability after stepping back was measured in terms of total sway path and total sway area. [Results] The older subjects had significantly longer reaction times and higher error rates in both single- and dual-tasking. When dual-tasking, both groups had significantly longer reaction times than when single-tasking. Only the older adults showed significantly higher error rates. The older adults also had significantly longer total sway paths and larger total sway areas of single-leg stance after stepping back. Neither group showed a significant difference in total sway path and sway area between single- and dual-tasking. [Conclusion] Older adults have poorer cognitive performance and postural stability during both single- and dual-tasking. They tend to prioritize postural control over cognition in dual-tasking. PMID:27821940

  7. The ecological approach to cognitive–motor dual-tasking: findings on the effects of expertise and age

    PubMed Central

    Schaefer, Sabine

    2014-01-01

    The underlying assumption of studies on cognitive–motor dual-tasking is that resources are limited, and when they have to be shared between a cognitive and a motor task, performances will suffer. Resource competition should therefore be particularly pronounced in children, older adults, or people who are just acquiring a new motor skill. The current review summarizes expertise and age comparative studies that have combined a cognitive and a motor task. Expertise studies have often assessed sports performances (e.g., golf putting, soccer dribbling, rugby drills) and have shown that experts are more successful than novices to keep up their performances in dual-task situations. The review also presents age-comparative studies that have used walking (on narrow tracks or on a treadmill) as the motor task. Older adults often show higher costs than young adults, and they tend to prioritize the motor domain. These findings are discussed in relation to the ecological approach to dual-task research originally introduced by Li et al. (2005). The approach proposes to study ecologically valid dual-task situations, and always to investigate dual-task costs for both domains (cognitive and motor performance) in order to assess potential tradeoffs. In addition, task difficulties should be individually adjusted, and differential-emphasis instructions should be included in the study design. PMID:25352820

  8. 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

  9. 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.

  10. Role of the Frontal Cortex in Standing Postural Sway Tasks While Dual-Tasking: A Functional Near-Infrared Spectroscopy Study Examining Working Memory Capacity

    PubMed Central

    Fujita, Hiroyuki; Kasubuchi, Kenji; Wakata, Satoshi; Hiyamizu, Makoto; Morioka, Shu

    2016-01-01

    Posture control during a dual-task involves changing the distribution of attention resources between the cognitive and motor tasks and involves the frontal cortex working memory (WM). The present study aimed to better understand the impact of frontal lobe activity and WM capacity in postural control during a dual-task. High and low WM-span groups were compared using their reading span test scores. High and low WM capacity were compared based on cognitive and balance performance and hemoglobin oxygenation (oxyHb) levels during standing during single (S-S), standing during dual (S-D), one leg standing during single (O-S), and one leg standing during dual (O-D) tasks. For sway pass length, significant difference in only the O-D task was observed between both groups. oxyHb levels were markedly increased in the right dorsolateral prefrontal cortex and supplementary motor area in the high-span group during a dual-task. Therefore, WM capacity influenced the allocation of attentional resources and motor performance. PMID:27034947

  11. Potential Benefits of Exergaming for Cognition and Dual-Task Function in Older Adults: A Systematic Review.

    PubMed

    Ogawa, Elisa F; You, Tongjian; Leveille, Suzanne G

    2016-04-01

    This paper provides a systematic review of current research findings using exergaming as a treatment for improving cognition and dual-task function in older adults. A literature search was conducted to collect exergaming intervention studies that were either randomized controlled or uncontrolled studies. Of the seven identified studies (five randomized controlled studies and two uncontrolled studies), three studies focused on cognitive function alone, two studies focused on dual-task function alone, and two studies measured both cognitive function and dual-task function. Current evidence supports that exergaming improves cognitive function and dual-task function, which potentially leads to fall prevention. However, it is unclear whether exergaming, which involves both cognitive input and physical exercise, has additional benefits compared with traditional physical exercise alone. Further studies should include traditional exercise as a control group to identify these potential, additional benefits.

  12. The immediate effect of a novel audio-visual cueing strategy (simulated traffic lights) on dual-task walking in people with Parkinson's disease.

    PubMed

    Mak, M K Y; Yu, L; Hui-Chan, C W Y

    2013-04-01

    Gait deficits are exacerbated during the addition of a concurrent cognitive task in individuals with Parkinson's disease (PD). The provision of auditory and/or visual cues has been reported to facilitate gait performance in these patients. To investigate whether individuals with PD could use traffic lights as an audio-visual cueing strategy to enhance dual-task walking performance. Cross-sectional comparative study. The Hong Kong Polytechnic University. Fifteen PD and 13 healthy individuals. All participants were instructed to walk at their natural pace, followed by 2 randomized conditions: 1) walking while doing serial subtractions of three, starting from a random number between 60 to 100; 2) doing the same tasks with the addition of traffic lights signals as audio-visual cues. Primary outcomes included stride length, cadence and gait velocity. Individuals with PD had more deterioration in all gait parameters than healthy controls for both single- and dual-task walking. With the use of traffic lights, individuals with PD showed significant increases in stride length (by 8.8%), cadence (by 9.6%), and gait velocity (by 21.0%, P=0.000). Traffic lights could be used as combined preparatory and ongoing audio-visual cues to enhance dual-task walking performance in people with PD. Positive findings from the present study suggest a promising treatment intervention to benefit people with PD, who often have to conduct concurrent cognitive task during walking in their daily activities.

  13. Frontoparietal EEG alpha-phase synchrony reflects differential attentional demands during word recall and oculomotor dual-tasks.

    PubMed

    Kwon, Gusang; Kim, Min-Young; Lim, Sanghyun; Kwon, Hyukchan; Lee, Yong-Ho; Kim, Kiwoong; Lee, Eun-Ju; Suh, Minah

    2015-12-16

    To study the relationship between the varying degrees of cognitive load and long-range synchronization among neural networks, we utilized a dual-task paradigm combining concurrent word recall working memory tasks and oculomotor tasks that differentially activate the common frontoparietal (FP) network. We hypothesized that each dual-task combination would generate differential neuronal activation patterns among long-range connection during word retention period. Given that the FP alpha-phase synchronization is involved in attentional top-down processes, one would expect that the long-range synchronization pattern is affected by the degrees of dual-task demand. We measured a single-trial phase locking value in the alpha frequency (8-12 Hz) with electroencephalography in healthy participants. Single-trial phase locking value characterized the synchronization between two brain signals. Our results revealed that different amounts of FP alpha-phase synchronization were produced by different dual-task combinations, particularly during the early phase of the word retention period. These differences were dependent on the individual's working memory capacity and memory load. Our study shows that during dual-task, each oculomotor task, which is subserved by distinct neural network, generates different modulation patterns on long-range neuronal activation and FP alpha-phase synchronization seems to reflect these differential cognitive loads.

  14. Dual Arm Work Package performance estimates and telerobot task network simulation

    SciTech Connect

    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 collected 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.

  15. Motor dual-task Timed Up & Go test better identifies prefrailty individuals than single-task Timed Up & Go test.

    PubMed

    Tang, Pei-Fang; Yang, Hao-Jan; Peng, Ya-Chi; Chen, Hui-Ya

    2015-02-01

    The present study investigated whether dual-task Timed Up & Go tests (TUG) could identify prefrail individuals more sensitively than the single-task TUG (TUGsingle ) in community-dwelling middle-aged and older adults. This cross-sectional study recruited adults aged 50 years and older who actively participated in local community programs. Time taken to complete single-task TUG and dual-task TUG, carrying a cup of water (TUGmanual ) or carrying out serial-3 subtraction (TUGcognitive ) while executing TUG, was measured. Prefrailty status was defined based on Fried's phenotypic definition. Of the 65 participants (mean age 71.5±8.1 years), 33.3% of the 12 middle-aged (50-64 years) and 62.3% of the 53 older (≥65 years) adults were prefrail, mainly as a result of weak grip strength. The receiver operating characteristic curve analyses for differentiating prefrailty from non-frailty showed that the area under the curve (AUC) for TUGmanual (0.73, 95% CI 0.60-0.86) was better than that for TUGsingle (0.67, 95% CI 0.54-0.80), whereas the AUC value was not significant for TUGcognitive (0.60, 95% CI 0.46-0.74). The optimal cut-off points for detecting prefrailty using TUGsingle , TUGmanual and TUGcognitive were 7.7 s (sensitivity 68%), 8.2 s (sensitivity 83%), and 14.3 s (sensitivity 29%), respectively. After adjusting for age, logistic regression analyses showed that individuals with TUGmanual 8.2 s or slower were 7.2-fold more likely to have prefrailty than those with TUGmanual faster than 8.2 s. TUGmanual is more valid and sensitive than TUGsingle in identifying prefrail individuals. The TUGmanual thus could serve as a screening tool for early detection of individuals with prefrailty in community-dwelling middle-aged and older adults. © 2014 Japan Geriatrics Society.

  16. Effect of dual tasking on postural responses to rapid lower limb movement while seated on an exercise ball.

    PubMed

    Jones, P; Sorinola, I; Strutton, P H

    2014-06-01

    Postural adjustments are used by the central nervous system to pre-empt and correct perturbations in balance during voluntary body movements. Alteration in these responses is associated with a number of neuromuscular/musculoskeletal conditions. Attention has been identified as important in this system; performing a concurrent cognitive task has been suggested to reduce the efficacy of this postural control. The aim of this study was to examine the effect of concurrent cognitive tasking on anticipatory postural adjustments while sitting on an exercise ball with a view to help inform future rehabilitation programmes. Bilateral EMG activity was recorded from the external and internal obliques, rectus abdominis, erector spinae and the right rectus femoris of 20 healthy subjects (9 males) with mean (SD) age of 21.88 (0.86) years (range 21-24 years). A rapid hip flexion protocol was carried out under three conditions: no concurrent task, counting out loud up from one and completing a serial sevens task. The addition of the cognitive task delayed and reduced the EMG in the prime mover muscle but had little impact on the responses of the trunk muscles within the time frame of the anticipatory responses; suggestive of a decoupling of voluntary and postural control mechanisms. The results of this study suggest that perhaps the clinical effects of dual task may not be largely due to changes in anticipatory postural adjustments. However, it would be important to compare these results to those seen in older and functionally impaired individuals as this would be more representative of the typical population undertaking such rehabilitation programmes.

  17. Locus of the single-channel bottleneck in dual-task interference

    NASA Technical Reports Server (NTRS)

    Mccann, Robert S.; Johnston, James C.

    1992-01-01

    Two experiments used the locus-of-cognitive-slack method to determine whether dual-task interference occurs before or after the response selection stage. The experiments used the overlapping tasks paradigm, in which two signals, each requiring a different speeded choice response, are presented in rapid succession. In Experiment 1, stimulus-response (S-R) compatibility was manipulated by varying whether Task 2 stimuli were mapped onto their responses by a rule or arbitrarily. Compatibility effects were additive with the effects of degree of task overlap, manipulated by varying the stimulus onset asynchrony between the signals. Experiment 2 examined 2 additional forms of S-R compatibility: symbolic compatability (arrows vs. letters) and spatial compatibility (the 'Simon' effect). Effects of symbolic compatibility were additive with effects of degree of task overlap, whereas the effects of spatial compatibility and degree of task overlap were underadditive. It is argued that only a central-bottleneck model provides a consistent account of these results. The nature of the central bottleneck is considered.

  18. Controlled but independent: effects of mental rotation and developmental dyslexia in dual-task settings.

    PubMed

    Lachmann, Thomas; Schumacher, Bettina; van Leeuwen, Cees

    2009-01-01

    In two experiments, we compared the performance of normal-reading (n = 26) and dyslexic children (n = 22) in discriminating letters from their mirrored images. In experiment 1, they were always presented in the upright orientation; in experiment 2, they were presented in different angular orientations (0 degrees, 90 degrees, 180 degrees). In order to determine whether task and dyslexia affect reaction times in early or late stages of processing, a dual-task paradigm was adopted in which the primary task was tone discrimination. Stimulus onset asynchrony (SOA) between first and second task was systematically varied (50 ms versus 400 ms). In both experiments dyslexics were slower overall than controls. No effects of mirror-image letters were found. In experiment 2, mental-rotation effects were additive with SOA. In accordance with earlier findings we concluded that the mental-rotation effect involves central processing capacity. Mental-rotation effects were the same for normal-reading and dyslexic children; mental rotation is not impaired in dyslexia. Remarkably, SOA effects were larger in normal readers than in dyslexics. This result was explained by observing that dyslexics experience decision difficulties already on the first task. As a result, they do not benefit optimally from increased latencies between first and second tasks.

  19. Baseline activity predicts working memory load of preceding task condition.

    PubMed

    Pyka, Martin; Hahn, Tim; Heider, Dominik; Krug, Axel; Sommer, Jens; Kircher, Tilo; Jansen, Andreas

    2013-11-01

    The conceptual notion of the so-called resting state of the brain has been recently challenged by studies indicating a continuing effect of cognitive processes on subsequent rest. In particular, activity in posterior parietal and medial prefrontal areas has been found to be modulated by preceding experimental conditions. In this study, we investigated which brain areas show working memory dependent patterns in subsequent baseline periods and how specific they are for the preceding experimental condition. During functional magnetic resonance imaging, 94 subjects performed a letter-version of the n-back task with the conditions 0-back and 2-back followed by a low-level baseline in which subjects had to passively observe the letters appearing. In a univariate analysis, 2-back served as control condition while 0-back, baseline after 0-back and baseline after 2-back were modeled as regressors to test for activity changes between both baseline conditions. Additionally, we tested, using Gaussian process classifiers, the recognition of task condition from functional images acquired during baseline. Besides the expected activity changes in the precuneus and medial prefrontal cortex, we found differential activity in the thalamus, putamen, and postcentral gyrus that were affected by the preceding task. The multivariate analysis revealed that images of the subsequent baseline block contain task related patterns that yield a recognition rate of 70%. The results suggest that the influence of a cognitive task on subsequent baseline is strong and specific for some areas but not restricted to areas of the so-called default mode network.

