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…

Can Spectro-Temporal Complexity Explain the Autistic Pattern of Performance on Auditory Tasks?

ERIC Educational Resources Information Center

Samson, Fabienne; Mottron, Laurent; Jemel, Boutheina; Belin, Pascal; Ciocca, Valter

2006-01-01

To test the hypothesis that level of neural complexity explain the relative level of performance and brain activity in autistic individuals, available behavioural, ERP and imaging findings related to the perception of increasingly complex auditory material under various processing tasks in autism were reviewed. Tasks involving simple material…

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…

Raised visual detection thresholds depend on the level of complexity of cognitive foveal loading.

PubMed

Plainis, S; Murray, I J; Chauhan, K

2001-01-01

The objective of the study was to measure the interactions between visual thresholds for a simple light (the secondary task) presented peripherally and a simultaneously performed cognitive task (the primary task) presented foveally The primary task was highly visible but varied according to its cognitive complexity. Interactions between the tasks were determined by measuring detection thresholds for the peripheral task and accuracy of performance of the foveal task. Effects were measured for 5, 10, 20, and 30 deg eccentricity of the peripherally presented light and for three levels of cognitive complexity. Mesopic conditions (0.5 lx) were used. As expected, the concurrent presentation of the foveal cognitive task reduced peripheral sensitivity. Moreover, performance of the foveal task was adversely affected when conducting the peripheral task. Performance on both tasks was reduced as the level of complexity of the cognitive task increased. There were qualitative differences in task interactions between the central 10 deg and at greater eccentricities. Within 10 deg there was a disproportionate effect of eccentricity, previously interpreted as the 'tunnel-vision' model of visual field narrowing. Interactions outside 10 deg were less affected by eccentricity. These results are discussed in terms of the known neurophysiological characteristics of the primary visual pathway.

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

PubMed

Patel, P; Lamar, M; Bhatt, T

2014-02-28

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

The disruptive effects of pain on multitasking in a virtual errands task.

PubMed

Moore, David J; Law, Anna S

2017-07-01

Pain is known to have a disruptive effect on cognitive performance, but prior studies have used highly constrained laboratory tasks that lack ecological validity. In everyday life people are required to complete more complex sets of tasks, prioritising task completion and recalling lists of tasks which need to be completed, and these tasks continue to be attempted during episodes or states of pain. The present study therefore examined the impact of thermal induced pain on a simulated errand task. Fifty-five healthy adults (36 female) performed the Edinburgh Virtual Errands Task (EVET) either during a painful thermal sensation or with no concurrent pain. Participants also completed the Experience of Cognitive Intrusion of Pain (ECIP) questionnaire to measure their self-reported cognitive impact of pain in general life. Participants who completed the EVET task in pain and who self-reported high intrusion of pain made significantly more errors than those who reported lower intrusion on the ECIP. Findings here support the growing literature that suggests that pain has a significant impact on cognitive performance. Furthermore, these findings support the developing literature suggesting that this relationship is complex when considering real world cognition, and that self-report on the ECIP relates well to performance on a task designed to reflect the complexities of everyday living. If extrapolated to chronic pain populations, these data suggest that pain during complex multitasking performance may have a significant impact on the number of errors made. For people highly vulnerable to cognitive intrusion by pain, this may result in errors such as selecting the wrong location or item to perform tasks, or forgetting to perform these tasks at the correct time. If these findings are shown to extend to chronic pain populations then occupational support to manage complex task performance, using for example diaries/electronic reminders, may help to improve everyday abilities. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

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…

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.

Complex monitoring performance and the coronary-prone Type A behavior pattern.

DOT National Transportation Integrated Search

1986-03-01

The present study examined the possible relationship of the coronary-prone Type A behavior pattern to performance of a complex monitoring task. The task was designed to functionally simulate the general task characteristics of future, highly automate...

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

PubMed

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

2015-08-01

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

Perceived task complexity of trunk stability exercises.

