Validation of time to task performance assessment method in simulation: A comparative design study.

PubMed

Shinnick, Mary Ann; Woo, Mary A

2018-05-01

There is a lack of objective and valid measures for assessing nursing clinical competence which could adversely impact patient safety. Therefore, we evaluated an objective assessment of clinical competence, Time to Task (ability to perform specific, critical nursing care activities within 5 min), and compared it to two subjective measures, (Lasater Clinical Judgement Rubric [LCJR] and common "pass/fail" assessment). Using a prospective, "Known Groups" (Expert vs. Novice nurses) comparative design, Expert nurses (ICU nurses with >5 years of ICU experience) and Novice nurses (senior prelicensure nursing students) participated individually in a simulation of a patient in decompensated heart failure. Fourteen nursing instructors or preceptors, blinded to group assignment, reviewed 28 simulation videos (15 Expert and 13 Novice) and scored them using the LCJR and pass/fail assessments. Time to Task assessment was scored based on time thresholds for specific nursing actions prospectively set by an expert clinical panel. Statistical analysis consisted of Medians Test and sensitivity and specificity analyses. The LCJR total score was significantly different between Experts and Novices (p < 0.01) and revealed adequate sensitivity (ability to correctly identify "Expert" nurses; 0.72) but had a low specificity (ability to correctly identify "Novice" nurses; 0.40). For the subjective measure 'pass/fail', sensitivity was high (0.90) but specificity was low (0.47). The Time to Task measure had statistical significance between Expert and Novice groups (p < 0.01) and sensitivity (0.80) and specificity (0.85) were good. Commonly used subjective measures of clinical nursing competence have difficulties with achieving acceptable specificity. However, an objective measure, Time to Task, had good sensitivity and specificity in differentiating between groups. While more than one assessment instrument should be used to determine nurse competency, an objective measure, such as

Exploring the role of task performance and learning style on prefrontal hemodynamics during a working memory task.

PubMed

Anderson, Afrouz A; Parsa, Kian; Geiger, Sydney; Zaragoza, Rachel; Kermanian, Riley; Miguel, Helga; Dashtestani, Hadis; Chowdhry, Fatima A; Smith, Elizabeth; Aram, Siamak; Gandjbakhche, Amir H

2018-01-01

Existing literature outlines the quality and location of activation in the prefrontal cortex (PFC) during working memory (WM) tasks. However, the effects of individual differences on the underlying neural process of WM tasks are still unclear. In this functional near infrared spectroscopy study, we administered a visual and auditory n-back task to examine activation in the PFC while considering the influences of task performance, and preferred learning strategy (VARK score). While controlling for age, results indicated that high performance (HP) subjects (accuracy > 90%) showed task dependent lower activation compared to normal performance subjects in PFC region Specifically HP groups showed lower activation in left dorsolateral PFC (DLPFC) region during performance of auditory task whereas during visual task they showed lower activation in the right DLPFC. After accounting for learning style, we found a correlation between visual and aural VARK score and level of activation in the PFC. Subjects with higher visual VARK scores displayed lower activation during auditory task in left DLPFC, while those with higher visual scores exhibited higher activation during visual task in bilateral DLPFC. During performance of auditory task, HP subjects had higher visual VARK scores compared to NP subjects indicating an effect of learning style on the task performance and activation. The results of this study show that learning style and task performance can influence PFC activation, with applications toward neurological implications of learning style and populations with deficits in auditory or visual processing.

Exploring the role of task performance and learning style on prefrontal hemodynamics during a working memory task

PubMed Central

Anderson, Afrouz A.; Parsa, Kian; Geiger, Sydney; Zaragoza, Rachel; Kermanian, Riley; Miguel, Helga; Chowdhry, Fatima A.; Smith, Elizabeth; Aram, Siamak; Gandjbakhche, Amir H.

2018-01-01

Existing literature outlines the quality and location of activation in the prefrontal cortex (PFC) during working memory (WM) tasks. However, the effects of individual differences on the underlying neural process of WM tasks are still unclear. In this functional near infrared spectroscopy study, we administered a visual and auditory n-back task to examine activation in the PFC while considering the influences of task performance, and preferred learning strategy (VARK score). While controlling for age, results indicated that high performance (HP) subjects (accuracy > 90%) showed task dependent lower activation compared to normal performance subjects in PFC region Specifically HP groups showed lower activation in left dorsolateral PFC (DLPFC) region during performance of auditory task whereas during visual task they showed lower activation in the right DLPFC. After accounting for learning style, we found a correlation between visual and aural VARK score and level of activation in the PFC. Subjects with higher visual VARK scores displayed lower activation during auditory task in left DLPFC, while those with higher visual scores exhibited higher activation during visual task in bilateral DLPFC. During performance of auditory task, HP subjects had higher visual VARK scores compared to NP subjects indicating an effect of learning style on the task performance and activation. The results of this study show that learning style and task performance can influence PFC activation, with applications toward neurological implications of learning style and populations with deficits in auditory or visual processing. PMID:29870536

Computer task performance by subjects with Duchenne muscular dystrophy.

PubMed

Malheiros, Silvia Regina Pinheiro; da Silva, Talita Dias; Favero, Francis Meire; de Abreu, Luiz Carlos; Fregni, Felipe; Ribeiro, Denise Cardoso; de Mello Monteiro, Carlos Bandeira

2016-01-01

Two specific objectives were established to quantify computer task performance among people with Duchenne muscular dystrophy (DMD). First, we compared simple computational task performance between subjects with DMD and age-matched typically developing (TD) subjects. Second, we examined correlations between the ability of subjects with DMD to learn the computational task and their motor functionality, age, and initial task performance. The study included 84 individuals (42 with DMD, mean age of 18±5.5 years, and 42 age-matched controls). They executed a computer maze task; all participants performed the acquisition (20 attempts) and retention (five attempts) phases, repeating the same maze. A different maze was used to verify transfer performance (five attempts). The Motor Function Measure Scale was applied, and the results were compared with maze task performance. In the acquisition phase, a significant decrease was found in movement time (MT) between the first and last acquisition block, but only for the DMD group. For the DMD group, MT during transfer was shorter than during the first acquisition block, indicating improvement from the first acquisition block to transfer. In addition, the TD group showed shorter MT than the DMD group across the study. DMD participants improved their performance after practicing a computational task; however, the difference in MT was present in all attempts among DMD and control subjects. Computational task improvement was positively influenced by the initial performance of individuals with DMD. In turn, the initial performance was influenced by their distal functionality but not their age or overall functionality.

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.

Continuous performance task in ADHD: Is reaction time variability a key measure?

PubMed

Levy, Florence; Pipingas, Andrew; Harris, Elizabeth V; Farrow, Maree; Silberstein, Richard B

2018-01-01

To compare the use of the Continuous Performance Task (CPT) reaction time variability (intraindividual variability or standard deviation of reaction time), as a measure of vigilance in attention-deficit hyperactivity disorder (ADHD), and stimulant medication response, utilizing a simple CPT X-task vs an A-X-task. Comparative analyses of two separate X-task vs A-X-task data sets, and subgroup analyses of performance on and off medication were conducted. The CPT X-task reaction time variability had a direct relationship to ADHD clinician severity ratings, unlike the CPT A-X-task. Variability in X-task performance was reduced by medication compared with the children's unmedicated performance, but this effect did not reach significance. When the coefficient of variation was applied, severity measures and medication response were significant for the X-task, but not for the A-X-task. The CPT-X-task is a useful clinical screening test for ADHD and medication response. In particular, reaction time variability is related to default mode interference. The A-X-task is less useful in this regard.

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

PubMed Central

Kiss, Rainer; Brueckner, Dennis; Muehlbauer, Thomas

2018-01-01

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

Emotional reactivity and awareness of task performance in Alzheimer's disease.

PubMed

Mograbi, Daniel C; Brown, Richard G; Salas, Christian; Morris, Robin G

2012-07-01

Lack of awareness about performance in tasks is a common feature of Alzheimer's disease. Nevertheless, clinical anecdotes have suggested that patients may show emotional or behavioural responses to the experience of failure despite reporting limited awareness, an aspect which has been little explored experimentally. The current study investigated emotional reactions to success or failure in tasks despite unawareness of performance in Alzheimer's disease. For this purpose, novel computerised tasks which expose participants to systematic success or failure were used in a group of Alzheimer's disease patients (n=23) and age-matched controls (n=21). Two experiments, the first with reaction time tasks and the second with memory tasks, were carried out, and in each experiment two parallel tasks were used, one in a success condition and one in a failure condition. Awareness of performance was measured comparing participant estimations of performance with actual performance. Emotional reactivity was assessed with a self-report questionnaire and rating of filmed facial expressions. In both experiments the results indicated that, relative to controls, Alzheimer's disease patients exhibited impaired awareness of performance, but comparable differential reactivity to failure relative to success tasks, both in terms of self-report and facial expressions. This suggests that affective valence of failure experience is processed despite unawareness of task performance, which might indicate implicit processing of information in neural pathways bypassing awareness. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sleep Deprivation and Time-on-Task Performance Decrement in the Rat Psychomotor Vigilance Task

PubMed Central

Oonk, Marcella; Davis, Christopher J.; Krueger, James M.; Wisor, Jonathan P.; Van Dongen, Hans P.A.

2015-01-01

Study Objectives: The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. Design: The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. Setting: The study was conducted in an academic research vivarium. Participants: Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Interventions: Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Measurements and Results: Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. Conclusions: The rat psychomotor vigilance task manifests similarities to the human psychomotor vigilance task in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. Citation: Oonk M, Davis CJ, Krueger JM, Wisor JP, Van Dongen HPA. Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task. SLEEP 2015;38(3):445–451. PMID:25515099

Comparing Cognitive Models of Domain Mastery and Task Performance in Algebra: Validity Evidence for a State Assessment

ERIC Educational Resources Information Center

Warner, Zachary B.

2013-01-01

This study compared an expert-based cognitive model of domain mastery with student-based cognitive models of task performance for Integrated Algebra. Interpretations of student test results are limited by experts' hypotheses of how students interact with the items. In reality, the cognitive processes that students use to solve each item may be…

Comparison of precision and speed in laparoscopic and robot-assisted surgical task performance.

PubMed

Zihni, Ahmed; Gerull, William D; Cavallo, Jaime A; Ge, Tianjia; Ray, Shuddhadeb; Chiu, Jason; Brunt, L Michael; Awad, Michael M

2018-03-01

Robotic platforms have the potential advantage of providing additional dexterity and precision to surgeons while performing complex laparoscopic tasks, especially for those in training. Few quantitative evaluations of surgical task performance comparing laparoscopic and robotic platforms among surgeons of varying experience levels have been done. We compared measures of quality and efficiency of Fundamentals of Laparoscopic Surgery task performance on these platforms in novices and experienced laparoscopic and robotic surgeons. Fourteen novices, 12 expert laparoscopic surgeons (>100 laparoscopic procedures performed, no robotics experience), and five expert robotic surgeons (>25 robotic procedures performed) performed three Fundamentals of Laparoscopic Surgery tasks on both laparoscopic and robotic platforms: peg transfer (PT), pattern cutting (PC), and intracorporeal suturing. All tasks were repeated three times by each subject on each platform in a randomized order. Mean completion times and mean errors per trial (EPT) were calculated for each task on both platforms. Results were compared using Student's t-test (P < 0.05 considered statistically significant). Among novices, greater errors were noted during laparoscopic PC (Lap 2.21 versus Robot 0.88 EPT, P < 0.001). Among expert laparoscopists, greater errors were noted during laparoscopic PT compared with robotic (PT: Lap 0.14 versus Robot 0.00 EPT, P = 0.04). Among expert robotic surgeons, greater errors were noted during laparoscopic PC compared with robotic (Lap 0.80 versus Robot 0.13 EPT, P = 0.02). Among expert laparoscopists, task performance was slower on the robotic platform compared with laparoscopy. In comparisons of expert laparoscopists performing tasks on the laparoscopic platform and expert robotic surgeons performing tasks on the robotic platform, expert robotic surgeons demonstrated fewer errors during the PC task (P = 0.009). Robotic assistance provided a reduction in errors at all

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

PubMed

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

2017-01-01

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

Impact of task design on task performance and injury risk: case study of a simulated drilling task.

PubMed

Alabdulkarim, Saad; Nussbaum, Maury A; Rashedi, Ehsan; Kim, Sunwook; Agnew, Michael; Gardner, Richard

2017-06-01

Existing evidence is limited regarding the influence of task design on performance and ergonomic risk, or the association between these two outcomes. In a controlled experiment, we constructed a mock fuselage to simulate a drilling task common in aircraft manufacturing, and examined the effect of three levels of workstation adjustability on performance as measured by productivity (e.g. fuselage completion time) and quality (e.g. fuselage defective holes), and ergonomic risk as quantified using two common methods (rapid upper limb assessment and the strain index). The primary finding was that both productivity and quality significantly improved with increased adjustability, yet this occurred only when that adjustability succeeded in reducing ergonomic risk. Supporting the inverse association between ergonomic risk and performance, the condition with highest adjustability created the lowest ergonomic risk and the best performance while there was not a substantial difference in ergonomic risk between the other two conditions, in which performance was also comparable. Practitioner Summary: Findings of this study supported a causal relationship between task design and both ergonomic risk and performance, and that ergonomic risk and performance are inversely associated. While future work is needed under more realistic conditions and a broader population, these results may be useful for task (re)design and to help cost-justify some ergonomic interventions.

A comparative analysis of multiple-choice and student performance-task assessment in the high school biology classroom

NASA Astrophysics Data System (ADS)

Cushing, Patrick Ryan

This study compared the performance of high school students on laboratory assessments. Thirty-four high school students who were enrolled in the second semester of a regular biology class or had completed the biology course the previous semester participated in this study. They were randomly assigned to examinations of two formats, performance-task and traditional multiple-choice, from two content areas, using a compound light microscope and diffusion. Students were directed to think-aloud as they performed the assessments. Additional verbal data were obtained during interviews following the assessment. The tape-recorded narrative data were analyzed for type and diversity of knowledge and skill categories, and percentage of in-depth processing demonstrated. While overall mean scores on the assessments were low, elicited statements provided additional insight into student cognition. Results indicated that a greater diversity of knowledge and skill categories was elicited by the two microscope assessments and by the two performance-task assessments. In addition, statements demonstrating in-depth processing were coded most frequently in narratives elicited during clinical interviews following the diffusion performance-task assessment. This study calls for individual teachers to design authentic assessment practices and apply them to daily classroom routines. Authentic assessment should be an integral part of the learning process and not merely an end result. In addition, teachers are encouraged to explicitly identify and model, through think-aloud methods, desired cognitive behaviors in the classroom.

Performance on a probabilistic inference task in healthy subjects receiving ketamine compared with patients with schizophrenia

PubMed Central

Almahdi, Basil; Sultan, Pervez; Sohanpal, Imrat; Brandner, Brigitta; Collier, Tracey; Shergill, Sukhi S; Cregg, Roman; Averbeck, Bruno B

2012-01-01

Evidence suggests that some aspects of schizophrenia can be induced in healthy volunteers through acute administration of the non-competitive NMDA-receptor antagonist, ketamine. In probabilistic inference tasks, patients with schizophrenia have been shown to ‘jump to conclusions’ (JTC) when asked to make a decision. We aimed to test whether healthy participants receiving ketamine would adopt a JTC response pattern resembling that of patients. The paradigmatic task used to investigate JTC has been the ‘urn’ task, where participants are shown a sequence of beads drawn from one of two ‘urns’, each containing coloured beads in different proportions. Participants make a decision when they think they know the urn from which beads are being drawn. We compared performance on the urn task between controls receiving acute ketamine or placebo with that of patients with schizophrenia and another group of controls matched to the patient group. Patients were shown to exhibit a JTC response pattern relative to their matched controls, whereas JTC was not evident in controls receiving ketamine relative to placebo. Ketamine does not appear to promote JTC in healthy controls, suggesting that ketamine does not affect probabilistic inferences. PMID:22389244

Investigating the visual span in comparative search: the effects of task difficulty and divided attention.

PubMed

Pomplun, M; Reingold, E M; Shen, J

2001-09-01

In three experiments, participants' visual span was measured in a comparative visual search task in which they had to detect a local match or mismatch between two displays presented side by side. Experiment 1 manipulated the difficulty of the comparative visual search task by contrasting a mismatch detection task with a substantially more difficult match detection task. In Experiment 2, participants were tested in a single-task condition involving only the visual task and a dual-task condition in which they concurrently performed an auditory task. Finally, in Experiment 3, participants performed two dual-task conditions, which differed in the difficulty of the concurrent auditory task. Both the comparative search task difficulty (Experiment 1) and the divided attention manipulation (Experiments 2 and 3) produced strong effects on visual span size.

Oddball and incongruity effects during Stroop task performance: a comparative fMRI study on selective attention.

PubMed

Melcher, Tobias; Gruber, Oliver

2006-11-22

The aim of this fMRI study was to investigate and compare the neural mechanisms of selective attention during two different operationalizations of competition between task-relevant and task-irrelevant information: Stroop-incongruity and oddballs. For this purpose, we employed a Stroop-like oddball task in which subjects responded to the font size of presented word stimuli. Stroop-incongruity was created by (response-)incongruent word information while oddballs comprised low-frequency events in a task-irrelevant, unattended dimension. Thereby, in order to elucidate the influence of processing domain from which competition emanates, oddball conditions were created in two different attribute dimensions, color and word meaning. Either oddball condition was expected to evoke an orienting response, which participants would have to override in order to maintain adequate performance. Incongruent Stroop trials were expected to produce Stroop-interference so that subjects would have to override the predominant tendency to read and respond to word meaning. All competition conditions exhibited significantly prolonged reaction times compared to control trials, demonstrating that our experimental manipulation was indeed effective. fMRI data analyses delineated two discriminative components of competition: one component mainly related to motor preparation and another, primarily attentional component. Regarding the first, Stroop-interference increased activation mainly in regions implicated in motor control or response preparation. Regarding the second, Word-oddballs increased activation in a frontoparietal "attention network". Furthermore, Word-oddballs and Color-oddballs exhibited striking activation overlap mainly in prefrontal regions but also in posterior processing areas. Here, the data emphasized a prominent role of posterior lateral PFC in implementing top-down attentional control.

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.

Sleep deprivation and time-on-task performance decrement in the rat psychomotor vigilance task.

PubMed

Oonk, Marcella; Davis, Christopher J; Krueger, James M; Wisor, Jonathan P; Van Dongen, Hans P A

2015-03-01

The rat psychomotor vigilance task (rPVT) was developed as a rodent analog of the human psychomotor vigilance task (hPVT). We examined whether rPVT performance displays time-on-task effects similar to those observed on the hPVT. The rPVT requires rats to respond to a randomly presented light stimulus to obtain a water reward. Rats were water deprived for 22 h prior to each 30-min rPVT session to motivate performance. We analyzed rPVT performance over time on task and as a function of the response-stimulus interval, at baseline and after sleep deprivation. The study was conducted in an academic research vivarium. Male Long-Evans rats were trained to respond to a 0.5 sec stimulus light within 3 sec of stimulus onset. Complete data were available for n = 20 rats. Rats performed the rPVT for 30 min at baseline and after 24 h total sleep deprivation by gentle handling. Compared to baseline, sleep deprived rats displayed increased performance lapses and premature responses, similar to hPVT lapses of attention and false starts. However, in contrast to hPVT performance, the time-on-task performance decrement was not significantly enhanced by sleep deprivation. Moreover, following sleep deprivation, rPVT response times were not consistently increased after short response-stimulus intervals. The rPVT manifests similarities to the hPVT in global performance outcomes, but not in post-sleep deprivation effects of time on task and response-stimulus interval. © 2015 Associated Professional Sleep Societies, LLC.

Comparing Auditory Noise Treatment with Stimulant Medication on Cognitive Task Performance in Children with Attention Deficit Hyperactivity Disorder: Results from a Pilot Study.

PubMed

Söderlund, Göran B W; Björk, Christer; Gustafsson, Peik

2016-01-01

Recent research has shown that acoustic white noise (80 dB) can improve task performance in people with attention deficits and/or Attention Deficit Hyperactivity Disorder (ADHD). This is attributed to the phenomenon of stochastic resonance in which a certain amount of noise can improve performance in a brain that is not working at its optimum. We compare here the effect of noise exposure with the effect of stimulant medication on cognitive task performance in ADHD. The aim of the present study was to compare the effects of auditory noise exposure with stimulant medication for ADHD children on a cognitive test battery. A group of typically developed children (TDC) took the same tests as a comparison. Twenty children with ADHD of combined or inattentive subtypes and twenty TDC matched for age and gender performed three different tests (word recall, spanboard and n-back task) during exposure to white noise (80 dB) and in a silent condition. The ADHD children were tested with and without central stimulant medication. In the spanboard- and the word recall tasks, but not in the 2-back task, white noise exposure led to significant improvements for both non-medicated and medicated ADHD children. No significant effects of medication were found on any of the three tasks. This pilot study shows that exposure to white noise resulted in a task improvement that was larger than the one with stimulant medication thus opening up the possibility of using auditory noise as an alternative, non-pharmacological treatment of cognitive ADHD symptoms.

Pre-task music improves swimming performance.

PubMed

Smirmaul, B P; Dos Santos, R V; Da Silva Neto, L V

2015-12-01

The purpose of this study was to investigate the effects of pre-task music on swimming performance and other psychological variables. A randomized counterbalanced within-subjects (experimental and control condition) design was employed. Eighteen regional level male swimmers performed two 200-m freestyle swimming time trials. Participants were exposed to either 5 minutes of self-selected music (pre-task music condition) or 5 minutes of silence (control condition) and, after 1 minute, performed the swimming task. Swimming time was significantly shorter (-1.44%) in the pre-task music condition. Listening to pre-task music increased motivation to perform the swimming task, while arousal remained unchanged. While fatigue increased after the swimming task in both conditions, vigor, ratings of perceived exertion and affective valence were unaltered. It is concluded, for the first time, that pre-task music improves swimming performance.

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

PubMed

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

2018-01-01

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

A Nonverbal False Belief Task: The Performance of Children and Great Apes.

ERIC Educational Resources Information Center

Call, Josep; Tomasello, Michael

1999-01-01

Compared performance of preschool children, chimpanzees, and orangutans on nonverbal task of false-belief understanding and tested children's performance on a verbal version of the same task. Found that children's performance on verbal and nonverbal tasks were highly correlated, and no chimp or orangutan succeeded in the nonverbal false-belief…

Performance Enhancements Under Dual-task Conditions

NASA Technical Reports Server (NTRS)

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

1984-01-01

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

Context matters: Social cognition task performance in psychometric schizotypes.

PubMed

Pflum, Madeline J; Gooding, Diane C

2018-06-01

Patients with schizophrenia show performance deficits on tasks requiring empathy-related social cognition. The extent to which empathy impairments are observed in psychometric schizotypy is unclear. We compared accuracy and reaction time in three groups of individuals characterized by positive schizotypy (n = 79), negative schizotypy (n = 123), or low schizotypy group (n = 137). On a social cognition task that provided context, namely, the Emotion Perspective Taking Task, the positive schizotypes showed poorer performance than the negative schizotypy and control groups. These results suggest that some schizotypes differ in their ability to make use of context (e.g., social cues from the environment) to affect their social cognitive performance. However, on the Affective Responsiveness Task, in which no context was given, both groups of psychometric schizotypes displayed lower performance than the controls. These findings highlight the importance of assessing multiple groups of schizotypes as well as the value of including several social cognition tasks in order to reveal relative performance deficits. Copyright © 2018 Elsevier B.V. All rights reserved.

Uniform task level definitions for robotic system performance comparisons

NASA Technical Reports Server (NTRS)

Price, Charles; Tesar, Delbert

1989-01-01

A series of ten task levels of increasing difficulty was compiled for use in comparative performance evaluations of available and future robotics technology. Each level has a breakdown of ten additional levels of difficulty to provide a layering of 100 levels. It is assumed that each level of task performance must be achieved by the system before it can be appropriately considered for the next level.

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.

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

PubMed

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

2017-02-01

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

Achievement Goals in a Presentation Task: Performance Expectancy, Achievement Goals, State Anxiety, and Task Performance

ERIC Educational Resources Information Center

Tanaka, Ayumi; Takehara, Takuma; Yamauchi, Hirotsugu

2006-01-01

The aims of the study were to test the linkages between achievement goals to task performance, as mediated by state anxiety arousal. Performance expectancy was also examined as antecedents of achievement goals. A presentation task in a computer practice class was used as achievement task. Fifty-three undergraduates (37 females and 16 males) were…

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

PubMed

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

2016-01-01

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

Comparison of School Counselors and School Social Workers: Performance of Tasks and Perceived Preparedness

ERIC Educational Resources Information Center

Feldman, Matthew

2010-01-01

This study compares the professional roles of school counselors and school social workers in terms of the frequency of performing various practice tasks, feelings of preparedness to perform various practice tasks, discrepancies between frequency of task performance and feelings of preparedness to perform said tasks, and factors that may affect…

Soft-light overhead illumination systems improve laparoscopic task performance.

PubMed

Takai, Akihiro; Takada, Yasutsugu; Motomura, Hideki; Teramukai, Satoshi

2014-02-01

The aim of this study was to evaluate the impact of attached shadow cues for laparoscopic task performance. We developed a soft-light overhead illumination system (SOIS) that produced attached shadows on objects. We compared results using the SOIS with those using a conventional illumination system with regard to laparoscopic experience and laparoscope-to-target distances (LTDs). Forty-two medical students and 23 surgeons participated in the study. A peg transfer task (LTD, 120 mm) for students and surgeons, and a suture removal task (LTD, 30 mm) for students were performed. Illumination systems were randomly assigned to each task. Endpoints were: total number of peg transfers; percentage of peg-dropping errors; and total execution time for suture removal. After the task, participants filled out a questionnaire on their preference for a particular illumination system. Total number of peg transfers was greater with the SOIS for both students and surgeons. Percentage of peg-dropping errors for surgeons was lower with the SOIS. Total execution time for suture removal was shorter with the SOIS. Forty-five participants (69% in total) evaluated the SOIS for easier task performance. The present results confirm that the SOIS improves laparoscopic task performance, regardless of previous laparoscopic experience or LTD.

Improving Physical Task Performance with Counterfactual and Prefactual Thinking

PubMed Central

Hammell, Cecilia; Chan, Amy Y. C.

2016-01-01

Counterfactual thinking (reflecting on “what might have been”) has been shown to enhance future performance by translating information about past mistakes into plans for future action. Prefactual thinking (imagining “what might be if…”) may serve a greater preparative function than counterfactual thinking as it is future-orientated and focuses on more controllable features, thus providing a practical script to prime future behaviour. However, whether or not this difference in hypothetical thought content may translate into a difference in actual task performance has been largely unexamined. In Experiment 1 (n = 42), participants performed trials of a computer-simulated physical task, in between which they engaged in either task-related hypothetical thinking (counterfactual or prefactual) or an unrelated filler task (control). As hypothesised, prefactuals contained more controllable features than counterfactuals. Moreover, participants who engaged in either form of hypothetical thinking improved significantly in task performance over trials compared to participants in the control group. The difference in thought content between counterfactuals and prefactuals, however, did not yield a significant difference in performance improvement. Experiment 2 (n = 42) replicated these findings in a dynamic balance task environment. Together, these findings provide further evidence for the preparatory function of counterfactuals, and demonstrate that prefactuals share this same functional characteristic. PMID:27942041

Improving Physical Task Performance with Counterfactual and Prefactual Thinking.

PubMed

Hammell, Cecilia; Chan, Amy Y C

2016-01-01

Counterfactual thinking (reflecting on "what might have been") has been shown to enhance future performance by translating information about past mistakes into plans for future action. Prefactual thinking (imagining "what might be if…") may serve a greater preparative function than counterfactual thinking as it is future-orientated and focuses on more controllable features, thus providing a practical script to prime future behaviour. However, whether or not this difference in hypothetical thought content may translate into a difference in actual task performance has been largely unexamined. In Experiment 1 (n = 42), participants performed trials of a computer-simulated physical task, in between which they engaged in either task-related hypothetical thinking (counterfactual or prefactual) or an unrelated filler task (control). As hypothesised, prefactuals contained more controllable features than counterfactuals. Moreover, participants who engaged in either form of hypothetical thinking improved significantly in task performance over trials compared to participants in the control group. The difference in thought content between counterfactuals and prefactuals, however, did not yield a significant difference in performance improvement. Experiment 2 (n = 42) replicated these findings in a dynamic balance task environment. Together, these findings provide further evidence for the preparatory function of counterfactuals, and demonstrate that prefactuals share this same functional characteristic.

Developmental hearing loss impedes auditory task learning and performance in gerbils.

PubMed

von Trapp, Gardiner; Aloni, Ishita; Young, Stephen; Semple, Malcolm N; Sanes, Dan H

2017-04-01

The consequences of developmental hearing loss have been reported to include both sensory and cognitive deficits. To investigate these issues in a non-human model, auditory learning and asymptotic psychometric performance were compared between normal hearing (NH) adult gerbils and those reared with conductive hearing loss (CHL). At postnatal day 10, before ear canal opening, gerbil pups underwent bilateral malleus removal to induce a permanent CHL. Both CHL and control animals were trained to approach a water spout upon presentation of a target (Go stimuli), and withhold for foils (Nogo stimuli). To assess the rate of task acquisition and asymptotic performance, animals were tested on an amplitude modulation (AM) rate discrimination task. Behavioral performance was calculated using a signal detection theory framework. Animals reared with developmental CHL displayed a slower rate of task acquisition for AM discrimination task. Slower acquisition was explained by an impaired ability to generalize to newly introduced stimuli, as compared to controls. Measurement of discrimination thresholds across consecutive testing blocks revealed that CHL animals required a greater number of testing sessions to reach asymptotic threshold values, as compared to controls. However, with sufficient training, CHL animals approached control performance. These results indicate that a sensory impediment can delay auditory learning, and increase the risk of poor performance on a temporal task. Copyright © 2016 Elsevier B.V. All rights reserved.

Developmental hearing loss impedes auditory task learning and performance in gerbils

PubMed Central

von Trapp, Gardiner; Aloni, Ishita; Young, Stephen; Semple, Malcolm N.; Sanes, Dan H.

2016-01-01

The consequences of developmental hearing loss have been reported to include both sensory and cognitive deficits. To investigate these issues in a non-human model, auditory learning and asymptotic psychometric performance were compared between normal hearing (NH) adult gerbils and those reared with conductive hearing loss (CHL). At postnatal day 10, before ear canal opening, gerbil pups underwent bilateral malleus removal to induce a permanent CHL. Both CHL and control animals were trained to approach a water spout upon presentation of a target (Go stimuli), and withhold for foils (Nogo stimuli). To assess the rate of task acquisition and asymptotic performance, animals were tested on an amplitude modulation (AM) rate discrimination task. Behavioral performance was calculated using a signal detection theory framework. Animals reared with developmental CHL displayed a slower rate of task acquisition for AM discrimination task. Slower acquisition was explained by an impaired ability to generalize to newly introduced stimuli, as compared to controls. Measurement of discrimination thresholds across consecutive testing blocks revealed that CHL animals required a greater number of testing sessions to reach asymptotic threshold values, as compared to controls. However, with sufficient training, CHL animals approached control performance. These results indicate that a sensory impediment can delay auditory learning, and increase the risk of poor performance on a temporal task. PMID:27746215

The Effect of Cerebellar Transcranial Direct Current Stimulation on A Throwing Task Depends on Individual Level of Task Performance.

PubMed

Mizuguchi, Nobuaki; Katayama, Takashi; Kanosue, Kazuyuki

2018-02-10

The effect of cerebellar transcranial direct current stimulation (tDCS) on motor performance remains controversial. Some studies suggest that the effect of tDCS depends upon task-difficulty and individual level of task performance. Here, we investigated whether the effect of cerebellar tDCS on the motor performance depends upon the individual's level of performance. Twenty-four naïve participants practiced dart throwing while receiving a 2-mA cerebellar tDCS for 20 min under three stimulus conditions (anodal-, cathodal-, and sham-tDCS) on separate days with a double-blind, counter-balanced cross-over design. Task performance was assessed by measuring the distance between the center of the bull's eye and the dart's position. Although task performance tended to improve throughout the practice under all stimulus conditions, improvement within a given day was not significant as compared to the first no-stimulus block. In addition, improvement did not differ among stimulation conditions. However, the magnitude of improvement was associated with an individual's level of task performance only under cathodal tDCS condition (p < 0.05). This resulted in a significant performance improvement only for the sub-group of participants with lower performance levels as compared to that with sham-tDCS (p < 0.05). These findings suggest that the facilitation effect of cerebellar cathodal tDCS on motor skill learning of complex whole-body movements depends on the level of an individual's task performance. Thus, cerebellar tDCS would facilitate learning of a complex motor skill task only in a subset of individuals. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Three-dimensional vision enhances task performance independently of the surgical method.

PubMed

Wagner, O J; Hagen, M; Kurmann, A; Horgan, S; Candinas, D; Vorburger, S A

2012-10-01

Within the next few years, the medical industry will launch increasingly affordable three-dimensional (3D) vision systems for the operating room (OR). This study aimed to evaluate the effect of two-dimensional (2D) and 3D visualization on surgical skills and task performance. In this study, 34 individuals with varying laparoscopic experience (18 inexperienced individuals) performed three tasks to test spatial relationships, grasping and positioning, dexterity, precision, and hand-eye and hand-hand coordination. Each task was performed in 3D using binocular vision for open performance, the Viking 3Di Vision System for laparoscopic performance, and the DaVinci robotic system. The same tasks were repeated in 2D using an eye patch for monocular vision, conventional laparoscopy, and the DaVinci robotic system. Loss of 3D vision significantly increased the perceived difficulty of a task and the time required to perform it, independently of the approach (P < 0.0001-0.02). Simple tasks took 25 % to 30 % longer to complete and more complex tasks took 75 % longer with 2D than with 3D vision. Only the difficult task was performed faster with the robot than with laparoscopy (P = 0.005). In every case, 3D robotic performance was superior to conventional laparoscopy (2D) (P < 0.001-0.015). The more complex the task, the more 3D vision accelerates task completion compared with 2D vision. The gain in task performance is independent of the surgical method.

Effects of Selected Task Performance Criteria at Initiating Adaptive Task Real locations

NASA Technical Reports Server (NTRS)

Montgomery, Demaris A.