  20. Buckling conditions for a dual-coated optical fiber

    NASA Astrophysics Data System (ADS)

    Suhir, Ephraim

    2013-03-01

    The elastic stability (buckling) condition for a short dual-coated optical-fiber experiencing mechanical and/or thermally induced compression is established based on the developed analytical (mathematical) predictive model. The problem is reduced to a situation when a cantilever beam of finite length is supported by a continuous elastic foundation and is subjected to a compressive force applied to the beam's free end. Easy-to-use practical guidelines and a simple diagram are suggested for choosing the adequate length of the fiber and/or its flexural rigidity and/or the characteristics of the coating materials, so that the fiber remains elastically stable. The developed model can be used also in the design and reliability evaluations of composites, including nano-composites, and in flexible (large area) photonics when high-modulus and lowexpansion fibers are embedded into a high-modulus-and-low-expansion matrix and experience axial compression at low temperature conditions.

  1. 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.

  2. 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

  3. 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.

  4. Misinterpretation of conditional statements in Wason's selection task.

    PubMed

    Osman, M; Laming, D

    2001-01-01

    Errors may be made on Wason's selection task because either (a) the rule to be tested is misunderstood, or (b) reasoning from that rule is inaccurate, or both. We report two experiments using the experimental paradigm introduced by Gebauer and Laming in which subjects are given six problems in succession. We use the subset of cards selected by each subject as (a) an indication of how the rule is understood and, when that selection is consistent throughout all six problems (so that we can infer a consistent understanding of the rule), as (b) a basis for evaluating the accuracy of the subject's reasoning according to three independent criteria. Experiment 1 adds an exactly parallel contextual version of the task to permit comparison between performances (by the same subjects) on the two versions. Experiment 2 repeats Exp. 1, but with negatives inserted in the conditional rule. Most subjects make a consistent selection of cards throughout all six problems, but typically appear to misunderstand the rule. This is so in both abstract and contextual tasks and replicates the finding by Gebauer and Laming. Most misunderstandings consisted of either (a) reading the simple conditional rule as a bi-conditional or (b) substituting "top/underneath" for "one side/other side". In Exp. 1 subjects seldom misevaluated the rule they appeared to be testing, but such "errors" of evaluation were common in Exp. 2. Negatives confuse the subjects and should not be used in any conditional application that matters. In Exp. 2 (but not 1) there was a significant correlation between interpretations of the two tasks. We provide an explanation of "matching bias" (it results from the confluence of the two common misunderstandings above) and comment on "mental models" which are, at present, unable to accommodate the variety of results we present here. We also relate our experimental paradigm to the conditional inference task and to truth tables.

  5. 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.

  6. Acute exercise improves cognition in the depressed elderly: the effect of dual-tasks.

    PubMed

    Vasques, Paulo Eduardo; Moraes, Helena; Silveira, Heitor; Deslandes, Andrea Camaz; Laks, Jerson

    2011-01-01

    The goal of this study was to assess the acute effect of physical exercise on the cognitive function of depressed elderly patients in a dual-task experiment. Physical exercise has a positive effect on the brain and may even act as a treatment for major depressive disorder. However, the effects of acute cardiovascular exercise on cognitive function during and after one session of aerobic training in elderly depressive patients are not known. Ten elderly subjects diagnosed with major depressive disorder performed neuropsychological tests during and after a moderate physical exercise session (65-75%HR(max)). A Digit Span Test (Forward and Backward) and a Stroop Color-Word Test were used to assess cognitive function. The elderly participants walked on an electric treadmill for 30 minutes and underwent the same cognitive testing before, during, immediately after, and 15 minutes after the exercise session. In the control session, the same cognitive testing was conducted, but without exercise training. The results of the Digit Span Test did not change between the control and the exercise sessions. The results of the Stroop Color-Word Test improved after physical exercise, indicating a positive effect of exercise on cognition. These data suggest that the cognitive functions of depressed elderly persons, especially attention and inhibitory control, are not impaired during and after an acute session of physical exercise. In contrast, the effect of dual-tasks showed beneficial results for these subjects, mainly after exercise. The dual-task may be a safe and useful tool for assessing cognitive function.

  7. Acute exercise improves cognition in the depressed elderly: the effect of dual-tasks

    PubMed Central

    Vasques, Paulo Eduardo; Moraes, Helena; Silveira, Heitor; Deslandes, Andrea Camaz; Laks, Jerson

    2011-01-01

    OBJECTIVE: The goal of this study was to assess the acute effect of physical exercise on the cognitive function of depressed elderly patients in a dual-task experiment. INTRODUCTION: Physical exercise has a positive effect on the brain and may even act as a treatment for major depressive disorder. However, the effects of acute cardiovascular exercise on cognitive function during and after one session of aerobic training in elderly depressive patients are not known. METHODS: Ten elderly subjects diagnosed with major depressive disorder performed neuropsychological tests during and after a moderate physical exercise session (65-75%HRmax). A Digit Span Test (Forward and Backward) and a Stroop Color-Word Test were used to assess cognitive function. The elderly participants walked on an electric treadmill for 30 minutes and underwent the same cognitive testing before, during, immediately after, and 15 minutes after the exercise session. In the control session, the same cognitive testing was conducted, but without exercise training. RESULTS: The results of the Digit Span Test did not change between the control and the exercise sessions. The results of the Stroop Color-Word Test improved after physical exercise, indicating a positive effect of exercise on cognition. CONCLUSIONS: These data suggest that the cognitive functions of depressed elderly persons, especially attention and inhibitory control, are not impaired during and after an acute session of physical exercise. In contrast, the effect of dual-tasks showed beneficial results for these subjects, mainly after exercise. The dual-task may be a safe and useful tool for assessing cognitive function. PMID:22179158

  8. 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"…

  9. Dual-task interference and brain structural connectivity in people with Parkinson’s disease who freeze

    PubMed Central

    Peterson, Daniel S; Fling, Brett W; Mancini, Martina; Cohen, Rajal G; Nutt, John G; Horak, Fay B

    2015-01-01

    Background Freezing of gait in people with Parkinson’s disease (PD) is likely related to attentional control (ie, ability to divide and switch attention). However, the neural pathophysiology of altered attentional control in individuals with PD who freeze is unknown. Structural connectivity of the pedunculopontine nucleus has been related to freezing and may play a role in altered attentional control; however, this relationship has not been investigated. We measured whether dual-task interference, defined as the reduction in gait performance during dual-task walking, is more pronounced in individuals with PD who freeze, and whether dual-task interference is associated with structural connectivity and/or executive function in this population. Methods We measured stride length in 13 people with PD with and 12 without freezing of gait during normal and dual-task walking. We also assessed asymmetry of pedunculopontine nucleus structural connectivity via diffusion tensor imaging and performance on cognitive tests assessing inhibition and set-shifting, cognitive domains related to freezing. Results Although stride length was not different across groups, change in stride length between normal and dual-task gait (ie, dual-task interference) was more pronounced in people with PD who freeze compared to non-freezers. Further, in people with PD who freeze, dual-task interference was correlated with asymmetry of pedunculopontine nucleus structural connectivity, Go-NoGo target accuracy (ability to release a response) and simple reaction time. Conclusions These results support the hypothesis that freezing is related to altered attentional control during gait, and suggest that differences in pedunculopontine nucleus connectivity contribute to poorer attentional control in people with PD who freeze. PMID:25224677

  10. Mental animation in the visuospatial sketchpad: evidence from dual-task studies.

    PubMed

    Sims, V K; Hegarty, M

    1997-05-01

    We used the dual-task paradigm to provide evidence that inferring the motion of a component of a mechanical system (mental animation) is a spatial visualization process. In two experiments, participants were asked to solve mental animation problems while simultaneously retaining either a visuospatial working memory load (a configuration of dots in a grid) or a verbal memory load (a list of letters). Both experiments showed that mental animation interferes more with memory for a concurrent visuospatial load than with memory for a verbal load. Experiment 1 also showed that a visuospatial working memory load interferes more with mental animation than does a verbal memory load. Furthermore, Experiment 2 showed that mental animation interferes more with a visuospatial memory load than does a verbal reasoning task that takes approximately the same amount of time.

  11. 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.

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

    PubMed Central

    Grarup, Bo; Bangshaab, Jette

    2016-01-01

    Introduction 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. Methods 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. Results 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. Conclusion 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. PMID:27487000

  13. 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…

  14. Cognition and dual-task performance in older adults with Parkinson’s and Alzheimer’s disease

    PubMed Central

    Christofoletti, Gustavo; Andrade, Larissa Pires; Beinotti, Fernanda; Borges, Guilherme

    2014-01-01

    Background Patients with neurodegenerative diseases usually experience significant functional deficits. Older adults with Parkinson’s disease (PD) and Alzheimer’s disease (AD) may suffer from both motor and cognitive impairments, making them especially vulnerable to poor dual-task performance. Objective To analyze the dual-task cost of walking in subjects with PD and AD exposed to motor and cognitive distracters. Methods A cross-sectional study was conducted involving 126 older adults comprising three groups: PD (n=43), AD (n=38), and control (n=45). The subjects were evaluated using the Timed Up and Go (TUG) test administered with motor and cognitive distracters. Mixed-design analysis of variance (ANOVA) with cognition as a covariant factor was used to test the possible main effects of dual-task on motion. A 5% threshold for significance was set, with a 95% confidence interval (CI). The partial eta square (n2p) analysis was included to estimate the magnitude of effect. Results Examining the effects for dual-task, ANOVA revealed the main effect for group×task interactions (F=13.09; P=0.001; n2p =0.178), for task (F=8.186; P=0.001; n2p =0.063) but not for group (F=2.954; P=0.056; n2p =0.047). Cognition applied as a covariant factor indicated interference on dual-tasks (F=30.43; P=0.001; n2p =0.201). Conclusion The findings of this study suggest that dual-task interference is a particularly noticeable problem in PD and AD, affecting subjects’ ability to appropriately adapt to environmental challenges. PMID:25092996

  15. 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.

  16. Memorizing while walking: increase in dual-task costs from young adulthood to old age.

    PubMed

    Lindenberger, U; Marsiske, M; Baltes, P B

    2000-09-01

    The dual task of memorizing word lists while walking was predicted to become more difficult with age because balance and gait are in greater need of "attentional resources." Forty-seven young (ages 20-30 years), 45 middle-aged (40-50), and 48 old (60-70) adults were trained to criterion in a mnemonic technique and instructed to walk quickly and accurately on 2 narrow tracks of different path complexity. Then. participants encoded the word lists while sitting, standing, or walking on either track; likewise, speed and accuracy of walking performance were assessed with and without concurrent memory encoding. Dual-task costs increased with age in both domains; relative to young adults, the effect size of the overall increase was 0.98 standard deviation units for middle-aged and 1.47 standard deviation units for old adults. It is argued that sensory and motor aspects of behavior are increasingly in need of cognitive control with advancing age.

  17. Effects of regular exercise and dual tasking on spatial and temporal parameters of obstacle negotiation in elderly women.

    PubMed

    Guadagnin, E C; da Rocha, E S; Mota, C B; Carpes, F P

    2015-09-01

    This study investigated the effects of regular exercise and dual tasking on bilateral spatial and temporal parameters of obstacle negotiation in elderly women. Sedentary (n=12) and physically active (n=12) elderly women volunteered to participate in this study. Gait kinematics were recorded during obstacle crossing when performing a dual task and when not performing a dual task. Physically active participants crossed obstacles more safely, in terms of clearance or distance to or over the obstacle, both with and without dual tasking, and usually for both lead and trail legs. Performing the dual task increased toe distance, and decreased heel distance and gait speed in the active participants, and increased toe clearance and heel distance, and decreased gait speed in the sedentary participants. Differences between preferred and non-preferred leg were accentuated for toe clearance in the lead limb. These results suggest that specialized exercises may not be needed for improvement in obstacle avoidance skills in the elderly, and participation in multi-activities, including aerobic exercises, may be sufficient. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. 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.

  19. Effect of dual-task-induced uncertainty on gait biomechanics in patients with multiple sclerosis with 2-6.5 EDSS grade.

    PubMed

    Gutiérrez Cruz, Carmen; Miangolarra Page, Juan Carlos; Rojas Ruiz, F Javier

    2016-09-01

    The goal of this study was to assess the effect that uncertainty induced by dual task conditions has on reaction-response time parameters and gait patterns of patients with multiple sclerosis (MS) with a 2-6.5 EDSS grade. The study involved eleven patients - nine women and two men - diagnosed with multiple sclerosis (age, 48±10years; height, 1.65±0.1m; weight, 72±22kg) with capacity to walk five meters without any aid or assistance. We employed an intra-group repeated measures design. Each participant was asked to walk with and without task-related uncertainty. Reaction-response and gait cycle times, as well as center of mass (CM) dynamics were measured using three force plates synchronized with a video camera through an electronic device that also controlled the system of uncertainty. The results obtained reveal that uncertainty induced by dual tasking is related to a reduction in the mean stride length and mean displacement and horizontal velocity of the CM in patients with MS. The values obtained for CM parameters indicate that uncertainty affects balance, as compared to no-uncertainty situations. These results confirm the necessity of including controlled dual-task-induced uncertainty in physical training programs for MS patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. 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

  1. The relationship between dual-task and cognitive performance among elderly participants who exercise regularly.

    PubMed

    Lima, Luciana C A; Ansai, Juliana H; Andrade, Larissa P; Takahashi, Anielle C M

    2015-01-01

    The dual-task performance is associated with the functionality of the elderly and it becomes more complex with age. To investigate the relationship between the Timed Up and Go dual task (TUG-DT) and cognitive tests among elderly participants who exercise regularly. 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. 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. 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.

  2. 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.