PubMed

McPhee, Megan; Tucker, Kylie J; Wan, Alan; MacDonald, David A

2017-02-01

Perceived task complexity can impact participation in an exercise programme and the level of skill acquisition resulting from participation. Although trunk stability exercises are commonly included in the management of people with low back pain, potential differences in perceived task complexity between those exercises have not been investigated previously. To investigate the perceived task complexity following first time instruction of two common stability exercises: the abdominal brace and abdominal hollow. Cross-sectional. Twenty-four naïve healthy participants received instruction in the performance of an abdominal brace and an abdominal hollow with feedback. Participants rated their perceived task complexity (mental, physical, and temporal demand, performance, effort, frustration) for each exercise on the NASA-Task Load Index. The abdominal hollow was associated with higher perceived mental demand than the abdominal brace (p = 0.01), and required more time to learn (p < 0.01). The abdominal brace was associated with greater mental demand and frustration when performed after the abdominal hollow than before. This study has provided the first evidence for differences in perceived task complexity between two commonly used trunk stability exercises. Those differences in perceived task complexity may influence the selection of exercises intended to enhance the robustness of spinal stability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Planning and task management in Parkinson's disease: differential emphasis in dual-task performance.

PubMed

Bialystok, Ellen; Craik, Fergus I M; Stefurak, Taresa

2008-03-01

Seventeen patients diagnosed with Parkinson's disease completed a complex computer-based task that involved planning and management while also performing an attention-demanding secondary task. The tasks were performed concurrently, but it was necessary to switch from one to the other. Performance was compared to a group of healthy age-matched control participants and a group of young participants. Parkinson's patients performed better than the age-matched controls on almost all measures and as well as the young controls in many cases. However, the Parkinson's patients achieved this by paying relatively less attention to the secondary task and focusing attention more on the primary task. Thus, Parkinson's patients can apparently improve their performance on some aspects of a multidimensional task by simplifying task demands. This benefit may occur as a consequence of their inflexible exaggerated attention to some aspects of a complex task to the relative neglect of other aspects.

Encoding and choice in the task span paradigm.

PubMed

Reiman, Kaitlin M; Weaver, Starla M; Arrington, Catherine M

2015-03-01

Cognitive control during sequences of planned behaviors requires both plan-level processes such as generating, maintaining, and monitoring the plan, as well as task-level processes such as selecting, establishing and implementing specific task sets. The task span paradigm (Logan in J Exp Psychol Gen 133:218-236, 2004) combines two common cognitive control paradigms, task switching and working memory span, to investigate the integration of plan-level and task-level processes during control of sequential behavior. The current study expands past task span research to include measures of encoding processes and choice behavior with volitional sequence generation, using the standard task span as well as a novel voluntary task span paradigm. In two experiments, we consider how sequence complexity, defined separately for plan-level and task-level complexity, influences sequence encoding (Experiment 1), sequence choice (Experiment 2), sequence memory, and task performance of planned sequences of action. Results indicate that participants were sensitive to sequence complexity, but that different aspects of behavior are most strongly influenced by different types of complexity. Hierarchical complexity at the plan level best predicts voluntary sequence generation and memory; while switch frequency at the task level best predicts encoding of externally defined sequences and task performance. Furthermore, performance RTs were similar for externally and internally defined plans, whereas memory was improved for internally defined sequences. Finally, participants demonstrated a significant sequence choice bias in the voluntary task span. Consistent with past research on choice behavior, volitional selection of plans was markedly influenced by both the ease of memory and performance.

Cognitive Task Complexity and Written Output in Italian and French as a Foreign Language

ERIC Educational Resources Information Center

Kuiken, Folkert; Vedder, Ineke

2008-01-01

This paper reports on a study on the relationship between cognitive task complexity and linguistic performance in L2 writing. In the study, two models proposed to explain the influence of cognitive task complexity on linguistic performance in L2 are tested and compared: Skehan and Foster's Limited Attentional Capacity Model (Skehan, 1998; Skehan…

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 performance reward programs, or to match workflow to clinician time and effort.

Task versus relationship conflict, team performance, and team member satisfaction: a meta-analysis.