2001-01-01

In the current report various performance assessment methods used to initiate mode transfers between manual control and automation for adaptive task reallocation were tested. Participants monitored two secondary tasks for critical events while actively controlling a process in a fictional system. One of the secondary monitoring tasks could be automated whenever operators' performance was below acceptable levels. Automation of the secondary task and transfer of the secondary task back to manual control were either human- or machine-initiated. Human-initiated transfers were based on the operator's assessment of the current task demands while machine-initiated transfers were based on the operators' performance. Different performance assessment methods were tested in two separate experiments.

Perceived control in rhesus monkeys (Macaca mulatta) - Enhanced video-task performance

NASA Technical Reports Server (NTRS)

Washburn, David A.; Hopkins, William D.; Rumbaugh, Duane M.

1991-01-01

This investigation was designed to determine whether perceived control effects found in humans extend to rhesus monkeys (Macaca mulatta) tested in a video-task format, using a computer-generated menu program, SELECT. Choosing one of the options in SELECT resulted in presentation of five trials of a corresponding task and subsequent return to the menu. In Experiments 1-3, the animals exhibited stable, meaningful response patterns in this task (i.e., they made choices). In Experiment 4, performance on tasks that were selected by the animals significantly exceeded performance on identical tasks when assigned by the experimenter under comparable conditions (e.g., time of day, order, variety). The reliable and significant advantage for performance on selected tasks, typically found in humans, suggests that rhesus monkeys were able to perceive the availability of choices.

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.

Highly automated driving, secondary task performance, and driver state.

PubMed

Merat, Natasha; Jamson, A Hamish; Lai, Frank C H; Carsten, Oliver

2012-10-01

A driving simulator study compared the effect of changes in workload on performance in manual and highly automated driving. Changes in driver state were also observed by examining variations in blink patterns. With the addition of a greater number of advanced driver assistance systems in vehicles, the driver's role is likely to alter in the future from an operator in manual driving to a supervisor of highly automated cars. Understanding the implications of such advancements on drivers and road safety is important. A total of 50 participants were recruited for this study and drove the simulator in both manual and highly automated mode. As well as comparing the effect of adjustments in driving-related workload on performance, the effect of a secondary Twenty Questions Task was also investigated. In the absence of the secondary task, drivers' response to critical incidents was similar in manual and highly automated driving conditions. The worst performance was observed when drivers were required to regain control of driving in the automated mode while distracted by the secondary task. Blink frequency patterns were more consistent for manual than automated driving but were generally suppressed during conditions of high workload. Highly automated driving did not have a deleterious effect on driver performance, when attention was not diverted to the distracting secondary task. As the number of systems implemented in cars increases, an understanding of the implications of such automation on drivers' situation awareness, workload, and ability to remain engaged with the driving task is important.

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

Effect of Spatial Titration on Task Performance

ERIC Educational Resources Information Center

Glowacki, Lawrence

1976-01-01

A reinforcement schedule and spatial titration method were used to determine task-reinforcement area separation most preferred and effective in two third-grade boys. Errors in task performance decreased task-reinforcement area separation, while correct responses in task performance increased task-reinforcement area separation. (Author)

Discrepancy of performance among working memory-related tasks in autism spectrum disorders was caused by task characteristics, apart from working memory, which could interfere with task execution.

PubMed

Nakahachi, Takayuki; Iwase, Masao; Takahashi, Hidetoshi; Honaga, Eiko; Sekiyama, Ryuji; Ukai, Satoshi; Ishii, Ryouhei; Ishigami, Wataru; Kajimoto, Osami; Yamashita, Ko; Hashimoto, Ryota; Tanii, Hisashi; Shimizu, Akira; Takeda, Masatoshi

2006-06-01

Working memory performance has been inconsistently reported in autism spectrum disorders (ASD). Several studies in ASD have found normal performance in digit span and poor performance in digit symbol task although these are closely related with working memory. It is assumed that poor performance in digit symbol could be explained by confirmatory behavior, which is induced due to the vague memory representation of number-symbol association. Therefore it was hypothesized that the performance of working memory task, in which vagueness did not cause confirmatory behavior, would be normal in ASD. For this purpose, the Advanced Trail Making Test (ATMT) was used. The performance of digit span, digit symbol and ATMT was compared between ASD and normal control. The digit span, digit symbol and ATMT was given to 16 ASD subjects and 28 IQ-, age- and sex-matched control subjects. The scores of these tasks were compared. A significantly lower score for ASD was found only in digit symbol compared with control subjects. There were no significant difference in digit span and working memory estimated by ATMT. Discrepancy of scores among working memory-related tasks was demonstrated in ASD. Poor digit symbol performance, normal digit span and normal working memory in ATMT implied that ASD subjects would be intact in working memory itself, and that superficial working memory dysfunction might be observed due to confirmatory behavior in digit symbol. Therefore, to evaluate working memory in ASD, tasks that could stimulate psychopathology specific to ASD should be avoided.

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

PubMed

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

2015-12-01

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

Comparative analysis of low-back loading on chiropractors using various workstation table heights and performing various tasks.

PubMed

Lorme, Kenneth J; Naqvi, Syed A

2003-01-01

There is epidemiologic evidence that chiropractors are a high-risk group for low-back disorders. However, to date there are no known biomechanical studies to determine whether their workstations may be a contributing factor. To investigate whether chiropractors' workstation table height or the tasks they perform make them susceptible to low-back strain. As well as investigating low-back strain, a screening was performed to determine whether chiropractors' upper extremities were at risk for undue strain as workstation table height was varied. Experimental pilot study. A university ergonomic laboratory. An adjustable manipulation table was set at 3 different heights: 465 mm, 665 mm and 845 mm. Each of the 7 volunteer chiropractors were fitted with a triaxial electrogoniometer and were videotaped and photographed for analysis while performing spinal manipulation to the cervical, thoracic, and lumbar spine of a volunteer patient at each workstation table height. Two biomechanical models, one static and one dynamic, were used to record the dependent variables. A screening of various upper extremity variables was also performed with the static model. For the subjects under study, a significant difference was found for the variables maximum sagittal flexion, disk compression force, and ligament strain as table height was varied. For the lumbar and thoracic manipulation tasks, the medium table height (655 mm) was found to create the least low-back strain. For the cervical manipulation task, the high table height (845 mm) was found to be the least straining on the low-back. The low height table (465 mm) was the most straining for all tasks. Upper extremities were not significantly affected by changes to table height. Significant differences were found for the task performed for axial rotational velocity, disk compression force, ligament strain, maximum sagittal flexion, dominant (right) elbow moment, and dominant (right) shoulder moment variables. There was no significant

Predictive performance models and multiple task performance

NASA Technical Reports Server (NTRS)

Wickens, Christopher D.; Larish, Inge; Contorer, Aaron

1989-01-01

Five models that predict how performance of multiple tasks will interact in complex task scenarios are discussed. The models are shown in terms of the assumptions they make about human operator divided attention. The different assumptions about attention are then empirically validated in a multitask helicopter flight simulation. It is concluded from this simulation that the most important assumption relates to the coding of demand level of different component tasks.

Comparing fusion techniques for the ImageCLEF 2013 medical case retrieval task.

PubMed

G Seco de Herrera, Alba; Schaer, Roger; Markonis, Dimitrios; Müller, Henning

2015-01-01

Retrieval systems can supply similar cases with a proven diagnosis to a new example case under observation to help clinicians during their work. The ImageCLEFmed evaluation campaign proposes a framework where research groups can compare case-based retrieval approaches. This paper focuses on the case-based task and adds results of the compound figure separation and modality classification tasks. Several fusion approaches are compared to identify the approaches best adapted to the heterogeneous data of the task. Fusion of visual and textual features is analyzed, demonstrating that the selection of the fusion strategy can improve the best performance on the case-based retrieval task. Copyright © 2014 Elsevier Ltd. All rights reserved.

Virtual street-crossing performance in persons with multiple sclerosis: Feasibility and task performance characteristics.

PubMed

Stratton, M E; Pilutti, L A; Crowell, J A; Kaczmarski, H; Motl, R W

2017-01-02

Multiple sclerosis (MS) is a neurological disease that commonly results in physical and cognitive dysfunction. Accordingly, MS might impact the ability to safely cross the street. The purpose of this study was to examine the feasibility of a simulated street-crossing task in persons with MS and to determine differences in street-crossing performance between persons with MS and non-MS controls. 26 participants with MS (median Expanded Disability Status Scale [EDSS] score = 3.5) and 19 controls completed 40 trials of a virtual street-crossing task. There were 2 crossing conditions (i.e., no distraction and phone conversation), and participants performed 20 trials per condition. Participants were instructed that the goal of the task was to cross the street successfully (i.e., without being hit be a vehicle). The primary outcome was task feasibility, assessed as completion and adverse events. Secondary outcomes were measures of street-crossing performance. Overall, the simulated street-crossing task was feasible (i.e., 90% completion, no adverse events) in participants with MS. Participants with MS waited longer and were less attentive to traffic before entering the street compared with controls (all P < .05). Participants with MS also took longer to cross the street and were closer to oncoming vehicles when exiting the street compared to controls (all P < .05). When distracted, all participants took longer to initiate crossing, took longer to cross the street, and made more head turns while crossing (all P < .05). There were no significant group by condition interaction effects (all P > .05). A virtual street-crossing task is feasible for studying street-crossing behavior in persons with mild MS and most individuals with moderate MS. Virtual street-crossing performance is impaired in persons with MS compared to controls; however, persons with MS do not appear to be more vulnerable to a distracting condition. The virtual reality environment presents a safe and useful

Development of Internet-Based Tasks for the Executive Function Performance Test.

PubMed

Rand, Debbie; Lee Ben-Haim, Keren; Malka, Rachel; Portnoy, Sigal

The Executive Function Performance Test (EFPT) is a reliable and valid performance-based tool to assess executive functions (EFs). This study's objective was to develop and verify two Internet-based tasks for the EFPT. A cross-sectional study assessed the alternate-form reliability of the Internet-based bill-paying and telephone-use tasks in healthy adults and people with subacute stroke (Study 1). It also sought to establish the tasks' criterion reliability for assessing EF deficits by correlating performance with that on the Trail Making Test in five groups: healthy young adults, healthy older adults, people with subacute stroke, people with chronic stroke, and young adults with attention deficit hyperactivity disorder (Study 2). The alternative-form reliability and initial construct validity for the Internet-based bill-paying task were verified. Criterion validity was established for both tasks. The Internet-based tasks are comparable to the original EFPT tasks and can be used for assessment of EF deficits. Copyright © 2018 by the American Occupational Therapy Association, Inc.

Task complexity, student perceptions of vocabulary learning in EFL, and task performance.

PubMed

Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan

2013-03-01

The study deepened our understanding of how students' self-efficacy beliefs contribute to the context of teaching English as a foreign language in the framework of cognitive mediational paradigm at a fine-tuned task-specific level. The aim was to examine the relationship among task complexity, self-efficacy beliefs, domain-related prior knowledge, learning strategy use, and task performance as they were applied to English vocabulary learning from reading tasks. Participants were 120 second-year university students (mean age 21) from a Chinese university. This experiment had two conditions (simple/complex). A vocabulary level test was first conducted to measure participants' prior knowledge of English vocabulary. Participants were then randomly assigned to one of the learning tasks. Participants were administered task booklets together with the self-efficacy scales, measures of learning strategy use, and post-tests. Data obtained were submitted to multivariate analysis of variance (MANOVA) and path analysis. Results from the MANOVA model showed a significant effect of vocabulary level on self-efficacy beliefs, learning strategy use, and task performance. Task complexity showed no significant effect; however, an interaction effect between vocabulary level and task complexity emerged. Results from the path analysis showed self-efficacy beliefs had an indirect effect on performance. Our results highlighted the mediating role of self-efficacy beliefs and learning strategy use. Our findings indicate that students' prior knowledge plays a crucial role on both self-efficacy beliefs and task performance, and the predictive power of self-efficacy on task performance may lie in its association with learning strategy use. © 2011 The British Psychological Society.

Topical Knowledge in L2 Speaking Assessment: Comparing Independent and Integrated Speaking Test Tasks

ERIC Educational Resources Information Center

Huang, Heng-Tsung Danny; Hung, Shao-Ting Alan; Plakans, Lia

2018-01-01

Integrated speaking test tasks (integrated tasks) provide reading and/or listening input to serve as the basis for test-takers to formulate their oral responses. This study examined the influence of topical knowledge on integrated speaking test performance and compared independent speaking test performance and integrated speaking test performance…

New paradigm for task switching strategies while performing multiple tasks: entropy and symbolic dynamics analysis of voluntary patterns.

PubMed

Guastello, Stephen J; Gorin, Hillary; Huschen, Samuel; Peters, Natalie E; Fabisch, Megan; Poston, Kirsten

2012-10-01

It has become well established in laboratory experiments that switching tasks, perhaps due to interruptions at work, incur costs in response time to complete the next task. Conditions are also known that exaggerate or lessen the switching costs. Although switching costs can contribute to fatigue, task switching can also be an adaptive response to fatigue. The present study introduces a new research paradigm for studying the emergence of voluntary task switching regimes, self-organizing processes therein, and the possibly conflicting roles of switching costs and minimum entropy. Fifty-four undergraduates performed 7 different computer-based cognitive tasks producing sets of 49 responses under instructional conditions requiring task quotas or no quotas. The sequences of task choices were analyzed using orbital decomposition to extract pattern types and lengths, which were then classified and compared with regard to Shannon entropy, topological entropy, number of task switches involved, and overall performance. Results indicated that similar but different patterns were generated under the two instructional conditions, and better performance was associated with lower topological entropy. Both entropy metrics were associated with the amount of voluntary task switching. Future research should explore conditions affecting the trade-off between switching costs and entropy, levels of automaticity between task elements, and the role of voluntary switching regimes on fatigue.

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.

Theory of mind performance using a story comprehension task in bipolar mania compared to schizophrenia and healthy controls.

PubMed

Rossell, Susan L; Van Rheenen, Tamsyn E

2013-01-01

Theory of mind (ToM) refers to the ability to understand the mental state of self and others. There is limited research into this topic in bipolar disorder (BD), with no previous study examining ToM in a BD group within a psychotic manic phase. Twenty-eight psychotic manic BD patients were compared with 30 schizophrenia (SCZ) patients and 29 healthy controls (HC). Participants performed a ToM story comprehension task that compared ToM stories and non-ToM stories (which we relabelled non-ToM "semantic" stories). Performance was examined by answering comprehension questions. Both patient groups were equally impaired on their scores for ToM stories (scores BD = 10/24, SCZ = 9/24, HC = 14/24, p < .001). Interestingly, both patient groups showed reduced performance on non-ToM semantic stories (scores BD = 12/24, SCZ = 9/24, HC = 15/24, p < .001); SCZ showed a larger deficit. Reduced ToM performance was correlated with delusion severity in the BD group only. ToM performance was impaired in BD patients experiencing psychotic symptoms. Patient performance was also impaired on the control condition (i.e., non-ToM semantic stories) supporting an additional deficit in semantic processing.

Children's construction task performance and spatial ability: controlling task complexity and predicting mathematics performance.

PubMed

Richardson, Miles; Hunt, Thomas E; Richardson, Cassandra

2014-12-01

This paper presents a methodology to control construction task complexity and examined the relationships between construction performance and spatial and mathematical abilities in children. The study included three groups of children (N = 96); ages 7-8, 10-11, and 13-14 years. Each group constructed seven pre-specified objects. The study replicated and extended previous findings that indicated that the extent of component symmetry and variety, and the number of components for each object and available for selection, significantly predicted construction task difficulty. Results showed that this methodology is a valid and reliable technique for assessing and predicting construction play task difficulty. Furthermore, construction play performance predicted mathematical attainment independently of spatial ability.

Effects of Information Visualization on Older Adults' Decision-Making Performance in a Medicare Plan Selection Task: A Comparative Usability Study.

PubMed

Price, Margaux M; Crumley-Branyon, Jessica J; Leidheiser, William R; Pak, Richard

2016-06-01

Technology gains have improved tools for evaluating complex tasks by providing environmental supports (ES) that increase ease of use and improve performance outcomes through the use of information visualizations (info-vis). Complex info-vis emphasize the need to understand individual differences in abilities of target users, the key cognitive abilities needed to execute a decision task, and the graphical elements that can serve as the most effective ES. Older adults may be one such target user group that would benefit from increased ES to mitigate specific declines in cognitive abilities. For example, choosing a prescription drug plan is a necessary and complex task that can impact quality of life if the wrong choice is made. The decision to enroll in one plan over another can involve comparing over 15 plans across many categories. Within this context, the large amount of complex information and reduced working memory capacity puts older adults' decision making at a disadvantage. An intentionally designed ES, such as an info-vis that reduces working memory demand, may assist older adults in making the most effective decision among many options. The objective of this study is to examine whether the use of an info-vis can lower working memory demands and positively affect complex decision-making performance of older adults in the context of choosing a Medicare prescription drug plan. Participants performed a computerized decision-making task in the context of finding the best health care plan. Data included quantitative decision-making performance indicators and surveys examining previous history with purchasing insurance. Participants used a colored info-vis ES or a table (no ES) to perform the decision task. Task difficulty was manipulated by increasing the number of selection criteria used to make an accurate decision. A repeated measures analysis was performed to examine differences between the two table designs. Twenty-three older adults between the ages of 66

Effects of Information Visualization on Older Adults’ Decision-Making Performance in a Medicare Plan Selection Task: A Comparative Usability Study

PubMed Central

Price, Margaux M; Crumley-Branyon, Jessica J; Leidheiser, William R

2016-01-01

Background Technology gains have improved tools for evaluating complex tasks by providing environmental supports (ES) that increase ease of use and improve performance outcomes through the use of information visualizations (info-vis). Complex info-vis emphasize the need to understand individual differences in abilities of target users, the key cognitive abilities needed to execute a decision task, and the graphical elements that can serve as the most effective ES. Older adults may be one such target user group that would benefit from increased ES to mitigate specific declines in cognitive abilities. For example, choosing a prescription drug plan is a necessary and complex task that can impact quality of life if the wrong choice is made. The decision to enroll in one plan over another can involve comparing over 15 plans across many categories. Within this context, the large amount of complex information and reduced working memory capacity puts older adults’ decision making at a disadvantage. An intentionally designed ES, such as an info-vis that reduces working memory demand, may assist older adults in making the most effective decision among many options. Objective The objective of this study is to examine whether the use of an info-vis can lower working memory demands and positively affect complex decision-making performance of older adults in the context of choosing a Medicare prescription drug plan. Methods Participants performed a computerized decision-making task in the context of finding the best health care plan. Data included quantitative decision-making performance indicators and surveys examining previous history with purchasing insurance. Participants used a colored info-vis ES or a table (no ES) to perform the decision task. Task difficulty was manipulated by increasing the number of selection criteria used to make an accurate decision. A repeated measures analysis was performed to examine differences between the two table designs. Results Twenty

The Role of Task Understanding on Younger and Older Adults' Performance.

PubMed

Frank, David J; Touron, Dayna R

2016-12-16

Age-related performance decrements have been linked to inferior strategic choices. Strategy selection models argue that accurate task representations are necessary for choosing appropriate strategies. But no studies to date have compared task representations in younger and older adults. Metacognition research suggests age-related deficits in updating and utilizing strategy knowledge, but other research suggests age-related sparing when information can be consolidated into a coherent mental model. Study 1 validated the use of concept mapping as a tool for measuring task representation accuracy. Study 2 measured task representations before and after a complex strategic task to test for age-related decrements in task representation formation and updating. Task representation accuracy and task performance were equivalent across age groups. Better task representations were related to better performance. However, task representation scores remained fairly stable over the task with minimal evidence of updating. Our findings mirror those in the mental model literature suggesting age-related sparing of strategy use when information can be integrated into a coherent mental model. Future research should manipulate the presence of a unifying context to better evaluate this hypothesis. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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.

Effects of Age, Task Performance, and Structural Brain Development on Face Processing

PubMed Central

Cohen Kadosh, Kathrin; Johnson, Mark H; Dick, Frederic; Cohen Kadosh, Roi; Blakemore, Sarah-Jayne

2013-01-01

In this combined structural and functional MRI developmental study, we tested 48 participants aged 7–37 years on 3 simple face-processing tasks (identity, expression, and gaze task), which were designed to yield very similar performance levels across the entire age range. The same participants then carried out 3 more difficult out-of-scanner tasks, which provided in-depth measures of changes in performance. For our analysis we adopted a novel, systematic approach that allowed us to differentiate age- from performance-related changes in the BOLD response in the 3 tasks, and compared these effects to concomitant changes in brain structure. The processing of all face aspects activated the core face-network across the age range, as well as additional and partially separable regions. Small task-specific activations in posterior regions were found to increase with age and were distinct from more widespread activations that varied as a function of individual task performance (but not of age). Our results demonstrate that activity during face-processing changes with age, and these effects are still observed when controlling for changes associated with differences in task performance. Moreover, we found that changes in white and gray matter volume were associated with changes in activation with age and performance in the out-of-scanner tasks. PMID:22661406

Characterization of task-free and task-performance brain states via functional connectome patterns.

PubMed

Zhang, Xin; Guo, Lei; Li, Xiang; Zhang, Tuo; Zhu, Dajiang; Li, Kaiming; Chen, Hanbo; Lv, Jinglei; Jin, Changfeng; Zhao, Qun; Li, Lingjiang; Liu, Tianming

2013-12-01

Both resting state fMRI (R-fMRI) and task-based fMRI (T-fMRI) have been widely used to study the functional activities of the human brain during task-free and task-performance periods, respectively. However, due to the difficulty in strictly controlling the participating subject's mental status and their cognitive behaviors during R-fMRI/T-fMRI scans, it has been challenging to ascertain whether or not an R-fMRI/T-fMRI scan truly reflects the participant's functional brain states during task-free/task-performance periods. This paper presents a novel computational approach to characterizing and differentiating the brain's functional status into task-free or task-performance states, by which the functional brain activities can be effectively understood and differentiated. Briefly, the brain's functional state is represented by a whole-brain quasi-stable connectome pattern (WQCP) of R-fMRI or T-fMRI data based on 358 consistent cortical landmarks across individuals, and then an effective sparse representation method was applied to learn the atomic connectome patterns (ACPs) of both task-free and task-performance states. Experimental results demonstrated that the learned ACPs for R-fMRI and T-fMRI datasets are substantially different, as expected. A certain portion of ACPs from R-fMRI and T-fMRI data were overlapped, suggesting some subjects with overlapping ACPs were not in the expected task-free/task-performance brain states. Besides, potential outliers in the T-fMRI dataset were further investigated via functional activation detections in different groups, and our results revealed unexpected task-performances of some subjects. This work offers novel insights into the functional architectures of the brain. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of Task-free and Task-performance Brain States via Functional Connectome Patterns

PubMed Central

Zhang, Xin; Guo, Lei; Li, Xiang; Zhang, Tuo; Zhu, Dajiang; Li, Kaiming; Chen, Hanbo; Lv, Jinglei; Jin, Changfeng; Zhao, Qun; Li, Lingjiang; Liu, Tianming

2014-01-01

Both resting state fMRI (R-fMRI) and task-based fMRI (T-fMRI) have been widely used to study the functional activities of the human brain during task-free and task-performance periods, respectively. However, due to the difficulty in strictly controlling the participating subject's mental status and their cognitive behaviors during R-fMRI/T-fMRI scans, it has been challenging to ascertain whether or not an R-fMRI/T-fMRI scan truly reflects the participant's functional brain states during task-free/task-performance periods. This paper presents a novel computational approach to characterizing and differentiating the brain's functional status into task-free or task-performance states, by which the functional brain activities can be effectively understood and differentiated. Briefly, the brain's functional state is represented by a whole-brain quasi-stable connectome pattern (WQCP) of R-fMRI or T-fMRI data based on 358 consistent cortical landmarks across individuals, and then an effective sparse representation method was applied to learn the atomic connectome patterns (ACP) of both task-free and task-performance states. Experimental results demonstrated that the learned ACPs for R-fMRI and T-fMRI datasets are substantially different, as expected. A certain portion of ACPs from R-fMRI and T-fMRI data were overlapped, suggesting some subjects with overlapping ACPs were not in the expected task-free/task-performance brain states. Besides, potential outliers in the T-fMRI dataset were further investigated via functional activation detections in different groups, and our results revealed unexpected task-performances of some subjects. This work offers novel insights into the functional architectures of the brain. PMID:23938590

Cognitive-evaluative features of childhood social anxiety in a performance task.

PubMed

Tuschen-Caffier, Brunna; Kühl, Sigrid; Bender, Caroline

2011-06-01

Using an experimental design, we analysed differences in the occurrence of cognitive-evaluative distortions and performance deficits across children with social anxiety disorder, with subclinical anxiety and without any anxiety symptoms. Twenty-one children with full syndrome social phobia, 18 children with partial syndrome social phobia and 20 children without any symptoms of social phobia were compared with respect to their degree of anxiety, negative thinking and task performance during two social-evaluative tasks. In addition, self-ratings of task performance, performance estimations for other children and objective behavioural ratings by two independent observers were obtained. Children with social anxiety disorder and subclinical social anxiety showed higher degrees of experienced anxiety and negative thinking than healthy control children. There was no group difference in respect to actual task performance. Findings are discussed with regard to the continuum assumption of childhood social anxiety disorder and the need of well-adapted early interventions. Copyright © 2010. Published by Elsevier Ltd.

Recoding low-level simulator data into a record of meaningful task performance: the integrated task modeling environment (ITME).

PubMed

King, Robert; Parker, Simon; Mouzakis, Kon; Fletcher, Winston; Fitzgerald, Patrick

2007-11-01

The Integrated Task Modeling Environment (ITME) is a user-friendly software tool that has been developed to automatically recode low-level data into an empirical record of meaningful task performance. The present research investigated and validated the performance of the ITME software package by conducting complex simulation missions and comparing the task analyses produced by ITME with taskanalyses produced by experienced video analysts. A very high interrater reliability (> or = .94) existed between experienced video analysts and the ITME for the task analyses produced for each mission. The mean session time:analysis time ratio was 1:24 using video analysis techniques and 1:5 using the ITME. It was concluded that the ITME produced task analyses that were as reliable as those produced by experienced video analysts, and significantly reduced the time cost associated with these analyses.

Embodied Information in Cognitive Tasks: Haptic Weight Sensations Affect Task Performance and Processing Style

PubMed Central

Kaspar, Kai; Vennekötter, Alina

2015-01-01

Research in the field of embodied cognition showed that incidental weight sensations influence peoples’ judgments about a variety of issues and objects. Most studies found that heaviness compared to lightness increases the perception of importance, seriousness, and potency. In two experiments, we broadened this scope by investigating the impact of weight sensations on cognitive performance. In Experiment 1, we found that the performance in an anagram task was reduced when participants held a heavy versus a light clipboard in their hands. Reduced performance was accompanied by an increase in the perceived effort. In Experiment 2, a heavy clipboard elicited a specific response heuristic in a two-alternative forced-choice task. Participants showed a significant right side bias when holding a heavy clipboard in their hands. After the task, participants in the heavy clipboard condition reported to be more frustrated than participants in the light clipboard condition. In both experiments, we did not find evidence for mediated effects that had been proposed by previous literature. Overall, the results indicate that weight effects go beyond judgment formation and highlight new avenues for future research. PMID:26421084

Comparative assessment of surgeons' task performance and surgical ergonomics associated with conventional and modified flank positions: a simulation study.

PubMed

Fan, Yu; Kong, Gaiqing; Meng, Yisen; Tan, Shutao; Wei, Kunlin; Zhang, Qian; Jin, Jie

2014-11-01

Flank position is extensively used in retroperitoneoscopic urological practice. Most surgeons follow the patients' position in open approaches. However, surgical ergonomics of the conventional position in the retroperitoneoscopic surgery is poor. We introduce a modified position and evaluated task performance and surgical ergonomics of both positions with simulated surgical tasks. Twenty-one novice surgeons were recruited to perform four tasks: bead transfer, ring transfer, continuous suturing, and cutting a circle. The conventional position was simulated by setting an endo-surgical simulator parallel to the long axis of a surgical desk. The modified position was simulated by rotating the simulator 30° with respect to the long axis of the desk. The outcome measurements include task performance measures, kinematic measures for body alignment, surface electromyography, relative loading between feet, and subjective ratings of fatigue. We observed significant improvements in both task performance and surgical ergonomics parameters under the modified position. For all four tasks, subjects finished tasks faster with higher accuracy (p < 0.005 or < 0.001). For ergonomics part: (1) The angle between the upper body and the head was decreased by 7.4 ± 1.7°; (2) The EMG amplitude collected from shoulders and left lumber was significantly lower (p < 0.05); (3) Relative loading between feet was more balanced (p < 0.001); (4) Manual-action muscles and postural muscles are rated less fatiguing according to the questionnaire (p < 0.05). Conventional position of patient in retroperitoneoscopic upper urinary tract surgery is associated with poor surgical ergonomics. With a simulated surgery, we demonstrated that our modified position could significantly improve task performance and surgical ergonomics. Further studies are still warranted to validate these benefits for both patients and surgeons.

Comparing kinematic changes between a finger-tapping task and unconstrained finger flexion-extension task in patients with Parkinson's disease.

PubMed

Teo, W P; Rodrigues, J P; Mastaglia, F L; Thickbroom, G W

2013-06-01

Repetitive finger tapping is a well-established clinical test for the evaluation of parkinsonian bradykinesia, but few studies have investigated other finger movement modalities. We compared the kinematic changes (movement rate and amplitude) and response to levodopa during a conventional index finger-thumb-tapping task and an unconstrained index finger flexion-extension task performed at maximal voluntary rate (MVR) for 20 s in 11 individuals with levodopa-responsive Parkinson's disease (OFF and ON) and 10 healthy age-matched controls. Between-task comparisons showed that for all conditions, the initial movement rate was greater for the unconstrained flexion-extension task than the tapping task. Movement rate in the OFF state was slower than in controls for both tasks and normalized in the ON state. The movement amplitude was also reduced for both tasks in OFF and increased in the ON state but did not reach control levels. The rate and amplitude of movement declined significantly for both tasks under all conditions (OFF/ON and controls). The time course of rate decline was comparable for both tasks and was similar in OFF/ON and controls, whereas the tapping task was associated with a greater decline in MA, both in controls and ON, but not OFF. The findings indicate that both finger movement tasks show similar kinematic changes during a 20-s sustained MVR, but that movement amplitude is less well sustained during the tapping task than the unconstrained finger movement task. Both movement rate and amplitude improved with levodopa; however, movement rate was more levodopa responsive than amplitude.

Sleep restriction during simulated wildfire suppression: effect on physical task performance.

PubMed

Vincent, Grace; Ferguson, Sally A; Tran, Jacqueline; Larsen, Brianna; Wolkow, Alexander; Aisbett, Brad

2015-01-01

To examine the effects of sleep restriction on firefighters' physical task performance during simulated wildfire suppression. Thirty-five firefighters were matched and randomly allocated to either a control condition (8-hour sleep opportunity, n = 18) or a sleep restricted condition (4-hour sleep opportunity, n = 17). Performance on physical work tasks was evaluated across three days. In addition, heart rate, core temperature, and worker activity were measured continuously. Rate of perceived and exertion and effort sensation were evaluated during the physical work periods. There were no differences between the sleep-restricted and control groups in firefighters' task performance, heart rate, core temperature, or perceptual responses during self-paced simulated firefighting work tasks. However, the sleep-restricted group were less active during periods of non-physical work compared to the control group. Under self-paced work conditions, 4 h of sleep restriction did not adversely affect firefighters' performance on physical work tasks. However, the sleep-restricted group were less physically active throughout the simulation. This may indicate that sleep-restricted participants adapted their behaviour to conserve effort during rest periods, to subsequently ensure they were able to maintain performance during the firefighter work tasks. This work contributes new knowledge to inform fire agencies of firefighters' operational capabilities when their sleep is restricted during multi-day wildfire events. The work also highlights the need for further research to explore how sleep restriction affects physical performance during tasks of varying duration, intensity, and complexity.

Sleep Restriction during Simulated Wildfire Suppression: Effect on Physical Task Performance

PubMed Central

Vincent, Grace; Ferguson, Sally A.; Tran, Jacqueline; Larsen, Brianna; Wolkow, Alexander; Aisbett, Brad

2015-01-01

Objectives To examine the effects of sleep restriction on firefighters’ physical task performance during simulated wildfire suppression. Methods Thirty-five firefighters were matched and randomly allocated to either a control condition (8-hour sleep opportunity, n = 18) or a sleep restricted condition (4-hour sleep opportunity, n = 17). Performance on physical work tasks was evaluated across three days. In addition, heart rate, core temperature, and worker activity were measured continuously. Rate of perceived and exertion and effort sensation were evaluated during the physical work periods. Results There were no differences between the sleep-restricted and control groups in firefighters’ task performance, heart rate, core temperature, or perceptual responses during self-paced simulated firefighting work tasks. However, the sleep-restricted group were less active during periods of non-physical work compared to the control group. Conclusions Under self-paced work conditions, 4 h of sleep restriction did not adversely affect firefighters’ performance on physical work tasks. However, the sleep-restricted group were less physically active throughout the simulation. This may indicate that sleep-restricted participants adapted their behaviour to conserve effort during rest periods, to subsequently ensure they were able to maintain performance during the firefighter work tasks. This work contributes new knowledge to inform fire agencies of firefighters’ operational capabilities when their sleep is restricted during multi-day wildfire events. The work also highlights the need for further research to explore how sleep restriction affects physical performance during tasks of varying duration, intensity, and complexity. PMID:25615988

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

PubMed

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

2013-01-01

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

Economic decision-making compared with an equivalent motor task.

PubMed

Wu, Shih-Wei; Delgado, Mauricio R; Maloney, Laurence T

2009-04-14

There is considerable evidence that human economic decision-making deviates from the predictions of expected utility theory (EUT) and that human performance conforms to EUT in many perceptual and motor decision tasks. It is possible that these results reflect a real difference in decision-making in the 2 domains but it is also possible that the observed discrepancy simply reflects typical differences in experimental design. We developed a motor task that is mathematically equivalent to choosing between lotteries and used it to compare how the same subject chose between classical economic lotteries and the same lotteries presented in equivalent motor form. In experiment 1, we found that subjects are more risk seeking in deciding between motor lotteries. In experiment 2, we used cumulative prospect theory to model choice and separately estimated the probability weighting functions and the value functions for each subject carrying out each task. We found no patterned differences in how subjects represented outcome value in the motor and the classical tasks. However, the probability weighting functions for motor and classical tasks were markedly and significantly different. Those for the classical task showed a typical tendency to overweight small probabilities and underweight large probabilities, and those for the motor task showed the opposite pattern of probability distortion. This outcome also accounts for the increased risk-seeking observed in the motor tasks of experiment 1. We conclude that the same subject distorts probability, but not value, differently in making identical decisions in motor and classical form.