  3. Locus of semantic interference in picture naming: Evidence from dual-task performance.

    PubMed

    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 perceptual or conceptual processing, prior to lexical response-selection. In these studies, participants manually responded to a tone and named a picture while ignoring a written distractor word. The stimulus onset asynchrony (SOA) between tone and picture-word stimulus was manipulated. Semantic interference in naming latencies was present at long tone pre-exposure SOAs, but reduced or absent at short SOAs. Under the prevailing structural or strategic response-selection bottleneck and central capacity sharing models of dual-task performance, the underadditivity of the effects of SOA and stimulus type suggests that semantic interference emerges before lexical response-selection. However, in more recent studies, additive effects of SOA and stimulus type were obtained. Here, we examined the discrepancy in results between these studies in 6 experiments in which we systematically manipulated various dimensions on which these earlier studies differed, including tasks, materials, stimulus types, and SOAs. In all our experiments, additive effects of SOA and stimulus type on naming latencies were obtained. These results strongly suggest that the semantic interference effect arises after perceptual and conceptual processing, during lexical response-selection or later. We discuss several theoretical alternatives with respect to their potential to account for the discrepancy between the present results and other studies showing underadditivity.

  4. Examining the time course of attention in a soccer kick using a dual task paradigm.

    PubMed

    Carr, Brendan M; Etnier, Jennifer L; Fisher, Kevin M

    2013-02-01

    A dual-task paradigm was implemented using a repeated measures design to determine the time course of attention demands during performance of a soccer penalty kick. Experienced soccer players (N=15) were asked to perform a 12-yard soccer-style penalty kick. As part of the dual task paradigm, participants were instructed to respond to an audible cue that was administered during one of three probe positions (PP) during the penalty kick. Probe position 1 (PP1) was operationalized as the participant's second to last step (taken with the non-kicking foot), probe position 2 (PP2) was the next to last step (taken with the kicking foot), and probe position 3 (PP3) was the last step (taken with the non-kicking, or "plant foot") just prior to the kicking foot making contact with the ball. Kicks were taken with both the dominant foot (DF) and the non-dominant foot (NDF). It was hypothesized that reaction time to the audible cue (RT) would be slowest at the beginning and end of the performance of the motor skill in both the DF and NDF situations and that RT would be slower when kicking with the NDF, but that the kicking foot would not affect the pattern of attentional demands. Results indicated that RT was slowest at PP1 for both the DF and the NDF and that RT was significantly slower at PP1 for the DF than for the NDF. This suggests that soccer players engage in more complex planning during the preparatory phases when executing a kick with their dominant foot. Future research should be designed to further our understanding of foot dominance with regard to kicking and to explore attentional demands of striking tasks. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. 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.

  6. 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

  7. Dual-task performance in space: results from a single-case study during a short-term space mission.

    PubMed

    Manzey, D; Lorenz, B; Schiewe, A; Finell, G; Thiele, G

    1995-12-01

    During spaceflights, astronauts are exposed to many stressors (e.g., microgravity, confinement) that may impair human information-processing capabilities. In order to analyze the possible effects of the space environment on human time-sharing efficiency, a single-case experiment was conducted in which the time course of dual-task performance (unstable tracking with concurrent memory search) of one space crew member was monitored repeatedly (13 times) throughout an 8-day space mission. Tasks were taken from the Advisory Group for Aerospace Research and Development battery of Standardized Tests for Research with Environmental Stressors. Comparisons of in-flight, preflight, and postflight performance revealed no decrements in single-task memory search performance but did reveal clear impairments in single-task tracking and dual-task performance. From these results we conclude that psychomotor processes and higher attentional functions are particularly prone to disturbance effects in space.

  8. 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.

  9. 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 F20,186  = 3.37, P < 0.001. No overall significant difference between faller and non-faller groups (Wilk's Lambda F10,96  = 1.469, P = 0.163) or significant interaction between task and faller status (Wilk's Lambda F20,192  = 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 fallers

  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. 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.

  12. 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.

  13. Electrocortical Sources Related to Whole-Body Surface Translations during a Single- and Dual-Task Paradigm

    PubMed Central

    Bogost, Mark D.; Burgos, Pablo I.; Little, C. Elaine; Woollacott, Marjorie H.; Dalton, Brian H.

    2016-01-01

    Appropriate reactive motor responses are essential in maintaining upright balance. However, little is known regarding the potential location of cortical sources that are related to the onset of a perturbation during single- and dual-task paradigms. The purpose of this study was to estimate the location of cortical sources in response to a whole-body surface translation and whether diverted attention decreases the N1 event-related potential (ERP) amplitude related to a postural perturbation. This study utilized high-resolution electroencephalography in conjunction with measure projection analysis from ERPs time-locked to backwards surface translation onsets to determine which cortical sources were related to whole-body postural perturbations. Subjects (n = 15) either reacted to whole-body surface translations with (dual task) or without (single task) performing a visual working memory task. For the single task, four domains were identified that were mainly localized within the frontal and parietal lobes and included sources from the prefrontal, premotor, primary and supplementary motor, somatosensory and anterior cingulate cortex. Five domains were estimated for the dual task and also included sources within the frontal and parietal lobes, but the sources also shifted to other locations that included areas within the temporal and occipital lobes. Additionally, mean absolute N1 ERP amplitudes representing the activity from similar locations in both tasks were greater for the single than dual task. The present localization results highlight the importance of frontal, parietal and anterior cingulate cortical areas in reactive postural control and suggest a re-allocation or shift of cortical sources related to reactive balance control in the presence of a secondary task. Thus, this study provides novel insight into the underlying neurophysiology and contribution of cortical sources in relation to the neural control of reactive balance. PMID:27803658

  14. Electrocortical Sources Related to Whole-Body Surface Translations during a Single- and Dual-Task Paradigm.

    PubMed

    Bogost, Mark D; Burgos, Pablo I; Little, C Elaine; Woollacott, Marjorie H; Dalton, Brian H

    2016-01-01

    Appropriate reactive motor responses are essential in maintaining upright balance. However, little is known regarding the potential location of cortical sources that are related to the onset of a perturbation during single- and dual-task paradigms. The purpose of this study was to estimate the location of cortical sources in response to a whole-body surface translation and whether diverted attention decreases the N1 event-related potential (ERP) amplitude related to a postural perturbation. This study utilized high-resolution electroencephalography in conjunction with measure projection analysis from ERPs time-locked to backwards surface translation onsets to determine which cortical sources were related to whole-body postural perturbations. Subjects (n = 15) either reacted to whole-body surface translations with (dual task) or without (single task) performing a visual working memory task. For the single task, four domains were identified that were mainly localized within the frontal and parietal lobes and included sources from the prefrontal, premotor, primary and supplementary motor, somatosensory and anterior cingulate cortex. Five domains were estimated for the dual task and also included sources within the frontal and parietal lobes, but the sources also shifted to other locations that included areas within the temporal and occipital lobes. Additionally, mean absolute N1 ERP amplitudes representing the activity from similar locations in both tasks were greater for the single than dual task. The present localization results highlight the importance of frontal, parietal and anterior cingulate cortical areas in reactive postural control and suggest a re-allocation or shift of cortical sources related to reactive balance control in the presence of a secondary task. Thus, this study provides novel insight into the underlying neurophysiology and contribution of cortical sources in relation to the neural control of reactive balance.

  15. 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.

  16. 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

  17. College students' awareness of irrational judgments on gambling tasks: a dual-process account.

    PubMed

    Amsel, Eric; Close, Jason; Sadler, Eric; Klaczynski, Paul A

    2009-05-01

    In 2 studies, the authors examined college students' awareness of irrational judgments on gambling tasks. Participants could express a preference between 2 gambles with equivalent ratios (1:10 vs. 10:100) for Study 1 or no preference for Study 2. Participants also rated their certainty that each response option (i.e., 1:10, 10:100, no preference) was rational (analytically based processing) or irrational (experientially based processing of the ratio information). Only a minority of participants in each study was certain that the only analytically based, rational response was no preference. Those participants who were unaware of the analytically based rational response engaged in more formal and informal gambling activities in comparison with others. The authors interpreted the results as evidence of the importance of regulating dual analytical and experiential processes on gambling-related decision making and behavior.

  18. A dual-pressure boundary condition for use in simulations of bifurcating conduits.

    PubMed

    Gin, Ron; Straatman, Anthony G; Steinman, David A

    2002-10-01

    A dual-pressure boundary condition has been developed for computational modelling of bifurcating conduits. The condition involves the imposition of a constant pressure on one branch while adjusting iteratively the pressure on the other branch until the desired flow division is obtained. The dual-pressure condition eliminates the need for specifying fully-developed flow conditions, which thereby enables significant reduction of the outlet branch lengths. The dual-pressure condition is suitable for both steady and time-periodic simulations of laminar or turbulent flows.

  19. Physical training-related changes in gait variability while single and dual tasking in older adults: magnitude of gait variability at baseline matters.

    PubMed

    Beauchet, O; Launay, C; Annweiler, C; Fantino, B; Allali, G; De Decker, L

    2013-12-01

    Few studies have examined the effects of physical training programs on gait variability while single and dual tasking, and they reported mixed results. The aim of this study was to compare the stride time variability while single and dual tasking before and after a physical training program developed to improve gait stability in French community-dwelling older adults. A prospective pre-post interventional cohort study. The community-dwelling area of "Pays de la Loire", France. Forty-eight older adults (mean age ± standard deviation 72.2±8 years; 75% female). Physical training program consisted in 12 sessions scheduled to attend physical exercises 1 time a week with total time duration of 3 months. Coefficient of variation (CoV) of stride time under three walking conditions (i.e., walking alone, walking while backward counting, and while performing a verbal fluency task) was determined while steady-state walking using the SMTEC® footswitches system before and after the physical training program. Participants were separated into two groups based on being or not in the highest tertile (i.e., worst performance with cutpoint >4.4%) of the CoV of stride time while walking alone. After physical training compared to before period, a significant decrease in CoV of stride time (i.e., better gait performance) while walking alone (2.8±2.8% versus 7±7.1%, P=0.001) but not while dual tasking (P=0.600 for counting backward and P=0.105 for verbal fluency task) was shown in participants who had highest (i.e., worst) gait variability at baseline. In addition, physical training modified the strategy of dual tasking in participants with highest gait variability at baseline compared to the other participants. Before training, a significant decrease in CoV of stride time (7±7.1% versus 4.9±4.6%, P=0.017) while counting backward was shown, but there was a significant increase after training (2.8±2.8% versus 5.4±5.8%, P=0.007). Physical training reduced gait variability while

  20. 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

  1. 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

  2. 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.

  3. 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…

  4. 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.

  5. Dual-task performance with ideomotor-compatible tasks: is the central processing bottleneck intact, bypassed, or shifted in locus?

    NASA Technical Reports Server (NTRS)

    Lien, Mei-Ching; McCann, Robert S.; Ruthruff, Eric; Proctor, Robert W.

    2005-01-01

    The present study examined whether the central bottleneck, assumed to be primarily responsible for the psychological refractory period (PRP) effect, is intact, bypassed, or shifted in locus with ideomotor (IM)-compatible tasks. In 4 experiments, factorial combinations of IM- and non-IM-compatible tasks were used for Task 1 and Task 2. All experiments showed substantial PRP effects, with a strong dependency between Task 1 and Task 2 response times. These findings, along with model-based simulations, indicate that the processing bottleneck was not bypassed, even with two IM-compatible tasks. Nevertheless, systematic changes in the PRP and correspondence effects across experiments suggest that IM compatibility shifted the locus of the bottleneck. The findings favor an engage-bottleneck-later hypothesis, whereby parallelism between tasks occurs deeper into the processing stream for IM- than for non-IM-compatible tasks, without the bottleneck being actually eliminated.

  6. Practice-related optimization and transfer of executive functions: a general review and a specific realization of their mechanisms in dual tasks.

    PubMed

    Strobach, Tilo; Salminen, Tiina; Karbach, Julia; Schubert, Torsten

    2014-11-01

    Improvements in performing demanding and complex task situations are typically related to the optimization of executive functions and efficient behavioral control. The present study systematizes and reviews the optimization of different executive function types: Shifting, Inhibition, Updating, and Dual tasking. In particular, we focus on optimisations of these functions with training and on transfer effects of related training skills to non-trained situations. The aim of the study's empirical part (see also Appendix) was to investigate the specific mechanisms of executive functions in the context of Dual tasking, leading to improved dual-task performance after practice. More specifically, we tested the Efficient Task Instantiation (ETI) model that includes specific assumptions regarding practice-related improvements of executive task coordination skills: Dual-task performance is improved with practice because of an efficient and conjoint instantiation of sets of relevant task information in working memory at the onset of a dual task. According to our knowledge, the ETI model is one of the first that allows illustrating the contribution of cognitive mechanisms underlying practice-related improvements in performing dual tasks and the impact of task coordination skills on this performance.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Field dependence-independence from a working memory perspective: A dual-task investigation of the Hidden Figures Test.

    PubMed

    Miyake, Akira; Witzki, Alexander H.; Emerson, Michael J.

    2001-07-01

    Field dependence-independence (FDI) is a construct intensively investigated within cognitive style research, but its cognitive underpinnings are not clearly specified. We propose that performance on FDI tasks primarily reflects the operations of the visuospatial and executive components of working memory. We tested this hypothesis in a dual-task experiment with a commonly used measure of FDI, the Hidden Figures Test. The results showed that performance on this test was impaired by concurrent performance of secondary tasks that primarily tap the visuospatial component (spatial tapping) and the executive component (2-back and random number generation), but was almost unaffected by other secondary tasks (simple tapping and articulatory suppression). Moreover, an analysis of secondary task performance ruled out the possibility of strategic trade-offs and revealed an intriguing dissociation for two different sets of "randomness" indices for the random number generation task. These results support the hypothesised mapping between FDI and working memory components and suggest that the dual-task paradigm can provide a useful way to bring underspecified constructs like FDI into closer alignment with theoretical ideas developed within cognitive psychology.

  13. Field dependence-independence from a working memory perspective: a dual-task investigation of the Hidden Figures test.