PubMed

De Dreu, Carsten K W; Weingart, Laurie R

2003-08-01

This study provides a meta-analysis of research on the associations between relationship conflict, task conflict, team performance, and team member satisfaction. Consistent with past theorizing, results revealed strong and negative correlations between relationship conflict, team performance, and team member satisfaction. In contrast to what has been suggested in both academic research and introductory textbooks, however, results also revealed strong and negative (instead of the predicted positive) correlations between task conflict team performance, and team member satisfaction. As predicted, conflict had stronger negative relations with team performance in highly complex (decision making, project, mixed) than in less complex (production) tasks. Finally, task conflict was less negatively related to team performance when task conflict and relationship conflict were weakly, rather than strongly, correlated.

Mind-wandering, cognition, and performance: a theory-driven meta-analysis of attention regulation.

PubMed

Randall, Jason G; Oswald, Frederick L; Beier, Margaret E

2014-11-01

The current meta-analysis accumulates empirical findings on the phenomenon of mind-wandering, integrating and interpreting findings in light of psychological theories of cognitive resource allocation. Cognitive resource theory emphasizes both individual differences in attentional resources and task demands together to predict variance in task performance. This theory motivated our conceptual and meta-analysis framework by introducing moderators indicative of task-demand to predict who is more likely to mind-wander under what conditions, and to predict when mind-wandering and task-related thought are more (or less) predictive of task performance. Predictions were tested via a random-effects meta-analysis of correlations obtained from normal adult samples (k = 88) based on measurement of specified episodes of off-task and/or on-task thought frequency and task performance. Results demonstrated that people with fewer cognitive resources tend to engage in more mind-wandering, whereas those with more cognitive resources are more likely to engage in task-related thought. Addressing predictions of resource theory, we found that greater time-on-task-although not greater task complexity-tended to strengthen the negative relation between cognitive resources and mind-wandering. Additionally, increases in mind-wandering were generally associated with decreases in task performance, whereas increases in task-related thought were associated with increased performance. Further supporting resource theory, the negative relation between mind-wandering and performance was more pronounced for more complex tasks, though not longer tasks. Complementarily, the positive association between task-related thought and performance was stronger for more complex tasks and for longer tasks. We conclude by discussing implications and future research directions for mind-wandering as a construct of interest in psychological research. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

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

Manipulating Cognitive Complexity across Task Types and Its Impact on Learners' Interaction during Oral Performance

ERIC Educational Resources Information Center

Gilabert, Roger; Baron, Julia; Llanes, Angels

2009-01-01

The goal of this study is to investigate the impact of manipulating the cognitive complexity of three different types of oral tasks on interaction. The study first considers the concepts of task complexity and interaction and then examines the specific studies that have looked at the effects of increasing task complexity on conversational…

The Combined Effects of Online Planning and Task Structure on Complexity, Accuracy and Fluency of L2 Speech

ERIC Educational Resources Information Center

Javad Ahmadian, Mohammad; Tavakoli, Mansoor; Vahid Dastjerdi, Hossein

2015-01-01

This study investigates the combined effects of task-based careful online planning and the storyline structure of a task on second language performance (complexity, accuracy and fluency). Sixty intermediate EFL learners were randomly assigned to four groups (n = 15). Participants were asked to perform two tasks with different degrees of storyline…

"One Task Fits All"? The Roles of Task Complexity, Modality, and Working Memory Capacity in L2 Performance

ERIC Educational Resources Information Center

Zalbidea, Janire

2017-01-01

The present study explores the independent and interactive effects of task complexity and task modality on linguistic dimensions of second language (L2) performance and investigates how these effects are modulated by individual differences in working memory capacity. Thirty-two intermediate learners of L2 Spanish completed less and more complex…

Variations in task constraints shape emergent performance outcomes and complexity levels in balancing.

PubMed

Caballero Sánchez, Carla; Barbado Murillo, David; Davids, Keith; Moreno Hernández, Francisco J