Interpersonal synergies: static prehension tasks performed by two actors.

PubMed

Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun; Zatsiorsky, Vladimir M; Latash, Mark L

2016-08-01

We investigated multidigit synergies stabilizing components of the resultant force vector during joint performance of a static prehension task by two persons as compared to similar tasks performed by a single person using both hands. Subjects transferred the instrumented handle from the right hand to the left hand (one-person condition) or passed that handle to another person (two-person condition) while keeping the handle's position and orientation stationary. Only three digits were involved per hand, the thumb, the index finger, and the middle finger; the forces and moments produced by the digits were measured by six-component sensors. We estimated the performance-stabilizing synergies within the uncontrolled manifold framework by quantifying the intertrial variance structure of digit forces and moments. The analysis was performed at three levels: between hands, between virtual finger and virtual thumb (imagined digits producing the same mechanical variables as the corresponding actual digits combined) produced by the two hands (in both interpersonal and intrapersonal conditions), and between the thumb and virtual finger for one hand only. Additionally, we performed correlation and phase synchronization analyses of resultant tangential forces and internal normal forces. Overall, the one-person conditions were characterized by higher amount of intertrial variance that did not affect resultant normal force components, higher internal components of normal forces, and stronger synchronization of the normal forces generated by the hands. Our observations suggest that in two-person tasks, when participants try to achieve a common mechanical outcome, the performance-stabilizing synergies depend on non-visual information exchange, possibly via the haptic and proprioceptive systems. Therefore, synergies quantified in tasks using visual feedback only may not be generalizable to more natural tasks.

An empirically derived figure of merit for the quality of overall task performance

NASA Technical Reports Server (NTRS)

Lemay, Moira

1989-01-01

The need to develop an operationally relevant figure of merit for the quality of performance of a complex system such as an aircraft cockpit stems from a hypothesized dissociation between measures of performance and those of workload. Performance can be measured in terms of time, errors, or a combination of these. In most tasks performed by expert operators, errors are relatively rare and often corrected in time to avoid consequences. Moreover, perfect performance is seldom necessary to accomplish a particular task. Moreover, how well an expert performs a complex task consisting of a series of discrete cognitive tasks superimposed on a continuous task, such as flying an aircraft, does not depend on how well each discrete task is performed, but on their smooth sequencing. This makes the amount of time spent on each subtask of paramount importance in measuring overall performance, since smooth sequencing requires a minimum amount of time spent on each task. Quality consists in getting tasks done within a crucial time interval while maintaining acceptable continuous task performance. Thus, a figure of merit for overall quality of performance should be primarily a measure of time to perform discrete subtasks combined with a measure of basic vehicle control. Thus, the proposed figure of merit requires doing a task analysis on a series of performance, or runs, of a particular task, listing each discrete task and its associated time, and calculating the mean and standard deviation of these times, along with the mean and standard deviation of tracking error for the whole task. A set of simulator data on 30 runs of a landing task was obtained and a figure of merit will be calculated for each run. The figure of merit will be compared for voice and data link, so that the impact of this technology on total crew performance (not just communication performance) can be assessed. The effect of data link communication on other cockpit tasks will also be considered.

Working memory in children predicts performance on a gambling task.

PubMed

Audusseau, Jean; Juhel, Jacques

2015-01-01

The authors investigated whether working memory (WM) plays a significant role in the development of decision making in children, operationalized by the Children's Gambling Task (CGT). A total of 105 children aged 6-7, 8-9, and 10-11 years old carried out the CGT. Children aged 6-7 years old were found to have a lower performance than older children, which shows that the CGT is sensitive to participant's age. The hypothesis that WM plays a significant role in decision making was then tested following two approaches: (a) an experimental approach, comparing between groups the performance on the CGT in a control condition (the CGT only was administered) to that in a double task condition (participants had to carry out a recall task in addition to the CGT); (b) an interindividual approach, probing the relationship between CGT performance and performance on tasks measuring WM efficiency. The between-groups approach evidenced a better performance in the control group. Moreover, the interindividual approach showed that the higher the participants' WM efficiency was, the higher their performance in the CGT was. Taken together, these two approaches yield converging results that support the hypothesis that WM plays a significant role in decision making in children.

Dual-Task Performance: Influence of Frailty, Level of Physical Activity, and Cognition.

PubMed

Giusti Rossi, Paulo; Pires de Andrade, Larissa; Hotta Ansai, Juliana; Silva Farche, Ana Claudia; Carnaz, Leticia; Dalpubel, Daniela; Ferriolli, Eduardo; Assis Carvalho Vale, Francisco; de Medeiros Takahashi, Anielle Cristhine

2018-03-08

Cognition and level of physical activity have been associated with frailty syndrome. The development of tools that assess deficits related to physical and cognitive frailties simultaneously are of common interest. However, little is known about how much these aspects influence the performance of dual-task tests. Our aims were (a) to verify the influence of frailty syndrome and objectively measured physical activity and cognition on the Timed Up and Go (TUG) test and Timed Up and Go associated with dual-task (TUG-DT) performances; and (b) to compare TUG and TUG-DT performances between older adults who develop frailty syndrome. Sixty-four community-dwelling older adults were divided into frail, prefrail, and nonfrail groups, according to frailty phenotype. Assessments included anamnesis, screening of frailty syndrome, cognitive assessment (Addenbrooke's cognitive examination), placement of a triaxial accelerometer to assess level of physical activity, and TUG and TUG-DT (TUG associated with a motor-cognitive task of calling a phone number) performances. After 7 days, the accelerometer was removed. A multiple linear regression was applied to identify which independent variables could explain performances in the TUG and TUG-DT. Subsequently, the analysis of covariance test, adjusted for age, cognition, and level of physical activity covariates, was used to compare test performances. There were no differences in cognition between groups. Significant differences in the level of physical activity were found in the frail group. Compared with the frail group, the nonfrail group required less time and fewer steps to complete the TUG. Regarding the TUG-DT, cognition and age influenced the time spent and number of steps, respectively; however, no differences were found between groups. Frail older adults presented worse performance in the TUG when compared with nonfrail older adults. The dual-task test does not differentiate older adults with frailty syndrome, regardless of

Is a Responsive Default Mode Network Required for Successful Working Memory Task Performance?

PubMed Central

Čeko, Marta; Gracely, John L.; Fitzcharles, Mary-Ann; Seminowicz, David A.; Schweinhardt, Petra

2015-01-01

In studies of cognitive processing using tasks with externally directed attention, regions showing increased (external-task-positive) and decreased or “negative” [default-mode network (DMN)] fMRI responses during task performance are dynamically responsive to increasing task difficulty. Responsiveness (modulation of fMRI signal by increasing load) has been linked directly to successful cognitive task performance in external-task-positive regions but not in DMN regions. To investigate whether a responsive DMN is required for successful cognitive performance, we compared healthy human subjects (n = 23) with individuals shown to have decreased DMN engagement (chronic pain patients, n = 28). Subjects performed a multilevel working-memory task (N-back) during fMRI. If a responsive DMN is required for successful performance, patients having reduced DMN responsiveness should show worsened performance; if performance is not reduced, their brains should show compensatory activation in external-task-positive regions or elsewhere. All subjects showed decreased accuracy and increased reaction times with increasing task level, with no significant group differences on either measure at any level. Patients had significantly reduced negative fMRI response (deactivation) of DMN regions (posterior cingulate/precuneus, medial prefrontal cortex). Controls showed expected modulation of DMN deactivation with increasing task difficulty. Patients showed significantly reduced modulation of DMN deactivation by task difficulty, despite their successful task performance. We found no evidence of compensatory neural recruitment in external-task-positive regions or elsewhere. Individual responsiveness of the external-task-positive ventrolateral prefrontal cortex, but not of DMN regions, correlated with task accuracy. These findings suggest that a responsive DMN may not be required for successful cognitive performance; a responsive external-task-positive network may be sufficient

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.

Part-task vs. whole-task training on a supervisory control task

NASA Technical Reports Server (NTRS)

Battiste, Vernol

1987-01-01

The efficacy of a part-task training for the psychomotor portion of a supervisory control simulation was compared to that of the whole-task training, using six subjects in each group, who were asked to perform a task as quickly as possible. Part-task training was provided with the cursor-control device prior to transition to the whole-task. The analysis of both the training and experimental trials demonstrated a significant performance advantage for the part-task group: the tasks were performed better and at higher speed. Although the subjects finally achieved the same level of performance in terms of score, the part-task method was preferable for economic reasons, since simple pretraining systems are significantly less expensive than the whole-task training systems.

Task performance in astronomical adaptive optics

NASA Astrophysics Data System (ADS)

Barrett, Harrison H.; Myers, Kyle J.; Devaney, Nicholas; Dainty, J. C.; Caucci, Luca

2006-06-01

In objective or task-based assessment of image quality, figures of merit are defined by the performance of some specific observer on some task of scientific interest. This methodology is well established in medical imaging but is just beginning to be applied in astronomy. In this paper we survey the theory needed to understand the performance of ideal or ideal-linear (Hotelling) observers on detection tasks with adaptive-optical data. The theory is illustrated by discussing its application to detection of exoplanets from a sequence of short-exposure images.

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.

Effects of Non-Driving Related Task Modalities on Takeover Performance in Highly Automated Driving.

PubMed

Wandtner, Bernhard; Schömig, Nadja; Schmidt, Gerald

2018-04-01

Aim of the study was to evaluate the impact of different non-driving related tasks (NDR tasks) on takeover performance in highly automated driving. During highly automated driving, it is allowed to engage in NDR tasks temporarily. However, drivers must be able to take over control when reaching a system limit. There is evidence that the type of NDR task has an impact on takeover performance, but little is known about the specific task characteristics that account for performance decrements. Thirty participants drove in a simulator using a highly automated driving system. Each participant faced five critical takeover situations. Based on assumptions of Wickens's multiple resource theory, stimulus and response modalities of a prototypical NDR task were systematically manipulated. Additionally, in one experimental group, the task was locked out simultaneously with the takeover request. Task modalities had significant effects on several measures of takeover performance. A visual-manual texting task degraded performance the most, particularly when performed handheld. In contrast, takeover performance with an auditory-vocal task was comparable to a baseline without any task. Task lockout was associated with faster hands-on-wheel times but not altered brake response times. Results showed that NDR task modalities are relevant factors for takeover performance. An NDR task lockout was highly accepted by the drivers and showed moderate benefits for the first takeover reaction. Knowledge about the impact of NDR task characteristics is an enabler for adaptive takeover concepts. In addition, it might help regulators to make decisions on allowed NDR tasks during automated driving.

Event-related potentials and secondary task performance during simulated driving.

PubMed

Wester, A E; Böcker, K B E; Volkerts, E R; Verster, J C; Kenemans, J L

2008-01-01

Inattention and distraction account for a substantial number of traffic accidents. Therefore, we examined the impact of secondary task performance (an auditory oddball task) on a primary driving task (lane keeping). Twenty healthy participants performed two 20-min tests in the Divided Attention Steering Simulator (DASS). The visual secondary task of the DASS was replaced by an auditory oddball task to allow recording of brain activity. The driving task and the secondary (distracting) oddball task were presented in isolation and simultaneously, to assess their mutual interference. In addition to performance measures (lane keeping in the primary driving task and reaction speed in the secondary oddball task), brain activity, i.e. event-related potentials (ERPs), was recorded. Performance parameters on the driving test and the secondary oddball task did not differ between performance in isolation and simultaneous performance. However, when both tasks were performed simultaneously, reaction time variability increased in the secondary oddball task. Analysis of brain activity indicated that ERP amplitude (P3a amplitude) related to the secondary task, was significantly reduced when the task was performed simultaneously with the driving test. This study shows that when performing a simple secondary task during driving, performance of the driving task and this secondary task are both unaffected. However, analysis of brain activity shows reduced cortical processing of irrelevant, potentially distracting stimuli from the secondary task during driving.

HIV+ Men and Women Show Different Performance Patterns on Procedural Learning Tasks

PubMed Central

Martin, Eileen; Gonzalez, Raul; Vassileva, Jasmin; Maki, Pauline

2010-01-01

The literature suggests that nondeclarative, or nonconscious, learning might be impaired among HIV+ individuals compared with HIV− matched control groups, but these studies have included relatively few women. We administered measures of motor skill and probabilistic learning, tasks with a nondeclarative or procedural learning component that are dependent on integrity of prefrontal-striatal systems, to well-matched groups of 148 men and 65 women with a history of substance dependence that included 45 men and 30 women seropositive for HIV. All participants were abstinent at testing. Compared to HIV− women, HIV+ women performed significantly more poorly on both tasks, but HIV+ men’s performance did not differ significantly compared to HIV− men on either task. These different patterns of performance indicate that features of HIV-associated neurocognitive disorder (HAND) can not always be generalized from men to women. Additional studies are needed to address directly the possibility of sex differences in HIV-associated neurocognitive disorder (HAND) and the possibility that women might be more vulnerable to the effects of HIV and substance dependence on some neurocognitive functions. PMID:20694870

Preferential processing of task-irrelevant beloved-related information and task performance: Two event-related potential studies.

PubMed

Langeslag, Sandra J E; van Strien, Jan W

2017-09-18

People who are in love have better attention for beloved-related information, but report having trouble focusing on other tasks, such as (home)work. So, romantic love can both improve and hurt cognition. Emotional information is preferentially processed, which improves task performance when the information is task-relevant, but hurts task performance when it is task-irrelevant. Because beloved-related information is highly emotional, the effects of romantic love on cognition may resemble these effects of emotion on cognition. We examined whether beloved-related information is preferentially processed even when it is task-irrelevant and whether this hurts task performance. In two event-related potential studies, participants who had recently fallen in love performed a visuospatial short-term memory task. Task-irrelevant beloved, friend, and stranger faces were presented during maintenance (Study 1), or encoding (Study 2). The Early Posterior Negativity (EPN) reflecting early automatic attentional capturing and the Late Positive Potential (LPP) reflecting sustained motivated attention were largest for beloved pictures. Thus, beloved pictures are preferentially processed even when they are task-irrelevant. Task performance and reaction times did not differ between beloved, friend, and stranger conditions. Nevertheless, self-reported obsessive thinking about the beloved tended to correlate negatively with task performance, and positively with reaction times, across conditions. So, although task-irrelevant beloved-related information does not impact task performance, more obsessive thinking about the beloved might relate to poorer and slower overall task performance. More research is needed to clarify why people experience trouble focusing on beloved-unrelated tasks and how this negative effect of love on cognition could be reduced. Copyright © 2017 Elsevier Ltd. All rights reserved.

Performance on verbal and low-verbal false belief tasks: evidence from children with Williams syndrome.

PubMed

Van Herwegen, Jo; Dimitriou, Dagmara; Rundblad, Gabriella

2013-01-01

Previous studies that have investigated the relationship between performance on theory of mind (ToM) tasks and verbal abilities in individuals with Williams syndrome (WS) have reported contradictory findings with some showing that language abilities aid performance on ToM tasks while others have found that participants with WS fail these tasks because of their verbal demands. The current study investigated this relationship again comparing performance on a classical change-location task to two newly developed low-verbal tasks, one change-location task and one unexpected content task. Thirty children with WS (aged 5-17;01 years) and 30 typically developing (TD) children (aged between 2;10 years and 9;09 years), who were matched for vocabulary comprehension scores were included in the study. Although performance in the WS group was significantly poorer compared to the TD group on all three tasks, performance was not predicted by their receptive vocabulary or grammatical ability scores. In addition, ToM abilities in both groups depended on the cognitive demands of the task at hand. This finding shows that performance on ToM tasks in WS is not necessarily hindered by their delayed language abilities but rather by the task administered. This could potentially affect the diagnosis of developmental disorders, such as Autism Spectrum Disorders, and comparison of ToM abilities across developmental disorders. Readers of this article should be able to (1) describe the current state of theory of mind research in Williams syndrome, (2) identify which cognitive abilities might explain performance on theory of mind tasks in both typically developing children and in children with Williams syndrome, and (3) interpret the importance of task demands when assessing children's theory of mind abilities. Copyright © 2013 Elsevier Inc. All rights reserved.

Is a Responsive Default Mode Network Required for Successful Working Memory Task Performance?

PubMed

Čeko, Marta; Gracely, John L; Fitzcharles, Mary-Ann; Seminowicz, David A; Schweinhardt, Petra; Bushnell, M Catherine

2015-08-19

In studies of cognitive processing using tasks with externally directed attention, regions showing increased (external-task-positive) and decreased or "negative" [default-mode network (DMN)] fMRI responses during task performance are dynamically responsive to increasing task difficulty. Responsiveness (modulation of fMRI signal by increasing load) has been linked directly to successful cognitive task performance in external-task-positive regions but not in DMN regions. To investigate whether a responsive DMN is required for successful cognitive performance, we compared healthy human subjects (n = 23) with individuals shown to have decreased DMN engagement (chronic pain patients, n = 28). Subjects performed a multilevel working-memory task (N-back) during fMRI. If a responsive DMN is required for successful performance, patients having reduced DMN responsiveness should show worsened performance; if performance is not reduced, their brains should show compensatory activation in external-task-positive regions or elsewhere. All subjects showed decreased accuracy and increased reaction times with increasing task level, with no significant group differences on either measure at any level. Patients had significantly reduced negative fMRI response (deactivation) of DMN regions (posterior cingulate/precuneus, medial prefrontal cortex). Controls showed expected modulation of DMN deactivation with increasing task difficulty. Patients showed significantly reduced modulation of DMN deactivation by task difficulty, despite their successful task performance. We found no evidence of compensatory neural recruitment in external-task-positive regions or elsewhere. Individual responsiveness of the external-task-positive ventrolateral prefrontal cortex, but not of DMN regions, correlated with task accuracy. These findings suggest that a responsive DMN may not be required for successful cognitive performance; a responsive external-task-positive network may be sufficient. We studied the

Performing a secondary executive task with affective stimuli interferes with decision making under risk conditions.

PubMed

Gathmann, Bettina; Pawlikowski, Mirko; Schöler, Tobias; Brand, Matthias

2014-05-01

Previous studies demonstrated that executive functions are crucial for advantageous decision making under risk and that therefore decision making is disrupted when working memory capacity is demanded while working on a decision task. While some studies also showed that emotions can affect decision making under risk, it is unclear how affective processing and executive functions predict decision-making performance in interaction. The current experimental study used a between-subjects design to examine whether affective pictures (positive and negative pictures compared to neutral pictures), included in a parallel executive task (working memory 2-back task), have an impact on decision making under risk as assessed by the Game of Dice Task (GDT). Moreover, the performance GDT plus 2-back task was compared to the performance in the GDT without any additional task (GDT solely). The results show that the performance in the GDT differed between groups (positive, negative, neutral, and GDT solely). The groups with affective pictures, especially those with positive pictures in the 2-back task, showed more disadvantageous decisions in the GDT than the groups with neutral pictures and the group performing the GDT without any additional task. However, executive functions moderated the effect of the affective pictures. Regardless of affective influence, subjects with good executive functions performed advantageously in the GDT. These findings support the assumption that executive functions and emotional processing interact in predicting decision making under risk.

Complexity, Accuracy, Fluency and Lexis in Task-Based Performance: A Synthesis of the Ealing Research

ERIC Educational Resources Information Center

Skehan, Peter; Foster, Pauline

2012-01-01

This chapter will present a research synthesis of a series of studies, termed here the Ealing research. The studies use the same general framework to conceptualise tasks and task performance, enabling easier comparability. The different studies, although each is self-contained, build into a wider picture of task performance. The major point of…

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…

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

PubMed

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

2017-06-01

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

Task-relevant cognitive and motor functions are prioritized during prolonged speed-accuracy motor task performance.

PubMed

Solianik, Rima; Satas, Andrius; Mickeviciene, Dalia; Cekanauskaite, Agne; Valanciene, Dovile; Majauskiene, Daiva; Skurvydas, Albertas

2018-06-01

This study aimed to explore the effect of prolonged speed-accuracy motor task on the indicators of psychological, cognitive, psychomotor and motor function. Ten young men aged 21.1 ± 1.0 years performed a fast- and accurate-reaching movement task and a control task. Both tasks were performed for 2 h. Despite decreased motivation, and increased perception of effort as well as subjective feeling of fatigue, speed-accuracy motor task performance improved during the whole period of task execution. After the motor task, the increased working memory function and prefrontal cortex oxygenation at rest and during conflict detection, and the decreased efficiency of incorrect response inhibition and visuomotor tracking were observed. The speed-accuracy motor task increased the amplitude of motor-evoked potentials, while grip strength was not affected. These findings demonstrate that to sustain the performance of 2-h speed-accuracy task under conditions of self-reported fatigue, task-relevant functions are maintained or even improved, whereas less critical functions are impaired.

The Indecision Model of Psychophysical Performance in Dual-Presentation Tasks: Parameter Estimation and Comparative Analysis of Response Formats

PubMed Central

García-Pérez, Miguel A.; Alcalá-Quintana, Rocío

2017-01-01

Psychophysical data from dual-presentation tasks are often collected with the two-alternative forced-choice (2AFC) response format, asking observers to guess when uncertain. For an analytical description of performance, psychometric functions are then fitted to data aggregated across the two orders/positions in which stimuli were presented. Yet, order effects make aggregated data uninterpretable, and the bias with which observers guess when uncertain precludes separating sensory from decisional components of performance. A ternary response format in which observers are also allowed to report indecision should fix these problems, but a comparative analysis with the 2AFC format has never been conducted. In addition, fitting ternary data separated by presentation order poses serious challenges. To address these issues, we extended the indecision model of psychophysical performance to accommodate the ternary, 2AFC, and same–different response formats in detection and discrimination tasks. Relevant issues for parameter estimation are also discussed along with simulation results that document the superiority of the ternary format. These advantages are demonstrated by fitting the indecision model to published detection and discrimination data collected with the ternary, 2AFC, or same–different formats, which had been analyzed differently in the sources. These examples also show that 2AFC data are unsuitable for testing certain types of hypotheses. matlab and R routines written for our purposes are available as Supplementary Material, which should help spread the use of the ternary format for dependable collection and interpretation of psychophysical data. PMID:28747893

The Role of Task Complexity, Modality, and Aptitude in Narrative Task Performance

ERIC Educational Resources Information Center

Kormos, Judit; Trebits, Anna

2012-01-01

The study reported in this paper investigated the relationship between components of aptitude and the fluency, lexical variety, syntactic complexity, and accuracy of performance in two types of written and spoken narrative tasks. We also addressed the question of how narrative performance varies in tasks of different cognitive complexity in the…

Performance tasks for operator-skills research.

DOT National Transportation Integrated Search

1966-06-01

The selection, development, and operation of several tasks for use in skilled-operator-performance research are described. The tasks are intended, collectively, to sample a broad spectrum of abilities required by complex operator systems; individuall...

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

PubMed

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

2017-01-01

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

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

PubMed Central

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

2017-01-01

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

A comparison of the effects of a secondary task and lorazepam on cognitive performance.

PubMed

File, S E

1992-01-01

In order to test whether the lorazepam-induced impairments in a variety of cognitive tasks were similar to those of divided attention, the effects of lorazepam (2.5 mg) in healthy volunteers were compared with those requiring subjects to perform an additional task (detecting silences superimposed onto classical music). Neither treatment impaired implicit memory or judgements of frequency. Both treatments impaired performance in tests of speed, lorazepam having the greatest effect on number cancellation and the additional task having the greatest effect on simple reaction time. Both treatments impaired performance in a coding task, in a test of explicit episodic memory and in judgements of recency (indicating impaired coding of contextual information). Lorazepam significantly reduced performance in a word completion task, but this was unimpaired in the group performing the additional task. In general, the pattern of results suggests that there are similarities between the effects of divided attention and lorazepam treatment, and that lorazepam-induced cognitive impairments are not restricted to explicit tests of episodic memory.

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.

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

PubMed

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

2005-08-01

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

Assessment of Joystick control during the performance of powered wheelchair driving tasks

PubMed Central

2011-01-01

Background Powered wheelchairs are essential for many individuals who have mobility impairments. Nevertheless, if operated improperly, the powered wheelchair poses dangers to both the user and to those in its vicinity. Thus, operating a powered wheelchair with some degree of proficiency is important for safety, and measuring driving skills becomes an important issue to address. The objective of this study was to explore the discriminate validity of outcome measures of driving skills based on joystick control strategies and performance recorded using a data logging system. Methods We compared joystick control strategies and performance during standardized driving tasks between a group of 10 expert and 13 novice powered wheelchair users. Driving tasks were drawn from the Wheelchair Skills Test (v. 4.1). Data from the joystick controller were collected on a data logging system. Joystick control strategies and performance outcome measures included the mean number of joystick movements, time required to complete tasks, as well as variability of joystick direction. Results In simpler tasks, the expert group's driving skills were comparable to those of the novice group. Yet, in more difficult and spatially confined tasks, the expert group required fewer joystick movements for task completion. In some cases, experts also completed tasks in approximately half the time with respect to the novice group. Conclusions The analysis of joystick control made it possible to discriminate between novice and expert powered wheelchair users in a variety of driving tasks. These results imply that in spatially confined areas, a greater powered wheelchair driving skill level is required to complete tasks efficiently. Based on these findings, it would appear that the use of joystick signal analysis constitutes an objective tool for the measurement of powered wheelchair driving skills. This tool may be useful for the clinical assessment and training of powered wheelchair skills. PMID

Nonparametric EROC analysis for observer performance evaluation on joint detection and estimation tasks

NASA Astrophysics Data System (ADS)

Wunderlich, Adam; Goossens, Bart

2014-03-01

The majority of the literature on task-based image quality assessment has focused on lesion detection tasks, using the receiver operating characteristic (ROC) curve, or related variants, to measure performance. However, since many clinical image evaluation tasks involve both detection and estimation (e.g., estimation of kidney stone composition, estimation of tumor size), there is a growing interest in performance evaluation for joint detection and estimation tasks. To evaluate observer performance on such tasks, Clarkson introduced the estimation ROC (EROC) curve, and the area under the EROC curve as a summary figure of merit. In the present work, we propose nonparametric estimators for practical EROC analysis from experimental data, including estimators for the area under the EROC curve and its variance. The estimators are illustrated with a practical example comparing MRI images reconstructed from different k-space sampling trajectories.

Developmental Progression of Looking and Reaching Performance on the A-not-B Task

PubMed Central

Cuevas, Kimberly; Bell, Martha Ann

2013-01-01

From a neuropsychological perspective, the cognitive skills of working memory, inhibition, and attention and the maturation of the frontal lobe are requisites for successful A-not-B performance on both the looking and reaching versions of the task. This study used a longitudinal design to examine the developmental progression of infants’ performance on the looking and reaching versions of the A-not-B task. Twenty infants were tested on both versions of the task once a month from 5 to 10 months of age. Infants had higher object permanence scores on the looking version of the task from 5 to 8 months, with comparable performance across response modalities at 9 and 10 months. The same pattern of performance was found on nonreversal (A) trials: Infants performed better on looking trials from 5 to 7 months and they performed equally on both response trials from 8 to 10 months. Overall, infants performed better on looking reversal (B) trials than reaching reversal trials. These data suggest that performance differences between response modalities early in development can be attributed to major differences in the maturation of brain circuitry associated with the actual task response. PMID:20822245

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.

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

Performance monitoring and response conflict resolution associated with choice stepping reaction tasks.

PubMed

Watanabe, Tatsunori; Tsutou, Kotaro; Saito, Kotaro; Ishida, Kazuto; Tanabe, Shigeo; Nojima, Ippei

2016-11-01

Choice reaction requires response conflict resolution, and the resolution processes that occur during a choice stepping reaction task undertaken in a standing position, which requires maintenance of balance, may be different to those processes occurring during a choice reaction task performed in a seated position. The study purpose was to investigate the resolution processes during a choice stepping reaction task at the cortical level using electroencephalography and compare the results with a control task involving ankle dorsiflexion responses. Twelve young adults either stepped forward or dorsiflexed the ankle in response to a visual imperative stimulus presented on a computer screen. We used the Simon task and examined the error-related negativity (ERN) that follows an incorrect response and the correct-response negativity (CRN) that follows a correct response. Error was defined as an incorrect initial weight transfer for the stepping task and as an incorrect initial tibialis anterior activation for the control task. Results revealed that ERN and CRN amplitudes were similar in size for the stepping task, whereas the amplitude of ERN was larger than that of CRN for the control task. The ERN amplitude was also larger in the stepping task than the control task. These observations suggest that a choice stepping reaction task involves a strategy emphasizing post-response conflict and general performance monitoring of actual and required responses and also requires greater cognitive load than a choice dorsiflexion reaction. The response conflict resolution processes appear to be different for stepping tasks and reaction tasks performed in a seated position.

Performance on a Stage IV Object-Permanence Task with Standard and Nonstandard Covers.

ERIC Educational Resources Information Center

And Others; Rader, Nancy

1979-01-01

Examined the role of perceptual-motor development in a typical Stage IV task. The performance of ten infants was compared on a Stage IV object permanence task when a cloth cover was used and when a small card cover was used. (JMB)

Lucid Dreaming and Ventromedial versus Dorsolateral Prefrontal Task Performance

PubMed Central

Neider, Michelle; Pace-Schott, Edward F.; Forselius, Erica; Pittman, Brian; Morgan, Peter T.

2010-01-01

Activity in the prefrontal cortex may distinguish the meta-awareness experienced during lucid dreams from its absence in normal dreams. To examine a possible relationship between dream lucidity and prefrontal task performance, we carried out a prospective study in 28 high school students. Participants performed the Wisconsin Card Sort and Iowa Gambling tasks, then for one week kept dream journals and reported sleep quality and lucidity-related dream characteristics. Participants who exhibited a greater degree of lucidity performed significantly better on the task that engages the ventromedial prefrontal cortex (the Iowa Gambling Task), but degree of lucidity achieved did not distinguish performance on the task that engages the dorsolateral prefrontal cortex (the Wisconsin Card Sort Task), nor did it distinguish self-reported sleep quality or baseline characteristics. The association between performance on the Iowa Gambling Task and lucidity suggests a connection between lucid dreaming and ventromedial prefrontal function. PMID:20829072

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

PubMed

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

2015-06-01

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

Child abuse and performance task assessments of executive functions in boys.

PubMed

Mezzacappa, E; Kindlon, D; Earls, F

2001-11-01

We examined executive functions using performance tasks in 126 boys aged 6 to 16 years. who attended public schools and therapeutic schools for children with emotional and behavioral problems. Children were further grouped based on the presence or absence of substantiated abuse histories. Based on their abuse histories and schools of origin, children were classified as Therapeutic, Abused (TA, N = 25). Therapeutic, Nonabused (TN, N = 52), and Public School (PS, N = 48). Controlling IQ and medication status, we compared children in the three groups on teacher ratings of behavior, on experimenter observations of behavior during testing, and on performance tasks challenging the capacities to inhibit an act in progress, and to passively avoid responses associated with adverse consequences. We examined mean group differences in symptoms, behaviors, and task performance, as well as differential age-dependent changes in these dimensions. Independent of abuse history, therapeutic school children demonstrated comparable levels of internalizing and externalizing symptoms, and comparable levels of redirections to task during testing-sessions, that were significantly higher than those of the public school children. Both groups of therapeutic school children also showed comparable overall performance on the capacities to inhibit an act in progress, and to passively avoid responses associated with adverse consequences that were poorer than the performance of children from the public school. Children with histories of substantiated abuse showed diminished improvement with increasing age in the capacity to passively avoid responses associated with adverse consequences when compared not only to the public school children, but also to the children from the therapeutic schools without histories of abuse. Our findings complement reports of behavioral observations of abused children, and reports associating child abuse with altered cognitive development in other areas of competence

Estimating endogenous changes in task performance from EEG

PubMed Central

Touryan, Jon; Apker, Gregory; Lance, Brent J.; Kerick, Scott E.; Ries, Anthony J.; McDowell, Kaleb

2014-01-01

Brain wave activity is known to correlate with decrements in behavioral performance as individuals enter states of fatigue, boredom, or low alertness.Many BCI technologies are adversely affected by these changes in user state, limiting their application and constraining their use to relatively short temporal epochs where behavioral performance is likely to be stable. Incorporating a passive BCI that detects when the user is performing poorly at a primary task, and adapts accordingly may prove to increase overall user performance. Here, we explore the potential for extending an established method to generate continuous estimates of behavioral performance from ongoing neural activity; evaluating the extended method by applying it to the original task domain, simulated driving; and generalizing the method by applying it to a BCI-relevant perceptual discrimination task. Specifically, we used EEG log power spectra and sequential forward floating selection (SFFS) to estimate endogenous changes in behavior in both a simulated driving task and a perceptual discrimination task. For the driving task the average correlation coefficient between the actual and estimated lane deviation was 0.37 ± 0.22 (μ ± σ). For the perceptual discrimination task we generated estimates of accuracy, reaction time, and button press duration for each participant. The correlation coefficients between the actual and estimated behavior were similar for these three metrics (accuracy = 0.25 ± 0.37, reaction time = 0.33 ± 0.23, button press duration = 0.36 ± 0.30). These findings illustrate the potential for modeling time-on-task decrements in performance from concurrent measures of neural activity. PMID:24994968

Functional Magnetic Resonance Imaging Correlates of First-Episode Psychoses during Attentional and Memory Task Performance.

PubMed

Del Casale, Antonio; Kotzalidis, Georgios D; Rapinesi, Chiara; Sorice, Serena; Girardi, Nicoletta; Ferracuti, Stefano; Girardi, Paolo

2016-01-01

The nature of the alteration of the response to cognitive tasks in first-episode psychosis (FEP) still awaits clarification. We used activation likelihood estimation, an increasingly used method in evaluating normal and pathological brain function, to identify activation changes in functional magnetic resonance imaging (fMRI) studies of FEP during attentional and memory tasks. We included 11 peer-reviewed fMRI studies assessing FEP patients versus healthy controls (HCs) during performance of attentional and memory tasks. Our database comprised 290 patients with FEP, matched with 316 HCs. Between-group analyses showed that HCs, compared to FEP patients, exhibited hyperactivation of the right middle frontal gyrus (Brodmann area, BA, 9), right inferior parietal lobule (BA 40), and right insula (BA 13) during attentional task performances and hyperactivation of the left insula (BA 13) during memory task performances. Right frontal, parietal, and insular dysfunction during attentional task performance and left insular dysfunction during memory task performance are significant neural functional FEP correlates. © 2016 S. Karger AG, Basel.