    PubMed

    Miyake, A; Witzki, A H; Emerson, M J

    2001-01-01

    Field dependence-independence (FDI) is a construct intensively investigated within cognitive style research, but its cognitive underpinnings are not clearly specified. We propose that performance on FDI tasks primarily reflects the operations of the visuospatial and executive components of working memory. We tested this hypothesis in a dual-task experiment with a commonly used measure of FDI, the Hidden Figures Test. The results showed that performance on this test was impaired by concurrent performance of secondary tasks that primarily tap the visuospatial component (spatial tapping) and the executive component (2-back and random number generation), but was almost unaffected by other secondary tasks (simple tapping and articulatory suppression). Moreover, an analysis of secondary task performance ruled out the possibility of strategic trade-offs and revealed an intriguing dissociation for two different sets of "randomness" indices for the random number generation task. These results support the hypothesised mapping between FDI and working memory components and suggest that the dual-task paradigm can provide a useful way to bring underspecified constructs like FDI into closer alignment with theoretical ideas developed within cognitive psychology.

  14. 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.

  15. Simulated Firefighting Task Performance and Physiology Under Very Hot Conditions

    PubMed Central

    Larsen, Brianna; Snow, Rod; Williams-Bell, Michael; Aisbett, Brad

    2015-01-01

    Purpose: To assess the impact of very hot (45°C) conditions on the performance of, and physiological responses to, a simulated firefighting manual-handling task compared to the same work in a temperate environment (18°C). Methods: Ten male volunteer firefighters performed a 3-h protocol in both 18°C (CON) and 45°C (VH). Participants intermittently performed 12 × 1-min bouts of raking, 6 × 8-min bouts of low-intensity stepping, and 6 × 20-min rest periods. The area cleared during the raking task determined work performance. Core temperature, skin temperature, and heart rate were measured continuously. Participants also periodically rated their perceived exertion (RPE) and thermal sensation. Firefighters consumed water ad libitum. Urine specific gravity (USG) and changes in body mass determined hydration status. Results: Firefighters raked 19% less debris during the VH condition. Core and skin temperature were 0.99 ± 0.20 and 5.45 ± 0.53°C higher, respectively, during the VH trial, and heart rate was 14–36 beats.min−1 higher in the VH trial. Firefighters consumed 2950 ± 1034 mL of water in the VH condition, compared to 1290 ± 525 in the CON trial. Sweat losses were higher in the VH (1886 ± 474 mL) compared to the CON trial (462 ± 392 mL), though both groups were hydrated upon protocol completion (USG < 1.020). Participants' average RPE was higher in the VH (15.6 ± 0.9) compared to the CON trial (12.6 ± 0.9). Similarly, the firefighers' thermal sensation scores were significantly higher in the VH (6.4 ± 0.5) compared to the CON trial (4.4 ± 0.4). Conclusions: Despite the decreased work output and aggressive fluid replacement observed in the VH trial, firefighters' experienced increases in thermal stress, and exertion. Fire agencies should prioritize the health and safety of fire personnel in very hot temperatures, and consider the impact of reduced productivity on fire suppression efforts. PMID:26617527

  16. A preliminary study of longitudinal differences in local dynamic stability between recently concussed and healthy athletes during single and dual-task gait.

    PubMed

    Fino, Peter C

    2016-06-14

    Concussed individuals commonly exhibit locomotor deficits during dual-task gait that can last substantially longer than clinical signs and symptoms. Previous studies have examined traditional stability measures, but nonlinear stability may offer further information about the health of the motor control system post-concussion. For up to one year post-concussion, this study longitudinally examined the local dynamic stability of five concussed athletes and four matched healthy controls during single- and dual-task gait. Local dynamic stability (LDS) was estimated using short-term, finite-time maximum Lyapunov exponents calculated from tri-axial accelerometers placed on the trunk and head. No main effects of group or task were found for LDS or stride time variability, but significant group*task interactions were apparent for trunk stability and stride time variability. Concussed individuals exhibited decreased trunk LDS and increased stride time variability during dual-task walking compared to matched controls despite similar single-task stability and variability. These preliminary results reinforce previous reports that concussions persistently affect dual-task processes even when single-tasks may be unaffected. Furthermore, the decreased local dynamic stability during dual-task gait indicates the concussed group attenuated local disturbances less than their healthy teammates. The decreased dynamic stability during dual-task activities was present after the athletes were cleared for competition and may be a contributing factor in the higher rates of musculoskeletal injuries in athletes post-concussion.

  17. Comparable Cerebral Oxygenation Patterns in Younger and Older Adults during Dual-Task Walking with Increasing Load

    PubMed Central

    Fraser, Sarah A.; Dupuy, Olivier; Pouliot, Philippe; Lesage, Frédéric; Bherer, Louis

    2016-01-01

    The neuroimaging literature on dual-task gait clearly demonstrates increased prefrontal cortex (PFC) involvement when performing a cognitive task while walking. However, findings from direct comparisons of the cerebral oxygenation patterns of younger (YA) and older (OA) adults during dual-task walking are mixed and it is unclear how YA and OA respond to increasing cognitive load (difficulty) while walking. This functional near infra-red (fNIRS) study examined cerebral oxygenation of YA and OA during self-paced dual-task treadmill walking at two different levels of cognitive load (auditory n-back). Changes in accuracy (%) as well as oxygenated (HbO) and deoxygenated (HbR) hemoglobin were examined. For the HbO and HbR measures, eight regions of interest (ROIs) were assessed: the anterior and posterior dorsolateral and ventrolateral PFC (aDLPFC, pDLPFC, aVLPFC, pVLPFC) in each hemisphere. Nineteen YA (M = 21.83 years) and 14 OA (M = 66.85 years) walked at a self-selected pace while performing auditory 1-back and 2-back tasks. Walking alone (single motor: SM) and performing the cognitive tasks alone (single cognitive: SC) were compared to dual-task walking (DT = SM + SC). In the behavioural data, participants were more accurate in the lowest level of load (1-back) compared to the highest (2-back; p < 0.001). YA were more accurate than OA overall (p = 0.009), and particularly in the 2-back task (p = 0.048). In the fNIRS data, both younger and older adults had task effects (SM < DT) in specific ROIs for ΔHbO (three YA, one OA) and ΔHbR (seven YA, eight OA). After controlling for walk speed differences, direct comparisons between YA and OA did not reveal significant age differences, but did reveal a difficulty effect in HbO in the left aDLPFC (p = 0.028) and significant task effects (SM < DT) in HbR for six of the eight ROIs. Findings suggest that YA and OA respond similarly to manipulations of cognitive load when walking on a treadmill at a self-selected pace. PMID

  18. Condition interference in rats performing a choice task with switched variable- and fixed-reward conditions

    PubMed Central

    Funamizu, Akihiro; Ito, Makoto; Doya, Kenji; Kanzaki, Ryohei; Takahashi, Hirokazu

    2015-01-01

    Because humans and animals encounter various situations, the ability to adaptively decide upon responses to any situation is essential. To date, however, decision processes and the underlying neural substrates have been investigated under specific conditions; thus, little is known about how various conditions influence one another in these processes. In this study, we designed a binary choice task with variable- and fixed-reward conditions and investigated neural activities of the prelimbic cortex and dorsomedial striatum in rats. Variable- and fixed-reward conditions induced flexible and inflexible behaviors, respectively; one of the two conditions was randomly assigned in each trial for testing the possibility of condition interference. Rats were successfully conditioned such that they could find the better reward holes of variable-reward-condition and fixed-reward-condition trials. A learning interference model, which updated expected rewards (i.e., values) used in variable-reward-condition trials on the basis of combined experiences of both conditions, better fit choice behaviors than conventional models which updated values in each condition independently. Thus, although rats distinguished the trial condition, they updated values in a condition-interference manner. Our electrophysiological study suggests that this interfering value-updating is mediated by the prelimbic cortex and dorsomedial striatum. First, some prelimbic cortical and striatal neurons represented the action-reward associations irrespective of trial conditions. Second, the striatal neurons kept tracking the values of variable-reward condition even in fixed-reward-condition trials, such that values were possibly interferingly updated even in the fixed-reward condition. PMID:25741231

  19. 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.

  20. Stimulus complexity and dual tasking effects on sustained auditory attention in noise.

    PubMed

    Abel, Sharon M

    2009-05-01

    The effect on sustained auditory attention of a constellation of factors that characterize aviation, maritime, and land environments was investigated. The ability to detect infrequent spoken messages while performing an unrelated visual motor tracking task was studied in the presence of background noise. Six subjects each were assigned to four conditions defined by the presence/absence of 80-dBA pink noise and presence/absence of the secondary task. Subjects were given three detection tests in which the 75-dB SPL critical signal was comprised of one, two, or three components. A button press with the left hand signified detection of the critical signal. For each test there were six consecutive 20-min vigils comprised of 150 trials. The critical signal was presented in 10 of these. For the tracking task subjects used a computer mouse controlled by the right hand to follow the sinusoidal movement of a 3-cm vertical line across a computer monitor. Background noise resulted in a significant decrease in hits, and significant increases in false alarms and response time. Since the signal and noise were both auditory, the noise was likely effective as a masker rather than a stressor. The secondary task did not impact performance, possibly because the auditory task was too easy and the event rate too slow. As in previous studies using alphanumeric events, there was no attention decrement over time. However, response time decreased as the number of components in the critical signal increased. Possible explanations are guided attention through priming or the provision of a temporal foreperiod.

  1. Amygdalar unit activity during three learning tasks: eyeblink classical conditioning, Pavlovian fear conditioning, and signaled avoidance conditioning.

    PubMed

    Rorick-Kehn, Linda M; Steinmetz, Joseph E

    2005-10-01

    Neural activity in central and basolateral amygdala nuclei (CeA and BLA, respectively) was recorded during delay eyeblink conditioning, Pavlovian fear conditioning, and signaled barpress avoidance. During paired training, the CeA exhibited robust learning-related excitatory activity during all 3 tasks. By contrast, the BLA exhibited minimal activity during eyeblink conditioning, while demonstrating pronounced increases in learning-related excitatory responsiveness during fear conditioning and barpress avoidance. In addition, the relative amount of amygdalar activation observed appeared to be related to the relative intensity of the unconditioned stimulus and somatic requirements of the task. Results suggest the CeA mediates the Pavlovian association between sensory stimuli and the BLA mediates the modulation of instrumental responding through the assignment of motivational value to the unconditioned stimulus.

  2. The efficacy and psychophysiological correlates of dual-attention tasks in eye movement desensitization and reprocessing (EMDR).

    PubMed

    Schubert, Sarah J; Lee, Christopher W; Drummond, Peter D

    2011-01-01

    This study aimed to investigate the psychophysiological correlates and the effectiveness of different dual-attention tasks used during eye movement desensitization and reprocessing (EMDR). Sixty-two non-clinical participants with negative autobiographical memories received a single session of EMDR without eye movements, or EMDR that included eye movements of either varied or fixed rate of speed. Subjective units of distress and vividness of the memory were recorded at pre-treatment, post-treatment, and 1 week follow-up. EMDR-with eye movements led to greater reduction in distress than EMDR-without eye movements. Heart rate decreased significantly when eye movements began; skin conductance decreased during eye movement sets; heart rate variability and respiration rate increased significantly as eye movements continued; and orienting responses were more frequent in the eye movement than no-eye movement condition at the start of exposure. Findings indicate that the eye movement component in EMDR is beneficial, and is coupled with distinct psychophysiological changes that may aid in processing negative memories.

  3. 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.

  4. Task Integration Facilitates Multitasking

    PubMed Central

    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. PMID:28360878

  5. The Role of Practice in Dual-Task Performance: Toward Workload Modelling in a Connectionist/Control Architecture

    DTIC Science & Technology

    1987-09-29

    with physiological data suggesting the existence of a two-speed learning system (see Mishkin , Malamut, & Bachevalier. 1984). Dual-task practice 28...Irlon, A. L. (1952). The psychology q human learning. 2nd Ed. New York: Longmans, Green, & Co. Mishkin , M.. & Appenzeller, T. (1987). The anatomy of...memory. Scientific American, 258s80-89. Mishkin , M.. Malamut, B., & Bachevaller, J. (1984). Memories and habits: Two neural systems. In G. Lynch. L

  6. 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…

  7. Impaired depth perception and restricted pitch head movement increase obstacle contacts when dual-tasking in older people.

    PubMed

    Menant, Jasmine C; St George, Rebecca J; Fitzpatrick, Richard C; Lord, Stephen R

    2010-07-01

    Trips are the largest contributor to falls in older people, yet little is known about the underlying physiological mechanisms for safe obstacle negotiation. The aims of the study were to determine (i) the effect of a secondary visual task on obstacle contacts when older people negotiated an obstacle course and (ii) physiological factors associated with obstacle contacts. Thirty community-living adults aged 65 years and older walked along a 14.5-m walkway containing 21 obstacles with and without a secondary task. The secondary task required participants to call out a series of letters presented in front of them at head height and the suit of a playing card framed on the sidewall. Obstacle contacts, secondary task errors, eye peak-to-peak pitch amplitude and head peak-to-peak pitch amplitude (PA-H), and head angle in pitch were measured. Participants also completed assessments of sensorimotor function and balance. Compared with the obstacle-only trials, participants performed the dual-task trials more slowly (p < .001), contacted more obstacles (p = .032), showed greater PA-H (p < .001), and an extended head position (p < .001). Most participants also made secondary task errors. Regression analysis revealed that depth perception was the only significant determinant of obstacle contacts (explaining 20.6% of the variance) in the obstacle-only task and that depth perception and PA-H were independent and significant determinants of obstacle contacts (explaining 42.3% of the variance) in the dual task. The findings demonstrate the importance of depth perception and head movement for safe negotiation of obstacles in older people and suggest that depth perception in particular should form part of fall risk assessments.