2016-06-01

This study investigated the extent to which specific interacting constraints of performance might increase or decrease the emergent complexity in a movement system, and whether this could affect the relationship between observed movement variability and the central nervous system's capacity to adapt to perturbations during balancing. Fifty-two healthy volunteers performed eight trials where different performance constraints were manipulated: task difficulty (three levels) and visual biofeedback conditions (with and without the center of pressure (COP) displacement and a target displayed). Balance performance was assessed using COP-based measures: mean velocity magnitude (MVM) and bivariate variable error (BVE). To assess the complexity of COP, fuzzy entropy (FE) and detrended fluctuation analysis (DFA) were computed. ANOVAs showed that MVM and BVE increased when task difficulty increased. During biofeedback conditions, individuals showed higher MVM but lower BVE at the easiest level of task difficulty. Overall, higher FE and lower DFA values were observed when biofeedback was available. On the other hand, FE reduced and DFA increased as difficulty level increased, in the presence of biofeedback. However, when biofeedback was not available, the opposite trend in FE and DFA values was observed. Regardless of changes to task constraints and the variable investigated, balance performance was positively related to complexity in every condition. Data revealed how specificity of task constraints can result in an increase or decrease in complexity emerging in a neurobiological system during balance performance.

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 Structure of Working Memory Abilities across the Adult Life Span

PubMed Central

Hale, Sandra; Rose, Nathan S.; Myerson, Joel; Strube, Michael J; Sommers, Mitchell; Tye-Murray, Nancy; Spehar, Brent

2010-01-01

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20–89 (n=388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation. PMID:21299306

Developing a Measurement for Task Complexity in Flight.

PubMed

Zheng, Yiyuan; Lu, Yanyu; Wang, Zhen; Huang, Dan; Fu, Shan

2015-08-01

Task complexity is regarded as an essential metric that is related to a pilot's performance and workload. Normally, pilots follow Standard Operating Procedures (SOPs) during a flight. In this study, we developed a measurement named Task Complexity in Flight (TCIF) to represent the task complexity in the SOPs. The TCIF measurement combined four complexity components into one index: actions logic complexity (ALC), actions size complexity (ASC), information control exchange complexity (ICEC), and control mode complexity (CMC).To verify the measurement, we calculated 11 tasks during the takeoff and landing phases from the SOPs, and invited 10 pilots to perform the same tasks in a flight simulator. After flight, the TCIF results were compared with two workload measurements: the Bedford scale and heart rate. The results of TCIF and the 4 components of the 11 tasks were calculated. Further, the TCIF results showed a significant correlation with the Bedford scores (R=0.851) and were also consistent with the difference in heart rate (R=0.816). Therefore, with the increased TCIF results, both the Bedford scale and the difference in heart rate increased. TCIF was proposed based on the flight operating conditions. Although additional studies of TCIF are necessary, the results of this study suggest this measurement could effectively indicate task complexity in flight, and could also be used to guide pilot training and task allocation on the flight deck.

Learner-controlled practice difficulty in the training of a complex task: cognitive and motivational mechanisms.

PubMed

Hughes, Michael G; Day, Eric Anthony; Wang, Xiaoqian; Schuelke, Matthew J; Arsenault, Matthew L; Harkrider, Lauren N; Cooper, Olivia D

2013-01-01

An inherent aspect of learner-controlled instructional environments is the ability of learners to affect the degree of difficulty faced during training. However, research has yet to examine how learner-controlled practice difficulty affects learning. Based on the notion of desirable difficulties (Bjork, 1994), this study examined the cognitive and motivational antecedents and outcomes of learner-controlled practice difficulty in relation to learning a complex task. Using a complex videogame involving both strong cognitive and psychomotor demands, 112 young adult males were given control over their practice difficulty, which was reflected in the complexity of the training task. Results show that general mental ability, prior experience, pre-training self-efficacy, and error encouragement were positively related to learner-controlled practice difficulty. In turn, practice difficulty was directly related to task knowledge and post-training performance, and it was related to adaptive performance through the mediating influences of task knowledge and post-training performance. In general, this study supports the notion that training difficulty operationalized in terms of task complexity is positively related to both knowledge and performance outcomes. Results are discussed with respect to the need for more research examining how task complexity and other forms of difficulty could be leveraged to advance learner-controlled instructional practices. PsycINFO Database Record (c) 2013 APA, all rights reserved.