A Novel Method for Assessing Task Complexity in Outpatient Clinical-Performance Measures.

PubMed

Hysong, Sylvia J; Amspoker, Amber B; Petersen, Laura A

2016-04-01

Clinical-performance measurement has helped improve the quality of health-care; yet success in attaining high levels of quality across multiple domains simultaneously still varies considerably. Although many sources of variability in care quality have been studied, the difficulty required to complete the clinical work itself has received little attention. We present a task-based methodology for evaluating the difficulty of clinical-performance measures (CPMs) by assessing the complexity of their component requisite tasks. Using Functional Job Analysis (FJA), subject-matter experts (SMEs) generated task lists for 17 CPMs; task lists were rated on ten dimensions of complexity, and then aggregated into difficulty composites. Eleven outpatient work SMEs; 133 VA Medical Centers nationwide. Clinical Performance: 17 outpatient CPMs (2000-2008) at 133 VA Medical Centers nationwide. Measure Difficulty: for each CPM, the number of component requisite tasks and the average rating across ten FJA complexity scales for the set of tasks comprising the measure. Measures varied considerably in the number of component tasks (M = 10.56, SD = 6.25, min = 5, max = 25). Measures of chronic care following acute myocardial infarction exhibited significantly higher measure difficulty ratings compared to diabetes or screening measures, but not to immunization measures ([Formula: see text] = 0.45, -0.04, -0.05, and -0.06 respectively; F (3, 186) = 3.57, p = 0.015). Measure difficulty ratings were not significantly correlated with the number of component tasks (r = -0.30, p = 0.23). Evaluating the difficulty of achieving recommended CPM performance levels requires more than simply counting the tasks involved; using FJA to assess the complexity of CPMs' component tasks presents an alternate means of assessing the difficulty of primary-care CPMs and accounting for performance variation among measures and performers. This in turn could be used in designing

The effect of a secondary cognitive task on landing mechanics and jump performance.

PubMed

Dai, Boyi; Cook, Ross F; Meyer, Elizabeth A; Sciascia, Yvonne; Hinshaw, Taylour J; Wang, Chaoyi; Zhu, Qin

2018-06-01

Anterior cruciate ligament (ACL) injuries commonly occur during jump-landing tasks when individuals' attention is simultaneously allocated to other objects and tasks. The purpose of the current study was to investigate the effect of allocation of attention imposed by a secondary cognitive task on landing mechanics and jump performance. Thirty-eight recreational athletes performed a jump-landing task in three conditions: no counting, counting backward by 1 s from a randomly given number, and counting backward by 7 s from a randomly given number. Three-dimensional kinematics and ground reaction forces were collected and analysed. Participants demonstrated decreased knee flexion angles at initial contact (p = 0.001) for the counting by 1 s condition compared with the no counting condition. Participants also showed increased peak posterior and vertical ground reaction forces during the first 100 ms of landing (p ≤ 0.023) and decreased jump height (p < 0.001) for the counting by 1 s and counting by 7 s conditions compared with the no counting condition. Imposition of a simultaneous cognitive challenge resulted in landing mechanics associated with increased ACL loading and decreased jump performance. ACL injury risk screening protocols and injury prevention programmes may incorporate cognitive tasks into jump-landing tasks to better simulate sports environments.

Pleasantness of Creative Tasks and Creative Performance

ERIC Educational Resources Information Center

Zenasni, Franck; Lubart, Todd

2011-01-01

To examine the impact of emotion on creative potential, experimental studies have typically focused on the impact of induced or spontaneous mood states on creative performance. In this report the relationship between the perceived pleasantness of tasks (using divergent thinking and story writing tasks) and creative performance was examined.…

Neuroimaging explanations of age-related differences in task performance.

PubMed

Steffener, Jason; Barulli, Daniel; Habeck, Christian; Stern, Yaakov

2014-01-01

Advancing age affects both cognitive performance and functional brain activity and interpretation of these effects has led to a variety of conceptual research models without always explicitly linking the two effects. However, to best understand the multifaceted effects of advancing age, age differences in functional brain activity need to be explicitly tied to the cognitive task performance. This work hypothesized that age-related differences in task performance are partially explained by age-related differences in functional brain activity and formally tested these causal relationships. Functional MRI data was from groups of young and old adults engaged in an executive task-switching experiment. Analyses were voxel-wise testing of moderated-mediation and simple mediation statistical path models to determine whether age group, brain activity and their interaction explained task performance in regions demonstrating an effect of age group. Results identified brain regions whose age-related differences in functional brain activity significantly explained age-related differences in task performance. In all identified locations, significant moderated-mediation relationships resulted from increasing brain activity predicting worse (slower) task performance in older but not younger adults. Findings suggest that advancing age links task performance to the level of brain activity. The overall message of this work is that in order to understand the role of functional brain activity on cognitive performance, analysis methods should respect theoretical relationships. Namely, that age affects brain activity and brain activity is related to task performance.

Improving older adults' memory performance using prior task success.

PubMed

Geraci, Lisa; Miller, Tyler M

2013-06-01

Holding negative aging stereotypes can lead older adults to perform poorly on memory tests. We attempted to improve older adults' memory performance by giving them task experience that would counter their negative performance expectations. Before participating in a memory experiment, younger and older adults were given a cognitive task that they could either successfully complete, not successfully complete, or they were given no prior task. For older adults, recall was significantly higher and self-reported anxiety was significantly lower for the prior task success group relative to the other groups. There was no effect of prior task experience on younger adults' memory performance. Results suggest that older adults' memory can be improved with a single successful prior task experience. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Brain Modularity Mediates the Relation between Task Complexity and Performance

NASA Astrophysics Data System (ADS)

Ye, Fengdan; Yue, Qiuhai; Martin, Randi; Fischer-Baum, Simon; Ramos-Nuã+/-Ez, Aurora; Deem, Michael

Recent work in cognitive neuroscience has focused on analyzing the brain as a network, rather than a collection of independent regions. Prior studies taking this approach have found that individual differences in the degree of modularity of the brain network relate to performance on cognitive tasks. However, inconsistent results concerning the direction of this relationship have been obtained, with some tasks showing better performance as modularity increases, and other tasks showing worse performance. A recent theoretical model suggests that these inconsistencies may be explained on the grounds that high-modularity networks favor performance on simple tasks whereas low-modularity networks favor performance on complex tasks. The current study tests these predictions by relating modularity from resting-state fMRI to performance on a set of behavioral tasks. Complex and simple tasks were defined on the basis of whether they drew on executive attention. Consistent with predictions, we found a negative correlation between individuals' modularity and their performance on the complex tasks but a positive correlation with performance on the simple tasks. The results presented here provide a framework for linking measures of whole brain organization to cognitive processing.

Thinking About a Task Is Associated with Increased Connectivity in Regions Activated by Task Performance

PubMed Central

Robertson, Edwin M.; Manoach, Dara S.; Stickgold, Robert

2016-01-01

Abstract We investigated whether functional neuroimaging of quiet “rest” can reveal the neural correlates of conscious thought. Using resting-state functional MRI, we measured functional connectivity during a resting scan that immediately followed performance of a finger tapping motor sequence task. Self-reports of the amount of time spent thinking about the task during the resting scan correlated with connectivity between regions of the motor network activated during task performance. Thus, thinking about a task is associated with coordinated activity in brain regions responsible for that task's performance. More generally, this study demonstrates the feasibility of using the combination of functional connectivity MRI and self-reports to examine the neural correlates of thought. PMID:26650337

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

PubMed

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

2018-04-01

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

Individual Differences in Dual Task Performance. Final Report.

ERIC Educational Resources Information Center

Lansman, Marcy; Hunt, Earl

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

U.S. Army physical demands study: Prevalence and frequency of performing physically demanding tasks in deployed and non-deployed settings.

PubMed

Boye, Michael W; Cohen, Bruce S; Sharp, Marilyn A; Canino, Maria C; Foulis, Stephen A; Larcom, Kathleen; Smith, Laurel

2017-11-01

To compare percentages of on-duty time spent performing physically demanding soldier tasks in non-deployed and deployed settings, and secondarily examine the number of physically demanding tasks performed among five Army combat arms occupational specialties. Job task analysis. Soldiers (n=1295; over 99% serving on active duty) across five Army jobs completed one of three questionnaires developed using reviews of job and task related documents, input from subject matter experts, observation of task performance, and conduct of focus groups. Soldiers reported estimates of the total on-duty time spent performing physically demanding tasks in both deployed and non-deployed settings. One-way analyses of variance and Duncan post-hoc tests were used to compare percentage time differences by job. Two-tailed t-tests were used to evaluate differences by setting. Frequency analyses were used to present supplementary findings. Soldiers reported performing physically demanding job-specific tasks 17.7% of the time while non-deployed and 19.6% of the time while deployed. There were significant differences in time spent on job-specific tasks across settings (p<0.05) for three of five occupational specialties. When categories of physically demanding tasks were grouped, all soldiers reported spending more time on physically demanding tasks when deployed (p<0.001). Twenty-five percent reported performing less than half the physically demanding tasks represented on the questionnaire in the last two years. Soldiers spent more time performing physically demanding tasks while deployed compared to non-deployed but spent similar amounts of time performing job-specific tasks. Published by Elsevier Ltd.

Students' Performance on a Symmetry Task

ERIC Educational Resources Information Center

Ho, Siew Yin; Logan, Tracy

2013-01-01

This paper describes Singapore and Australian Grade 6 students' (n=1,187) performance on a symmetry task in a recently developed Mathematics Processing Instrument (MPI). The MPI comprised tasks sourced from Australia and Singapore's national assessments, NAPLAN and PSLE. Only half of the cohort solved the item successfully. It is possible that…

An initial test of a normative Figure Of Merit for the quality of overall task performance

NASA Technical Reports Server (NTRS)

Lemay, Moira; Comstock, J. R., Jr.

1990-01-01

An overall indicator, or Figure Of Merit (FOM), of the quality of crew/vehicle system performance is needed to establish the effect of workload on efficiency and to identify overload conditions. A normative FOM is proposed in which performance is measured on a representative task and a normative data base obtained. FOMs for subsequent executions of the task are then reported in terms of weighted deviations from average task performance. Performance of discrete tasks is measured primarily in terms of subtask time and errors. Discrete task performance is then combined with a measure of continuous vehicle control. In order to test the normative FOM procedure, the technique was applied to an existing set of data from a simulated landing task in which standard communications with ATC was compared with a data link communications system. The results indicated that while mean task performance was not affected, task variability, as measured by the FOM, was significantly higher when data link communications were used. In order to establish the sensitivity of the normative FOM method, further testing of the measure is recommended.

Analysis of Skeletal Muscle Metrics as Predictors of Functional Task Performance

NASA Technical Reports Server (NTRS)

Ryder, Jeffrey W.; Buxton, Roxanne E.; Redd, Elizabeth; Scott-Pandorf, Melissa; Hackney, Kyle J.; Fiedler, James; Ploutz-Snyder, Robert J.; Bloomberg, Jacob J.; Ploutz-Snyder, Lori L.

2010-01-01

PURPOSE: The ability to predict task performance using physiological performance metrics is vital to ensure that astronauts can execute their jobs safely and effectively. This investigation used a weighted suit to evaluate task performance at various ratios of strength, power, and endurance to body weight. METHODS: Twenty subjects completed muscle performance tests and functional tasks representative of those that would be required of astronauts during planetary exploration (see table for specific tests/tasks). Subjects performed functional tasks while wearing a weighted suit with additional loads ranging from 0-120% of initial body weight. Performance metrics were time to completion for all tasks except hatch opening, which consisted of total work. Task performance metrics were plotted against muscle metrics normalized to "body weight" (subject weight + external load; BW) for each trial. Fractional polynomial regression was used to model the relationship between muscle and task performance. CONCLUSION: LPMIF/BW is the best predictor of performance for predominantly lower-body tasks that are ambulatory and of short duration. LPMIF/BW is a very practical predictor of occupational task performance as it is quick and relatively safe to perform. Accordingly, bench press work best predicts hatch-opening work performance.

Tool and Task Analysis Guide for Vocational Welding (150 Tasks). Performance Based Vocational Education.

ERIC Educational Resources Information Center

John H. Hinds Area Vocational School, Elwood, IN.

This book contains a task inventory, a task analysis of 150 tasks from that inventory, and a tool list for performance-based welding courses in the state of Indiana. The task inventory and tool list reflect 28 job titles found in Indiana. In the first part of the guide, tasks are listed by these domains: carbon-arc, electron beam, G.M.A.W., gas…

Effects of speech intelligibility level on concurrent visual task performance.

PubMed

Payne, D G; Peters, L J; Birkmire, D P; Bonto, M A; Anastasi, J S; Wenger, M J

1994-09-01

Four experiments were performed to determine if changes in the level of speech intelligibility in an auditory task have an impact on performance in concurrent visual tasks. The auditory task used in each experiment was a memory search task in which subjects memorized a set of words and then decided whether auditorily presented probe items were members of the memorized set. The visual tasks used were an unstable tracking task, a spatial decision-making task, a mathematical reasoning task, and a probability monitoring task. Results showed that performance on the unstable tracking and probability monitoring tasks was unaffected by the level of speech intelligibility on the auditory task, whereas accuracy in the spatial decision-making and mathematical processing tasks was significantly worse at low speech intelligibility levels. The findings are interpreted within the framework of multiple resource theory.

Spatial task performance, sex differences, and motion sickness susceptibility.

PubMed

Levine, Max E; Stern, Robert M

2002-10-01

There are substantial individual differences in susceptibility to motion sickness, yet little is known about what mediates these differences. Spatial ability and sex have been suggested as possible factors in this relationship. 89 participants (57 women) were administered a Motion Sickness Questionnaire that assesses motion sickness susceptibility, a Water-level Task that gauges sensitivity to gravitational upright, and a Mental Rotation Task that tests an individual's awareness of how objects typically move in space. Significant sex differences were observed in performance of both the Water-level Task (p<.01), and the Mental Rotation Task (p<.005), with women performing less accurately than men. Women also had significantly higher scores on the Motion Sickness Questionnaire (p<.005). Among men, but not women, significant negative relationships were observed between Water-level Task performance and Motion Sickness Questionnaire score (p<.001) and between Mental Rotation Task performance and Motion Sickness Questionnaire score (p<.005). In conclusion, women performed significantly more poorly than men did on the spatial ability tasks and reported significantly more bouts of motion sickness. In addition, men showed a significant negative relationship between spatial ability and motion sickness susceptibility.

Manipulator Performance Evaluation Using Fitts' Taping Task

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

Draper, J.V.; Jared, B.C.; Noakes, M.W.

1999-04-25

Metaphorically, a teleoperator with master controllers projects the user's arms and hands into a re- mote area, Therefore, human users interact with teleoperators at a more fundamental level than they do with most human-machine systems. Instead of inputting decisions about how the system should func- tion, teleoperator users input the movements they might make if they were truly in the remote area and the remote machine must recreate their trajectories and impedance. This intense human-machine inter- action requires displays and controls more carefully attuned to human motor capabilities than is neces- sary with most systems. It is important for teleoperatedmore » manipulators to be able to recreate human trajectories and impedance in real time. One method for assessing manipulator performance is to observe how well a system be- haves while a human user completes human dexterity tasks with it. Fitts' tapping task has been, used many times in the past for this purpose. This report describes such a performance assessment. The International Submarine Engineering (ISE) Autonomous/Teleoperated Operations Manipulator (ATOM) servomanipulator system was evalu- ated using a generic positioning accuracy task. The task is a simple one but has the merits of (1) pro- ducing a performance function estimate rather than a point estimate and (2) being widely used in the past for human and servomanipulator dexterity tests. Results of testing using this task may, therefore, allow comparison with other manipulators, and is generically representative of a broad class of tasks. Results of the testing indicate that the ATOM manipulator is capable of performing the task. Force reflection had a negative impact on task efficiency in these data. This was most likely caused by the high resistance to movement the master controller exhibited with the force reflection engaged. Measurements of exerted forces were not made, so it is not possible to say whether the force reflection helped partici

A study of performance assessment task organization in high school optics

NASA Astrophysics Data System (ADS)

Zawicki, Joseph Leo

2002-01-01

independent or the surrogate form. A set of ten questions, compiled from past New York State Regents Examinations in Physics, was used as an additional measurement of student conceptual understanding. This question set was identified as the "Optics Baseline Test" (OBT). Additionally, classroom teachers ranked the academic performance of each of the students in their classroom on the outcomes of the physics course; these rankings were compared with student scores on the performance assessment tasks. The process skills incorporated within the individual questions on each task were reviewed by a panel of expert teachers. Student scores on the tasks themselves were examined using a principal component analysis. This analysis provided support for the process skill subtests organized around the general process skills of planning, performing, and reasoning. Scoring guides and inter-rater reliabilities were established for each task. The reliabilities for tasks, subtests and questions were fairly high, indicting adequate task reliability. Correlations between student performance on the individual tasks and the OBT were not significant. Teacher ranking of student achievement in individual classrooms also failed to correlate significantly with student performance on tasks. The lack of correlation could be attributed to several factors, including (among others) a wide range of student opportunities to learn from the seven schools in the sample. As has been reported in the performance assessment literature, there were no significant differences between the performance of male and female students. (Abstract shortened by UMI.)

Priming performance-related concerns induces task-related mind-wandering.

PubMed

Jordano, Megan L; Touron, Dayna R

2017-10-01

Two experiments tested the hypothesis that priming of performance-related concerns would (1) increase the frequency of task-related mind-wandering (i.e., task-related interference; TRI) and (2) decrease task performance. In each experiment, sixty female participants completed an operation span task (OSPAN) containing thought content probes. The task was framed as a math task for those in a condition primed for math-related stereotype threat and as a memory task for those in a control condition. In both studies, women whose performance-related concerns were primed via stereotype threat reported more TRI than women in the control. The second experiment used a more challenging OSPAN task and stereotype primed women also had lower math accuracy than controls. These results support the "control failures×current concerns" framework of mind-wandering, which posits that the degree to which the environmental context triggers personal concerns influences both mind-wandering frequency and content. Copyright © 2017 Elsevier Inc. All rights reserved.

Investigating Conversational Dynamics: Interactive Alignment, Interpersonal Synergy, and Collective Task Performance

ERIC Educational Resources Information Center

Fusaroli, Riccardo; Tylén, Kristian

2016-01-01

This study investigates interpersonal processes underlying dialog by comparing two approaches, "interactive alignment" and "interpersonal synergy", and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between interlocutors, the synergy…

High variability impairs motor learning regardless of whether it affects task performance.

PubMed

Cardis, Marco; Casadio, Maura; Ranganathan, Rajiv

2018-01-01

Motor variability plays an important role in motor learning, although the exact mechanisms of how variability affects learning are not well understood. Recent evidence suggests that motor variability may have different effects on learning in redundant tasks, depending on whether it is present in the task space (where it affects task performance) or in the null space (where it has no effect on task performance). We examined the effect of directly introducing null and task space variability using a manipulandum during the learning of a motor task. Participants learned a bimanual shuffleboard task for 2 days, where their goal was to slide a virtual puck as close as possible toward a target. Critically, the distance traveled by the puck was determined by the sum of the left- and right-hand velocities, which meant that there was redundancy in the task. Participants were divided into five groups, based on both the dimension in which the variability was introduced and the amount of variability that was introduced during training. Results showed that although all groups were able to reduce error with practice, learning was affected more by the amount of variability introduced rather than the dimension in which variability was introduced. Specifically, groups with higher movement variability during practice showed larger errors at the end of practice compared with groups that had low variability during learning. These results suggest that although introducing variability can increase exploration of new solutions, this may adversely affect the ability to retain the learned solution. NEW & NOTEWORTHY We examined the role of introducing variability during motor learning in a redundant task. The presence of redundancy allows variability to be introduced in different dimensions: the task space (where it affects task performance) or the null space (where it does not affect task performance). We found that introducing variability affected learning adversely, but the amount of

Performance in complex motor tasks deteriorates in hyperthermic humans.

PubMed

Piil, Jacob F; Lundbye-Jensen, Jesper; Trangmar, Steven J; Nybo, Lars

2017-01-01

Heat stress, leading to elevations in whole-body temperature, has a marked impact on both physical performance and cognition in ecological settings. Lab experiments confirm this for physically demanding activities, whereas observations are inconsistent for tasks involving cognitive processing of information or decision-making prior to responding. We hypothesized that divergences could relate to task complexity and developed a protocol consisting of 1) simple motor task [TARGET_pinch], 2) complex motor task [Visuo-motor tracking], 3) simple math task [MATH_type], 4) combined motor-math task [MATH_pinch]. Furthermore, visuo-motor tracking performance was assessed both in a separate- and a multipart protocol (complex motor tasks alternating with the three other tasks). Following familiarization, each of the 10 male subjects completed separate and multipart protocols in randomized order in the heat (40°C) or control condition (20°C) with testing at baseline (seated rest) and similar seated position, following exercise-induced hyperthermia (core temperature ∼ 39.5°C in the heat and 38.2°C in control condition). All task scores were unaffected by control exercise or passive heat exposure, but visuo-motor tracking performance was reduced by 10.7 ± 6.5% following exercise-induced hyperthermia when integrated in the multipart protocol and 4.4 ± 5.7% when tested separately (both P < 0.05 ). TARGET_pinch precision declined by 2.6 ± 1.3% ( P < 0.05 ), while no significant changes were observed for the math tasks. These results indicate that heat per se has little impact on simple motor or cognitive test performance, but complex motor performance is impaired by hyperthermia and especially so when multiple tasks are combined.

Within-person relationship between self-efficacy and performance across trials. Effect of task objective and task type.

PubMed

Hepler, Teri J; Ritchie, Jason; Hill, Christopher R

2017-07-05

Self-efficacy has been shown to be a consistent, positive predictor of between-persons performance in sport. However, there have been equivocal results regarding the influence of self-efficacy on a person's performance over time. This study investigated the influence of self-efficacy on motor skill performance across trials with respect to two different task objectives and task types. Participants (N=84) performed 4 blocks of 10 trials of a dart throwing (closed skill) and a hitting (open skill) task under 2 different task objectives: competitive and goal-striving. For the goal-striving condition, success was defined as reaching a pre-determined performance level. The competitive condition involved competing against an opponent. Hierarchical linear modeling was used to examine the influence of past performance and self-efficacy on the within-person performance across multiple trials. Previous performance was negatively related with subsequent performance on all conditions. Self-efficacy was not a significant predictor of performance on any of the conditions. While task objective and task type did not moderate the efficacy-performance relationship in the current study, it is important to consider the role of other moderators in future research.

Performance of Brazilian children on phonemic and semantic verbal fluency tasks

PubMed Central

Charchat-Fichman, Helenice; Oliveira, Rosinda Martins; da Silva, Andreza Morais

2011-01-01

The most used verbal fluency paradigms are semantic and letter fluency tasks. Studies suggest that these paradigms access semantic memory and executive function and are sensitive to frontal lobe disturbances. There are few studies in Brazilian samples on these paradigms. Objective The present study investigated performance, and the effects of age, on verbal fluency tasks in Brazilian children. The results were compared with those of other studies, and the consistency of the scoring criteria data is presented. Methods A sample of 119 children (7 to 10 years old) was submitted to the three phonemic fluency (F, A, M) tasks and three semantic fluency (animals, clothes, fruits) tasks. The results of thirty subjects were scored by two independent examiners. Results A significant positive correlation was found between the scores calculated by the two independent examiners. Significant positive correlations were found between performance on the semantic fluency task and the phonemic fluency task. The effect of age was significant for both tasks, and a significant difference was found between the 7- and 9-year-old subjects and between the 7- and 10-year-old subjects. The 8-year-old group did not differ to any of the other age groups. Conclusion The pattern of results was similar to that observed in previous Brazilian and international studies. PMID:29213727

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

PubMed

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

2017-06-22

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

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

PubMed

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

2017-01-01

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

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

Self-Efficacy, Task Complexity and Task Performance: Exploring Interactions in Two Versions of Vocabulary Learning Tasks

ERIC Educational Resources Information Center

Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan

2012-01-01

The present study aimed for better understanding of the interactions between task complexity and students' self-efficacy beliefs and students' use of learning strategies, and finally their interacting effects on task performance. This investigation was carried out in the context of Chinese students learning English as a foreign language in a…

Cerebellar tDCS Does Not Enhance Performance in an Implicit Categorization Learning Task.

PubMed

Verhage, Marie C; Avila, Eric O; Frens, Maarten A; Donchin, Opher; van der Geest, Jos N

2017-01-01

Background: Transcranial Direct Current Stimulation (tDCS) is a form of non-invasive electrical stimulation that changes neuronal excitability in a polarity and site-specific manner. In cognitive tasks related to prefrontal and cerebellar learning, cortical tDCS arguably facilitates learning, but the few studies investigating cerebellar tDCS, however, are inconsistent. Objective: We investigate the effect of cerebellar tDCS on performance of an implicit categorization learning task. Methods: Forty participants performed a computerized version of an implicit categorization learning task where squares had to be sorted into two categories, according to an unknown but fixed rule that integrated both the size and luminance of the square. Participants did one round of categorization to familiarize themselves with the task and to provide a baseline of performance. After that, 20 participants received anodal tDCS (20 min, 1.5 mA) over the right cerebellum, and 19 participants received sham stimulation and simultaneously started a second session of the categorization task using a new rule. Results: As expected, subjects performed better in the second session than in the first, baseline session, showing increased accuracy scores and reduced reaction times. Over trials, participants learned the categorization rule, improving their accuracy and reaction times. However, we observed no effect of anodal tDCS stimulation on overall performance or on learning, compared to sham stimulation. Conclusion: These results suggest that cerebellar tDCS does not modulate performance and learning on an implicit categorization task.

Alterations in Resting-State Activity Relate to Performance in a Verbal Recognition Task

PubMed Central

López Zunini, Rocío A.; Thivierge, Jean-Philippe; Kousaie, Shanna; Sheppard, Christine; Taler, Vanessa

2013-01-01

In the brain, resting-state activity refers to non-random patterns of intrinsic activity occurring when participants are not actively engaged in a task. We monitored resting-state activity using electroencephalogram (EEG) both before and after a verbal recognition task. We show a strong positive correlation between accuracy in verbal recognition and pre-task resting-state alpha power at posterior sites. We further characterized this effect by examining resting-state post-task activity. We found marked alterations in resting-state alpha power when comparing pre- and post-task periods, with more pronounced alterations in participants that attained higher task accuracy. These findings support a dynamical view of cognitive processes where patterns of ongoing brain activity can facilitate –or interfere– with optimal task performance. PMID:23785436

Analysis of Time-on-Task, Behavior Experiences, and Performance in Two Online Courses with Different Authentic Learning Tasks

ERIC Educational Resources Information Center

Park, Sanghoon

2017-01-01

This paper reports the findings of a comparative analysis of online learner behavioral interactions, time-on-task, attendance, and performance at different points throughout a semester (beginning, during, and end) based on two online courses: one course offering authentic discussion-based learning activities and the other course offering authentic…

Effects of cues in a binary categorization task on dual-task performance, mental workload, and effort.

PubMed

Botzer, Assaf; Meyer, Joachim; Parmet, Yisrael

2016-09-01

Binary cues help operators perform binary categorization tasks, such as monitoring for system failures. They may also allow them to attend to other tasks they concurrently perform. If the time saved by using cues is allocated to other concurrent tasks, users' overall effort may remain unchanged. In 2 experiments, participants performed a simulated quality control task, together with a tracking task. In half the experimental blocks cues were available, and participants could use them in their decisions about the quality of products (intact or faulty). In Experiment 1, the difficulty of tracking was constant, while in Experiment 2, tracking difficulty differed in the 2 halves of the experiment. In both experiments, participants reported on the NASA Task Load Index that cues improved their performance and reduced their frustration. Consequently, their overall score on mental workload (MWL) was lower with cues. They also reported, however, that cues did not reduce their effort. We conclude that cues and other forms of automation may support task performance and reduce overall MWL, but this will not necessarily mean that users will work less hard. Thus, effort and overall MWL should be evaluated separately, if one wants to obtain a full picture of the effects of automation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Performance of an Additional Task During Level 2 Automated Driving: An On-Road Study Comparing Drivers With and Without Experience With Partial Automation.

PubMed

Solís-Marcos, Ignacio; Ahlström, Christer; Kircher, Katja

2018-05-01

To investigate the influence of prior experience with Level 2 automation on additional task performance during manual and Level 2 partially automated driving. Level 2 automation is now on the market, but its effects on driver behavior remain unclear. Based on previous studies, we could expect an increase in drivers' engagement in secondary tasks during Level 2 automated driving, but it is yet unknown how drivers will integrate all the ongoing demands in such situations. Twenty-one drivers (12 without, 9 with Level 2 automation experience) drove on a highway manually and with Level 2 automation (exemplified by Volvo Pilot Assist generation 2; PA2) while performing an additional task. In half of the conditions, the task could be interrupted (self-paced), and in the other half, it could not (system-paced). Drivers' visual attention, additional task performance, and other compensatory strategies were analyzed. Driving with PA2 led to decreased scores in the additional task and more visual attention to the dashboard. In the self-paced condition, all drivers looked more to the task and perceived a lower mental demand. The drivers experienced with PA2 used the system and the task more than the novice group and performed more overtakings. The additional task interfered more with Level 2 automation than with manual driving. The drivers, particularly the automation novice drivers, used some compensatory strategies. Automation designers need to consider these potential effects in the development of future automated systems.

Does dual-task coordination performance decline in later life?

PubMed

Sebastián, María V; Mediavilla, Roberto

2017-05-01

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

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

PubMed

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

2015-05-01

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

Effect of pre-task music on sports or exercise performance.

PubMed

Smirmaul, Bruno P

2017-01-01

Pre-task music is a very common strategy among sports competitors. However, as opposed to in-task music, the scientific evidence to support its ergogenic effects on either sports or exercise performance is limited. This brief review critically addresses the existing literature investigating the effects of pre-task music on sports and exercise performance, focusing on the methods and results of experimental studies, and offers basic and practical recommendations. In July 2015, a comprehensive literature search was performed in Web of Science, PubMed, and Google Scholar using the following key words in combination: "pre-task music," "pre-test music," "pre-exercise music," "exercise performance," "sports performance." The literature search was further expanded by both hand searching review articles on the topic and by searching the reference lists from the articles retrieved for any relevant references. Overall, a total of 15 studies in 14 articles were included. Pre-task music research has been unsystematic, methodologically limited and infrequent. Using this review as a starting point to overcome previous methodological limitations when designing future experiments may contribute to the development of pre-task music research, which is still in its infancy. Currently, there is no sufficient evidence to support the overall ergogenic effects of pre-task music on sports or exercise performance. Nonetheless, pre-task music has showed a likely ergogenic effect on shorter and predominantly anaerobic tasks such as grip strength, Wingate test, and short-duration sports or sports-like tasks, in contrast to longer and predominantly aerobic tasks.

Ability Beliefs, Task Value, and Performance as a Function of Race in a Dart-Throwing Task

ERIC Educational Resources Information Center

Gao, Zan; Kosma, Maria; Harrison, Louis, Jr.

2009-01-01

This study examines differences in self-efficacy, expectancy-related beliefs, task value, and performance in a dart-throwing task as a function of race among diverse college students using the expectancy-value model and self-efficacy theory. It also examines the predictive contributions of these beliefs on task performance within each racial…

Variability and Variation of L2 Grammar: A Cross-Sectional Analysis of German Learners' Performance on Two Tasks

ERIC Educational Resources Information Center

Abrams, Zsuzsanna; Rott, Susanne

2017-01-01

Research on second language (L2) grammar in task-based language learning has yielded inconsistent results regarding the effects of task-complexity, prompting calls for more nuanced analyses of L2 development and task performance. The present cross-sectional study contributes to this discussion by comparing the performance of 245 learners of German…

Bilinguals Use Language-Control Brain Areas More Than Monolinguals to Perform Non-Linguistic Switching Tasks

PubMed Central

Rodríguez-Pujadas, Aina; Sanjuán, Ana; Ventura-Campos, Noelia; Román, Patricia; Martin, Clara; Barceló, Francisco; Costa, Albert; Ávila, César

2013-01-01

We tested the hypothesis that early bilinguals use language-control brain areas more than monolinguals when performing non-linguistic executive control tasks. We do so by exploring the brain activity of early bilinguals and monolinguals in a task-switching paradigm using an embedded critical trial design. Crucially, the task was designed such that the behavioural performance of the two groups was comparable, allowing then to have a safer comparison between the corresponding brain activity in the two groups. Despite the lack of behavioural differences between both groups, early bilinguals used language-control areas – such as left caudate, and left inferior and middle frontal gyri – more than monolinguals, when performing the switching task. Results offer direct support for the notion that, early bilingualism exerts an effect in the neural circuitry responsible for executive control. This effect partially involves the recruitment of brain areas involved in language control when performing domain-general executive control tasks, highlighting the cross-talk between these two domains. PMID:24058456

A Hybrid Task Graph Scheduler for High Performance Image Processing Workflows.

PubMed

Blattner, Timothy; Keyrouz, Walid; Bhattacharyya, Shuvra S; Halem, Milton; Brady, Mary

2017-12-01

Designing applications for scalability is key to improving their performance in hybrid and cluster computing. Scheduling code to utilize parallelism is difficult, particularly when dealing with data dependencies, memory management, data motion, and processor occupancy. The Hybrid Task Graph Scheduler (HTGS) improves programmer productivity when implementing hybrid workflows for multi-core and multi-GPU systems. The Hybrid Task Graph Scheduler (HTGS) is an abstract execution model, framework, and API that increases programmer productivity when implementing hybrid workflows for such systems. HTGS manages dependencies between tasks, represents CPU and GPU memories independently, overlaps computations with disk I/O and memory transfers, keeps multiple GPUs occupied, and uses all available compute resources. Through these abstractions, data motion and memory are explicit; this makes data locality decisions more accessible. To demonstrate the HTGS application program interface (API), we present implementations of two example algorithms: (1) a matrix multiplication that shows how easily task graphs can be used; and (2) a hybrid implementation of microscopy image stitching that reduces code size by ≈ 43% compared to a manually coded hybrid workflow implementation and showcases the minimal overhead of task graphs in HTGS. Both of the HTGS-based implementations show good performance. In image stitching the HTGS implementation achieves similar performance to the hybrid workflow implementation. Matrix multiplication with HTGS achieves 1.3× and 1.8× speedup over the multi-threaded OpenBLAS library for 16k × 16k and 32k × 32k size matrices, respectively.