  8. Sequential search asymmetry: Behavioral and psychophysiological evidence from a dual oddball task.

    PubMed

    Blundon, Elizabeth G; Rumak, Samuel P; Ward, Lawrence M

    2017-01-01

    We conducted five experiments in order to explore the generalizability of a new type of search asymmetry, which we have termed sequential search asymmetry, across sensory modalities, and to better understand its origin. In all five experiments rare oddballs occurred randomly within longer sequences of more frequent standards. Oddballs and standards all consisted of rapidly-presented runs of five pure tones (Experiments 1 and 5) or five colored annuli (Experiments 2 through 4) somewhat analogous to simultaneously-presented feature-present and feature-absent stimuli in typical visual search tasks. In easy tasks feature-present reaction times and P300 latencies were shorter than feature-absent ones, similar to findings in search tasks with simultaneously-presented stimuli. Moreover the P3a subcomponent of the P300 ERP was strongly apparent only in the feature-present condition. In more difficult tasks requiring focused attention, however, RT and P300 latency differences disappeared but the P300 amplitude difference was significant. Importantly in all five experiments d' for feature-present targets was larger than that for feature-absent targets. These results imply that sequential search asymmetry arises from discriminability differences between feature-present and feature-absent targets. Response time and P300 latency differences can be attributed to the use of different attention strategies in search for feature-present and feature-absent targets, indexed by the presence of a dominant P3a subcomponent in the feature-present target-evoked P300s that is lacking in the P300s to the feature-absent targets.

  9. Sequential search asymmetry: Behavioral and psychophysiological evidence from a dual oddball task

    PubMed Central

    Blundon, Elizabeth G.; Rumak, Samuel P.

    2017-01-01

    We conducted five experiments in order to explore the generalizability of a new type of search asymmetry, which we have termed sequential search asymmetry, across sensory modalities, and to better understand its origin. In all five experiments rare oddballs occurred randomly within longer sequences of more frequent standards. Oddballs and standards all consisted of rapidly-presented runs of five pure tones (Experiments 1 and 5) or five colored annuli (Experiments 2 through 4) somewhat analogous to simultaneously-presented feature-present and feature-absent stimuli in typical visual search tasks. In easy tasks feature-present reaction times and P300 latencies were shorter than feature-absent ones, similar to findings in search tasks with simultaneously-presented stimuli. Moreover the P3a subcomponent of the P300 ERP was strongly apparent only in the feature-present condition. In more difficult tasks requiring focused attention, however, RT and P300 latency differences disappeared but the P300 amplitude difference was significant. Importantly in all five experiments d’ for feature-present targets was larger than that for feature-absent targets. These results imply that sequential search asymmetry arises from discriminability differences between feature-present and feature-absent targets. Response time and P300 latency differences can be attributed to the use of different attention strategies in search for feature-present and feature-absent targets, indexed by the presence of a dominant P3a subcomponent in the feature-present target-evoked P300s that is lacking in the P300s to the feature-absent targets. PMID:28278202

  10. 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

  11. Optimization of dual-energy imaging systems using generalized NEQ and imaging task.

    PubMed

    Richard, S; Siewerdsen, J H

    2007-01-01

    Dual-energy (DE) imaging is a promising advanced application of flat-panel detectors (FPDs) with a potential host of applications ranging from thoracic and cardiac imaging to interventional procedures. The performance of FPD-based DE imaging systems is investigated in this work by incorporating the noise-power spectrum associated with overlying anatomical structures ("anatomical noise" modeled according to a 1/f characteristic) into descriptions of noise-equivalent quanta (NEQ) to yield the generalized NEQ (GNEQ). Signal and noise propagation in the DE imaging chain is modeled by cascaded systems analysis. A Fourier-based description of the imaging task is integrated with the GNEQ to yield a detectability index used as an objective function for optimizing DE image reconstruction, allocation of dose between low- and high-energy images, and selection of low- and high-kVp. Optimal reconstruction and acquisition parameters were found to depend on dose; for example, optimal kVp varied from [60/150] kVp at typical radiographic dose levels (approximately 0.5 mGy entrance surface dose, ESD) but increased to [90/150] kVp at high dose (ESD approximately 5.0 mGy). At very low dose (ESD approximately 0.05 mGy), detectability index indicates an optimal low-energy technique of 60 kVp but was largely insensitive to the choice of high-kVp in the range 120-150 kVp. Similarly, optimal dose allocation, defined as the ratio of low-energy ESD and the total ESD, varied from 0.2 to 0.4 over the range ESD=(0.05-5.0) mGy. Furthermore, two applications of the theoretical framework were explored: (i) the increase in detectability for DE imaging compared to conventional radiography; and (ii) the performance of single-shot vs double-shot DE imaging, wherein the latter is found to have a DQE approximately twice that of the former. Experimental and theoretical analysis of GNEQ and task-based detectability index provides a fundamental understanding of the factors governing DE imaging performance

  12. Predicting falls with the cognitive timed up-and-go dual task in frail older patients.

    PubMed

    Cardon-Verbecq, Charlotte; Loustau, Marine; Guitard, Emilie; Bonduelle, Marie; Delahaye, Emmanuelle; Koskas, Pierre; Raynaud-Simon, Agathe

    2017-04-01

    The cognitive timed up-and-go dual task (CogTUG) has been proposed to improve the performance of the timed up-and-go (TUG) test for predicting falls in older patients and as a screening tool for early detection of frailty. We aimed to determine whether the CogTUG score is associated with a history of falls in frail older outpatients with gait disorders. This retrospective study involved outpatients >75 years old with or without previous falls who were admitted from 2012 to 2014 to a geriatric day hospital for gait disorders. Patients took the TUG and CogTUG tests on the day of comprehensive geriatric assessment. Among the 161 patients included (157 analyzed; mean age 84.4±6.2 years; 72% women), 84 (53.5%) had fallen in the previous year: 105 (66.9%) were considered pre-frail and 52 (33.1%) frail. As compared with non-fallers, fallers had lower Tinetti balance scores (P=0.0004) and handgrip strength (P=0.03), more lost weight (P=0.04), and they took longer to perform the TUG test (P=0.04). Fallers and non-fallers did not differ in time taken to perform the CogTUG test (30.7±11.2 vs. 28.5±10.2s, P=0.20). History of falls was associated with only weight loss (odds ratio 3.43; 95% CI 1.13-11.30, P=0.03) and handgrip strength (0.88; 0.78-0.97, P=0.02) on multivariate analysis. Unlike TUG scores, the CogTUG score was not associated a history of falls in frail older outpatients with gait disorders. Our results underline that weight loss and low muscle strength are related to falls. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. A training approach to improve stepping automaticity while dual-tasking in Parkinson's disease

    PubMed Central

    Chomiak, Taylor; Watts, Alexander; Meyer, Nicole; Pereira, Fernando V.; Hu, Bin

    2017-01-01

    Abstract Background: Deficits in motor movement automaticity in Parkinson's disease (PD), especially during multitasking, are early and consistent hallmarks of cognitive function decline, which increases fall risk and reduces quality of life. This study aimed to test the feasibility and potential efficacy of a wearable sensor-enabled technological platform designed for an in-home music-contingent stepping-in-place (SIP) training program to improve step automaticity during dual-tasking (DT). Methods: This was a 4-week prospective intervention pilot study. The intervention uses a sensor system and algorithm that runs off the iPod Touch which calculates step height (SH) in real-time. These measurements were then used to trigger auditory (treatment group, music; control group, radio podcast) playback in real-time through wireless headphones upon maintenance of repeated large amplitude stepping. With small steps or shuffling, auditory playback stops, thus allowing participants to use anticipatory motor control to regain positive feedback. Eleven participants were recruited from an ongoing trial (Trial Number: ISRCTN06023392). Fear of falling (FES-I), general cognitive functioning (MoCA), self-reported freezing of gait (FOG-Q), and DT step automaticity were evaluated. Results: While we found no significant effect of training on FES-I, MoCA, or FOG-Q, we did observe a significant group (music vs podcast) by training interaction in DT step automaticity (P<0.01). Conclusion: Wearable device technology can be used to enable musically-contingent SIP training to increase motor automaticity for people living with PD. The training approach described here can be implemented at home to meet the growing demand for self-management of symptoms by patients. PMID:28151878

  14. Dual-task training for balance and mobility in a person with severe traumatic brain injury: a case study.

    PubMed

    Fritz, Nora E; Basso, D Michele

    2013-03-01

    Attentional impairments following severe traumatic brain injury (TBI) are common and can lead to decreased functional mobility and balance, as well as deficits in previously automatic movements such as walking and stair climbing. The purpose of this case study was to determine the feasibility and potential value of incorporating a cognitive-motor dual-task training program into physical therapy for a patient with a severe TBI. The patient was a 26-year-old woman who sustained a severe TBI during a motor vehicle accident 46 days prior to physical therapy evaluation. On the 8-level Rancho Los Amigos Cognitive Function Scale, her functioning was classified as level IV. She had impairments in attention, functional mobility, and balance, all of which limited her ability to participate in activities of daily living. : Physical therapy was provided over 26 days within the inpatient rehabilitation setting. Interventions included mobility tasks such as walking, balancing, and stair climbing. Mobility training was paired with specific secondary cognitive and motor tasks. Dual-task training may have contributed to improvements on outcome measures designed to test divided attention including the Walking While Talking Test and Trail Making Test and a greater rate of improvement in walking speed and time to descend stairs when compared to the baseline phase. Addition of cognitive-motor dual-task training to standard physical therapy in the inpatient rehabilitation setting appears to be feasible and may have value for improving function in individuals with severe TBI. (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A41) for more insights from the authors.

  15. 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

  16. Dual-task and electrophysiological markers of executive cognitive processing in older adult gait and fall-risk.

    PubMed

    Walshe, Elizabeth A; Patterson, Matthew R; Commins, Seán; Roche, Richard A P

    2015-01-01

    The role of cognition is becoming increasingly central to our understanding of the complexity of walking gait. In particular, higher-level executive functions are suggested to play a key role in gait and fall-risk, but the specific underlying neurocognitive processes remain unclear. Here, we report two experiments which investigated the cognitive and neural processes underlying older adult gait and falls. Experiment 1 employed a dual-task (DT) paradigm in young and older adults, to assess the relative effects of higher-level executive function tasks (n-Back, Serial Subtraction and visuo-spatial Clock task) in comparison to non-executive distracter tasks (motor response task and alphabet recitation) on gait. All DTs elicited changes in gait for both young and older adults, relative to baseline walking. Significantly greater DT costs were observed for the executive tasks in the older adult group. Experiment 2 compared normal walking gait, seated cognitive performances and concurrent event-related brain potentials (ERPs) in healthy young and older adults, to older adult fallers. No significant differences in cognitive performances were found between fallers and non-fallers. However, an initial late-positivity, considered a potential early P3a, was evident on the Stroop task for older non-fallers, which was notably absent in older fallers. We argue that executive control functions play a prominent role in walking and gait, but the use of neurocognitive processes as a predictor of fall-risk needs further investigation.

  17. Dual-task and electrophysiological markers of executive cognitive processing in older adult gait and fall-risk

    PubMed Central

    Walshe, Elizabeth A.; Patterson, Matthew R.; Commins, Seán; Roche, Richard A. P.

    2015-01-01

    The role of cognition is becoming increasingly central to our understanding of the complexity of walking gait. In particular, higher-level executive functions are suggested to play a key role in gait and fall-risk, but the specific underlying neurocognitive processes remain unclear. Here, we report two experiments which investigated the cognitive and neural processes underlying older adult gait and falls. Experiment 1 employed a dual-task (DT) paradigm in young and older adults, to assess the relative effects of higher-level executive function tasks (n-Back, Serial Subtraction and visuo-spatial Clock task) in comparison to non-executive distracter tasks (motor response task and alphabet recitation) on gait. All DTs elicited changes in gait for both young and older adults, relative to baseline walking. Significantly greater DT costs were observed for the executive tasks in the older adult group. Experiment 2 compared normal walking gait, seated cognitive performances and concurrent event-related brain potentials (ERPs) in healthy young and older adults, to older adult fallers. No significant differences in cognitive performances were found between fallers and non-fallers. However, an initial late-positivity, considered a potential early P3a, was evident on the Stroop task for older non-fallers, which was notably absent in older fallers. We argue that executive control functions play a prominent role in walking and gait, but the use of neurocognitive processes as a predictor of fall-risk needs further investigation. PMID:25941481

  18. 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…

  19. 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

  20. Examining depletion theories under conditions of within-task transfer.

    PubMed

    Brewer, Gene A; Lau, Kevin K H; Wingert, Kimberly M; Ball, B Hunter; Blais, Chris

    2017-07-01

    In everyday life, mental fatigue can be detrimental across many domains including driving, learning, and working. Given the importance of understanding and accounting for the deleterious effects of mental fatigue on behavior, a growing body of literature has studied the role of motivational and executive control processes in mental fatigue. In typical laboratory paradigms, participants complete a task that places demand on these self-control processes and are later given a subsequent task. Generally speaking, decrements to subsequent task performance are taken as evidence that the initial task created mental fatigue through the continued engagement of motivational and executive functions. Several models have been developed to account for negative transfer resulting from this "ego depletion." In the current study, we provide a brief literature review, specify current theoretical approaches to ego-depletion, and report an empirical test of current models of depletion. Across 4 experiments we found minimal evidence for executive control depletion along with strong evidence for motivation mediated ego depletion. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  1. Conditional Reasoning in Context: A Dual-Source Model of Probabilistic Inference

    ERIC Educational Resources Information Center

    Klauer, Karl Christoph; Beller, Sieghard; Hutter, Mandy

    2010-01-01

    A dual-source model of probabilistic conditional inference is proposed. According to the model, inferences are based on 2 sources of evidence: logical form and prior knowledge. Logical form is a decontextualized source of evidence, whereas prior knowledge is activated by the contents of the conditional rule. In Experiments 1 to 3, manipulations of…

  2. Dual Functions of Perirhinal Cortex in Fear Conditioning

    PubMed Central

    Kent, Brianne A.; Brown, Thomas H.