How students process equations in solving quantitative synthesis problems? Role of mathematical complexity in students' mathematical performance

NASA Astrophysics Data System (ADS)

Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

2017-12-01

We examine students' mathematical performance on quantitative "synthesis problems" with varying mathematical complexity. Synthesis problems are tasks comprising multiple concepts typically taught in different chapters. Mathematical performance refers to the formulation, combination, and simplification of equations. Generally speaking, formulation and combination of equations require conceptual reasoning; simplification of equations requires manipulation of equations as computational tools. Mathematical complexity is operationally defined by the number and the type of equations to be manipulated concurrently due to the number of unknowns in each equation. We use two types of synthesis problems, namely, sequential and simultaneous tasks. Sequential synthesis tasks require a chronological application of pertinent concepts, and simultaneous synthesis tasks require a concurrent application of the pertinent concepts. A total of 179 physics major students from a second year mechanics course participated in the study. Data were collected from written tasks and individual interviews. Results show that mathematical complexity negatively influences the students' mathematical performance on both types of synthesis problems. However, for the sequential synthesis tasks, it interferes only with the students' simplification of equations. For the simultaneous synthesis tasks, mathematical complexity additionally impedes the students' formulation and combination of equations. Several reasons may explain this difference, including the students' different approaches to the two types of synthesis problems, cognitive load, and the variation of mathematical complexity within each synthesis type.

Are we under-utilizing the talents of primary care personnel? A job analytic examination

PubMed Central

Hysong, Sylvia J; Best, Richard G; Moore, Frank I

2007-01-01

Background Primary care staffing decisions are often made unsystematically, potentially leading to increased costs, dissatisfaction, turnover, and reduced quality of care. This article aims to (1) catalogue the domain of primary care tasks, (2) explore the complexity associated with these tasks, and (3) examine how tasks performed by different job titles differ in function and complexity, using Functional Job Analysis to develop a new tool for making evidence-based staffing decisions. Methods Seventy-seven primary care personnel from six US Department of Veterans Affairs (VA) Medical Centers, representing six job titles, participated in two-day focus groups to generate 243 unique task statements describing the content of VA primary care. Certified job analysts rated tasks on ten dimensions representing task complexity, skills, autonomy, and error consequence. Two hundred and twenty-four primary care personnel from the same clinics then completed a survey indicating whether they performed each task. Tasks were catalogued using an adaptation of an existing classification scheme; complexity differences were tested via analysis of variance. Results Objective one: Task statements were categorized into four functions: service delivery (65%), administrative duties (15%), logistic support (9%), and workforce management (11%). Objective two: Consistent with expectations, 80% of tasks received ratings at or below the mid-scale value on all ten scales. Objective three: Service delivery and workforce management tasks received higher ratings on eight of ten scales (multiple functional complexity dimensions, autonomy, human error consequence) than administrative and logistic support tasks. Similarly, tasks performed by more highly trained job titles received higher ratings on six of ten scales than tasks performed by lower trained job titles. Contrary to expectations, the distribution of tasks across functions did not significantly vary by job title. Conclusion Primary care personnel are not being utilized to the extent of their training; most personnel perform many tasks that could reasonably be performed by personnel with less training. Primary care clinics should use evidence-based information to optimize job-person fit, adjusting clinic staff mix and allocation of work across staff to enhance efficiency and effectiveness. PMID:17397534

Students' conceptual performance on synthesis physics problems with varying mathematical complexity

NASA Astrophysics Data System (ADS)

Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

2017-06-01

A body of research on physics problem solving has focused on single-concept problems. In this study we use "synthesis problems" that involve multiple concepts typically taught in different chapters. We use two types of synthesis problems, sequential and simultaneous synthesis tasks. Sequential problems require a consecutive application of fundamental principles, and simultaneous problems require a concurrent application of pertinent concepts. We explore students' conceptual performance when they solve quantitative synthesis problems with varying mathematical complexity. Conceptual performance refers to the identification, follow-up, and correct application of the pertinent concepts. Mathematical complexity is determined by the type and the number of equations to be manipulated concurrently due to the number of unknowns in each equation. Data were collected from written tasks and individual interviews administered to physics major students (N =179 ) enrolled in a second year mechanics course. The results indicate that mathematical complexity does not impact students' conceptual performance on the sequential tasks. In contrast, for the simultaneous problems, mathematical complexity negatively influences the students' conceptual performance. This difference may be explained by the students' familiarity with and confidence in particular concepts coupled with cognitive load associated with manipulating complex quantitative equations. Another explanation pertains to the type of synthesis problems, either sequential or simultaneous task. The students split the situation presented in the sequential synthesis tasks into segments but treated the situation in the simultaneous synthesis tasks as a single event.