Characterizing "fibrofog": Subjective appraisal, objective performance, and task-related brain activity during a working memory task.

PubMed

Walitt, Brian; Čeko, Marta; Khatiwada, Manish; Gracely, John L; Rayhan, Rakib; VanMeter, John W; Gracely, Richard H

2016-01-01

The subjective experience of cognitive dysfunction ("fibrofog") is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, "fibrofog" appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks.

Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance.

PubMed

Molero-Chamizo, Andrés; Alameda Bailén, José R; Garrido Béjar, Tamara; García López, Macarena; Jaén Rodríguez, Inmaculada; Gutiérrez Lérida, Carolina; Pérez Panal, Silvia; González Ángel, Gloria; Lemus Corchero, Laura; Ruiz Vega, María J; Nitsche, Michael A; Rivera-Urbina, Guadalupe N

2018-02-01

Anodal transcranial direct current stimulation (tDCS) induces long-term potentiation-like plasticity, which is associated with long-lasting effects on different cognitive, emotional, and motor performances. Specifically, tDCS applied over the motor cortex is considered to improve reaction time in simple and complex tasks. The timing of tDCS relative to task performance could determine the efficacy of tDCS to modulate performance. The aim of this study was to compare the effects of a single session of anodal tDCS (1.5 mA, for 15 min) applied over the left primary motor cortex (M1) versus sham stimulation on performance of a go/no-go simple reaction-time task carried out at three different time points after tDCS-namely, 0, 30, or 60 min after stimulation. Performance zero min after anodal tDCS was improved during the whole course of the task. Performance 30 min after anodal tDCS was improved only in the last block of the reaction-time task. Performance 60 min after anodal tDCS was not significantly different throughout the entire task. These findings suggest that the motor cortex excitability changes induced by tDCS can improve motor responses, and these effects critically depend on the time interval between stimulation and task performance.

Does dual task training improve walking performance of older adults with concern of falling?

PubMed

Wollesen, B; Schulz, S; Seydell, L; Delbaere, K

2017-09-11

Older adults with concerns of falling show decrements of gait stability under single (ST) and dual task (DT) conditions. To compare the effects of a DT training integrating task managing strategies for independent living older adults with and without concern about falling (CoF) to a non-training control group on walking performance under ST and DT conditions. Single center parallel group single blind randomized controlled trial with group-based interventions (DT-managing balance training) compared to a control group (Ninety-five independent living older adults; 71.5 ± 5.2 years). A progressive DT training (12 sessions; 60 min each; 12 weeks) including task-managing strategies was compared to a non-training control group. group based intervention for independent living elderly in a gym. ST and DT walking (visual verbal Stroop task) were measured on a treadmill. Gait parameters (step length, step width, and gait line) and cognitive performance while walking were compared with a 2x2x2 Repeated Measures Analyses of Variance. Participants in the intervention group showed an increased step length under ST and DT conditions following the intervention, for both people with and without CoF compared to their respective control groups. Foot rolling movement and cognitive performance while walking however only improved in participants without CoF. The results showed that DT managing training can improve walking performance under ST and DT conditions in people with and without CoF. Additional treatment to directly address CoF, such as cognitive behavioural therapy, should be considered to further improve the cautious gait pattern (as evidenced by reduced foot rolling movements). The study was retrospectively registered in the German Clinical Trials Register (DRKS; Identification number DRKS00012382 , 11.05.2017).

Mental and psychomotor task performance in noise

NASA Technical Reports Server (NTRS)

1984-01-01

The possible adverse effects of noise on mental and psychomotor task performance were a matter of practical concern for centuries and continue to be a matter of scientific controversy. A review indicates that except for the masking or interferences with the hearing of sounds needed to perform a given task, noise does not necessarily interfer with work performance. However, because of difficulties in the experimental control of some of these possible effects, the results of research on work performance in noise were inconsistent and difficult to encompass in any simple theoretical construct. Indeed, reviews of research in this area conclude that simple generalizations about possible effects of noise on work performance cannot be made. Nevertheless, several general theories were put forth.

Hysteresis in Mental Workload and Task Performance: The Influence of Demand Transitions and Task Prioritization.

PubMed

Jansen, Reinier J; Sawyer, Ben D; van Egmond, René; de Ridder, Huib; Hancock, Peter A

2016-12-01

We examine how transitions in task demand are manifested in mental workload and performance in a dual-task setting. Hysteresis has been defined as the ongoing influence of demand levels prior to a demand transition. Authors of previous studies predominantly examined hysteretic effects in terms of performance. However, little is known about the temporal development of hysteresis in mental workload. A simulated driving task was combined with an auditory memory task. Participants were instructed to prioritize driving or to prioritize both tasks equally. Three experimental conditions with low, high, and low task demands were constructed by manipulating the frequency of lane changing. Multiple measures of subjective mental workload were taken during experimental conditions. Contrary to our prediction, no hysteretic effects were found after the high- to low-demand transition. However, a hysteretic effect in mental workload was found within the high-demand condition, which degraded toward the end of the high condition. Priority instructions were not reflected in performance. Online assessment of both performance and mental workload demonstrates the transient nature of hysteretic effects. An explanation for the observed hysteretic effect in mental workload is offered in terms of effort regulation. An informed arrival at the scene is important in safety operations, but peaks in mental workload should be avoided to prevent buildup of fatigue. Therefore, communication technologies should incorporate the historical profile of task demand. © 2016, Human Factors and Ergonomics Society.

The Effects of Expectancy-Incongruent Feedback and Self-Affirmation on Task Performance of Secondary School Students

ERIC Educational Resources Information Center

Baadte, Christiane; Kurenbach, Friederike

2017-01-01

In the present study, the assumption was tested that expectancy-incongruent feedback in conjunction with explicit self-affirmation directs attention away from the task and to the self. As a result, performance should decrease in resource-sensitive text/picture comprehension tasks as compared to resource-insensitive tasks. Three hundred and…

Menstrual cycle phase effects on memory and Stroop task performance.

PubMed

Hatta, Takeshi; Nagaya, Keiko

2009-10-01

The present study examined differences in Stroop and memory task performances modulated by gonadal steroid hormones during the menstrual cycle in women. Thirty women with regular menstrual cycles performed a logical memory task (Wechsler Memory Scale) and the Stroop task. The results showed a significant difference in Stroop task performance between low and high levels of estradiol and progesterone during the menstrual cycle, but there was no significant difference in memory performance between the two phases, nor was there any significant mood change that might have influenced cognitive performance. These findings suggest that sex-related hormone modulation selectively affects cognitive functions depending on the type of task and low level secretion of estradiol appears to contribute to reducing the level of attention that relates to the prefrontal cortex.

Training Attentional Control Improves Cognitive and Motor Task Performance.

PubMed

Ducrocq, Emmanuel; Wilson, Mark; Vine, Sam; Derakshan, Nazanin

2016-10-01

Attentional control is a necessary function for the regulation of goal-directed behavior. In three experiments we investigated whether training inhibitory control using a visual search task could improve task-specific measures of attentional control and performance. In Experiment 1 results revealed that training elicited a near-transfer effect, improving performance on a cognitive (antisaccade) task assessing inhibitory control. In Experiment 2 an initial far-transfer effect of training was observed on an index of attentional control validated for tennis. The principal aim of Experiment 3 was to expand on these findings by assessing objective gaze measures of inhibitory control during the performance of a tennis task. Training improved inhibitory control and performance when pressure was elevated, confirming the mechanisms by which cognitive anxiety impacts performance. These results suggest that attentional control training can improve inhibition and reduce taskspecific distractibility with promise of transfer to more efficient sporting performance in competitive contexts.

The Curvilinear Relationship between State Neuroticism and Momentary Task Performance

PubMed Central

Debusscher, Jonas; Hofmans, Joeri; De Fruyt, Filip

2014-01-01

A daily diary and two experience sampling studies were carried out to investigate curvilinearity of the within-person relationship between state neuroticism and task performance, as well as the moderating effects of within-person variation in momentary job demands (i.e., work pressure and task complexity). In one, results showed that under high work pressure, the state neuroticism–task performance relationship was best described by an exponentially decreasing curve, whereas an inverted U-shaped curve was found for tasks low in work pressure, while in another study, a similar trend was visible for task complexity. In the final study, the state neuroticism–momentary task performance relationship was a linear one, and this relationship was moderated by momentary task complexity. Together, results from all three studies showed that it is important to take into account the moderating effects of momentary job demands because within-person variation in job demands affects the way in which state neuroticism relates to momentary levels of task performance. Specifically, we found that experiencing low levels of state neuroticism may be most beneficial in high demanding tasks, whereas more moderate levels of state neuroticism are optimal under low momentary job demands. PMID:25238547

The effect of divided attention on novices and experts in laparoscopic task performance.

PubMed

Ghazanfar, Mudassar Ali; Cook, Malcolm; Tang, Benjie; Tait, Iain; Alijani, Afshin

2015-03-01

Attention is important for the skilful execution of surgery. The surgeon's attention during surgery is divided between surgery and outside distractions. The effect of this divided attention has not been well studied previously. We aimed to compare the effect of dividing attention of novices and experts on a laparoscopic task performance. Following ethical approval, 25 novices and 9 expert surgeons performed a standardised peg transfer task in a laboratory setup under three randomly assigned conditions: silent as control condition and two standardised auditory distracting tasks requiring response (easy and difficult) as study conditions. Human reliability assessment was used for surgical task analysis. Primary outcome measures were correct auditory responses, task time, number of surgical errors and instrument movements. Secondary outcome measures included error rate, error probability and hand specific differences. Non-parametric statistics were used for data analysis. 21109 movements and 9036 total errors were analysed. Novices had increased mean task completion time (seconds) (171 ± 44SD vs. 149 ± 34, p < 0.05), number of total movements (227 ± 27 vs. 213 ± 26, p < 0.05) and number of errors (127 ± 51 vs. 96 ± 28, p < 0.05) during difficult study conditions compared to control. The correct responses to auditory stimuli were less frequent in experts (68 %) compared to novices (80 %). There was a positive correlation between error rate and error probability in novices (r (2) = 0.533, p < 0.05) but not in experts (r (2) = 0.346, p > 0.05). Divided attention conditions in theatre environment require careful consideration during surgical training as the junior surgeons are less able to focus their attention during these conditions.

Training improves laparoscopic tasks performance and decreases operator workload.

PubMed

Hu, Jesse S L; Lu, Jirong; Tan, Wee Boon; Lomanto, Davide

2016-05-01

It has been postulated that increased operator workload during task performance may increase fatigue and surgical errors. The National Aeronautics and Space Administration-Task Load Index (NASA-TLX) is a validated tool for self-assessment for workload. Our study aims to assess the relationship of workload and performance of novices in simulated laparoscopic tasks of different complexity levels before and after training. Forty-seven novices without prior laparoscopic experience were recruited in a trial to investigate whether training improves task performance as well as mental workload. The participants were tested on three standard tasks (ring transfer, precision cutting and intracorporeal suturing) in increasing complexity based on the Fundamentals of Laparoscopic Surgery (FLS) curriculum. Following a period of training and rest, participants were tested again. Test scores were computed from time taken and time penalties for precision errors. Test scores and NASA-TLX scores were recorded pre- and post-training and analysed using paired t tests. One-way repeated measures ANOVA was used to analyse differences in NASA-TLX scores between the three tasks. NASA-TLX score was lowest with ring transfer and highest with intracorporeal suturing. This was statistically significant in both pre-training (p < 0.001) and post-training (p < 0.001). NASA-TLX scores mirror the changes in test scores for the three tasks. Workload scores decreased significantly after training for all three tasks (ring transfer = 2.93, p < 0.001, precision cutting = 3.74, p < 0.001, intracorporeal suturing = 2.98, p < 0.001). NASA-TLX score is an accurate reflection of the complexity of simulated laparoscopic tasks in the FLS curriculum. This also correlates with the relationship of test scores between the three tasks. Simulation training improves both performance score and workload score across the tasks.

Self-Reported Stickiness of Mind-Wandering Affects Task Performance

PubMed Central

van Vugt, Marieke K.; Broers, Nico

2016-01-01

When asked to perform a certain task, we typically spend a decent amount of time thinking thoughts unrelated to that task–a phenomenon referred to as “mind-wandering.” It is thought that this mind-wandering is driven at least in part by our unfinished goals and concerns. Previous studies have shown that just after presenting a participant with their own concerns, their reports of task-unrelated thinking increased somewhat. However, effects of these concerns on task performance were somewhat inconsistent. In this study we take the opposite approach, and examine whether task performance depends on the self-reported thought content. Specifically, a particularly intriguing aspect of mind-wandering that has hitherto received little attention is the difficulty of disengaging from it, in other words, the “stickiness” of the thoughts. While presenting participants with their own concerns was not associated with clear effects on task performance, we showed that the reports of off-task thinking and variability of response times increased with the amount of self-reported stickiness of thoughts. This suggests that the stickiness of mind-wandering is a relevant variable, and participants are able to meaningfully report on it. PMID:27242636

Benefits of Stimulus Exposure: Developmental Learning Independent of Task Performance

PubMed Central

Green, David B.; Ohlemacher, Jocelyn; Rosen, Merri J.

2016-01-01

Perceptual learning (training-induced performance improvement) can be elicited by task-irrelevant stimulus exposure in humans. In contrast, task-irrelevant stimulus exposure in animals typically disrupts perception in juveniles while causing little to no effect in adults. This may be due to the extent of exposure, which is brief in humans while chronic in animals. Here we assessed the effects of short bouts of passive stimulus exposure on learning during development in gerbils, compared with non-passive stimulus exposure (i.e., during testing). We used prepulse inhibition of the acoustic startle response, a method that can be applied at any age, to measure gap detection thresholds across four age groups, spanning development. First, we showed that both gap detection thresholds and gap detection learning across sessions displayed a long developmental trajectory, improving throughout the juvenile period. Additionally, we demonstrated larger within- and across-animal performance variability in younger animals. These results are generally consistent with results in humans, where there are extended developmental trajectories for both the perception of temporally-varying signals, and the effects of perceptual training, as well as increased variability and poorer performance consistency in children. We then chose an age (mid-juveniles) that displayed clear learning over sessions in order to assess effects of brief passive stimulus exposure on this learning. We compared learning in mid-juveniles exposed to either gap detection testing (gaps paired with startles) or equivalent gap exposure without testing (gaps alone) for three sessions. Learning was equivalent in both these groups and better than both naïve age-matched animals and controls receiving no gap exposure but only startle testing. Thus, short bouts of exposure to gaps independent of task performance is sufficient to induce learning at this age, and is as effective as gap detection testing. PMID:27378837

Rules and more rules: the effects of multiple tasks, extensive training, and aging on task-switching performance.

PubMed

Buchler, Norbou G; Hoyer, William J; Cerella, John

2008-06-01

Task-switching performance was assessed in young and older adults as a function of the number of task sets to be actively maintained in memory (varied from 1 to 4) over the course of extended training (5 days). Each of the four tasks required the execution of a simple computational algorithm, which was instantaneously cued by the color of the two-digit stimulus. Tasks were presented in pure (task set size 1) and mixed blocks (task set sizes 2, 3, 4), and the task sequence was unpredictable. By considering task switching beyond two tasks, we found evidence for a cognitive control system that is not overwhelmed by task set size load manipulations. Extended training eliminated age effects in task-switching performance, even when the participants had to manage the execution of up to four tasks. The results are discussed in terms of current theories of cognitive control, including task set inertia and production system postulates.

Selecting Tasks for Evaluating Human Performance as a Function of Gravity

NASA Technical Reports Server (NTRS)

Norcross, Jason R.; Gernhardt, Michael L.

2011-01-01

A challenge in understanding human performance as a function of gravity is determining which tasks to research. Initial studies began with treadmill walking, which was easy to quantify and control. However, with the development of pressurized rovers, it is less important to optimize human performance for ambulation as pressurized rovers will likely perform gross translation for them. Future crews are likely to spend much of their extravehicular activity (EVA) performing geology, construction,a nd maintenance type tasks. With these types of tasks, people have different performance strategies, and it is often difficult to quantify the task and measure steady-state metabolic rates or perform biomechanical analysis. For many of these types of tasks, subjective feedback may be the only data that can be collected. However, subjective data may not fully support a rigorous scientific comparison of human performance across different gravity levels and suit factors. NASA would benefit from having a wide variety of quantifiable tasks that allow human performance comparison across different conditions. In order to determine which tasks will effectively support scientific studies, many different tasks and data analysis techniques will need to be employed. Many of these tasks and techniques will not be effective, but some will produce quantifiable results that are sensitive enough to show performance differences. One of the primary concerns related to EVA performance is metabolic rate. The higher the metabolic rate, the faster the astronaut will exhaust consumables. The focus of this poster will be on how different tasks affect metabolic rate across different gravity levels.

Performance on a stage IV object-permanence task with standard and nonstandard covers.

PubMed

Rader, N; Spiro, D J; Firestone, P B

1979-09-01

Piaget's description of object concept development is based on success in performing a series of search tasks. However, failure to perform successfully may result from undeveloped aspects of the cognitive or motor system unrelated to a concept of objects. This study examined the role of perceptual-motor development in a typical Stage IV task by comparing performance given a standard cloth cover or a small card cover. Subjects were 10 infants 147--187 days old (median age = 160 days). A pass was defined as the retrieval of the toy within 30 sec on 2 out of 3 trials. The difference in performance between the 2 cover conditions was significant (p = .032). These results advise caution in interpreting Stage IV performance in terms of a developing object concept.

Individual Differences in Secondary Task Performance.

DTIC Science & Technology

1980-09-01

applied than in the experimental literature (e.g. Brown, 1968). The assertion that primary and secondary tasks compete for mental resources has a further...Subjects were paid $8.00 for participation in two 1 -hour sessions. Bonus points were awarded on the basis of performance in the experimental tasks...the experimental measures are presented in Table 3. Reliabilities, shown in the diagonal, are based on correlations between measures from Day 1 and Day

A Comparative Analysis of Tasks Essential to Successful Performance in Three Veterinarian Lay Occupations. Summary Research 5.

ERIC Educational Resources Information Center

McCracken, J. David; Cooke, Frederick C.

The occupational survey's purpose was to identify the skills which are performed and essential for success in three veterinary lay occupations: animal health assistant, animal hospital receptionist, and animal health technician. Survey objectives were accomplished by constructing an initial task inventory of 21 duty areas, validating the initial…

Effects of Dual-Task Management and Resistance Training on Gait Performance in Older Individuals: A Randomized Controlled Trial.

PubMed

Wollesen, Bettina; Mattes, Klaus; Schulz, Sören; Bischoff, Laura L; Seydell, L; Bell, Jeffrey W; von Duvillard, Serge P

2017-01-01

Background: Dual-task (DT) training is a well-accepted modality for fall prevention in older adults. DT training should include task-managing strategies such as task switching or task prioritization to improve gait performance under DT conditions. Methods: We conducted a randomized controlled trial to evaluate a balance and task managing training (BDT group) in gait performance compared to a single task (ST) strength and resistance training and a control group, which received no training. A total of 78 older individuals (72.0 ± 4.9 years) participated in this study. The DT group performed task managing training incorporating balance and coordination tasks while the ST group performed resistance training only. Training consisted of 12 weekly sessions, 60 min each, for 12 weeks. We assessed the effects of ST and BDT training on walking performance under ST and DT conditions in independent living elderly adults. ST and DT walking (visual verbal Stroop task) were measured utilizing a treadmill at self-selected walking speed (mean for all groups: 4.4 ± 1 km h -1 ). Specific gait variables, cognitive performance, and fear of falling were compared between all groups. > Results: Training improved gait performance for step length ( p < 0.001) and gait-line (ST: p < 0.01; DT p < 0.05) in both training groups. The BDT training group showed greater improvements in step length ( p < 0.001) and gait-line ( p < 0.01) during DT walking but did not have changes in cognitive performance. Both interventions reduced fear of falling ( p < 0.05). Conclusion: Implementation of task management strategies into balance and strength training in our population revealed a promising modality to prevent falls in older individuals. Trial registration: German register of clinical trials DRKS00012382.

Operational testing of a figure of merit for overall task performance

NASA Technical Reports Server (NTRS)

Lemay, Moira

1990-01-01

An overall indicator or figure of merit (FOM), for the quality of pilot performance is needed to define optimal workload levels, predict system failure, measure the impact of new automation in the cockpit, and define the relative contributions of subtasks to overall task performance. A normative FOM was developed based on the calculation of a standard score for each component of a complex task. It reflected some effects, detailed in an earlier study, of the introduction of new data link technology into the cockpit. Since the technique showed promise, further testing was done. A new set of data was obtained using the recently developed Multi-Attribute Task Battery. This is a complex battery consisting of four tasks which can be varied in task demand, and on which performance measures can be obtained. This battery was presented to 12 subjects in a 20 minute trial at each of three levels of workload or task demand, and performance measures collected on all four tasks. The NASA-TLX workload rating scale was presented at minutes 6, 12, and 18, of each trial. A figure of merit was then obtained for each run of the battery by calculating a mean, SD, and standard score for each task. Each task contributed its own proportion to the overall FOM, and relative contributions changed with increasing workload. Thus, the FOM shows the effect of task changes, not only on the individual task that is changed, but also on the performance of other tasks and of the whole task. The cost to other tasks of maintaining constant performance on an individual task can be quantified.

Strategic predictors of performance in a divided attention task

PubMed Central

Faragó, Kinga Bettina; Lőrincz, András

2018-01-01

In this study we investigate the strategies of subjects in a complex divided attention task. We conducted a series of experiments with ten participants and evaluated their performance. After an extensive analysis, we identified four strategic measures that justify the achievement of the participants, by highlighting the individual differences and predicting performance in a regression analysis using generalized estimating equations. Selecting the more urgent task and user action between multiple simultaneous possibilities form two of the strategic decisions, respectively. The third one refers to choosing a response within the same task when the opportunity is present. The fourth and most important measure of strategy involves thinking ahead and executing an action before a situation would become critical. This latter one has the effect of reducing later cognitive load or timing constraints and it is shown to explain almost as much variance in performance as the other three, more straightforward predictors together. In addition to determining these strategic predictors, we also show how manipulating task difficulty induces a shift in strategy, thus impairing human performance in the rehearsed task. The results of this study indicate that considerable differences in the divided attention ability of normal subjects can be identified early and with simple measurements. The importance of describing and analyzing strategies is also emphasized, which can substantially influence performance in complex tasks and may serve training needs. PMID:29621292

Strategic predictors of performance in a divided attention task.

PubMed

Rill, Róbert Adrian; Faragó, Kinga Bettina; Lőrincz, András

2018-01-01

In this study we investigate the strategies of subjects in a complex divided attention task. We conducted a series of experiments with ten participants and evaluated their performance. After an extensive analysis, we identified four strategic measures that justify the achievement of the participants, by highlighting the individual differences and predicting performance in a regression analysis using generalized estimating equations. Selecting the more urgent task and user action between multiple simultaneous possibilities form two of the strategic decisions, respectively. The third one refers to choosing a response within the same task when the opportunity is present. The fourth and most important measure of strategy involves thinking ahead and executing an action before a situation would become critical. This latter one has the effect of reducing later cognitive load or timing constraints and it is shown to explain almost as much variance in performance as the other three, more straightforward predictors together. In addition to determining these strategic predictors, we also show how manipulating task difficulty induces a shift in strategy, thus impairing human performance in the rehearsed task. The results of this study indicate that considerable differences in the divided attention ability of normal subjects can be identified early and with simple measurements. The importance of describing and analyzing strategies is also emphasized, which can substantially influence performance in complex tasks and may serve training needs.

Computer-mediated communication: task performance and satisfaction.

PubMed

Simon, Andrew F

2006-06-01

The author assessed satisfaction and performance on 3 tasks (idea generation, intellective, judgment) among 75 dyads (N = 150) working through 1 of 3 modes of communication (instant messaging, videoconferencing, face to face). The author based predictions on the Media Naturalness Theory (N. Kock, 2001, 2002) and on findings from past researchers (e.g., D. M. DeRosa, C. Smith, & D. A. Hantula, in press) of the interaction between tasks and media. The present author did not identify task performance differences, although satisfaction with the medium was lower among those dyads communicating through an instant-messaging system than among those interacting face to face or through videoconferencing. The findings support the Media Naturalness Theory. The author discussed them in relation to the participants' frequent use of instant messaging and their familiarity with new communication media.

How do task characteristics affect learning and performance? The roles of variably mapped and dynamic tasks.

PubMed

Macnamara, Brooke N; Frank, David J

2018-05-01

For well over a century, scientists have investigated individual differences in performance. The majority of studies have focused on either differences in practice, or differences in cognitive resources. However, the predictive ability of either practice or cognitive resources varies considerably across tasks. We are the first to examine task characteristics' impact on learning and performance in a complex task while controlling for other task characteristics. In 2 experiments we test key theoretical task characteristic thought to moderate the relationship between practice, cognitive resources, and performance. We devised a task where each of several key task characteristics can be manipulated independently. Participants played 5 rounds of a game similar to the popular tower defense videogame Plants vs. Zombies where both cognitive load and game characteristics were manipulated. In Experiment 1, participants either played a consistently mapped version-the stimuli and the associated meaning of their properties were constant across the 5 rounds-or played a variably mapped version-the stimuli and the associated meaning of their properties changed every few minutes. In Experiment 2, participants either played a static version-that is, turn taking with no time pressure-or played a dynamic version-that is, the stimuli moved regardless of participants' response rates. In Experiment 1, participants' accuracy and efficiency were substantially hindered in the variably mapped conditions. In Experiment 2, learning and performance accuracy were hindered in the dynamic conditions, especially when under cognitive load. Our results suggest that task characteristics impact the relative importance of cognitive resources and practice on predicting learning and performance. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Performance comparison of heuristic algorithms for task scheduling in IaaS cloud computing environment.

PubMed

Madni, Syed Hamid Hussain; Abd Latiff, Muhammad Shafie; Abdullahi, Mohammed; Abdulhamid, Shafi'i Muhammad; Usman, Mohammed Joda

2017-01-01

Cloud computing infrastructure is suitable for meeting computational needs of large task sizes. Optimal scheduling of tasks in cloud computing environment has been proved to be an NP-complete problem, hence the need for the application of heuristic methods. Several heuristic algorithms have been developed and used in addressing this problem, but choosing the appropriate algorithm for solving task assignment problem of a particular nature is difficult since the methods are developed under different assumptions. Therefore, six rule based heuristic algorithms are implemented and used to schedule autonomous tasks in homogeneous and heterogeneous environments with the aim of comparing their performance in terms of cost, degree of imbalance, makespan and throughput. First Come First Serve (FCFS), Minimum Completion Time (MCT), Minimum Execution Time (MET), Max-min, Min-min and Sufferage are the heuristic algorithms considered for the performance comparison and analysis of task scheduling in cloud computing.

Performance comparison of heuristic algorithms for task scheduling in IaaS cloud computing environment

PubMed Central

Madni, Syed Hamid Hussain; Abd Latiff, Muhammad Shafie; Abdullahi, Mohammed; Usman, Mohammed Joda

2017-01-01

Cloud computing infrastructure is suitable for meeting computational needs of large task sizes. Optimal scheduling of tasks in cloud computing environment has been proved to be an NP-complete problem, hence the need for the application of heuristic methods. Several heuristic algorithms have been developed and used in addressing this problem, but choosing the appropriate algorithm for solving task assignment problem of a particular nature is difficult since the methods are developed under different assumptions. Therefore, six rule based heuristic algorithms are implemented and used to schedule autonomous tasks in homogeneous and heterogeneous environments with the aim of comparing their performance in terms of cost, degree of imbalance, makespan and throughput. First Come First Serve (FCFS), Minimum Completion Time (MCT), Minimum Execution Time (MET), Max-min, Min-min and Sufferage are the heuristic algorithms considered for the performance comparison and analysis of task scheduling in cloud computing. PMID:28467505

Performance of children with developmental dyslexia on high and low topological entropy artificial grammar learning task.

PubMed

Katan, Pesia; Kahta, Shani; Sasson, Ayelet; Schiff, Rachel

2017-07-01

Graph complexity as measured by topological entropy has been previously shown to affect performance on artificial grammar learning tasks among typically developing children. The aim of this study was to examine the effect of graph complexity on implicit sequential learning among children with developmental dyslexia. Our goal was to determine whether children's performance depends on the complexity level of the grammar system learned. We conducted two artificial grammar learning experiments that compared performance of children with developmental dyslexia with that of age- and reading level-matched controls. Experiment 1 was a high topological entropy artificial grammar learning task that aimed to establish implicit learning phenomena in children with developmental dyslexia using previously published experimental conditions. Experiment 2 is a lower topological entropy variant of that task. Results indicated that given a high topological entropy grammar system, children with developmental dyslexia who were similar to the reading age-matched control group had substantial difficulty in performing the task as compared to typically developing children, who exhibited intact implicit learning of the grammar. On the other hand, when tested on a lower topological entropy grammar system, all groups performed above chance level, indicating that children with developmental dyslexia were able to identify rules from a given grammar system. The results reinforced the significance of graph complexity when experimenting with artificial grammar learning tasks, particularly with dyslexic participants.

Task-specific motor performance and musculoskeletal response in self-classified right handers.

PubMed

Kumar, Sameer; Mandal, Manas K

2003-11-01

We examined the difference between the left and right hand motor performance (in terms of erg produced) of self-classified right handers (15 men, 15 women) for power (task involving muscle force) and skilled (task involving precision and eye hand coordination) tasks. Musculoskeletal response during task performance was measured by electromyogram to test the hypothesis that performance with the nondominant hand would trigger more generalized muscle tension. The difference between the left and right hand performance of men was nonsignificant for power task; for women, right hand performance was significantly superior than left for such task. Men excelled in power and women excelled in skilled tasks relative to their counterparts. Generalized muscle tension was significantly more during the left than the right hand performance for power but not for skilled tasks.

Improving balance by performing a secondary cognitive task.

PubMed

Swan, Laurie; Otani, Hajime; Loubert, Peter V; Sheffert, Sonya M; Dunbar, Gary L

2004-02-01

Contrary to general findings in the attention and memory literature, some studies have shown that performing a secondary cognitive task produces an improvement in balance performance. The purpose of the present experiment was to investigate under what condition such an improvement would occur. Young and older adults were asked to hold as still as possible on a platform that measured sway while performing or not performing the encoding phase of the Brooks' (1967) spatial or non-spatial memory task. The difficulty of maintaining balance was manipulated by varying the availability of visual input and sway-referenced motion of the platform. Sway scores were computed based on the distance between the individual pressure centres and the average centre of pressure during each 20-s trial. The results indicated that both the spatial and non-spatial memory tasks improved balance for older adults under the most difficult balance condition.

Measuring cognitive load: performance, mental effort and simulation task complexity.

PubMed

Haji, Faizal A; Rojas, David; Childs, Ruth; de Ribaupierre, Sandrine; Dubrowski, Adam

2015-08-01

Interest in applying cognitive load theory in health care simulation is growing. This line of inquiry requires measures that are sensitive to changes in cognitive load arising from different instructional designs. Recently, mental effort ratings and secondary task performance have shown promise as measures of cognitive load in health care simulation. We investigate the sensitivity of these measures to predicted differences in intrinsic load arising from variations in task complexity and learner expertise during simulation-based surgical skills training. We randomly assigned 28 novice medical students to simulation training on a simple or complex surgical knot-tying task. Participants completed 13 practice trials, interspersed with computer-based video instruction. On trials 1, 5, 9 and 13, knot-tying performance was assessed using time and movement efficiency measures, and cognitive load was assessed using subjective rating of mental effort (SRME) and simple reaction time (SRT) on a vibrotactile stimulus-monitoring secondary task. Significant improvements in knot-tying performance (F(1.04,24.95)  = 41.1, p < 0.001 for movements; F(1.04,25.90)  = 49.9, p < 0.001 for time) and reduced cognitive load (F(2.3,58.5)  = 57.7, p < 0.001 for SRME; F(1.8,47.3)  = 10.5, p < 0.001 for SRT) were observed in both groups during training. The simple-task group demonstrated superior knot tying (F(1,24)  = 5.2, p = 0.031 for movements; F(1,24)  = 6.5, p = 0.017 for time) and a faster decline in SRME over the first five trials (F(1,26)  = 6.45, p = 0.017) compared with their peers. Although SRT followed a similar pattern, group differences were not statistically significant. Both secondary task performance and mental effort ratings are sensitive to changes in intrinsic load among novices engaged in simulation-based learning. These measures can be used to track cognitive load during skills training. Mental effort ratings are also sensitive to small

Performance monitoring in obsessive-compulsive undergraduates: Effects of task difficulty.

PubMed

Riesel, Anja; Richter, Anika; Kaufmann, Christian; Kathmann, Norbert; Endrass, Tanja

2015-08-01

Both obsessive-compulsive disorder and subclinical obsessive-compulsive (OC) symptoms seem to be associated with hyperactive error-related brain activity. The current study examined performance monitoring in subjects with subclinical OC symptoms using a new task with different levels of difficulty. Nineteen subjects with high and 18 subjects with low OC characteristics performed a random dot cinematogram (RDC) task with three levels of difficulty. The high and low OC groups did not differ in error-related negativity (ERN), correct-related negativity (CRN) and performance irrespective of task difficulty. The amplitude of the ERN decreased with increasing difficulty whereas the magnitude of CRN did not vary. ERN and CRN approached in size and topography with increasing difficulty, which suggests that errors and correct responses are processed more similarly. These results add to a growing number of studies that fail to replicate hyperactive performance monitoring in individuals with OC symptoms in task with higher difficulty or requiring learning. Together with these findings our results suggest that the relationship between OC symptoms and performance monitoring may be sensitive to type of task and task characteristics and cannot be observed in a RDC that differs from typically used tasks in difficulty and the amount of response-conflict. Copyright © 2015 Elsevier Inc. All rights reserved.