    2012-01-01

    The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. In addition, the neuroanatomy and neurophysiology of rat PRC have been described in considerable detail at the cellular and systems levels. The evidence suggests that PRC can serve at least two types of mnemonic functions in Pavlovian fear conditioning. The first function, termed "stimulus unitization," refers to the ability to treat two or more separate items or stimulus elements as a single entity. Supporting evidence for this perceptual function comes from studies of context conditioning as well as delay conditioning to discontinuous auditory cues. In a delay paradigm, the conditional stimulus (CS) and unconditional stimulus (US) overlap temporally and co-terminate. The second PRC function entails a type of "transient memory." Supporting evidence comes from studies of trace cue conditioning, where there is a temporal gap or trace interval between the CS offset and the US onset. For learning to occur, there must be a transient CS representation during the trace interval. We advance a novel neurophysiological mechanism for this transient representation. These two hypothesized functions of PRC are consistent with inferences based on non-aversive forms of learning. PMID:22903623

  3. Dual functions of perirhinal cortex in fear conditioning.

    PubMed

    Kent, Brianne A; Brown, Thomas H

    2012-10-01

    The present review examines the role of perirhinal cortex (PRC) in Pavlovian fear conditioning. The focus is on rats, partly because so much is known, behaviorally and neurobiologically, about fear conditioning in these animals. In addition, the neuroanatomy and neurophysiology of rat PRC have been described in considerable detail at the cellular and systems levels. The evidence suggests that PRC can serve at least two types of mnemonic functions in Pavlovian fear conditioning. The first function, termed "stimulus unitization," refers to the ability to treat two or more separate items or stimulus elements as a single entity. Supporting evidence for this perceptual function comes from studies of context conditioning as well as delay conditioning to discontinuous auditory cues. In a delay paradigm, the conditional stimulus (CS) and unconditional stimulus (US) overlap temporally and co-terminate. The second PRC function entails a type of "transient memory." Supporting evidence comes from studies of trace cue conditioning, where there is a temporal gap or trace interval between the CS offset and the US onset. For learning to occur, there must be a transient CS representation during the trace interval. We advance a novel neurophysiological mechanism for this transient representation. These two hypothesized functions of PRC are consistent with inferences based on non-aversive forms of learning.

  4. Variation in dual-task performance reveals late initiation of speech planning in turn-taking.

    PubMed

    Sjerps, Matthias J; Meyer, Antje S

    2015-03-01

    The smooth transitions between turns in natural conversation suggest that speakers often begin to plan their utterances while listening to their interlocutor. The presented study investigates whether this is indeed the case and, if so, when utterance planning begins. Two hypotheses were contrasted: that speakers begin to plan their turn as soon as possible (in our experiments less than a second after the onset of the interlocutor's turn), or that they do so close to the end of the interlocutor's turn. Turn-taking was combined with a finger tapping task to measure variations in cognitive load. We assumed that the onset of speech planning in addition to listening would be accompanied by deterioration in tapping performance. Two picture description experiments were conducted. In both experiments there were three conditions: (1) Tapping and Speaking, where participants tapped a complex pattern while taking over turns from a pre-recorded speaker, (2) Tapping and Listening, where participants carried out the tapping task while overhearing two pre-recorded speakers, and (3) Speaking Only, where participants took over turns as in the Tapping and Speaking condition but without tapping. The experiments differed in the amount of tapping training the participants received at the beginning of the session. In Experiment 2, the participants' eye-movements were recorded in addition to their speech and tapping. Analyses of the participants' tapping performance and eye movements showed that they initiated the cognitively demanding aspects of speech planning only shortly before the end of the turn of the preceding speaker. We argue that this is a smart planning strategy, which may be the speakers' default in many everyday situations.

  5. 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.

  6. 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

  7. The role of domain-general frontal systems in language comprehension: evidence from dual-task interference and semantic ambiguity.

    PubMed

    Rodd, Jennifer M; Johnsrude, Ingrid S; Davis, Matthew H

    2010-12-01

    Neuroimaging studies have shown that the left inferior frontal gyrus (LIFG) plays a critical role in semantic and syntactic aspects of speech comprehension. It appears to be recruited when listeners are required to select the appropriate meaning or syntactic role for words within a sentence. However, this region is also recruited during tasks not involving sentence materials, suggesting that the systems involved in processing ambiguous words within sentences are also recruited for more domain-general tasks that involve the selection of task-relevant information. We use a novel dual-task methodology to assess whether the cognitive system(s) that are engaged in selecting word meanings are also involved in non-sentential tasks. In Experiment 1, listeners were slower to decide whether a visually presented letter is in upper or lower case when the sentence that they are simultaneously listening to contains words with multiple meanings (homophones), compared to closely matched sentences without homophones. Experiment 2 indicates that this interference effect is not tied to the occurrence of the homophone itself, but rather occurs when listeners must reinterpret a sentence that was initially misparsed. These results suggest some overlap between the cognitive system involved in semantic disambiguation and the domain-general process of response selection required for the case-judgement task. This cognitive overlap may reflect neural overlap in the networks supporting these processes, and is consistent with the proposal that domain-general selection processes in inferior frontal regions are critical for language comprehension.

  8. 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.

  9. The Association between High Neuroticism-Low Extraversion and Dual-Task Performance during Walking While Talking in Non-demented Older Adults.

    PubMed

    LeMonda, Brittany C; Mahoney, Jeannette R; Verghese, Joe; Holtzer, Roee

    2015-08-01

    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.

  10. 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

  11. Assessment of upper body accelerations in young adults with intellectual disabilities while walking, running, and dual-task running.

    PubMed

    Iosa, Marco; Morelli, Daniela; Nisi, Enrica; Sorbara, Carlo; Negrini, Stefano; Gentili, Paola; Paolucci, Stefano; Fusco, Augusto

    2014-04-01

    There is an increasing interest about upper body accelerations during locomotion and how they are altered by physical impairments. Recent studies have demonstrated that cognitive impairments affect gait stability in the elderly (i.e., their capacity for smoothing upper body accelerations during walking) but little attention has been paid to young adults with intellectual disabilities. The purpose of this study was to examine upright stability in young adults with intellectual disabilities during walking, running, and dual-task running (playing soccer). To this aim a wearable trunk-mounted device that permits on-field assessment was used to quantify trunk acceleration of 18 male teenagers with intellectual disabilities (IDG) and 7 mental-age-matched healthy children (HCG) who participated in the same soccer program. We did not find any significant difference during walking in terms of speed, whereas speed differences were found during running (p=.001). Upper body accelerations were altered in a pathology-specific manner during the dual task: the performance of subjects with autistic disorders was compromised while running and controlling the ball with the feet. Differences in upright locomotor patterns between IDG and HCG emerged during more demanding motor tasks in terms of a loss in the capacity of smoothing accelerations at the trunk level.

  12. Effectiveness of dual-task functional power training for preventing falls in older people: study protocol for a cluster randomised controlled trial.

    PubMed

    Daly, Robin M; Duckham, Rachel L; Tait, Jamie L; Rantalainen, Timo; Nowson, Caryl A; Taaffe, Dennis R; Sanders, Kerrie; Hill, Keith D; Kidgell, Dawson J; Busija, Lucy

    2015-03-27

    Falls are a major public health concern with at least one third of people aged 65 years and over falling at least once per year, and half of these will fall repeatedly, which can lead to injury, pain, loss of function and independence, reduced quality of life and even death. Although the causes of falls are varied and complex, the age-related loss in muscle power has emerged as a useful predictor of disability and falls in older people. In this population, the requirements to produce explosive and rapid movements often occurs whilst simultaneously performing other attention-demanding cognitive or motor tasks, such as walking while talking or carrying an object. The primary aim of this study is to determine whether dual-task functional power training (DT-FPT) can reduce the rate of falls in community-dwelling older people. The study design is an 18-month cluster randomised controlled trial in which 280 adults aged ≥65 years residing in retirement villages, who are at increased risk of falling, will be randomly allocated to: 1) an exercise programme involving DT-FPT, or 2) a usual care control group. The intervention is divided into 3 distinct phases: 6 months of supervised DT-FPT, a 6-month 'step down' maintenance programme, and a 6-month follow-up. The primary outcome will be the number of falls after 6, 12 and 18 months. Secondary outcomes will include: lower extremity muscle power and strength, grip strength, functional assessments of gait, reaction time and dynamic balance under single- and dual-task conditions, activities of daily living, quality of life, cognitive function and falls-related self-efficacy. We will also evaluate the cost-effectiveness of the programme for preventing falls. The study offers a novel approach that may guide the development and implementation of future community-based falls prevention programmes that specifically focus on optimising muscle power and dual-task performance to reduce falls risk under 'real life' conditions in older

  13. Cross-Modal Transfer of Conditioned Suppression in Rats: Effects of US Intensity and Extinction of the Initial Conditioning Task

    ERIC Educational Resources Information Center

    Doe, Nobutaka; Nakajima, Sadahiko; Tamai, Noriko

    2004-01-01

    In conditioned suppression of water licking behavior by rats, we obtained data indicating general transfer of fear conditioning. A series of experiments resulted in two major findings. First, pairing of a neutral stimulus with a shock in the initial conditioning task facilitated acquisition of subsequent fear conditioning to another neutral…

  14. Fear conditioning and extinction in anxious and nonanxious youth and adults: examining a novel developmentally appropriate fear-conditioning task.

    PubMed

    Shechner, Tomer; Britton, Jennifer C; Ronkin, Emily G; Jarcho, Johanna M; Mash, Jamie A; Michalska, Kalina J; Leibenluft, Ellen; Pine, Daniel S

    2015-04-01

    Fear conditioning and extinction have been implicated in the pathogenesis of anxiety disorders. However, due to ethical and methodological limitations, few studies have examined these learning processes across development, particularly among anxious individuals. The present study examined differences in fear conditioning and extinction in anxious and nonanxious youth and adults using a novel task designed to be more tolerable for children than existing paradigms. Twenty-two anxious adults, 15 anxious youth, 30 healthy adults, and 17 healthy youth completed two discriminative fear-conditioning tasks. A well-validated task paired a woman's fearful face with a scream as the unconditioned stimulus. The novel task paired a bell with an aversive alarm as the unconditioned stimulus. Self-reported fear, skin conductance response, and fear-potentiated startle eye blink were measured. Both tasks were well tolerated and elicited fear responses with moderate stability. Anxious youth and adults reported overall greater fear than healthy participants during the tasks, although no group differences occurred in discriminative fear conditioning or extinction, as assessed by self-report or physiology. The novel bell-conditioning task is potent in eliciting fear responses but tolerable for pediatric and anxious populations. Our findings are consistent with prior studies that have shown comparable fear learning processes in anxious and nonanxious youth, but dissimilar from studies exhibiting between-group differences in extinction. Given the limited research on fear conditioning in youth, methodological issues and suggestions for future work are discussed. © 2014 Wiley Periodicals, Inc.

  15. Do Children with Autism Use Inner Speech and Visuospatial Resources for the Service of Executive Control? Evidence From Suppression in Dual Tasks

    ERIC Educational Resources Information Center

    Holland, Lucy; Low, Jason

    2010-01-01

    Three experiments used dual-task suppression methodology to study the use of inner speech and visuospatial resources for mediating central executive performance by children with autism (CWA) and group-matched typically developing (TD) controls. Expt 1 revealed that CWA did not recruit inner speech to facilitate arithmetic task-switching…

  16. [Effects of motor activity on cognitive performance of patients with traumatic brain injury during dual tasking].

    PubMed

    Useros-Olmo, A I; Perianez, J A; Miangolarra-Page, J C

    2015-09-01

    Introduccion. El empleo de paradigmas de tarea dual ha mostrado interacciones conductuales entre ciertas tareas motoras, como el equilibrio o la marcha, y tareas cognitivas al ser realizadas simultaneamente. Pese a la potencial relevancia de estos hallazgos en la explicacion de ciertos sintomas neurologicos (por ejemplo, caidas) o en el diseño de nuevas intervenciones, son escasos los datos sobre tales efectos en traumatismos craneoencefalicos (TCE). Objetivo. Evaluar la presencia de interacciones cognitivomotoras durante la realizacion de tareas duales en TCE. Sujetos y metodos. Veinte pacientes con TCE y 19 controles sanos realizaron diferentes tareas cognitivas de atencion y memoria operativa (tareas de tiempo de reaccion simple, tiempo de reaccion compleja, 1-back numerica y 1-back espacial) en tarea dual, es decir, al tiempo que una tarea motora (bipedestacion y marcha), y en tarea simple (sin tarea motora). Se registraron los tiempos de reaccion en respuesta a las tareas cognitivas. Resultados. Los pacientes mostraron peor rendimiento que los controles en todas las tareas (p < 0,05). Mientras que ninguno de los grupos mostro cambios en los tiempos de reaccion medidos en las tareas atencionales durante la ejecucion dual en comparacion con la ejecucion simple, los pacientes con TCE si mostraron mejoria en las tareas de memoria operativa (F(2, 74) = 2,9; p < 0,05) durante la tarea dual de marcha (p < 0,02). Conclusiones. Se discuten las posibles causas de interacciones cognitivomotoras positivas durante la ejecucion simultanea de tareas de marcha y memoria operativa en pacientes con TCE, y el potencial valor terapeutico de los paradigmas duales en la rehabilitacion de estos pacientes.

  17. Paap and Noel revisited: individual differences in independent word recognition tasks in relation to the dual-task paradigm.

    PubMed

    Hayes, Maureen; Masterson, Jackie

    2002-07-01

    Paap and Noel (1991) found that participants' pronunciation latencies were faster for low-frequency irregular words when named under a concurrent high digit memory load than when named under a low load. The effects reported by Paap and Noel haveproved difficult to replicate in subsequent studies. The present research suggests that individual differences in word recognition skill relate to who will or will not show these effects. In two experiments, participants were allocated to skill groups on the basis of latency in tasks tapping lexical and sub-lexical reading processes. In both studies, only one group (the "intermediate skilled"), showed evidence of such effects. A combined analysis of the data from Experiments 1 and 2 was carried out. This confirmed and extended the analyses of the individual experiments. The results are discussed in relation to contemporary models of word recognition.