Video game performances are preserved in ADHD children compared with controls.

PubMed

Bioulac, Stéphanie; Lallemand, Stéphanie; Fabrigoule, Colette; Thoumy, Anne-Laure; Philip, Pierre; Bouvard, Manuel Pierre

2014-08-01

Although ADHD and excessive video game playing have received some attention, few studies have explored the performances of ADHD children when playing video games. The authors hypothesized that performances of ADHD children would be as good as those of control children in motivating video games tasks but not in the Continuous Performance Test II (CPT II). The sample consisted of 26 ADHD children and 16 control children. Performances of ADHD and control children were compared on three commercially available games, on the repetition of every game, and on the CPT II. ADHD children had lower performances on the CPT II than did controls, but they exhibited equivalent performances to controls when playing video games at both sessions and on all three games. When playing video games, ADHD children present no difference in inhibitory performances compared with control children. This demonstrates that cognitive difficulties in ADHD are task dependent. © 2012 SAGE Publications.

Effects of social incentives on task performance in the elderly.

PubMed

Levendusky, P G

1978-07-01

The performance of 60 elderly volunteers (mean age = 74.5 years) on two cancellation tasks was examined under one of three experimental conditions: social praise, social reproof, or no comment. When compared with the no-comment group, subjects in the reproof condition showed response increments over baseline performance (p less than .05). Praise, when compared with no comment, failed to reach statistical significance. Results are interpreted in terms of the possible negative reinforcement, challenge, or informational properties of reproof. The clear implications from these data are that social incentives may well facilitate behavioral change in the aged and that there is a need for further examination of the effects of this variable.

Characterizing “fibrofog”: Subjective appraisal, objective performance, and task-related brain activity during a working memory task

PubMed Central

Walitt, Brian; Čeko, Marta; Khatiwada, Manish; Gracely, John L.; Rayhan, Rakib; VanMeter, John W.; Gracely, Richard H.

2016-01-01

The subjective experience of cognitive dysfunction (“fibrofog”) is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, “fibrofog” appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks. PMID:26955513

The effects of aging on postural control and selective attention when stepping down while performing a concurrent auditory response task.

PubMed

Tsang, William W N; Lam, Nazca K Y; Lau, Kit N L; Leung, Harry C H; Tsang, Crystal M S; Lu, Xi

2013-12-01

To investigate the effects of aging on postural control and cognitive performance in single- and dual-tasking. A cross-sectional comparative design was conducted in a university motion analysis laboratory. Young adults (n = 30; age 21.9 ± 2.4 years) and older adults (n = 30; age 71.9 ± 6.4 years) were recruited. Postural control after stepping down was measured with and without performing a concurrent auditory response task. Measurement included: (1) reaction time and (2) error rate in performing the cognitive task; (3) total sway path and (4) total sway area after stepping down. Our findings showed that the older adults had significantly longer reaction times and higher error rates than the younger subjects in both the single-tasking and dual-tasking conditions. The older adults had significantly longer reaction times and higher error rates when dual-tasking compared with single-tasking, but the younger adults did not. The older adults demonstrated significantly less total sway path, but larger total sway area in single-leg stance after stepping down than the young adults. The older adults showed no significant change in total sway path and area between the dual-tasking and when compared with single-tasking conditions, while the younger adults showed significant decreases in sway. Older adults prioritize postural control by sacrificing cognitive performance when faced with dual-tasking.

Reduced Electromyographic Fatigue Threshold after Performing a Cognitive Fatiguing Task.

PubMed

Ferris, Justine R; Tomlinson, Mary A; Ward, Tayler N; Pepin, Marie E; Malek, Moh H

2018-02-22

Cognitive fatigue tasks performed prior to exercise may reduce exercise capacity. The electromyographic fatigue threshold (EMGFT) is the highest exercise intensity that can be maintained without significant increase in the EMG amplitude versus time relationship. To date, no studies have examined the effect of cognitive fatigue on the estimation of the EMGFT. The purpose of this study, therefore, was to determine whether or not cognitive fatigue prior to performing exercise reduces the estimated EMGFT. Eight healthy college-aged men were recruited from a university student population and visited the laboratory on multiple occasions. In a randomized order, subjects performed either the cognitive fatigue task (AX Continuous Performance Test; AX-CPT) for 60 min on one visit (experimental condition) or watched a video on trains for 60 min on the other visit (control condition). After each condition, subjects performed the incremental single-leg knee-extensor ergometry test while the EMG amplitude was recorded from the rectus femoris muscle and heart rate was monitored throughout. Thereafter, the EMGFT was calculated for each participant for each visit and compared using paired samples t-test. For exercise outcomes, there were no significant mean differences for maximal power output between the two conditions (control: 51 ± 5 vs. fatigue: 50 ± 3 W), but a significant decrease in EMGFT between the two conditions (control: 31 ± 3 vs. fatigue: 24 ± 2 W; p = 0.013). Moreover, maximal heart rate was significantly different between the two conditions (control: 151 ± 5 vs. fatigue: 132 ± 6; p = 0.027). These results suggest that performing the cognitive fatiguing task reduces the EMGFT with a corresponding reduction in maximal heart rate response.

Aging and Concurrent Task Performance: Cognitive Demand and Motor Control

ERIC Educational Resources Information Center

Albinet, Cedric; Tomporowski, Phillip D.; Beasman, Kathryn

2006-01-01

A motor task that requires fine control of upper limb movements and a cognitive task that requires executive processing--first performing them separately and then concurrently--was performed by 18 young and 18 older adults. The motor task required participants to tap alternatively on two targets, the sizes of which varied systematically. The…

Modeling Task Switching without Switching Tasks: A Short-Term Priming Account of Explicitly Cued Performance

ERIC Educational Resources Information Center

Schneider, Darryl W.; Logan, Gordon D.

2005-01-01

Switch costs in task switching are commonly attributed to an executive control process of task-set reconfiguration, particularly in studies involving the explicit task-cuing procedure. The authors propose an alternative account of explicitly cued performance that is based on 2 mechanisms: priming of cue encoding from residual activation of cues in…

Is performance in task-cuing experiments mediated by task set selection or associative compound retrieval?

PubMed

Forrest, Charlotte L D; Monsell, Stephen; McLaren, Ian P L

2014-07-01

Task-cuing experiments are usually intended to explore control of task set. But when small stimulus sets are used, they plausibly afford learning of the response associated with a combination of cue and stimulus, without reference to tasks. In 3 experiments we presented the typical trials of a task-cuing experiment: a cue (colored shape) followed, after a short or long interval, by a digit to which 1 of 2 responses was required. In a tasks condition, participants were (as usual) directed to interpret the cue as an instruction to perform either an odd/even or a high/low classification task. In a cue + stimulus → response (CSR) condition, to induce learning of mappings between cue-stimulus compound and response, participants were, in Experiment 1, given standard task instructions and additionally encouraged to learn the CSR mappings; in Experiment 2, informed of all the CSR mappings and asked to learn them, without standard task instructions; in Experiment 3, required to learn the mappings by trial and error. The effects of a task switch, response congruence, preparation, and transfer to a new set of stimuli differed substantially between the conditions in ways indicative of classification according to task rules in the tasks condition, and retrieval of responses specific to stimulus-cue combinations in the CSR conditions. Qualitative features of the latter could be captured by an associative learning network. Hence associatively based compound retrieval can serve as the basis for performance with a small stimulus set. But when organization by tasks is apparent, control via task set selection is the natural and efficient strategy. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Task Performance and Meta-Cognitive Outcomes When Using Activity Workstations and Traditional Desks

PubMed Central

Pilcher, June J.; Baker, Victoria C.

2016-01-01

The purpose of the current study is to compare the effects of light physical activity to sedentary behavior on cognitive task performance and meta-cognitive responses. Thirty-eight undergraduate students participated in the study. The participants used a stationary bicycle with a desk top and a traditional desk while completing two complex cognitive tasks and measures of affect, motivation, morale, and engagement. The participants pedaled the stationary bicycle at a slow pace (similar in exertion to a normal walking pace) while working. The results indicated that cognitive task performance did not change between the two workstations. However, positive affect, motivation, and morale improved when using the stationary bicycle. These results suggest that activity workstations could be implemented in the work place and in educational settings to help decrease sedentary behavior without negatively affecting performance. Furthermore, individuals could experience a positive emotional response when working on activity workstations which in turn could help encourage individuals to choose to be more physical active during daily activities. PMID:27445921

Performance-based workload assessment: Allocation strategy and added task sensitivity

NASA Technical Reports Server (NTRS)

Vidulich, Michael A.

1990-01-01

The preliminary results of a research program investigating the use of added tasks to evaluate mental workload are reviewed. The focus of the first studies was a reappraisal of the traditional secondary task logic that encouraged the use of low-priority instructions for the added task. It was believed that such low-priority tasks would encourage subjects to split their available resources among the two tasks. The primary task would be assigned all the resources it needed, and any remaining reserve capacity would be assigned to the secondary task. If the model were correct, this approach was expected to combine sensitivity to primary task difficulty with unintrusiveness to primary task performance. The first studies of the current project demonstrated that a high-priority added task, although intrusive, could be more sensitive than the traditional low-priority secondary task. These results suggested that a more appropriate model of the attentional effects associated with added task performance might be based on capacity switching, rather than the traditional optimal allocation model.

Video-task acquisition in rhesus monkeys (Macaca mulatta) and chimpanzees (Pan troglodytes): a comparative analysis

NASA Technical Reports Server (NTRS)

Hopkins, W. D.; Washburn, D. A.; Hyatt, C. W.; Rumbaugh, D. M. (Principal Investigator)

1996-01-01

This study describes video-task acquisition in two nonhuman primate species. The subjects were seven rhesus monkeys (Macaca mulatta) and seven chimpanzees (Pan troglodytes). All subjects were trained to manipulate a joystick which controlled a cursor displayed on a computer monitor. Two criterion levels were used: one based on conceptual knowledge of the task and one based on motor performance. Chimpanzees and rhesus monkeys attained criterion in a comparable number of trials using a conceptually based criterion. However, using a criterion based on motor performance, chimpanzees reached criterion significantly faster than rhesus monkeys. Analysis of error patterns and latency indicated that the rhesus monkeys had a larger asymmetry in response bias and were significantly slower in responding than the chimpanzees. The results are discussed in terms of the relation between object manipulation skills and video-task acquisition.

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

PubMed

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

2016-11-01

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

Accommodation in Astigmatic Children During Visual Task Performance

PubMed Central

Harvey, Erin M.; Miller, Joseph M.; Apple, Howard P.; Parashar, Pavan; Twelker, J. Daniel; Crescioni, Mabel; Davis, Amy L.; Leonard-Green, Tina K.; Campus, Irene; Sherrill, Duane L.

2014-01-01

Purpose. To determine the accuracy and stability of accommodation in uncorrected children during visual task performance. Methods. Subjects were second- to seventh-grade children from a highly astigmatic population. Measurements of noncycloplegic right eye spherical equivalent (Mnc) were obtained while uncorrected subjects performed three visual tasks at near (40 cm) and distance (2 m). Tasks included reading sentences with stimulus letter size near acuity threshold and an age-appropriate letter size (high task demands) and viewing a video (low task demand). Repeated measures ANOVA assessed the influence of astigmatism, task demand, and accommodative demand on accuracy (mean Mnc) and variability (mean SD of Mnc) of accommodation. Results. For near and distance analyses, respectively, sample size was 321 and 247, mean age was 10.37 (SD 1.77) and 10.30 (SD 1.74) years, mean cycloplegic M was 0.48 (SD 1.10) and 0.79 diopters (D) (SD 1.00), and mean astigmatism was 0.99 (SD 1.15) and 0.75 D (SD 0.96). Poor accommodative accuracy was associated with high astigmatism, low task demand (video viewing), and high accommodative demand. The negative effect of accommodative demand on accuracy increased with increasing astigmatism, with the poorest accommodative accuracy observed in high astigmats (≥3.00 D) with high accommodative demand/high hyperopia (1.53 D and 2.05 D of underaccommodation for near and distant stimuli, respectively). Accommodative variability was greatest in high astigmats and was uniformly high across task condition. No/low and moderate astigmats showed higher variability for the video task than the reading tasks. Conclusions. Accuracy of accommodation is reduced in uncorrected children with high astigmatism and high accommodative demand/high hyperopia, but improves with increased visual task demand (reading). High astigmats showed the greatest variability in accommodation. PMID:25103265

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

The Effects of Self-Esteem and Task Perception on Goal Setting, Efficacy, and Task Performance.

ERIC Educational Resources Information Center

Tang, Thomas Li-Ping; Reynolds, David Bryan

This study examined the effects of self-esteem and task perception on goal setting, efficacy, and task performance in 52 recreational dart throwers who were members of two dart organizations. Task perception was manipulated by asking each dart thrower to compete against self, a difficult competitor, and an easy competitor on the same dart game.…

High-definition television evaluation for remote handling task performance

NASA Astrophysics Data System (ADS)

Fujita, Y.; Omori, E.; Hayashi, S.; Draper, J. V.; Herndon, J. N.

Described are experiments designed to evaluate the impact of HDTV (High-Definition Television) on the performance of typical remote tasks. The experiments described in this paper compared the performance of four operators using HDTV with their performance while using other television systems. The experiments included four television systems: (1) high-definition color television, (2) high-definition monochromatic television, (3) standard-resolution monochromatic television, and (4) standard-resolution stereoscopic monochromatic television. The stereo system accomplished stereoscopy by displaying two cross-polarized images, one reflected by a half-silvered mirror and one seen through the mirror. Observers wore spectacles with cross-polarized lenses so that the left eye received only the view from the left camera and the right eye received only the view from the right camera.

How age affects memory task performance in clinically normal hearing persons.

PubMed

Vercammen, Charlotte; Goossens, Tine; Wouters, Jan; van Wieringen, Astrid

2017-05-01

The main objective of this study is to investigate memory task performance in different age groups, irrespective of hearing status. Data are collected on a short-term memory task (WAIS-III Digit Span forward) and two working memory tasks (WAIS-III Digit Span backward and the Reading Span Test). The tasks are administered to young (20-30 years, n = 56), middle-aged (50-60 years, n = 47), and older participants (70-80 years, n = 16) with normal hearing thresholds. All participants have passed a cognitive screening task (Montreal Cognitive Assessment (MoCA)). Young participants perform significantly better than middle-aged participants, while middle-aged and older participants perform similarly on the three memory tasks. Our data show that older clinically normal hearing persons perform equally well on the memory tasks as middle-aged persons. However, even under optimal conditions of preserved sensory processing, changes in memory performance occur. Based on our data, these changes set in before middle age.

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

PubMed

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

2016-02-01

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

An Experimental Study of Team Size and Performance on a Complex Task.

PubMed

Mao, Andrew; Mason, Winter; Suri, Siddharth; Watts, Duncan J

2016-01-01

The relationship between team size and productivity is a question of broad relevance across economics, psychology, and management science. For complex tasks, however, where both the potential benefits and costs of coordinated work increase with the number of workers, neither theoretical arguments nor empirical evidence consistently favor larger vs. smaller teams. Experimental findings, meanwhile, have relied on small groups and highly stylized tasks, hence are hard to generalize to realistic settings. Here we narrow the gap between real-world task complexity and experimental control, reporting results from an online experiment in which 47 teams of size ranging from n = 1 to 32 collaborated on a realistic crisis mapping task. We find that individuals in teams exerted lower overall effort than independent workers, in part by allocating their effort to less demanding (and less productive) sub-tasks; however, we also find that individuals in teams collaborated more with increasing team size. Directly comparing these competing effects, we find that the largest teams outperformed an equivalent number of independent workers, suggesting that gains to collaboration dominated losses to effort. Importantly, these teams also performed comparably to a field deployment of crisis mappers, suggesting that experiments of the type described here can help solve practical problems as well as advancing the science of collective intelligence.

An Experimental Study of Team Size and Performance on a Complex Task

PubMed Central

Mao, Andrew; Mason, Winter; Suri, Siddharth; Watts, Duncan J.

2016-01-01

The relationship between team size and productivity is a question of broad relevance across economics, psychology, and management science. For complex tasks, however, where both the potential benefits and costs of coordinated work increase with the number of workers, neither theoretical arguments nor empirical evidence consistently favor larger vs. smaller teams. Experimental findings, meanwhile, have relied on small groups and highly stylized tasks, hence are hard to generalize to realistic settings. Here we narrow the gap between real-world task complexity and experimental control, reporting results from an online experiment in which 47 teams of size ranging from n = 1 to 32 collaborated on a realistic crisis mapping task. We find that individuals in teams exerted lower overall effort than independent workers, in part by allocating their effort to less demanding (and less productive) sub-tasks; however, we also find that individuals in teams collaborated more with increasing team size. Directly comparing these competing effects, we find that the largest teams outperformed an equivalent number of independent workers, suggesting that gains to collaboration dominated losses to effort. Importantly, these teams also performed comparably to a field deployment of crisis mappers, suggesting that experiments of the type described here can help solve practical problems as well as advancing the science of collective intelligence. PMID:27082239

Development of task network models of human performance in microgravity

NASA Technical Reports Server (NTRS)

Diaz, Manuel F.; Adam, Susan

1992-01-01

This paper discusses the utility of task-network modeling for quantifying human performance variability in microgravity. The data are gathered for: (1) improving current methodologies for assessing human performance and workload in the operational space environment; (2) developing tools for assessing alternative system designs; and (3) developing an integrated set of methodologies for the evaluation of performance degradation during extended duration spaceflight. The evaluation entailed an analysis of the Remote Manipulator System payload-grapple task performed on many shuttle missions. Task-network modeling can be used as a tool for assessing and enhancing human performance in man-machine systems, particularly for modeling long-duration manned spaceflight. Task-network modeling can be directed toward improving system efficiency by increasing the understanding of basic capabilities of the human component in the system and the factors that influence these capabilities.

Selecting Tasks for Evaluating Human Performance as a Function of Gravity

NASA Technical Reports Server (NTRS)

Norcross, J. R.; Gernhardt, M. L.

2010-01-01

A challenge in understanding human performance as a function of gravity is determining which tasks to research. Initial studies began with treadmill walking, which was easy to quantify and control. However, with the development of pressurized rovers, it is less important to optimize human performance for ambulation as rovers will likely perform gross translation for them. Future crews are likely to spend much of their extravehicular activity (EVA) performing geology, construction and maintenance type tasks, for which it is difficult to measure steady-state-workloads. To evaluate human performance in reduced gravity, we have collected metabolic, biomechanical and subjective data for different tasks at varied gravity levels. Methods: Ten subjects completed 5 different tasks including weight transfer, shoveling, treadmill walking, treadmill running and treadmill incline walking. All tasks were performed shirt-sleeved at 1-g, 3/8-g and 1/6-g. Off-loaded conditions were achieved via the Active Response Gravity Offload System. Treadmill tasks were performed for 3 minutes with reported oxygen consumption (VO2) averaged over the last 2 minutes. Shoveling was performed for 3 minutes with metabolic cost reported as ml O2 consumed per kg material shoveled. Weight transfer reports metabolic cost as liters O2 consumed to complete the task. Statistical analysis was performed via repeated measures ANOVA. Results: Statistically significant metabolic differences were noted between all 3 gravity levels for treadmill running and incline walking. For the other 3 tasks, there were significant differences between 1-g and each reduced gravity, but not between 1/6-g and 3/8-g. For weight transfer, significant differences were seen between gravities in both trial-average VO2 and time-to-completion with noted differences in strategy for task completion. Conclusion: To determine if gravity has a metabolic effect on human performance, this research may indicate that tasks should be selected

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

PubMed Central

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

2017-01-01

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

Video-task assessment of learning and memory in Macaques (Macaca mulatta) - Effects of stimulus movement on performance

NASA Technical Reports Server (NTRS)

Washburn, David A.; Hopkins, William D.; Rumbaugh, Duane M.

1989-01-01

Effects of stimulus movement on learning, transfer, matching, and short-term memory performance were assessed with 2 monkeys using a video-task paradigm in which the animals responded to computer-generated images by manipulating a joystick. Performance on tests of learning set, transfer index, matching to sample, and delayed matching to sample in the video-task paradigm was comparable to that obtained in previous investigations using the Wisconsin General Testing Apparatus. Additionally, learning, transfer, and matching were reliably and significantly better when the stimuli or discriminanda moved than when the stimuli were stationary. External manipulations such as stimulus movement may increase attention to the demands of a task, which in turn should increase the efficiency of learning. These findings have implications for the investigation of learning in other populations, as well as for the application of the video-task paradigm to comparative study.

Subjective and objective quantification of physician's workload and performance during radiation therapy planning tasks.

PubMed

Mazur, Lukasz M; Mosaly, Prithima R; Hoyle, Lesley M; Jones, Ellen L; Marks, Lawrence B

2013-01-01

To quantify, and compare, workload for several common physician-based treatment planning tasks using objective and subjective measures of workload. To assess the relationship between workload and performance to define workload levels where performance could be expected to decline. Nine physicians performed the same 3 tasks on each of 2 cases ("easy" vs "hard"). Workload was assessed objectively throughout the tasks (via monitoring of pupil size and blink rate), and subjectively at the end of each case (via National Aeronautics and Space Administration Task Load Index; NASA-TLX). NASA-TLX assesses the 6 dimensions (mental, physical, and temporal demands, frustration, effort, and performance); scores > or ≈ 50 are associated with reduced performance in other industries. Performance was measured using participants' stated willingness to approve the treatment plan. Differences in subjective and objective workload between cases, tasks, and experience were assessed using analysis of variance (ANOVA). The correlation between subjective and objective workload measures were assessed via the Pearson correlation test. The relationships between workload and performance measures were assessed using the t test. Eighteen case-wise and 54 task-wise assessments were obtained. Subjective NASA-TLX scores (P < .001), but not time-weighted averages of objective scores (P > .1), were significantly lower for the easy vs hard case. Most correlations between the subjective and objective measures were not significant, except between average blink rate and NASA-TLX scores (r = -0.34, P = .02), for task-wise assessments. Performance appeared to decline at NASA-TLX scores of ≥55. The NASA-TLX may provide a reasonable method to quantify subjective workload for broad activities, and objective physiologic eye-based measures may be useful to monitor workload for more granular tasks within activities. The subjective and objective measures, as herein quantified, do not necessarily track each

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

PubMed

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

2017-06-01

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

Attention tasks as skills performance measures of drug effects.

PubMed

Moskowitz, H

1984-01-01

Both empirical epidemiological data on the causes of traffic accidents and conceptual models of skilled human performance stress the central role of perception and cognition. This paper examines the effects of drugs on two major components of cognitive perceptual performance, namely, concentrated attention or vigilance and divided attention. It is demonstrated that these two types of attention tasks are differentially affected by various drugs, so that sometimes one and sometimes another of these tasks is impaired. Various experimental paradigms to investigate these two attention functions are presented. It is demonstrated that attention tasks are frequently highly sensitive to drug effects, suggesting the importance of examining these functions when investigating the effects of drugs on skills performance.

Is Adaptation to Task Complexity Really Beneficial for Performance?

ERIC Educational Resources Information Center

Pieschl, Stephanie; Stahl, Elmar; Murray, Tom; Bromme, Rainer

2012-01-01

Theories of self-regulated learning assume that learners flexibly adapt their learning process to external task demands and that this is positively related to performance. In this study, university students (n = 119) solved three tasks that greatly differed in complexity. Their learning processes were captured in detail by task-specific…

Comparing the Effects of Different Body Armor Systems on the Occupational Performance of Police Officers.

PubMed

Schram, Ben; Orr, Robin; Pope, Rodney; Hinton, Ben; Norris, Geoff

2018-05-01

Policing duties may inherently be dangerous due to stab, blunt trauma and ballistic threats. The addition of individual light armor vests (ILAVs) has been suggested as a means to protect officers. However, the addition of the extra load of the ILAV may affect officer ability to conduct occupational tasks. The purpose of this study was to determine if wearing any of three different ILAVs made by different companies with their preferred materials and designs (ILAV A, 4.68 percent body weight, ILAV B, 4.05 percent body weight, & ILAV C, 3.71 percent body weight) affected occupational task performance when compared to that in normal station wear. A prospective, within-subjects repeated measures design was employed, using a counterbalanced randomization in which each ILAV was worn for an entire day while officers completed a variety of occupationally relevant tasks. These tasks included a victim drag, car exit and 5-meter sprint, step down and marksmanship task. To compare the effects of the ILAVs on these tasks, a multivariate repeated measures analysis of variance (ANOVA) was conducted, with post hoc pairwise comparisons using a Bonferroni adjustment. Results showed that performance in each task did not vary between any of the ILAV or normal station wear conditions. There was less variability in the marksmanship task with ILAV B, however. The results suggest that none of the ILAVs used in this study were heavy enough to significantly affect task performance in the assessed tasks when compared to wearing normal station wear.

Comparing the Effects of Different Body Armor Systems on the Occupational Performance of Police Officers

PubMed Central

Orr, Robin; Hinton, Ben; Norris, Geoff

2018-01-01

Policing duties may inherently be dangerous due to stab, blunt trauma and ballistic threats. The addition of individual light armor vests (ILAVs) has been suggested as a means to protect officers. However, the addition of the extra load of the ILAV may affect officer ability to conduct occupational tasks. The purpose of this study was to determine if wearing any of three different ILAVs made by different companies with their preferred materials and designs (ILAV A, 4.68 percent body weight, ILAV B, 4.05 percent body weight, & ILAV C, 3.71 percent body weight) affected occupational task performance when compared to that in normal station wear. A prospective, within-subjects repeated measures design was employed, using a counterbalanced randomization in which each ILAV was worn for an entire day while officers completed a variety of occupationally relevant tasks. These tasks included a victim drag, car exit and 5-meter sprint, step down and marksmanship task. To compare the effects of the ILAVs on these tasks, a multivariate repeated measures analysis of variance (ANOVA) was conducted, with post hoc pairwise comparisons using a Bonferroni adjustment. Results showed that performance in each task did not vary between any of the ILAV or normal station wear conditions. There was less variability in the marksmanship task with ILAV B, however. The results suggest that none of the ILAVs used in this study were heavy enough to significantly affect task performance in the assessed tasks when compared to wearing normal station wear. PMID:29723995

Selective impairment of masked priming in dual-task performance.

PubMed

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

2011-03-01

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

The Impact of Assessment Tasks on Subsequent Examination Performance

ERIC Educational Resources Information Center

Van Gaal, Frank; De Ridder, Annemieke

2013-01-01

In this article, the impact of assessment tasks on examination result (measured by examination grades) is investigated. Although many describe the advantages of electronic assessment tasks, few studies have been undertaken which compare a traditional approach using a classical examination with a new approach using assessment tasks. The main…

Children's difficulty with true belief tasks: Competence deficit or performance problem?

PubMed

Oktay-Gür, Nese; Rakoczy, Hannes

2017-09-01

According to the standard picture of explicit theory of mind (ToM) development, children begin to (explicitly) ascribe beliefs to others and themselves from around age 4. The empirical basis of this picture comes from numerous studies consistently showing that children master verbal false belief (FB) tasks from around age 4 while children much younger have no difficulty in mastering structurally analogous true belief (TB) tasks. The standard picture, though, has come under serious attack from recent studies using TB tasks with wider age ranges. These studies have found that, paradoxically, children begin to fail TB tasks once they master FB tasks. Such findings cast doubt on the standard picture and suggest, instead, that FB tasks may be solved by much simpler strategies than proper belief reasoning. In the present study, we tested for the development of FB and TB performance in comprehensive and systematic ways. In particular, we tested the competing predictions of competence accounts (according to which TB failure reflects lack of conceptual competence) versus performance limitation accounts (according to which the standard picture is true yet children from around age 4 fail TB tasks due to performance factors). Studies 1 and 2 showed that performance in a variety of novel TB tasks showed a clear U-shaped curve, with children until age 3 and from age 10 performing competently and children in between failing, with strong negative correlations between TB and FB. Crucially, these patterns were found for various kinds of TB tasks, including those for which existing competence limitation accounts would not even predict any difficulty. Study 3, therefore, directly tested performance limitation accounts in terms of pragmatic and related factors and found that these patterns (failure in TB and negative TB-FB correlations) disappear once the relevant performance factors have been removed from the TB tasks. Taken together, these findings suggest that previous TB findings

Circadian Effects on Simple Components of Complex Task Performance

NASA Technical Reports Server (NTRS)

Clegg, Benjamin A.; Wickens, Christopher D.; Vieane, Alex Z.; Gutzwiller, Robert S.; Sebok, Angelia L.

2015-01-01

The goal of this study was to advance understanding and prediction of the impact of circadian rhythm on aspects of complex task performance during unexpected automation failures, and subsequent fault management. Participants trained on two tasks: a process control simulation, featuring automated support; and a multi-tasking platform. Participants then completed one task in a very early morning (circadian night) session, and the other during a late afternoon (circadian day) session. Small effects of time of day were seen on simple components of task performance, but impacts on more demanding components, such as those that occur following an automation failure, were muted relative to previous studies where circadian rhythm was compounded with sleep deprivation and fatigue. Circadian low participants engaged in compensatory strategies, rather than passively monitoring the automation. The findings and implications are discussed in the context of a model that includes the effects of sleep and fatigue factors.

Sensorimotor Rhythm BCI with Simultaneous High Definition-Transcranial Direct Current Stimulation Alters Task Performance.

PubMed

Baxter, Bryan S; Edelman, Bradley J; Nesbitt, Nicholas; He, Bin

Transcranial direct current stimulation (tDCS) has been used to alter the excitability of neurons within the cerebral cortex. Improvements in motor learning have been found in multiple studies when tDCS was applied to the motor cortex before or during task learning. The motor cortex is also active during the performance of motor imagination, a cognitive task during which a person imagines, but does not execute, a movement. Motor imagery can be used with noninvasive brain computer interfaces (BCIs) to control virtual objects in up to three dimensions, but to master control of such devices requires long training times. To evaluate the effect of high-definition tDCS on the performance and underlying electrophysiology of motor imagery based BCI. We utilize high-definition tDCS to investigate the effect of stimulation on motor imagery-based BCI performance across and within sessions over multiple training days. We report a decreased time-to-hit with anodal stimulation both within and across sessions. We also found differing electrophysiological changes of the stimulated sensorimotor cortex during online BCI task performance for left vs. right trials. Cathodal stimulation led to a decrease in alpha and beta band power during task performance compared to sham stimulation for right hand imagination trials. These results suggest that unilateral tDCS over the sensorimotor motor cortex differentially affects cortical areas based on task specific neural activation. Copyright © 2016 Elsevier Inc. All rights reserved.

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…

Time-on-task decrements in "steer clear" performance of patients with sleep apnea and narcolepsy

NASA Technical Reports Server (NTRS)

Findley, L. J.; Suratt, P. M.; Dinges, D. F.

1999-01-01

Loss of attention with time-on-task reflects the increasing instability of the waking state during performance in experimentally induced sleepiness. To determine whether patients with disorders of excessive sleepiness also displayed time-on-task decrements indicative of wake state instability, visual sustained attention performance on "Steer Clear," a computerized simple RT driving simulation task, was compared among 31 patients with untreated sleep apnea, 16 patients with narcolepsy, and 14 healthy control subjects. Vigilance decrement functions were generated by analyzing the number of collisions in each of six four-minute periods of Steer Clear task performance in a mixed-model analysis of variance and linear regression equations. As expected, patients had more Steer Clear collisions than control subjects (p=0.006). However, the inter-subject variability in errors among the narcoleptic patients was four-fold that of the apnea patients, and 100-fold that of the controls volunteers; the variance in errors among untreated apnea patients was 27-times that of controls. The results of transformed collision data revealed main effects for group (p=0.006), time-on-task (p=0.001), and a significant interaction (p=0.022). Control subjects showed no clear evidence of increasing collision errors with time-on-task (adjusted R2=0.22), while apnea patients showed a trend toward vigilance decrement (adjusted R2=0.42, p=0.097), and narcolepsy patients evidenced a robust linear vigilance decrement (adjusted R2=0.87, p=0.004). The association of disorders of excessive somnolence with escalating time-on-task decrements makes it imperative that when assessment of neurobehavioral performance is conducted in patients, it involves task durations and analyses that will evaluate the underlying vulnerability of potentially sleepy patients to decrements over time in tasks that require sustained attention and timely responses, both of which are key components in safe driving performance.

Functional Task Test: 1. Sensorimotor changes Associated with Postflight Alterations in Astronaut Functional Task Performance

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Arzeno, N. H.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Miller, C. A.; Mulavara, A. P.; Platts, S. H.; Peters, B. T.;

Children's mathematical performance: five cognitive tasks across five grades.

PubMed

Moore, Alex M; Ashcraft, Mark H

2015-07-01

Children in elementary school, along with college adults, were tested on a battery of basic mathematical tasks, including digit naming, number comparison, dot enumeration, and simple addition or subtraction. Beyond cataloguing performance to these standard tasks in Grades 1 to 5, we also examined relationships among the tasks, including previously reported results on a number line estimation task. Accuracy and latency improved across grades for all tasks, and classic interaction patterns were found, for example, a speed-up of subitizing and counting, increasingly shallow slopes in number comparison, and progressive speeding of responses especially to larger addition and subtraction problems. Surprisingly, digit naming was faster than subitizing at all ages, arguing against a pre-attentive processing explanation for subitizing. Estimation accuracy and speed were strong predictors of children's addition and subtraction performance. Children who gave exponential responses on the number line estimation task were slower at counting in the dot enumeration task and had longer latencies on addition and subtraction problems. The results provided further support for the importance of estimation as an indicator of children's current and future mathematical expertise. Copyright © 2015 Elsevier Inc. All rights reserved.

Executive and attentional functions in chronic pain: Does performance decrease with increasing task load?