  18. A dual phosphorylation switch controls 14-3-3-dependent cell surface expression of TASK-1

    PubMed Central

    Kilisch, Markus; Lytovchenko, Olga; Arakel, Eric C.; Bertinetti, Daniela; Schwappach, Blanche

    2016-01-01

    ABSTRACT The transport of the K+ channels TASK-1 and TASK-3 (also known as KCNK3 and KCNK9, respectively) to the cell surface is controlled by the binding of 14-3-3 proteins to a trafficking control region at the extreme C-terminus of the channels. The current model proposes that phosphorylation-dependent binding of 14-3-3 sterically masks a COPI-binding motif. However, the direct effects of phosphorylation on COPI binding and on the binding parameters of 14-3-3 isoforms are still unknown. We find that phosphorylation of the trafficking control region prevents COPI binding even in the absence of 14-3-3, and we present a quantitative analysis of the binding of all human 14-3-3 isoforms to the trafficking control regions of TASK-1 and TASK-3. Surprisingly, the affinities of 14-3-3 proteins for TASK-1 are two orders of magnitude lower than for TASK-3. Furthermore, we find that phosphorylation of a second serine residue in the C-terminus of TASK-1 inhibits 14-3-3 binding. Thus, phosphorylation of the trafficking control region can stimulate or inhibit transport of TASK-1 to the cell surface depending on the target serine residue. Our findings indicate that control of TASK-1 trafficking by COPI, kinases, phosphatases and 14-3-3 proteins is highly dynamic. PMID:26743085

  19. 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.

  20. Cognitive and Neural Determinants of Response Strategy in the Dual-Solution Plus-Maze Task

    ERIC Educational Resources Information Center

    De Leonibus, Elvira; Costantini, Vivian J. A.; Massaro, Antonio; Mandolesi, Georgia; Vanni, Valentina; Luvisetto, Siro; Pavone, Flaminia; Oliverio, Alberto; Mele, Andrea

    2011-01-01

    Response strategy in the dual-solution plus maze is regarded as a form of stimulus-response learning. In this study, by using an outcome devaluation procedure, we show that it can be based on both action-outcome and stimulus-response habit learning, depending on the amount of training that the animals receive. Furthermore, we show that…

  1. Cognitive and Neural Determinants of Response Strategy in the Dual-Solution Plus-Maze Task

    ERIC Educational Resources Information Center

    De Leonibus, Elvira; Costantini, Vivian J. A.; Massaro, Antonio; Mandolesi, Georgia; Vanni, Valentina; Luvisetto, Siro; Pavone, Flaminia; Oliverio, Alberto; Mele, Andrea

    2011-01-01

    Response strategy in the dual-solution plus maze is regarded as a form of stimulus-response learning. In this study, by using an outcome devaluation procedure, we show that it can be based on both action-outcome and stimulus-response habit learning, depending on the amount of training that the animals receive. Furthermore, we show that…

  2. Peculiarities of latent inhibition formation in SHR rats in conditioned task of different complexity.

    PubMed

    Kostyunina, N V; Loskutova, L V

    2012-05-01

    Inhibition of attention to irrelevant stimuli was studied in SHR rats using latent inhibition test. Latent inhibition was formed in two types of conditioned tasks with different levels of complexity and stress. Passive and active avoidance conditioning was preceded by preexposure to conditioned stimulus consisting of 20 and 100 non-reinforced presentations, respectively. Control Wistar rats demonstrated successful formation of latent inhibition in both tasks. SHR rats showed different degree of disruption of latent inhibition depending on the type of behavioral task. We assume that learning defect in these animals in respect to both novel and preexposed conditioned stimuli is associated with the lack of behavioral inhibition.

  3. Crafting Instructions Collaboratively: Student Questions and Dual Addressivity in Classroom Task Instructions

    ERIC Educational Resources Information Center

    St. John, Oliver; Cromdal, Jakob

    2016-01-01

    This study examines classroom task instructions--phases traditionally associated with noninteractional objectives and operations--and reveals their composition as interactionally complex and cocrafted. Analyses of video sequences of task instructional activity from three different secondary school lessons show that student questions routinely…

  4. Evaluation of 2 cognitive abilities tests in a dual-task environment

    NASA Technical Reports Server (NTRS)

    Vidulich, M. A.; Tsang, P. S.

    1986-01-01

    Most real world operators are required to perform multiple tasks simultaneously. In some cases, such as flying a high performance aircraft or trouble shooting a failing nuclear power plant, the operator's ability to time share or process in parallel" can be driven to extremes. This has created interest in selection tests of cognitive abilities. Two tests that have been suggested are the Dichotic Listening Task and the Cognitive Failures Questionnaire. Correlations between these test results and time sharing performance were obtained and the validity of these tests were examined. The primary task was a tracking task with dynamically varying bandwidth. This was performed either alone or concurrently with either another tracking task or a spatial transformation task. The results were: (1) An unexpected negative correlation was detected between the two tests; (2) The lack of correlation between either test and task performance made the predictive utility of the tests scores appear questionable; (3) Pilots made more errors on the Dichotic Listening Task than college students.

  5. Role of Dual Task Design When Measuring Cognitive Load during Multimedia Learning

    ERIC Educational Resources Information Center

    Schoor, Cornelia; Bannert, Maria; Brunken, Roland

    2012-01-01

    This study assessed the role different kinds of secondary tasks play for researching the modality effect of cognitive load theory. Ninety-six university students worked with a computer-based training program for approximately 13 min and had to fulfill an additional secondary task. In a 2 x 2 factorial design, modality of information presentation…

  6. Working Memory Deficits in Children with Reading Difficulties: Memory Span and Dual Task Coordination

    ERIC Educational Resources Information Center

    Wang, Shinmin; Gathercole, Susan E.

    2013-01-01

    The current study investigated the cause of the reported problems in working memory in children with reading difficulties. Verbal and visuospatial simple and complex span tasks, and digit span and reaction times tasks performed singly and in combination, were administered to 46 children with single word reading difficulties and 45 typically…

  7. Working Memory Deficits in Children with Reading Difficulties: Memory Span and Dual Task Coordination

    ERIC Educational Resources Information Center

    Wang, Shinmin; Gathercole, Susan E.

    2013-01-01

    The current study investigated the cause of the reported problems in working memory in children with reading difficulties. Verbal and visuospatial simple and complex span tasks, and digit span and reaction times tasks performed singly and in combination, were administered to 46 children with single word reading difficulties and 45 typically…

  8. Assessing Relational Complexity in Hierarchical Reasoning: A Dual-Task Approach.

    ERIC Educational Resources Information Center

    Foley, Elizabeth J.; Berch, Daniel B.

    This study used the "double easy-to-hard" paradigm to examine the hypothesis that the class inclusion (CI) task should be equivalent in relational complexity to the transitive inference (TI) problem. Participating in the study were 64 girls and 50 boys, with a mean age of 8 years, 6 months. Stimuli for easy versions of the tasks were…

  9. The Effects of Context Changes on the Reinstatement of Extinguished Conditioned Behavior in a Conditioned Suppression Task with Humans

    ERIC Educational Resources Information Center

    Neumann, David L.

    2008-01-01

    Reinstatement refers to the return of previously extinguished conditioned responses to test trials of a conditional stimulus (CS) when presentations of the unconditional stimulus (US) alone are given following extinction. Four experiments were conducted to determine whether reinstatement could be found in a conditioned suppression task with humans…

  10. A dual-task investigation of automaticity in visual word processing

    NASA Technical Reports Server (NTRS)

    McCann, R. S.; Remington, R. W.; Van Selst, M.

    2000-01-01

    An analysis of activation models of visual word processing suggests that frequency-sensitive forms of lexical processing should proceed normally while unattended. This hypothesis was tested by having participants perform a speeded pitch discrimination task followed by lexical decisions or word naming. As the stimulus onset asynchrony between the tasks was reduced, lexical-decision and naming latencies increased dramatically. Word-frequency effects were additive with the increase, indicating that frequency-sensitive processing was subject to postponement while attention was devoted to the other task. Either (a) the same neural hardware shares responsibility for lexical processing and central stages of choice reaction time task processing and cannot perform both computations simultaneously, or (b) lexical processing is blocked in order to optimize performance on the pitch discrimination task. Either way, word processing is not as automatic as activation models suggest.

  11. A dual-task investigation of automaticity in visual word processing

    NASA Technical Reports Server (NTRS)

    McCann, R. S.; Remington, R. W.; Van Selst, M.

    2000-01-01

    An analysis of activation models of visual word processing suggests that frequency-sensitive forms of lexical processing should proceed normally while unattended. This hypothesis was tested by having participants perform a speeded pitch discrimination task followed by lexical decisions or word naming. As the stimulus onset asynchrony between the tasks was reduced, lexical-decision and naming latencies increased dramatically. Word-frequency effects were additive with the increase, indicating that frequency-sensitive processing was subject to postponement while attention was devoted to the other task. Either (a) the same neural hardware shares responsibility for lexical processing and central stages of choice reaction time task processing and cannot perform both computations simultaneously, or (b) lexical processing is blocked in order to optimize performance on the pitch discrimination task. Either way, word processing is not as automatic as activation models suggest.

  12. Dual-task motor performance with a tongue-operated assistive technology compared with hand operations

    PubMed Central

    2012-01-01

    Background To provide an alternative motor modality for control, navigation, and communication in individuals suffering from impairment or disability in hand functions, a Tongue Drive System (TDS) has been developed that allows for real time tracking of tongue motion in an unobtrusive, wireless, and wearable device that utilizes the magnetic field generated by a miniature disk shaped magnetic tracer attached to the tip of the tongue. The purpose of the study was to compare the influence of a concurrent motor or cognitive task on various aspects of simple movement control between hand and tongue using the TDS technology. Methods Thirteen young able-bodied adults performed rapid and slow goal-directed movements of hand and tongue (with TDS) with and without a concurrent motor (hand or tongue) or cognitive (arithmetic and memory) task. Changes in reaction time, completion time, speed, correctness, accuracy, variability of displacement, and variability of time due to the addition of a concurrent task were compared between hand and tongue. Results The influence of an additional concurrent task on motor performance was similar between the hand and tongue for slow movement in controlling their displacement. In rapid movement with a concurrent motor task, most aspects of motor performance were degraded in hand, while tongue speed during rapid continuous task was maintained. With a concurrent cognitive task, most aspects of motor performance were degraded in tongue, while hand accuracy during the rapid discrete task and hand speed during the rapid continuous task were maintained. Conclusion Rapid goal-directed hand and tongue movements were more consistently susceptible to interference from concurrent motor and cognitive tasks, respectively, compared with the other movement. PMID:22244362

  13. Functional balance and dual-task reaction times in older adults are improved by virtual reality and biofeedback training.

    PubMed

    Bisson, E; Contant, B; Sveistrup, H; Lajoie, Y

    2007-02-01

    Virtual reality (VR) training has been used successfully to rehabilitate functional balance and mobility in both traumatic brain injury (TBI) survivors and elderly subjects. Similarly, computer-based biofeedback (BF) training has resulted in decreased sway during quiet stance and decreased reaction times during a dual-task reaction time paradigm in elderly subjects. The objective of this study was to determine the effect of VR and BF training on balance and reaction time in older adults. Two groups of twelve healthy older adults completed 10-week training programs consisting of two 30-min sessions per week. VR training required that participants lean sideways to juggle a virtual ball. Participants in the BF group viewed a red dot representing their center of gravity on a screen and were required to move the dot to the four corners of the monitor. Measures of functional balance and mobility (Community Balance and Mobility Scale [CB&M]), sway during quiet stance, and reaction time during a dual task paradigm were recorded before training, as well as 1 week and 1 month after the end of the program. Both groups showed significant improvements on the CB&M, as well as decreased reaction times with training. Postural sway during quiet stance did not change significantly.

  14. On the Interpretation of Response Time vs Onset Asynchrony Functions: Application to Dual-Task and Precue-Utilization Paradigms.

    PubMed

    Schwarz, Wolfgang; Ischebeck, Anja

    2001-06-01

    The central bottleneck model of dual-task performance (H. Pashler and J. C. Johnston, 1998, Quarterly Journal of Experimental Psychology, 46A, 51-82) and the serial processing model of precue utilization (R. Gottsdanker, 1992, Acta Psychologica, 79, 21-43) are based on a common formal structure: They both represent response time as RT(tau)=max(X-tau, Y)+Z, where X, Y, Z denote the duration of certain processing stages specified by the models and tau denotes the onset asynchrony (SOA) between two stimuli. We consider this model within a stochastic framework in which the stage durations are random variables following an arbitrary joint distribution and derive properties of the function relating E[RT(tau)] to SOA. We present a distribution-free result which relates the slope of this function to the distribution of the random durations of the assumed processing stages. Our results allow for a direct, model-based interpretation of data from related experiments; specifically, they show how the slope of the SOA-function depends on experimental factors which selectively influence individual processing stages. We explain the implications of our results for models of dual-task performance and precue utilization and illustrate their application to data obtained by M. C. Smith (1969, Acta Psychologica, 30, 220-231) and R. Gottsdanker (1992, loc. cit.) Copyright 2001 Academic Press.

  15. Simultaneous recording of EEG and fNIRS during visuo-spatial and facial expression processing in a dual task paradigm.

    PubMed

    Herrmann, Martin J; Neueder, Dorothea; Troeller, Anna K; Schulz, Stefan M

    2016-11-01

    Emotional processing is probably the most crucial tool for orienting oneself in our everyday social life and has been considered to be highly automatic for a long time. Dual task (DT) research shows that information competing for working memory resources impairs the identification of emotional facial expressions. Effects of cognitive load in DT paradigms have been confirmed in numerous neuroimaging studies. However, interference occurring during a DT comprised of decoding emotional facial expressions and a visuo-spatial working memory task has yet to be visualized. To investigate the DT interference effect on brain areas associated not only with working memory, but also emotional and visuo-spatial processing, we recorded brain activation within the prefrontal cortex and parietal-occipital sensory areas using functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) simultaneously. Our study consisted of N = 36 participants (27 female) performing the following tasks: a) Corsi blocks, b) identification of emotional facial expressions or c) DT comprising of tasks a) and b). We predicted higher activation of the prefrontal cortex during DT and corresponding reduced P100 and P300 amplitudes. As expected, fNIRS measurements revealed significantly higher neuronal activation within the prefrontal cortex in the DT condition. When comparing DT to the single tasks, the P100 amplitude was reduced, but the P300 amplitude did not show the expected reduction. Our findings underline that at least some aspects of emotional processing are not entirely automatic, but depend on prefrontal control and are therefore affected by cognitive load, in particular visuo-spatial working memory resources.

  16. Multi-muscle synergies in a dual postural task: evidence for the principle of superposition.

    PubMed

    Klous, Miriam; Danna-dos-Santos, Alessander; Latash, Mark L

    2010-04-01

    We used the framework of the uncontrolled manifold hypothesis to quantify multi-muscle synergies stabilizing the moment of force about the frontal axis (M(Y)) and the shear force in the anterior-posterior direction (F(X)) during voluntary body sway performed by standing subjects. We tested a hypothesis whether the controller could stabilize both M(Y) and F(X) at the same time when the task and the visual feedback was provided only on one of the variables (M(Y)). Healthy young subjects performed voluntary body sway in the anterior-posterior direction while different loads were attached at the ankle level producing horizontal forces acting forward or backwards. Principal component analysis was used to identify three M-modes within the space of integrated indices of muscle activation. Variance in the M-mode space across sway cycles was partitioned into two components, one that did not affect a selected performance variable (M(Y) or F(X)) and the other that did. Under all loading conditions and for each performance variable, a higher value for the former variance component was found. We interpret these results as reflections of two multi-M-mode synergies stabilizing both F(X) and M(Y). The indices of synergies were modulated within the sway cycle; both performance variables were better stabilized when the body moved forward than when it moved backward. The results show that the controller can use a set of three elemental variables (M-modes) to stabilize two performance variables at the same time. No negative interference was seen between the synergy indices computed for the two performance variables supporting the principle of superposition with respect to multi-muscle postural control.

  17. Variability of human gait: effect of backward walking and dual-tasking on the presence of long-range autocorrelations.

    PubMed

    Bollens, Benjamin; Crevecoeur, Frédéric; Detrembleur, Christine; Warlop, Thibault; Lejeune, Thierry M

    2014-04-01

    Information from the central and peripheral nervous systems is continuously integrated to produce a stable gait pattern. However, stride duration fluctuates in a complex manner in healthy subjects, exhibiting long-range autocorrelations that can span over hundreds of consecutive strides. The present study was conducted to explore the mechanisms controlling the long-term fluctuation dynamics of gait. In the first part of the study, stride duration variability was evaluated on a treadmill during forward (FW) and backward walking (BW). Despite the modification of the biomechanical constraints imposed on the locomotor system, the characteristics of the long-range autocorrelations remained unchanged in both modes of locomotion (FW: H = 0.79 ± 0.04 and α = 0.58 ± 0.13; BW: H = 0.79 ± 0.11 and α = 0.53 ± 0.25). In the second part of the study, stride duration variability was assessed while the subjects were performing a dual-task paradigm that combined gait and mental calculation. The long-term variability of stride duration was similar during usual walking (H = 0.80 ± 0.06 and α = 0.57 ± 0.13) and in dual-tasking (H = 0.77 ± 0.06 and α = 0.52 ± 0.16), whereas walking altered the performance of the cognitive task. Hence, the biomechanical and cognitive interferences imposed in the present study were not sufficient to induce a modification of the long-range autocorrelations highlighted in walking variability. These observations underline the robustness of the long-range autocorrelations.

  18. 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.

  19. 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.

  20. Limits of spatial attention in three-dimensional space and dual-task driving performance.

    PubMed

    Andersen, George J; Ni, Rui; Bian, Zheng; Kang, Julie

    2011-01-01

    The present study examined the limits of spatial attention while performing two driving relevant tasks that varied in depth. The first task was to maintain a fixed headway distance behind a lead vehicle that varied speed. The second task was to detect a light-change target in an array of lights located above the roadway. In Experiment 1 the light detection task required drivers to encode color and location. The results indicated that reaction time to detect a light-change target increased and accuracy decreased as a function of the horizontal location of the light-change target and as a function of the distance from the driver. In a second experiment the light change task was changed to a singleton search (detect the onset of a yellow light) and the workload of the car following task was systematically varied. The results of Experiment 2 indicated that RT increased as a function of task workload, the 2D position of the light-change target and the distance of the light-change target. A multiple regression analysis indicated that the effect of distance on light detection performance was not due to changes in the projected size of the light target. In Experiment 3 we found that the distance effect in detecting a light change could not be explained by the location of eye fixations. The results demonstrate that when drivers attend to a roadway scene attention is limited in three-dimensional space. These results have important implications for developing tests for assessing crash risk among drivers as well as the design of in vehicle technologies such as head-up displays. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Limits of Spatial Attention in Three-Dimensional Space and Dual-task Driving Performance

    PubMed Central

    Andersen, George J.; Ni, Rui; Bian, Zheng; Kang, Julie

    2010-01-01

    The present study examined the limits of spatial attention while performing two driving relevant tasks that varied in depth. The first task was to maintain a fixed headway distance behind a lead vehicle that varied speed. The second task was to detect a light-change target in an array of lights located above the roadway. In Experiment 1 the light detection task required drivers to encode color and location. The results indicated that reaction time to detect a light-change target increased and accuracy decreased as a function of the horizontal location of the light-change target and as a function of the distance from the driver. In a second experiment the light change task was changed to a singleton search (detect the onset of a yellow light) and the workload of the car following task was systematically varied. The results of Experiment 2 indicated that RT increased as a function of task workload, the 2D position of the light-change target and the distance of the light-change target. A multiple regression analysis indicated that the effect of distance on light detection performance was not due to changes in the projected size of the light target. In Experiment 3 we found that the distance effect in detecting a light change could not be explained by the location of eye fixations. The results demonstrate that when drivers attend to a roadway scene attention is limited in three-dimensional space. These results have important implications for developing tests for assessing crash risk among drivers as well as the design of in vehicle technologies such as head-up displays. PMID:21094336

  2. Left visual-field advantage in the dual-stream RSVP task and reading-direction: a study in three nations.

    PubMed

    Smigasiewicz, Kamila; Shalgi, Shani; Hsieh, Shulan; Möller, Friderike; Jaffe, Sagi; Chang, Chi-Chih; Verleger, Rolf

    2010-08-01

    In the dual-stream Rapid Serial Visual Presentation task, a stream of stimuli containing two target stimuli is rapidly presented left and right. In previous studies, the second target was better identified in the left than in the right hemifield. In all those studies, alphanumeric stimuli were used both as targets and distracters. We examined to what extent this left visual-field advantage is dependent on reading-direction. The task was performed by Germans (with Latin characters), Israelis (with Latin and Hebrew characters) and Taiwanese (with Latin and Chinese characters). If caused by overlearnt associative links between Latin characters and left-to-right reading, the prominent left visual-field bias should be reversed in Hebrew and disappear in Chinese. Furthermore, if caused by direction of reading in the participant's native language, the left visual-field advantage in Latin conditions should be larger in Germans than in Israelis and Taiwanese. A left visual-field advantage was always observed, though slightly smaller in Hebrew and in Chinese, and there was no difference in the Latin conditions between the three nations. Therefore, it seems that the left visual-field advantage in speeded target identification is not primarily caused by the left-to-right reading-direction, but may be a combined effect resulting from the asymmetric organization of general mechanisms of visual processing and from stimulus-induced preferences.

  3. Dual Diffusion Model for Single-Cell Recording Data From the Superior Colliculus in a Brightness-Discrimination Task

    PubMed Central

    Ratcliff, Roger; Hasegawa, Yukako T.; Hasegawa, Ryohei P.; Smith, Philip L.; Segraves, Mark A.

    2008-01-01

    Monkeys made saccades to one of two peripheral targets based on the brightness of a central stimulus. Task difficulty was manipulated by varying the ratio of stimulus black-and-white pixels. Correct response probability for two monkeys varied directly with difficulty. Deep layer SC neurons exhibited robust presaccadic activity the magnitude of which was unaffected by task difficulty when the stimulus specified a saccade toward a target within the neuron’s response field. Activity after stimuli specifying saccades to targets outside the response field was affected by task difficulty, increasing as the task became more difficult. A quantitative model derived from studies of human decision-making was fit to the behavioral data. The model assumes that information from the stimulus drives two independent diffusion processes. Simulated paths from the model were compared with neuron activity, assuming that firing rate is linearly related to position in the accumulation process. The firing rate data show delayed availability of discriminative information for fast, intermediate, and slow decisions when activity is aligned on the stimulus and very small differences in discriminative information when aligned on the saccade. The model produces exactly these patterns of results. The accumulation process is highly variable, allowing the process both to make errors, as is the case for the behavioral performance, and also to account for the firing rate results. Thus the dual diffusion model provides a quantitative account for both the behavior in a simple decision-making task as well as the patterns of activity in competing populations of neurons. PMID:17122324

  4. Molindone: effects in pigeons responding under conditional discrimination tasks.

    PubMed

    Picker, M J; Cleary, J P; Berens, K; Oliveto, A H; Dykstra, L A

    1989-02-01

    Pigeons were trained to respond under three conditional discrimination procedures; 1) a fixed-consecutive-number procedure with (FCN 8-SD) and without (FCN 8) an added external discriminative stimulus, 2) a delayed matching-to-sample (DMTS) procedure using 0-sec, 2-sec and 8-sec delay intervals, and 3) a repeated acquisition of behavioral chains (RA) procedure using a four-link response chain with three stimulus keys. The atypical neuroleptic agent molindone decreased accuracy under the FCN 8 at doses that had no effect on accuracy under the FCN 8-SD. Under the DMTS procedure, molindone-induced decreases in accuracy were directly related to the delay interval, with the largest relative decrements obtained at the 8-sec delay and the smallest at the 0-sec delay. Under the RA procedure, molindone decreased accuracy at doses that had little or no effect on the number of correct responses emitted. Relative to control values, molindone-induced decreases in accuracy were smallest under the DMTS and FCN 8-SD procedures and largest under the FCN 8 and RA procedures. The differential effects obtained with molindone under each of these procedures illustrate the need to employ a variety of assays when determining the behavioral actions of neuroleptics. In addition, this battery of behavioral tests may provide a useful tool for assessing the different neurochemical actions of neuroleptic compounds.

  5. Dual-task interference is greater in delayed grasping than in visually guided grasping.

    PubMed

    Singhal, Anthony; Culham, Jody C; Chinellato, Eris; Goodale, Melvyn A

    2007-05-04

    Previous kinematic research suggests that visually guided grasping employs an accurate real-time control system in the dorsal stream, whereas delayed grasping relies on less accurate stored information derived by the perceptual system in the ventral stream. We explored these ideas in two experiments combining visually guided and delayed grasping with auditory tasks involving perception-based imagery and semantic memory. In both experiments, participants were cued to grasp three-dimensional objects of varying sizes. During visually guided trials, objects were visible during the interval between the cue and movement onset. During delayed trials, objects were occluded at the time of the cue. In Experiment 1, the second task required participants to listen to object names and vocally respond if the objects were of a particular shape. In Experiment 2, participants studied a paired-associates list prior to testing and then performed cued recall while grasping. The results of these experiments showed that there was reciprocal interference on both tasks, which was consistently greater during delayed grasping. Experiment 2 showed that the introduction of the second task resulted in larger grip apertures during delayed grasping. This supports the idea that delayed grasping involves processing of stored perception-based information that shares resources with cross-modal tasks involving imagery and memory.

  6. Effects of a mental task on splanchnic blood flow in fasting and postprandial conditions.

    PubMed

    Someya, Nami; Endo, Masako Yamaoka; Fukuba, Yoshiyuki; Hirooka, Yoshitaka; Hayashi, Naoyuki

    2010-04-01

    We tested the hypothesis that a mental task attenuates the meal-induced vasodilation in the splanchnic vasculature. Ten subjects performed a 5-min colour-word conflict test (CWT) under fasting and postprandial conditions. Subjects in the postprandial condition had ingested solid food with an energy content of 300 kcal (1,255 kJ) before either performing the CWT (mental task trial) or resting (resting control trial). The mean blood velocities (MBV) in the coeliac artery (CA) and superior mesenteric artery (SMA), and the mean arterial pressure (MAP) were measured. The MBV in the CA and SMA were divided by the MAP to assess the vascular conductance (VC). The MBV in the CA and SMA were significantly increased by the CWT under fasting conditions. In the postprandial condition, the MBV in the CA and SMA significantly increased immediately after the meal in both the mental task and resting control trials. The VC in the SMA, but not in the CA, was significantly decreased by the CWT under fasting conditions. In the postprandial conditions, there was no significant difference in the VC in both arteries between mental task and resting control trials. These results suggest that a mental task exerts different effects on the CA and SMA under fasting but not postprandial condition. The vasoconstrictive effect of a mental task on the SMA does not counter the vasodilatory effect of meal ingestion.

  7. 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.

  8. 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

  9. Processing bottlenecks in dual-task performance: structural limitation or strategic postponement?

    NASA Technical Reports Server (NTRS)

    Ruthruff, E.; Pashler, H. E.; Klaassen, A.

    2001-01-01

    Recent evidence indicates that a central bottleneck causes much of the slowing that occurs when two tasks are performed at the same time. This bottleneck might reflect a structural limitation inherent in the cognitive architecture. Alternatively, the bottleneck might reflect strategic (i.e., voluntary) postponement, induced by instructions to emphasize one task over the other. To distinguish structural limitations from strategic postponem