PubMed Central

Oosterman, Joukje M; Derksen, Laura C; van Wijck, Albert JM; Kessels, Roy PC; Veldhuijzen, Dieuwke S

2012-01-01

BACKGROUND: Diminished executive function and attentional control has been reported in chronic pain patients. However, the precise pattern of impairment in these aspects of cognition in chronic pain remains unclear. Moreover, a decline in psychomotor speed could potentially influence executive and attentional control performance in pain patients. OBJECTIVE: To examine different aspects of executive and attentional control in chronic pain together with the confounding role of psychomotor slowing. METHODS: Neuropsychological tests of sustained attention, planning ability, inhibition and mental flexibility were administered to 34 participants with chronic pain and 32 control participants. RESULTS: Compared with the controls, participants with chronic pain took longer to complete tests of sustained attention and mental flexibility, but did not perform worse on inhibition or planning tasks. The decreased performance on the mental flexibility task likely reflects a reduction in psychomotor speed. The pattern of performance on the sustained attention task reveals a specific decline in attention, indicated by a disproportionate decline in performance with an increase in task duration and by increased fluctuations in attention during task performance. No additional effect was noted of pain intensity, pain duration, pain catastrophizing, depressive symptoms, reduced sleep because of the pain or opioid use. CONCLUSIONS: Executive and attention functions are not uniformly affected in chronic pain. At least part of the previously reported decline in executive function in this group may reflect psychomotor slowing. Overall, limited evidence was found that executive and attention performance is indeed lower in chronic pain. Therefore, it can be concluded that in chronic pain sustained attention performance is diminished while mental flexibility, planning and inhibition appear to be intact. PMID:22606680

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

PubMed Central

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

2012-01-01

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

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…

Does Performance on the Standard Antisaccade Task Meet the Co-Familiality Criterion for an Endophenotype?

ERIC Educational Resources Information Center

Levy, Deborah L.; Bowman, Elizabeth A.; Abel, Larry; Krastoshevsky, Olga; Krause, Verena; Mendell, Nancy R.

2008-01-01

The "co-familiality" criterion for an endophenotype has two requirements: (1) clinically unaffected relatives as a group should show both a shift in mean performance and an increase in variance compared with controls; (2) performance scores should be heritable. Performance on the antisaccade task is one of several candidate endophenotypes for…

Method and Apparatus for Performance Optimization Through Physical Perturbation of Task Elements

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III (Inventor); Pope, Alan T. (Inventor); Palsson, Olafur S. (Inventor); Turner, Marsha J. (Inventor)

2016-01-01

The invention is an apparatus and method of biofeedback training for attaining a physiological state optimally consistent with the successful performance of a task, wherein the probability of successfully completing the task is made is inversely proportional to a physiological difference value, computed as the absolute value of the difference between at least one physiological signal optimally consistent with the successful performance of the task and at least one corresponding measured physiological signal of a trainee performing the task. The probability of successfully completing the task is made inversely proportional to the physiological difference value by making one or more measurable physical attributes of the environment in which the task is performed, and upon which completion of the task depends, vary in inverse proportion to the physiological difference value.

Modeling Cognitive Strategies during Complex Task Performing Process

ERIC Educational Resources Information Center

Mazman, Sacide Guzin; Altun, Arif

2012-01-01

The purpose of this study is to examine individuals' computer based complex task performing processes and strategies in order to determine the reasons of failure by cognitive task analysis method and cued retrospective think aloud with eye movement data. Study group was five senior students from Computer Education and Instructional Technologies…

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.

Assessment of the dose reduction potential of a model-based iterative reconstruction algorithm using a task-based performance metrology

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

Samei, Ehsan, E-mail: samei@duke.edu; Richard, Samuel

2015-01-15

Purpose: Different computed tomography (CT) reconstruction techniques offer different image quality attributes of resolution and noise, challenging the ability to compare their dose reduction potential against each other. The purpose of this study was to evaluate and compare the task-based imaging performance of CT systems to enable the assessment of the dose performance of a model-based iterative reconstruction (MBIR) to that of an adaptive statistical iterative reconstruction (ASIR) and a filtered back projection (FBP) technique. Methods: The ACR CT phantom (model 464) was imaged across a wide range of mA setting on a 64-slice CT scanner (GE Discovery CT750 HD,more » Waukesha, WI). Based on previous work, the resolution was evaluated in terms of a task-based modulation transfer function (MTF) using a circular-edge technique and images from the contrast inserts located in the ACR phantom. Noise performance was assessed in terms of the noise-power spectrum (NPS) measured from the uniform section of the phantom. The task-based MTF and NPS were combined with a task function to yield a task-based estimate of imaging performance, the detectability index (d′). The detectability index was computed as a function of dose for two imaging tasks corresponding to the detection of a relatively small and a relatively large feature (1.5 and 25 mm, respectively). The performance of MBIR in terms of the d′ was compared with that of ASIR and FBP to assess its dose reduction potential. Results: Results indicated that MBIR exhibits a variability spatial resolution with respect to object contrast and noise while significantly reducing image noise. The NPS measurements for MBIR indicated a noise texture with a low-pass quality compared to the typical midpass noise found in FBP-based CT images. At comparable dose, the d′ for MBIR was higher than those of FBP and ASIR by at least 61% and 19% for the small feature and the large feature tasks, respectively. Compared to FBP and ASIR

Effects of scaling task constraints on emergent behaviours in children's racquet sports performance.

PubMed

Fitzpatrick, Anna; Davids, Keith; Stone, Joseph A

2018-04-01

Manipulating task constraints by scaling key features like space and equipment is considered an effective method for enhancing performance development and refining movement patterns in sport. Despite this, it is currently unclear whether scaled manipulation of task constraints would impact emergent movement behaviours in young children, affording learners opportunities to develop relevant skills. Here, we sought to investigate how scaling task constraints during 8 weeks of mini tennis training shaped backhand stroke development. Two groups, control (n = 8, age = 7.2 ± 0.6 years) and experimental (n = 8, age 7.4 ± 0.4 years), underwent practice using constraints-based manipulations, with a specific field of affordances designed for backhand strokes as the experimental treatment. To evaluate intervention effects, pre- and post-test match-play characteristics (e.g. forehand and backhand percentage strokes) and measures from a tennis-specific skills test (e.g. forehand and backhand technical proficiency), were evaluated. Post intervention, the experimental group performed a greater percentage of backhand strokes out of total number of shots played (46.7 ± 3.3%). There was also a significantly greater percentage of backhand winners out of total backhand strokes observed (5.5 ± 3.0%), compared to the control group during match-play (backhands = 22.4 ± 6.5%; backhand winners = 1.0 ± 3.6%). The experimental group also demonstrated improvements in forehand and backhand technical proficiency and the ability to maintain a rally with a coach, compared to the control group. In conclusion, scaled manipulations implemented here elicited more functional performance behaviours than standard Mini Tennis Red constraints. Results suggested how human movement scientists may scale task constraint manipulations to augment young athletes' performance development. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Grip type and task goal modify reach-to-grasp performance in post-stroke hemiparesis

PubMed Central

Schaefer, Sydney Y.; DeJong, Stacey L.; Cherry, Kendra M.; Lang, Catherine E.

2011-01-01

This study investigated whether grip type and/or task goal influenced reaching and grasping performance in post-stroke hemiparesis. Sixteen adults with post-stroke hemiparesis and twelve healthy adults reached to and grasped a cylindrical object using one of two grip types (3-finger or palmar) to achieve one of two task goals (hold or lift). Performance of the stroke group was characteristic of hemiparetic limb movement during reach-to-grasp, with more curved handpaths and slower velocities compared to the control group. These effects were present regardless of grip type or task goal. Other measures of reaching (reach time and reach velocity at object contact) and grasping (peak thumb-index finger aperture during the reach and peak grip force during the grasp) were differentially affected by grip type, task goal, or both, despite the presence of hemiparesis, providing new evidence that changes in motor patterns after stroke may occur to compensate for stroke-related motor impairment. PMID:22357103

Grip type and task goal modify reach-to-grasp performance in post-stroke hemiparesis.

PubMed

Schaefer, Sydney Y; DeJong, Stacey L; Cherry, Kendra M; Lang, Catherine E

2012-04-01

This study investigated whether grip type and/or task goal influenced reaching and grasping performance in poststroke hemiparesis. Sixteen adults with poststroke hemiparesis and twelve healthy adults reached to and grasped a cylindrical object using one of two grip types (3-finger or palmar) to achieve one of two task goals (hold or lift). Performance of the stroke group was characteristic of hemiparetic limb movement during reach-to-grasp, with more curved handpaths and slower velocities compared with the control group. These effects were present regardless of grip type or task goal. Other measures of reaching (reach time and reach velocity at object contact) and grasping (peak thumb-index finger aperture during the reach and peak grip force during the grasp) were differentially affected by grip type, task goal, or both, despite the presence of hemiparesis, providing new evidence that changes in motor patterns after stroke may occur to compensate for stroke-related motor impairment.

Autonomy and Task Performance: Explaining the Impact of Grades on Intrinsic Motivation

ERIC Educational Resources Information Center

Pulfrey, Caroline; Darnon, Celine; Butera, Fabrizio

2013-01-01

The use of grades to motivate constitutes an unresolved theoretical controversy. In 2 experiments carried out with different age groups and academic tracks, a standard-grade condition was compared with a condition in which differential scoring engendered higher grades and with a no-grade condition. The relative power of task performance and task…

Using Performance Tasks to Improve Quantitative Reasoning in an Introductory Mathematics Course

ERIC Educational Resources Information Center

Kruse, Gerald; Drews, David

2013-01-01

A full-cycle assessment of our efforts to improve quantitative reasoning in an introductory math course is described. Our initial iteration substituted more open-ended performance tasks for the active learning projects than had been used. Using a quasi-experimental design, we compared multiple sections of the same course and found non-significant…

The Effect of Focus on Form and Task Complexity on L2 Learners' Oral Task Performance

ERIC Educational Resources Information Center

Salimi, Asghar

2015-01-01

Second Language learners' oral task performance has been one of interesting and research generating areas of investigations in the field of second language acquisition specially, task-based language teaching and learning. The main purpose of the present study is to investigate the effect of focus on form and task complexity on L2 learners' oral…

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.

Workload and Performance in Air Traffic Control: Exploring the Influence of Levels of Automation and Variation in Task Demand

NASA Technical Reports Server (NTRS)

Edwards, Tamsyn El; Martin, Lynne; Bienert, Nancy; Mercer, Joey

2017-01-01

In air traffic control, task demand and workload have important implications for the safety and efficiency of air traffic. Task demand is dynamic, however, research on demand transitions and associated controller perception and performance is limited. In addition, there is a comparatively restricted understanding of the influence of task demand transitions on workload and performance, in association with automation. This study used an air traffic control simulation to investigate the influence of task demand transitions and two conditions of varying automation, on workload and efficiency-related performance. Findings showed that a both the direction of the task demand variation, and the amount of automation, influenced the relationship between workload and performance. Further research is needed to enhance understanding of demand transition and workload history effects on operator experience and performance, in both air traffic control and other safety-critical domains.

Using Performance Task Data to Improve Instruction

ERIC Educational Resources Information Center

Abbott, Amy L.; Wren, Douglas G.

2016-01-01

Two well-accepted ideas among educators are (a) performance assessment is an effective means of assessing higher-order thinking skills and (b) data-driven instruction planning is a valuable tool for optimizing student learning. This article describes a locally developed performance task (LDPT) designed to measure critical thinking, problem…

Pointing Device Performance in Steering Tasks.

PubMed

Senanayake, Ransalu; Goonetilleke, Ravindra S

2016-06-01

Use of touch-screen-based interactions is growing rapidly. Hence, knowing the maneuvering efficacy of touch screens relative to other pointing devices is of great importance in the context of graphical user interfaces. Movement time, accuracy, and user preferences of four pointing device settings were evaluated on a computer with 14 participants aged 20.1 ± 3.13 years. It was found that, depending on the difficulty of the task, the optimal settings differ for ballistic and visual control tasks. With a touch screen, resting the arm increased movement time for steering tasks. When both performance and comfort are considered, whether to use a mouse or a touch screen for person-computer interaction depends on the steering difficulty. Hence, a input device should be chosen based on the application, and should be optimized to match the graphical user interface. © The Author(s) 2016.

Manipulating perceptual parameters in a continuous performance task.

PubMed

Shalev, Nir; Humphreys, Glyn; Demeyere, Nele

2018-02-01

Sustained attention (SA) is among the most studied faculties of human cognition, and thought to be crucial for many aspects of behavior. Measuring SA often relies on performance on a continuous, low-demanding task. Such continuous performance tasks (CPTs) have many variations, and sustained attention is typically estimated based on variability in reaction times. While relying on reaction times may be useful in some cases, it can pose a challenge when working with clinical populations. To increase interpersonal variability in task parameters that do not rely on speed, researchers have increased demands for memory and response inhibition. These approaches, however, may be confounded when used to assess populations that suffer from multiple cognitive deficits. In the current study, we propose a new approach for increasing task variability by increasing the attentional demands. In order to do so, we created a new variation of a CPT - a masked version, where inattention is more likely to cause misidentifying a target. After establishing that masking indeed decreases target detection, we further investigated which task parameter may influence response biases. To do so, we contrasted two versions of the CPT with different target/distractor ratio. We then established how perceptual parameters can be controlled independently in a CPT. Following the experimental manipulations, we tested the MCCPT with aging controls and chronic stroke patients to assure the task can be used with target populations. The results confirm the MCCPT as a task providing high sensitivity without relying on reaction speed, and feasible for patients.

Do tasks make a difference? Accounting for heterogeneity of performance of children with reading difficulties on tasks of executive function: findings from a meta-analysis.

PubMed

Booth, Josephine N; Boyle, James M E; Kelly, Steve W

2010-03-01

Research studies have implicated executive functions in reading difficulties (RD). But while some studies have found children with RD to be impaired on tasks of executive function other studies report unimpaired performance. A meta-analysis was carried out to determine whether these discrepant findings can be accounted for by differences in the tasks of executive function that are utilized. A total of 48 studies comparing the performance on tasks of executive function of children with RD with their typically developing peers were included in the meta-analysis, yielding 180 effect sizes. An overall effect size of 0.57 (SE .03) was obtained, indicating that children with RD have impairments on tasks of executive function. However, effect sizes varied considerably suggesting that the impairment is not uniform. Moderator analysis revealed that task modality and IQ-achievement discrepancy definitions of RD influenced the magnitude of effect; however, the age and gender of participants and the nature of the RD did not have an influence. While the children's RD were associated with executive function impairments, variation in effect size is a product of the assessment task employed, underlying task demands, and definitional criteria.

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.

Shift Work and Cognitive Flexibility: Decomposing Task Performance.

PubMed

Cheng, Philip; Tallent, Gabriel; Bender, Thomas John; Tran, Kieulinh Michelle; Drake, Christopher L

2017-04-01

Deficits in cognitive functioning associated with shift work are particularly relevant to occupational performance; however, few studies have examined how cognitive functioning is associated with specific components of shift work. This observational study examined how circadian phase, nocturnal sleepiness, and daytime insomnia in a sample of shift workers ( N = 30) were associated with cognitive flexibility during the night shift. Cognitive flexibility was measured using a computerized task-switching paradigm, which produces 2 indexes of flexibility: switch cost and set inhibition. Switch cost represents the additional cognitive effort required in switching to a different task and can impact performance when multitasking is involved. Set inhibition is the efficiency in returning to previously completed tasks and represents the degree of cognitive perseveration, which can lead to reduced accuracy. Circadian phase was measured via melatonin assays, nocturnal sleepiness was assessed using the Multiple Sleep Latency Test, and daytime insomnia was assessed using the Insomnia Severity Index. Results indicated that those with an earlier circadian phase, insomnia, and sleepiness exhibited reduced cognitive flexibility; however, specific components of cognitive flexibility were differentially associated with circadian phase, insomnia, and sleepiness. Individuals with an earlier circadian phase (thus more misaligned to the night shift) exhibited larger switch costs, which was also associated with reduced task efficiency. Shift workers with more daytime insomnia demonstrated difficulties with cognitive inhibition, whereas nocturnal sleepiness was associated with difficulties in reactivating previous tasks. Deficits in set inhibition were also related to reduced accuracy and increased perseverative errors. Together, this study indicates that task performance deficits in shift work are complex and are variably impacted by different mechanisms. Future research may examine

An opportunity cost model of subjective effort and task performance

PubMed Central

Kurzban, Robert; Duckworth, Angela; Kable, Joseph W.; Myers, Justus

2013-01-01

Why does performing certain tasks cause the aversive experience of mental effort and concomitant deterioration in task performance? One explanation posits a physical resource that is depleted over time. We propose an alternate explanation that centers on mental representations of the costs and benefits associated with task performance. Specifically, certain computational mechanisms, especially those associated with executive function, can be deployed for only a limited number of simultaneous tasks at any given moment. Consequently, the deployment of these computational mechanisms carries an opportunity cost – that is, the next-best use to which these systems might be put. We argue that the phenomenology of effort can be understood as the felt output of these cost/benefit computations. In turn, the subjective experience of effort motivates reduced deployment of these computational mechanisms in the service of the present task. These opportunity cost representations, then, together with other cost/benefit calculations, determine effort expended and, everything else equal, result in performance reductions. In making our case for this position, we review alternate explanations both for the phenomenology of effort associated with these tasks and for performance reductions over time. Likewise, we review the broad range of relevant empirical results from across subdisciplines, especially psychology and neuroscience. We hope that our proposal will help to build links among the diverse fields that have been addressing similar questions from different perspectives, and we emphasize ways in which alternate models might be empirically distinguished. PMID:24304775

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

PubMed

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

2015-01-01

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

Cardiac data increase association between self-report and both expert ratings of task load and task performance in flight simulator tasks: An exploratory study.

PubMed

Lehrer, Paul; Karavidas, Maria; Lu, Shou-En; Vaschillo, Evgeny; Vaschillo, Bronya; Cheng, Andrew

2010-05-01

Seven professional airplane pilots participated in a one-session test in a Boeing 737-800 simulator. Mental workload for 18 flight tasks was rated by experienced test pilots (hereinafter called "expert ratings") and by study participants' self-report on NASA's Task Load Index (TLX) scale. Pilot performance was rated by a check pilot. The standard deviation of R-R intervals (SDNN) significantly added 3.7% improvement over the TLX in distinguishing high from moderate-load tasks and 2.3% improvement in distinguishing high from combined moderate and low-load tasks. Minimum RRI in the task significantly discriminated high- from medium- and low-load tasks, but did not add significant predictive variance to the TLX. The low-frequency/high-frequency (LF:HF) RRI ratio based on spectral analysis of R-R intervals, and ventricular relaxation time were each negatively related to pilot performance ratings independently of TLX values, while minimum and average RRI were positively related, showing added contribution of these cardiac measures for predicting performance. Cardiac results were not affected by controlling either for respiration rate or motor activity assessed by accelerometry. The results suggest that cardiac assessment can be a useful addition to self-report measures for determining flight task mental workload and risk for performance decrements. Replication on a larger sample is needed to confirm and extend the results. Copyright 2010 Elsevier B.V. All rights reserved.

The Effect of Prior Task Success on Older Adults' Memory Performance: Examining the Influence of Different Types of Task Success.

PubMed

Geraci, Lisa; Hughes, Matthew L; Miller, Tyler M; De Forrest, Ross L

2016-01-01

Negative aging stereotypes can lead older adults to perform poorly on memory tests. Yet, memory performance can be improved if older adults have a single successful experience on a cognitive test prior to participating in a memory experiment (Geraci & Miller, 2013, Psychology and Aging, 28, 340-345). The current study examined the effects of different types of prior task experience on subsequent memory performance. Before participating in a verbal free recall experiment, older adults in Experiment 1 successfully completed either a verbal or a visual cognitive task or no task. In Experiment 2, they successfully completed either a motor task or no task before participating in the free recall experiment. Results from Experiment 1 showed that relative to control (no prior task), participants who had prior success, either on a verbal or a visual task, had better subsequent recall performance. Experiment 2 showed that prior success on a motor task, however, did not lead to a later memory advantage relative to control. These findings demonstrate that older adults' memory can be improved by a successful prior task experience so long as that experience is in a cognitive domain.

Motor expertise and performance in spatial tasks: A meta-analysis.

PubMed

Voyer, Daniel; Jansen, Petra

2017-08-01

The present study aimed to provide a summary of findings relevant to the influence of motor expertise on performance in spatial tasks and to examine potential moderators of this effect. Studies of relevance were those in which individuals involved in activities presumed to require motor expertise were compared to non-experts in such activities. A final set of 62 effect sizes from 33 samples was included in a multilevel meta-analysis. The results showed an overall advantage in favor of motor experts in spatial tasks (d=0.38). However, the magnitude of that effect was moderated by expert type (athlete, open skills/ball sports, runner/cyclist, gymnast/dancers, musicians), stimulus type (2D, blocks, bodies, others), test category (mental rotation, spatial perception, spatial visualization), specific test (Mental Rotations Test, generic mental rotation, disembedding, rod-and-frame test, other), and publication status. These findings are discussed in the context of embodied cognition and the potential role of activities requiring motor expertise in promoting good spatial performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Performance Trends During Sleep Deprivation on a Tilt-Based Control Task.

PubMed

Bolkhovsky, Jeffrey B; Ritter, Frank E; Chon, Ki H; Qin, Michael

2018-07-01

Understanding human behavior under the effects of sleep deprivation allows for the mitigation of risk due to reduced performance. To further this goal, this study investigated the effects of short-term sleep deprivation using a tilt-based control device and examined whether existing user models accurately predict targeting performance. A task in which the user tilts a surface to roll a ball into a target was developed to examine motor performance. A model was built to predict human performance for this task under various levels of sleep deprivation. Every 2 h, 10 subjects completed the task until they reached 24 h of wakefulness. Performance measurements of this task, which were based on Fitts' law, included movement time, task throughput, and time intercept. The model predicted significant performance decrements over the 24-h period with an increase in movement time (R2 = 0.61), a decrease in throughput (R2 = 0.57), and an increase in time intercept (R2 = 0.60). However, it was found that in experimental trials there was no significant change in movement time (R2 = 0.11), throughput (R2 = 0.15), or time intercept (R2 = 0.27). The results found were unexpected as performance decrement is frequently reported during sleep deprivation. These findings suggest a reexamination of the initial thought of sleep loss leading to a decrement in all aspects of performance.Bolkovsky JB, Ritter FE, Chon KH, Qin M. Performance trends during sleep deprivation on a tilt-based control task. Aerosp Med Hum Perform. 2018; 89(7):626-633.

Computer Menu Task Performance Model Development

DTIC Science & Technology

1990-11-01

effect that all three of these factors have on menu task performance Results showed that all three factors significantly influenced menu search and...applications. The work was sponsored by the AFHRL Operations Training Division (AFHRL/OT) and performed under Work Unit 1123-34-02, User/System Interface...capabilities effectively are often either not available or configured in a manner that is difficult to use. These findings provided the genesis for the work

Examining Associations between Psychosis Risk, Social Anhedonia, and Performance of Striatum-Related Behavioral Tasks

PubMed Central

Karcher, Nicole R.; Martin, Elizabeth A.; Kerns, John G.

2015-01-01

Both psychosis and anhedonia have been associated to some extent with striatal functioning. The current study examined whether either psychosis risk or social anhedonia was associated with performance on three tasks related to striatal functioning. Psychosis risk participants had extremely elevated Perceptual Aberration/Magical Ideation (PerMag) scores (n=69), with 43% of psychosis risk participants also having semi-structured interview-assessed psychotic-like experiences which further heightens their risk of psychotic disorder (Chapman, Chapman, Kwapil, Eckblad, & Zinser, 1994). Compared to both extremely elevated Social Anhedonia (n=60) and control (n=68) groups, the PerMag group exhibited poorer performance on two of the striatum-related tasks, the Weather Prediction Task (WPT) and the Learned Irrelevance Paradigm, but not on Finger Tapping. In addition, PerMag participants with psychotic-like experiences were especially impaired on the WPT. Overall, this study arguably provides the first evidence that psychosis risk but not social anhedonia is associated with performance on the WPT, a task thought to be strongly associated with activation in the associative striatum, and also suggests that the WPT might be especially useful as a behavioral measure of psychosis risk. PMID:26075968

Examining associations between psychosis risk, social anhedonia, and performance of striatum-related behavioral tasks.

PubMed

Karcher, Nicole R; Martin, Elizabeth A; Kerns, John G

2015-08-01

Both psychosis and anhedonia have been associated to some extent with striatal functioning. The current study examined whether either psychosis risk or social anhedonia was associated with performance on 3 tasks related to striatal functioning. Psychosis risk participants had extremely elevated Perceptual Aberration/Magical Ideation (PerMag) scores (n = 69), with 43% of psychosis risk participants also having semistructured interview-assessed psychotic-like experiences which further heightens their risk of psychotic disorder (Chapman, Chapman, Kwapil, Eckblad, & Zinser, 1994). Compared with both extremely elevated social anhedonia (n = 60) and control (n = 68) groups, the PerMag group exhibited poorer performance on 2 of the striatum-related tasks, the Weather Prediction Task (WPT) and the Learned Irrelevance Paradigm, but not on Finger Tapping. In addition, PerMag participants with psychotic-like experiences were especially impaired on the WPT. Overall, this study arguably provides the first evidence that psychosis risk but not social anhedonia is associated with performance on the WPT, a task thought to be strongly associated with activation in the associative striatum, and also suggests that the WPT might be especially useful as a behavioral measure of psychosis risk. (c) 2015 APA, all rights reserved).

The effects of 2 landing techniques on knee kinematics, kinetics, and performance during stop-jump and side-cutting tasks.

PubMed

Dai, Boyi; Garrett, William E; Gross, Michael T; Padua, Darin A; Queen, Robin M; Yu, Bing

2015-02-01

Anterior cruciate ligament injuries (ACL) commonly occur during jump landing and cutting tasks. Attempts to land softly and land with greater knee flexion are associated with decreased ACL loading. However, their effects on performance are unclear. Attempts to land softly will decrease peak posterior ground-reaction force (PPGRF) and knee extension moment at PPGRF compared with a natural landing during stop-jump and side-cutting tasks. Attempts to land with greater knee flexion at initial ground contact will increase knee flexion at PPGRF compared with a natural landing during both tasks. In addition, both landing techniques will increase stance time and lower extremity mechanical work as well as decrease jump height and movement speed compared with a natural landing during both tasks. Controlled laboratory study. A total of 18 male and 18 female recreational athletes participated in the study. Three-dimensional kinematic and kinetic data were collected during stop-jump and side-cutting tasks under 3 conditions: natural landing, soft landing, and landing with greater knee flexion at initial ground contact. Attempts to land softly decreased PPGRF and knee extension moment at PPGRF compared with a natural landing during stop-jump tasks. Attempts to land softly decreased PPGRF compared with a natural landing during side-cutting tasks. Attempts to land with greater knee flexion at initial ground contact increased knee flexion angle at PPGRF compared with a natural landing during both stop-jump and side-cutting tasks. Attempts to land softly and land with greater knee flexion at initial ground contact increased stance time and lower extremity mechanical work, as well as decreased jump height and movement speed during both stop-jump and side-cutting tasks. Although landing softly and landing with greater knee flexion at initial ground contact may reduce ACL loading during stop-jump and side-cutting tasks, the performance of these tasks decreased, as indicated by

Human problem solving performance in a fault diagnosis task

NASA Technical Reports Server (NTRS)

Rouse, W. B.

1978-01-01

It is proposed that humans in automated systems will be asked to assume the role of troubleshooter or problem solver and that the problems which they will be asked to solve in such systems will not be amenable to rote solution. The design of visual displays for problem solving in such situations is considered, and the results of two experimental investigations of human problem solving performance in the diagnosis of faults in graphically displayed network problems are discussed. The effects of problem size, forced-pacing, computer aiding, and training are considered. Results indicate that human performance deviates from optimality as problem size increases. Forced-pacing appears to cause the human to adopt fairly brute force strategies, as compared to those adopted in self-paced situations. Computer aiding substantially lessens the number of mistaken diagnoses by performing the bookkeeping portions of the task.

Human factors with nonhumans - Factors that affect computer-task performance

NASA Technical Reports Server (NTRS)

Washburn, David A.

1992-01-01

There are two general strategies that may be employed for 'doing human factors research with nonhuman animals'. First, one may use the methods of traditional human factors investigations to examine the nonhuman animal-to-machine interface. Alternatively, one might use performance by nonhuman animals as a surrogate for or model of performance by a human operator. Each of these approaches is illustrated with data in the present review. Chronic ambient noise was found to have a significant but inconsequential effect on computer-task performance by rhesus monkeys (Macaca mulatta). Additional data supported the generality of findings such as these to humans, showing that rhesus monkeys are appropriate models of human psychomotor performance. It is argued that ultimately the interface between comparative psychology and technology will depend on the coordinated use of both strategies of investigation.

Consistency of performance of robot-assisted surgical tasks in virtual reality.

PubMed

Suh, I H; Siu, K-C; Mukherjee, M; Monk, E; Oleynikov, D; Stergiou, N

2009-01-01

The purpose of this study was to investigate consistency of performance of robot-assisted surgical tasks in a virtual reality environment. Eight subjects performed two surgical tasks, bimanual carrying and needle passing, with both the da Vinci surgical robot and a virtual reality equivalent environment. Nonlinear analysis was utilized to evaluate consistency of performance by calculating the regularity and the amount of divergence in the movement trajectories of the surgical instrument tips. Our results revealed that movement patterns for both training tasks were statistically similar between the two environments. Consistency of performance as measured by nonlinear analysis could be an appropriate methodology to evaluate the complexity of the training tasks between actual and virtual environments and assist in developing better surgical training programs.

Effects of noise on the performance of a memory decision response task

NASA Technical Reports Server (NTRS)

Lawton, B. W.

1972-01-01

An investigation has been made to determine the effects of noise on human performance. Fourteen subjects performed a memory-decision-response task in relative quiet and while listening to tape recorded noises. Analysis of the data obtained indicates that performance was degraded in the presence of noise. Significant increases in problem solution times were found for impulsive noise conditions as compared with times found for the no-noise condition. Performance accuracy was also degraded. Significantly more error responses occurred at higher noise levels; a direct or positive relation was found between error responses and noise level experienced by the subjects.

The significance of task significance: Job performance effects, relational mechanisms, and boundary conditions.

PubMed

Grant, Adam M

2008-01-01

Does task significance increase job performance? Correlational designs and confounded manipulations have prevented researchers from assessing the causal impact of task significance on job performance. To address this gap, 3 field experiments examined the performance effects, relational mechanisms, and boundary conditions of task significance. In Experiment 1, fundraising callers who received a task significance intervention increased their levels of job performance relative to callers in 2 other conditions and to their own prior performance. In Experiment 2, task significance increased the job dedication and helping behavior of lifeguards, and these effects were mediated by increases in perceptions of social impact and social worth. In Experiment 3, conscientiousness and prosocial values moderated the effects of task significance on the performance of new fundraising callers. The results provide fresh insights into the effects, relational mechanisms, and boundary conditions of task significance, offering noteworthy implications for theory, research, and practice on job design, social information processing, and work motivation and performance. 2008 APA

The Functional Effect of Teacher Positive and Neutral Affect on Task Performance of Students with Significant Disabilities

ERIC Educational Resources Information Center

Park, Sungho; Singer, George H. S.; Gibson, Mary

2005-01-01

The study uses an alternating treatment design to evaluate the functional effect of teacher's affect on students' task performance. Tradition in special education holds that teachers should engage students using positive and enthusiastic affect for task presentations and praise. To test this assumption, we compared two affective conditions. Three…

The effects of a concurrent task on walking in persons with transfemoral amputation compared to persons without limb loss.

PubMed

Morgan, Sara J; Hafner, Brian J; Kelly, Valerie E

2016-08-01

Many people with lower limb loss report the need to concentrate on walking. This may indicate increased reliance on cognitive resources when walking compared to individuals without limb loss. This study quantified changes in walking associated with addition of a concurrent cognitive task in persons with transfemoral amputation using microprocessor knees compared to age- and sex-matched controls. Observational, cross-sectional study. Quantitative motion analysis was used to assess walking under both single-task (walking alone) and dual-task (walking while performing a cognitive task) conditions. Primary outcomes were walking speed, step width, step time asymmetry, and cognitive task response latency and accuracy. Repeated-measures analysis of variance was used to examine the effects of task (single-task and dual-task) and group (transfemoral amputation and control) for each outcome. No significant interactions between task and group were observed (all p > 0.11) indicating that a cognitive task did not differentially affect walking between groups. However, walking was slower with wider steps and more asymmetry in people with transfemoral amputation compared to controls under both conditions. Although there were significant differences in walking between people with transfemoral amputation and matched controls, the effects of a concurrent cognitive task on walking were similar between groups. The addition of a concurrent task did not differentially affect walking outcomes in people with and without transfemoral amputation. However, compared to people without limb loss, people with transfemoral amputation adopted a conservative walking strategy. This strategy may reduce the need to concentrate on walking but also contributed to notable gait deviations. © The International Society for Prosthetics and Orthotics 2015.

Relationships Among Lower Body Strength, Power, and Performance of Functional Tasks

NASA Technical Reports Server (NTRS)

Ploutz-Snyder, Lori; Ryder, J.; Hackney, K.; Scott-Pandorf, M.; Redd, E.; Buxton, R.; Bloomberg, J.

2010-01-01

There is a large degree of variability among crewmembers with respect to decrements in muscle strength and power following long duration spaceflight, ranging from 0 to approx.30% reductions. The purpose of this study was to investigate the influence of varying decrements in lower body muscle strength and power (relative to body weight) on the performance of 2 occupationally relevant tasks (ladder climb and supine egress & walk). Seventeen participants with leg strength similar to US crewmembers performed a leg press power test, an isokinetic knee extension strength test and they were asked to complete the 2 functional tasks as quickly as possible. On additional test days the participants were asked to repeat the functional tasks under 3 conditions where a different external load was applied each time using a weighted suit in order to experimentally manipulate participants strength/body weight and power/body weight ratios. The weight in the suit ranged from 20-120% of body weight and was distributed in proportion to limb segment weights to minimize changes in center of gravity. The ladder task consisted of climbing 40 rungs on a ladder treadmill as fast as possible. The supine egress & walk task consisted of rising from a supine position and walking through an obstacle course. Results show a relatively linear relationship between strength/body weight and task time and power/body weight with task time such that the fastest performance times are associated with higher strength and power with about half the variance in task time is accounted for by a single variable (either strength or power). For the average person, a 20% reduction in power/body weight (from 18 to 14.4 W/kg) induces an increase (slowing) of about 10 seconds in the ladder climb task from 14 to 24 seconds (approx.70%) and a slowing of the supine egress & walk task from 14 to 21 seconds (approx.50%). Similar relationships were observed with strength/body weight and task performance. For the average

Your brain on speed: cognitive performance of a spatial working memory task is not affected by walking speed

PubMed Central

Kline, Julia E.; Poggensee, Katherine; Ferris, Daniel P.

2014-01-01

When humans walk in everyday life, they typically perform a range of cognitive tasks while they are on the move. Past studies examining performance changes in dual cognitive-motor tasks during walking have produced a variety of results. These discrepancies may be related to the type of cognitive task chosen, differences in the walking speeds studied, or lack of controlling for walking speed. The goal of this study was to determine how young, healthy subjects performed a spatial working memory task over a range of walking speeds. We used high-density electroencephalography to determine if electrocortical activity mirrored changes in cognitive performance across speeds. Subjects stood (0.0 m/s) and walked (0.4, 0.8, 1.2, and 1.6 m/s) with and without performing a Brooks spatial working memory task. We hypothesized that performance of the spatial working memory task and the associated electrocortical activity would decrease significantly with walking speed. Across speeds, the spatial working memory task caused subjects to step more widely compared with walking without the task. This is typically a sign that humans are adapting their gait dynamics to increase gait stability. Several cortical areas exhibited power fluctuations time-locked to memory encoding during the cognitive task. In the somatosensory association cortex, alpha power increased prior to stimulus presentation and decreased during memory encoding. There were small significant reductions in theta power in the right superior parietal lobule and the posterior cingulate cortex around memory encoding. However, the subjects did not show a significant change in cognitive task performance or electrocortical activity with walking speed. These findings indicate that in young, healthy subjects walking speed does not affect performance of a spatial working memory task. These subjects can devote adequate cortical resources to spatial cognition when needed, regardless of walking speed. PMID:24847239

An analysis of functional shoulder movements during task performance using Dartfish movement analysis software.

PubMed

Khadilkar, Leenesh; MacDermid, Joy C; Sinden, Kathryn E; Jenkyn, Thomas R; Birmingham, Trevor B; Athwal, George S

2014-01-01

Video-based movement analysis software (Dartfish) has potential for clinical applications for understanding shoulder motion if functional measures can be reliably obtained. The primary purpose of this study was to describe the functional range of motion (ROM) of the shoulder used to perform a subset of functional tasks. A second purpose was to assess the reliability of functional ROM measurements obtained by different raters using Dartfish software. Ten healthy participants, mean age 29 ± 5 years, were videotaped while performing five tasks selected from the Disabilities of the Arm, Shoulder and Hand (DASH). Video cameras and markers were used to obtain video images suitable for analysis in Dartfish software. Three repetitions of each task were performed. Shoulder movements from all three repetitions were analyzed using Dartfish software. The tracking tool of the Dartfish software was used to obtain shoulder joint angles and arcs of motion. Test-retest and inter-rater reliability of the measurements were evaluated using intraclass correlation coefficients (ICC). Maximum (coronal plane) abduction (118° ± 16°) and (sagittal plane) flexion (111° ± 15°) was observed during 'washing one's hair;' maximum extension (-68° ± 9°) was identified during 'washing one's own back.' Minimum shoulder ROM was observed during 'opening a tight jar' (33° ± 13° abduction and 13° ± 19° flexion). Test-retest reliability (ICC = 0.45 to 0.94) suggests high inter-individual task variability, and inter-rater reliability (ICC = 0.68 to 1.00) showed moderate to excellent agreement. KEY FINDINGS INCLUDE: 1) functional shoulder ROM identified in this study compared to similar studies; 2) healthy individuals require less than full ROM when performing five common ADL tasks 3) high participant variability was observed during performance of the five ADL tasks; and 4) Dartfish software provides a clinically relevant tool to analyze shoulder function.

Co-Constructional Task Analysis: Moving beyond Adult-Based Models to Assess Young Children's Task Performance

ERIC Educational Resources Information Center

Lee, Scott Weng Fai

2013-01-01

The assessment of young children's thinking competence in task performances has typically followed the novice-to-expert regimen involving models of strategies that adults use when engaged in cognitive tasks such as problem-solving and decision-making. Socio-constructivists argue for a balanced pedagogical approach between the adult and child that…

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

PubMed

Aravind, Gayatri; Lamontagne, Anouk

2017-01-01

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

Individual personality differences in goats predict their performance in visual learning and non-associative cognitive tasks.

PubMed

Nawroth, Christian; Prentice, Pamela M; McElligott, Alan G

2017-01-01

Variation in common personality traits, such as boldness or exploration, is often associated with risk-reward trade-offs and behavioural flexibility. To date, only a few studies have examined the effects of consistent behavioural traits on both learning and cognition. We investigated whether certain personality traits ('exploration' and 'sociability') of individuals were related to cognitive performance, learning flexibility and learning style in a social ungulate species, the goat (Capra hircus). We also investigated whether a preference for feature cues rather than impaired learning abilities can explain performance variation in a visual discrimination task. We found that personality scores were consistent across time and context. Less explorative goats performed better in a non-associative cognitive task, in which subjects had to follow the trajectory of a hidden object (i.e. testing their ability for object permanence). We also found that less sociable subjects performed better compared to more sociable goats in a visual discrimination task. Good visual learning performance was associated with a preference for feature cues, indicating personality-dependent learning strategies in goats. Our results suggest that personality traits predict the outcome in visual discrimination and non-associative cognitive tasks in goats and that impaired performance in a visual discrimination tasks does not necessarily imply impaired learning capacities, but rather can be explained by a varying preference for feature cues. Copyright © 2016 Elsevier B.V. All rights reserved.

Functional performance comparison between real and virtual tasks in older adults

PubMed Central

Bezerra, Ítalla Maria Pinheiro; Crocetta, Tânia Brusque; Massetti, Thais; da Silva, Talita Dias; Guarnieri, Regiani; Meira, Cassio de Miranda; Arab, Claudia; de Abreu, Luiz Carlos; de Araujo, Luciano Vieira; Monteiro, Carlos Bandeira de Mello

2018-01-01

Abstract Introduction: Ageing is usually accompanied by deterioration of physical abilities, such as muscular strength, sensory sensitivity, and functional capacity, making chronic diseases, and the well-being of older adults new challenges to global public health. Objective: The purpose of this study was to evaluate whether a task practiced in a virtual environment could promote better performance and enable transfer to the same task in a real environment. Method: The study evaluated 65 older adults of both genders, aged 60 to 82 years (M = 69.6, SD = 6.3). A timing coincident task was applied to measure the perceptual-motor ability to perform a motor response. The participants were divided into 2 groups: started in a real interface and started in a virtual interface. Results: All subjects improved their performance during the practice, but improvement was not observed for the real interface, as the participants were near maximum performance from the beginning of the task. However, there was no transfer of performance from the virtual to real environment or vice versa. Conclusions: The virtual environment was shown to provide improvement of performance with a short-term motor learning protocol in a timing coincident task. This result suggests that the practice of tasks in a virtual environment seems to be a promising tool for the assessment and training of healthy older adults, even though there was no transfer of performance to a real environment. Trial registration: ISRCTN02960165. Registered 8 November 2016. PMID:29369177

Allocation of Attentional Resources toward a Secondary Cognitive Task Leads to Compromised Ankle Proprioceptive Performance in Healthy Young Adults

PubMed Central

Yasuda, Kazuhiro; Iimura, Naoyuki; Iwata, Hiroyasu

2014-01-01

The objective of the present study was to determine whether increased attentional demands influence the assessment of ankle joint proprioceptive ability in young adults. We used a dual-task condition, in which participants performed an ankle ipsilateral position-matching task with and without a secondary serial auditory subtraction task during target angle encoding. Two experiments were performed with two different cohorts: one in which the auditory subtraction task was easy (experiment 1a) and one in which it was difficult (experiment 1b). The results showed that, compared with the single-task condition, participants had higher absolute error under dual-task conditions in experiment 1b. The reduction in position-matching accuracy with an attentionally demanding cognitive task suggests that allocation of attentional resources toward a difficult second task can lead to compromised ankle proprioceptive performance. Therefore, these findings indicate that the difficulty level of the cognitive task might be the possible critical factor that decreased accuracy of position-matching task. We conclude that increased attentional demand with difficult cognitive task does influence the assessment of ankle joint proprioceptive ability in young adults when measured using an ankle ipsilateral position-matching task. PMID:24523966

Effect of task load and task load increment on performance and workload

NASA Technical Reports Server (NTRS)

Hancock, P. A.; Williams, G.

1993-01-01

The goal of adaptive automated task allocation is the 'seamless' transfer of work demand between human and machine. Clearly, at the present time, we are far from this objective. One of the barriers to achieving effortless human-machine symbiosis is an inadequate understanding of the way in which operators themselves seek to reallocate demand among their own personal 'resources.' The paper addresses this through an examination of workload response, which scales an individual's reaction to common levels of experienced external demand. The results indicate the primary driver of performance is the absolute level of task demand over the increment in that demand.

Functional Task Test: 3. Skeletal Muscle Performance Adaptations to Space Flight

NASA Technical Reports Server (NTRS)

Ryder, Jeffrey W.; Wickwire, P. J.; Buxton, R. E.; Bloomberg, J. J.; Ploutz-Snyder, L.

2011-01-01

The functional task test is a multi-disciplinary study investigating how space-flight induced changes to physiological systems impacts functional task performance. Impairment of neuromuscular function would be expected to negatively affect functional performance of crewmembers following exposure to microgravity. This presentation reports the results for muscle performance testing in crewmembers. Functional task performance will be presented in the abstract "Functional Task Test 1: sensory motor adaptations associated with postflight alternations in astronaut functional task performance." METHODS: Muscle performance measures were obtained in crewmembers before and after short-duration space flight aboard the Space Shuttle and long-duration International Space Station (ISS) missions. The battery of muscle performance tests included leg press and bench press measures of isometric force, isotonic power and total work. Knee extension was used for the measurement of central activation and maximal isometric force. Upper and lower body force steadiness control were measured on the bench press and knee extension machine, respectively. Tests were implemented 60 and 30 days before launch, on landing day (Shuttle crew only), and 6, 10 and 30 days after landing. Seven Space Shuttle crew and four ISS crew have completed the muscle performance testing to date. RESULTS: Preliminary results for Space Shuttle crew reveal significant reductions in the leg press performance metrics of maximal isometric force, power and total work on R+0 (p<0.05). Bench press total work was also significantly impaired, although maximal isometric force and power were not significantly affected. No changes were noted for measurements of central activation or force steadiness. Results for ISS crew were not analyzed due to the current small sample size. DISCUSSION: Significant reductions in lower body muscle performance metrics were observed in returning Shuttle crew and these adaptations are likely

The performance of ravens on simple discrimination tasks: a preliminary study

PubMed Central

Range, Friederike; Bugnyar, Thomas; Kotrschal, Kurt

2015-01-01

Recent studies suggest the existence of primate-like cognitive abilities in corvids. Although the learning abilities of corvids in comparison to other species have been investigated before, little is known on how corvids perform on simple discrimination tasks if tested in experimental settings comparable to those that have been used for studying complex cognitive abilities. In this study, we tested a captive group of 12 ravens (Corvus corax) on four discrimination problems and their reversals. In contrast to other studies investigating learning abilities, our ravens were not food deprived and participation in experiments was voluntary. This preliminary study showed that all ravens successfully solved feature and position discriminations and several of the ravens could solve new tasks in a few trials, making very few mistakes. PMID:25948877

The Attentional Boost Effect: Transient increases in attention to one task enhance performance in a second task.

PubMed

Swallow, Khena M; Jiang, Yuhong V

2010-04-01

Recent work on event perception suggests that perceptual processing increases when events change. An important question is how such changes influence the way other information is processed, particularly during dual-task performance. In this study, participants monitored a long series of distractor items for an occasional target as they simultaneously encoded unrelated background scenes. The appearance of an occasional target could have two opposite effects on the secondary task: It could draw attention away from the second task, or, as a change in the ongoing event, it could improve secondary task performance. Results were consistent with the second possibility. Memory for scenes presented simultaneously with the targets was better than memory for scenes that preceded or followed the targets. This effect was observed when the primary detection task involved visual feature oddball detection, auditory oddball detection, and visual color-shape conjunction detection. It was eliminated when the detection task was omitted, and when it required an arbitrary response mapping. The appearance of occasional, task-relevant events appears to trigger a temporal orienting response that facilitates processing of concurrently attended information (Attentional Boost Effect). Copyright 2009 Elsevier B.V. All rights reserved.

The Attentional Boost Effect: Transient Increases in Attention to One Task Enhance Performance in a Second Task

PubMed Central

Swallow, Khena M.; Jiang, Yuhong V.

2009-01-01

Recent work on event perception suggests that perceptual processing increases when events change. An important question is how such changes influence the way other information is processed, particularly during dual-task performance. In this study, participants monitored a long series of distractor items for an occasional target as they simultaneously encoded unrelated background scenes. The appearance of an occasional target could have two opposite effects on the secondary task: It could draw attention away from the second task, or, as a change in the ongoing event, it could improve secondary task performance. Results were consistent with the second possibility. Memory for scenes presented simultaneously with the targets was better than memory for scenes that preceded or followed the targets. This effect was observed when the primary detection task involved visual feature oddball detection, auditory oddball detection, and visual color-shape conjunction detection. It was eliminated when the detection task was omitted, and when it required an arbitrary response mapping. The appearance of occasional, task-relevant events appears to trigger a temporal orienting response that facilitates processing of concurrently attended information (Attentional Boost Effect). PMID:20080232

Performance drifts in two-finger cyclical force production tasks performed by one and two actors.

PubMed

Hasanbarani, Fariba; Reschechtko, Sasha; Latash, Mark L

2018-03-01

We explored changes in the cyclical two-finger force performance task caused by turning visual feedback off performed either by the index and middle fingers of the dominant hand or by two index fingers of two persons. Based on an earlier study, we expected drifts in finger force amplitude and midpoint without a drift in relative phase. The subjects performed two rhythmical tasks at 1 Hz while paced by an auditory metronome. One of the tasks required cyclical changes in total force magnitude without changes in the sharing of the force between the two fingers. The other task required cyclical changes in the force sharing without changing total force magnitude. Subjects were provided with visual feedback, which showed total force magnitude and force sharing via cursor motion along the vertical and horizontal axes, respectively. Further, visual feedback was turned off, first on the variable that was not required to change and then on both variables. Turning visual feedback off led to a mean force drift toward lower magnitudes while force amplitude increased. There was a consistent drift in the relative phase in the one-hand task with the index finger leading the middle finger. No consistent relative phase drift was seen in the two-person tasks. The shape of the force cycle changed without visual feedback reflected in the lower similarity to a perfect cosine shape and in the higher time spent at lower force magnitudes. The data confirm findings of earlier studies regarding force amplitude and midpoint changes, but falsify predictions of an earlier proposed model with respect to the relative phase changes. We discuss factors that could contribute to the observed relative phase drift in the one-hand tasks including the leader-follower pattern generalized for two-effector tasks performed by one person.

The Effect of Secondary Task Engagement on Adolescents' Driving Performance and Crash Risk.

PubMed

Klauer, Sheila G; Ehsani, Johnathon P; McGehee, Daniel V; Manser, Michael

2015-07-01

The purpose of this review was to synthesize the evidence of the effects of secondary task engagement on novice adolescent's driving performance and crash risk. Searches of multiple databases were conducted using search terms related to secondary task engagement and teenage drivers. Articles were selected for inclusion if they were: written in English, an empirical study assessing the impact of secondary task engagement on driving, and included study participants who were licensed drivers between the ages of 14 and 17 years (if research was conducted in the United States) or within 18 months licensure in other countries. Thirty-eight abstracts were reviewed. Fifteen studies met the inclusion criteria. Most studies examined the effects of electronic device use as the secondary task. Effects were assessed using crash databases, simulator, instrumented vehicle, and naturalistic driving studies. Texting resulted in increased lane deviations and eyes off road time in simulated driving, whereas talking on a cell phone had little effect. Naturalistic studies, which use vehicle instrumentation to measure actual driving, found secondary tasks that required drivers to look away from the forward roadway also increased the risk of crashes and near-crashes for young novice drivers, whereas tasks that did not require eyes to be off the forward roadway (e.g., talking on cell phone) had no effect on crash risk. Methodological differences in the definition and measurement of driving performance make it difficult to directly compare findings, even among the limited number of studies conducted. Despite this, results suggest that secondary tasks degrade driving performance and increase risk only when they require drivers to look away from the forward roadway. Future research needs to focus more explicitly on the ways in which secondary task engagement influences drivers' behavior (e.g., interfering with information acquisition or manual control of the vehicle). This, along with the

The effects of age, illustrations, and task variables on the performance of procedural assembly tasks.

PubMed

Morrell, R W; Park, D C

1993-09-01

Older adults may be disadvantaged in the performance of procedural assembly tasks because of age-related declines in working memory operations. It was hypothesized that adding illustrations to instructional text may lessen age-related performance differences by minimizing processing demands on working memory in the elderly. In the present study, younger and older adults constructed a series of 3-dimensional objects from 3 types of instructions (text only, illustration only, or text and illustrations). Results indicated that instructions consisting of text and illustrations reduced errors in construction for both age groups compared with the other formats. Younger adults, however, outperformed older adults under all instructional format conditions. Measures of spatial and verbal working memory and text comprehension ability accounted for substantial age-related variance across the different format conditions but did not fully account for the age differences observed.

The Role of Physical Fitness in the Neurocognitive Performance of Task Switching in Older Persons with Mild Cognitive Impairment.

PubMed

Tsai, Chia-Liang; Pai, Ming-Chyi; Ukropec, Jozef; Ukropcová, Barbara

2016-04-23

Although elderly people with amnestic mild cognitive impairment (aMCI) have been found to show impaired behavioral performance in task switching, no research has yet explored the electrophysiological mechanisms and the potential correlation between physical fitness and neurocognitive (i.e., behavioral and electrophysiological) performance in aMCI. The present study was thus aimed to examine whether there are differences in electrophysiological (i.e., event-related potential) performance between aMCI participants and controls when performing a task-switching paradigm, and to investigate the role of physical fitness in the relationship between neurocognitive performance and aMCI. Sixty participants were classified into aMCI (n = 30) and control (n = 30) groups, and performed a task-switching paradigm with concomitant electrophysiological recording, as well as underwent senior functional physical fitness tests. The aMCI group showed comparable scores on most parts of the physical fitness tests, but reduced lower body flexibility and VO2max as compared to the control group. When performing the task-switching paradigm, the aMCI group showed slower reaction times in the heterogeneous condition and larger global switching costs, although no significant difference was observed in accuracy rates between the two groups. In addition, the aMCI group showed significantly prolonged P3 latencies in the homogeneous and heterogeneous conditions, and a smaller P3 amplitude only in the heterogeneous condition. The level of cardiorespiratory fitness was significantly correlated with P3 amplitude in the aMCI group, particularly in the heterogeneous condition of the task-switching paradigm. These results show that the aMCI group exhibited abnormalities in their neurocognitive performance when performing the task-switching paradigm and such a deficit was likely associated with reduced cardiorespiratory fitness, which was shown to be the important predictor of neurocognitive

Comparing surgical experience with performance on a sinus surgery simulator.

PubMed

Diment, Laura E; Ruthenbeck, Greg S; Dharmawardana, Nuwan; Carney, A Simon; Woods, Charmaine M; Ooi, Eng H; Reynolds, Karen J

2016-12-01

This study evaluates whether surgical experience influences technical competence using the Flinders sinus surgery simulator, a virtual environment designed to teach nasal endoscopic surgical skills. Ten experienced sinus surgeons (five consultants and five registrars) and 14 novices (seven resident medical officers and seven interns/medical students) completed three simulation tasks using haptic controllers. Task 1 required navigation of the sinuses and identification of six anatomical landmarks, Task 2 required removal of unhealthy tissue while preserving healthy tissue and Task 3 entailed backbiting within pre-set lines on the uncinate process and microdebriding tissue between the cuts. Novices were compared with experts on a range of measures, using Mann-Whitney U -tests. Novices took longer on all tasks (Task 1: 278%, P < 0.005; Task 2: 112%, P < 0.005; Task 3: 72%, P < 0.005). In Task 1, novices' instruments travelled further than experts' (379%, P < 0.005), and provided greater maximum force (12%, P < 0.05). In Tasks 2 and 3 novices performed more cutting movements to remove the tissue (Task 2: 1500%, P < 0.005; Task 3: 72%, P < 0.005). Experts also completed more of Task 3 (66%, P < 0.05). The study demonstrated the Flinders sinus simulator's construct validity, differentiating between experts and novices with respect to procedure time, instrument distance travelled and number of cutting motions to complete the task. © 2015 Royal Australasian College of Surgeons.

Increasing Optimism Protects Against Pain-Induced Impairment in Task-Shifting Performance.

PubMed

Boselie, Jantine J L M; Vancleef, Linda M G; Peters, Madelon L

2017-04-01

Persistent pain can lead to difficulties in executive task performance. Three core executive functions that are often postulated are inhibition, updating, and shifting. Optimism, the tendency to expect that good things happen in the future, has been shown to protect against pain-induced performance deterioration in executive function updating. This study tested whether this protective effect of a temporary optimistic state by means of a writing and visualization exercise extended to executive function shifting. A 2 (optimism: optimism vs no optimism) × 2 (pain: pain vs no pain) mixed factorial design was conducted. Participants (N = 61) completed a shifting task once with and once without concurrent painful heat stimulation after an optimism or neutral manipulation. Results showed that shifting performance was impaired when experimental heat pain was applied during task execution, and that optimism counteracted pain-induced deterioration in task-shifting performance. Experimentally-induced heat pain impairs shifting task performance and manipulated optimism or induced optimism counteracted this pain-induced performance deterioration. Identifying psychological factors that may diminish the negative effect of persistent pain on the ability to function in daily life is imperative. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

Temporal prediction errors modulate task-switching performance

PubMed Central

Limongi, Roberto; Silva, Angélica M.; Góngora-Costa, Begoña

2015-01-01

We have previously shown that temporal prediction errors (PEs, the differences between the expected and the actual stimulus’ onset times) modulate the effective connectivity between the anterior cingulate cortex and the right anterior insular cortex (rAI), causing the activity of the rAI to decrease. The activity of the rAI is associated with efficient performance under uncertainty (e.g., changing a prepared behavior when a change demand is not expected), which leads to hypothesize that temporal PEs might disrupt behavior-change performance under uncertainty. This hypothesis has not been tested at a behavioral level. In this work, we evaluated this hypothesis within the context of task switching and concurrent temporal predictions. Our participants performed temporal predictions while observing one moving ball striking a stationary ball which bounced off with a variable temporal gap. Simultaneously, they performed a simple color comparison task. In some trials, a change signal made the participants change their behaviors. Performance accuracy decreased as a function of both the temporal PE and the delay. Explaining these results without appealing to ad hoc concepts such as “executive control” is a challenge for cognitive neuroscience. We provide a predictive coding explanation. We hypothesize that exteroceptive and proprioceptive minimization of PEs would converge in a fronto-basal ganglia network which would include the rAI. Both temporal gaps (or uncertainty) and temporal PEs would drive and modulate this network respectively. Whereas the temporal gaps would drive the activity of the rAI, the temporal PEs would modulate the endogenous excitatory connections of the fronto-striatal network. We conclude that in the context of perceptual uncertainty, the system is not able to minimize perceptual PE, causing the ongoing behavior to finalize and, in consequence, disrupting task switching. PMID:26379568

Temporal prediction errors modulate task-switching performance.

PubMed

Limongi, Roberto; Silva, Angélica M; Góngora-Costa, Begoña

2015-01-01

We have previously shown that temporal prediction errors (PEs, the differences between the expected and the actual stimulus' onset times) modulate the effective connectivity between the anterior cingulate cortex and the right anterior insular cortex (rAI), causing the activity of the rAI to decrease. The activity of the rAI is associated with efficient performance under uncertainty (e.g., changing a prepared behavior when a change demand is not expected), which leads to hypothesize that temporal PEs might disrupt behavior-change performance under uncertainty. This hypothesis has not been tested at a behavioral level. In this work, we evaluated this hypothesis within the context of task switching and concurrent temporal predictions. Our participants performed temporal predictions while observing one moving ball striking a stationary ball which bounced off with a variable temporal gap. Simultaneously, they performed a simple color comparison task. In some trials, a change signal made the participants change their behaviors. Performance accuracy decreased as a function of both the temporal PE and the delay. Explaining these results without appealing to ad hoc concepts such as "executive control" is a challenge for cognitive neuroscience. We provide a predictive coding explanation. We hypothesize that exteroceptive and proprioceptive minimization of PEs would converge in a fronto-basal ganglia network which would include the rAI. Both temporal gaps (or uncertainty) and temporal PEs would drive and modulate this network respectively. Whereas the temporal gaps would drive the activity of the rAI, the temporal PEs would modulate the endogenous excitatory connections of the fronto-striatal network. We conclude that in the context of perceptual uncertainty, the system is not able to minimize perceptual PE, causing the ongoing behavior to finalize and, in consequence, disrupting task switching.

When Task Conflict Becomes Personal: The Impact of Perceived Team Performance.

PubMed

Guenter, Hannes; van Emmerik, Hetty; Schreurs, Bert; Kuypers, Tom; van Iterson, Ad; Notelaers, Guy

2016-10-01

Although potentially beneficial, task conflict may threaten teams because it often leads to relationship conflict. Prior research has identified a set of interpersonal factors (e.g., team communication, team trust) that help attenuate this association. The purpose of this article is to provide an alternative perspective that focuses on the moderating role of performance-related factors (i.e., perceived team performance). Using social identity theory, we build a model that predicts how task conflict associates with growth in relationship conflict and how perceived team performance influences this association. We test a three-wave longitudinal model by means of random coefficient growth modeling, using data from 60 ongoing teams working in a health care organization. Results provide partial support for our hypotheses. Only when perceived team performance is low, do task conflicts relate with growth in relationship conflict. We conclude that perceived team performance seems to enable teams to uncouple task from relationship conflict.

Group social rank is associated with performance on a spatial learning task.

PubMed

Langley, Ellis J G; van Horik, Jayden O; Whiteside, Mark A; Madden, Joah R

2018-02-01

Dominant individuals differ from subordinates in their performances on cognitive tasks across a suite of taxa. Previous studies often only consider dyadic relationships, rather than the more ecologically relevant social hierarchies or networks, hence failing to account for how dyadic relationships may be adjusted within larger social groups. We used a novel statistical method: randomized Elo-ratings, to infer the social hierarchy of 18 male pheasants, Phasianus colchicus , while in a captive, mixed-sex group with a linear hierarchy. We assayed individual learning performance of these males on a binary spatial discrimination task to investigate whether inter-individual variation in performance is associated with group social rank. Task performance improved with increasing trial number and was positively related to social rank, with higher ranking males showing greater levels of success. Motivation to participate in the task was not related to social rank or task performance, thus indicating that these rank-related differences are not a consequence of differences in motivation to complete the task. Our results provide important information about how variation in cognitive performance relates to an individual's social rank within a group. Whether the social environment causes differences in learning performance or instead, inherent differences in learning ability predetermine rank remains to be tested.

Student performance on argumentation task in the Swedish National Assessment in science

NASA Astrophysics Data System (ADS)

Jönsson, Anders

2016-07-01

The aim of this study is to investigate the influence of content knowledge on students' socio-scientific argumentation in the Swedish National Assessment in biology, chemistry and physics for 12-year-olds. In Sweden, the assessment of socio-scientific argumentation has been a major part of the National Assessment during three consecutive years and this study utilizes data on student performance to investigate (a) the relationship between tasks primarily addressing argumentation and tasks addressing primarily content knowledge as well as (b) students' performance on argumentation tasks, which differ in relation to content, subject, aspect of argumentation and assessment criteria. Findings suggest a strong and positive relationship between content knowledge and students' performance on argumentation tasks. The analysis also provides some hypotheses about the task difficulty of argumentation tasks that may be pursued in future investigations.

Cerebellar tDCS does not affect performance in the N-back task.

PubMed

van Wessel, Brenda W V; Claire Verhage, M; Holland, Peter; Frens, Maarten A; van der Geest, Jos N

2016-01-01

The N-back task is widely used in cognitive research. Furthermore, the cerebellum's role in cognitive processes is becoming more widely recognized. Studies using transcranial direct current stimulation (tDCS) have demonstrated effects of cerebellar stimulation on several cognitive tasks. Therefore, the aim of this study was to investigate the effects of cerebellar tDCS on cognitive performance by using the N-back task. The cerebellum of 12 participants was stimulated during the task. Moreover, the cognitive load was manipulated in N = 2, N = 3, and N = 4. Every participant received three tDCS conditions (anodal, cathodal, and sham) divided over three separated days. It was expected that anodal stimulation would improve performance on the task. Each participant performed 6 repetitions of every load in which correct responses, false alarms, and reaction times were recorded. We found significant differences between the three levels of load in the rate of correct responses and false alarms, indicating that subjects followed the expected pattern of performance for the N-back task. However, no significant differences between the three tDCS conditions were found. Therefore, it was concluded that in this study cognitive performance on the N-back task was not readily influenced by cerebellar tDCS, and any true effects are likely to be small. We discuss several limitations in task design and suggest future experiments to address such issues.

Physical Activity Predicts Performance in an Unpracticed Bimanual Coordination Task.

PubMed

Boisgontier, Matthieu P; Serbruyns, Leen; Swinnen, Stephan P

2017-01-01

Practice of a given physical activity is known to improve the motor skills related to this activity. However, whether unrelated skills are also improved is still unclear. To test the impact of physical activity on an unpracticed motor task, 26 young adults completed the international physical activity questionnaire and performed a bimanual coordination task they had never practiced before. Results showed that higher total physical activity predicted higher performance in the bimanual task, controlling for multiple factors such as age, physical inactivity, music practice, and computer games practice. Linear mixed models allowed this effect of physical activity to be generalized to a large population of bimanual coordination conditions. This finding runs counter to the notion that generalized motor abilities do not exist and supports the existence of a "learning to learn" skill that could be improved through physical activity and that impacts performance in tasks that are not necessarily related to the practiced activity.

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

PubMed

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

2017-02-01

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

Dealing with prospective memory demands while performing an ongoing task: Shared processing, increased on-task focus, or both?

PubMed

Rummel, Jan; Smeekens, Bridget A; Kane, Michael J

2017-07-01

Prospective memory (PM) is the cognitive ability to remember to fulfill intended action plans at the appropriate future moment. Current theories assume that PM fulfillment draws on attentional processes. Accordingly, pending PM intentions interfere with other ongoing tasks to the extent to which both tasks rely on the same processes. How do people manage the competition between PM and ongoing-task demands? Based on research relating mind wandering and attentional control (Kane & McVay, 2012), we argue that people may not only change the way they process ongoing-task stimuli when given a PM intention, but they may also engage in less off-task thinking than they otherwise would. That is, people focus more strongly on the tasks at hand and dedicate considerable conscious thought to the PM goal. We tested this hypothesis by asking subjects to periodically report on their thoughts during prototypical PM (and control) tasks. Task-unrelated thought rates dropped when participants performed an ongoing task while holding a PM intention versus performing the ongoing task alone (Experiment 1), even when PM demands were minimized (Experiment 2) and more so when PM execution was especially rewarded (Experiment 3). Our findings suggest that PM demands not only elicit a cost to ongoing-task processing, but they also induce a stronger on-task focus and promote conscious thoughts about the PM intention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

SpaceDock: A Performance Task Platform for Spaceflight Operations

NASA Technical Reports Server (NTRS)

Marshburn, Thomas H.; Strangman, Gary E.; Strauss, Monica S.; Sutton, Jeffrey P.

2003-01-01

Preliminary evidence during both short- and long-duration spaceflight indicates that perceptual-motor coordination changes occur and persist in-flight. However, there is presently no in-flight method for evaluating astronaut performance on mission-critical tasks such as docking. We present a portable platform we have developed for attempting and evaluating docking, and describe the results of a pilot study wherein flight novices learned the docking task. Methods: A dual-joystick, six degrees of freedom platform-called SpaceDock-was developed to enable portable, adaptable performance testing in a spaceflight operations setting. Upon this platform, a simplified docking task was created, involving a constant rate of approach towards a docking target and requiring the user to correct translation in two dimensions and attitude orientation along one dimension (either pitch or roll). Ten flight naive subjects performed the task over a 45 min period and all joystick inputs and timings were collected, from which we could successfully reconstruct travel paths, input profiles and relative target displacements. Results: Subjects exhibited significant improvements in docking over the course of the experiment. Learning to compensate for roll-alterations was robust, whereas compensation for pitch-alterations was not in evidence in this population and relatively short training period. Conclusion: The SpaceDock platform can provide a novel method for training and testing subjects, on a spaceflight-relevant task, and can be used to examine behavioral learning, strategy use, and has been adapted for use in brain imaging experiments.

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

The Independence and Interdependence of Coacting Observers in Regard to Performance Efficiency, Workload, and Stress in a Vigilance Task.

PubMed

Funke, Gregory J; Warm, Joel S; Baldwin, Carryl L; Garcia, Andre; Funke, Matthew E; Dillard, Michael B; Finomore, Victor S; Matthews, Gerald; Greenlee, Eric T

2016-09-01

We investigated performance, workload, and stress in groups of paired observers who performed a vigilance task in a coactive (independent) manner. Previous studies have demonstrated that groups of coactive observers detect more signals in a vigilance task than observers working alone. Therefore, the use of such groups might be effective in enhancing signal detection in operational situations. However, concern over appearing less competent than one's cohort might induce elevated levels of workload and stress in coactive group members and thereby undermine group performance benefits. Accordingly, we performed the initial experiment comparing workload and stress in observers who performed a vigilance task coactively with those of observers who performed the vigilance task alone. Observers monitored a video display for collision flight paths in a simulated unmanned aerial vehicle control task. Self-reports of workload and stress were secured via the NASA-Task Load Index and the Dundee Stress State Questionnaire, respectively. Groups of coactive observers detected significantly more signals than did single observers. Coacting observers did not differ significantly from those operating by themselves in terms of workload but did in regard to stress; posttask distress was significantly lower for coacting than for single observers. Performing a visual vigilance task in a coactive manner with another observer does not elevate workload above that of observers working alone and serves to attenuate the stress associated with vigilance task performance. The use of coacting observers could be an effective vehicle for enhancing performance efficiency in operational vigilance. © 2016, Human Factors and Ergonomics Society.

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)…

Can spectro-temporal complexity explain the autistic pattern of performance on auditory tasks?