Gaze entropy reflects surgical task load.

PubMed

Di Stasi, Leandro L; Diaz-Piedra, Carolina; Rieiro, Héctor; Sánchez Carrión, José M; Martin Berrido, Mercedes; Olivares, Gonzalo; Catena, Andrés

2016-11-01

Task (over-)load imposed on surgeons is a main contributing factor to surgical errors. Recent research has shown that gaze metrics represent a valid and objective index to asses operator task load in non-surgical scenarios. Thus, gaze metrics have the potential to improve workplace safety by providing accurate measurements of task load variations. However, the direct relationship between gaze metrics and surgical task load has not been investigated yet. We studied the effects of surgical task complexity on the gaze metrics of surgical trainees. We recorded the eye movements of 18 surgical residents, using a mobile eye tracker system, during the performance of three high-fidelity virtual simulations of laparoscopic exercises of increasing complexity level: Clip Applying exercise, Cutting Big exercise, and Translocation of Objects exercise. We also measured performance accuracy and subjective rating of complexity. Gaze entropy and velocity linearly increased with increased task complexity: Visual exploration pattern became less stereotyped (i.e., more random) and faster during the more complex exercises. Residents performed better the Clip Applying exercise and the Cutting Big exercise than the Translocation of Objects exercise and their perceived task complexity differed accordingly. Our data show that gaze metrics are a valid and reliable surgical task load index. These findings have potential impacts to improve patient safety by providing accurate measurements of surgeon task (over-)load and might provide future indices to assess residents' learning curves, independently of expensive virtual simulators or time-consuming expert evaluation.

Investigating the Interactions among Genre, Task Complexity, and Proficiency in L2 Writing: A Comprehensive Text Analysis and Study of Learner Perceptions

ERIC Educational Resources Information Center

Yoon, Hyung-Jo

2017-01-01

In this study, I explored the interactions among genre, task complexity, and L2 proficiency in learners' writing task performance. Specifically, after identifying the lack of valid operationalizations of genre and task dimensions in L2 writing research, I examined how genre functions as a task complexity variable, and how learners' perceptions and…

Toward a Learning Science for Complex Crowdsourcing Tasks

ERIC Educational Resources Information Center

Doroudi, Shayan; Kamar, Ece; Brunskill, Emma; Horvitz, Eric

2016-01-01

We explore how crowdworkers can be trained to tackle complex crowdsourcing tasks. We are particularly interested in training novice workers to perform well on solving tasks in situations where the space of strategies is large and workers need to discover and try different strategies to be successful. In a first experiment, we perform a comparison…

The Effects of Mode and Task Complexity on Second Language Production

ERIC Educational Resources Information Center

Vasylets, Olena; Gilabert, Roger; Manchón, Rosa M.

2017-01-01

Taking a psycholinguistic orientation within task-based language teaching scholarship, this study investigated the effects of mode (oral vs. written) and task complexity on second language (L2) performance. The participants were 78 Catalan/Spanish learners of English as a foreign language. Half of the participants performed the simple and complex…

The Impact of Communication Mode and Task Complexity on Small Group Performance and Member Satisfaction.

ERIC Educational Resources Information Center

Carey, Jane M.; Kacmar, Charles, J.

1997-01-01

It is often presumed that software technology will increase group productivity, but this may not be the case. Examines the impact of technology on time-to-complete-task, member satisfaction, perceived information load, number of contributing transactions, and task complexity. Three appendices provide examples of complex and simple tasks and the…

Costs and benefits of integrating information between the cerebral hemispheres: a computational perspective.

PubMed

Belger, A; Banich, M T

1998-07-01

Because interaction of the cerebral hemispheres has been found to aid task performance under demanding conditions, the present study examined how this effect is moderated by computational complexity, the degree of lateralization for a task, and individual differences in asymmetric hemispheric activation (AHA). Computational complexity was manipulated across tasks either by increasing the number of inputs to be processed or by increasing the number of steps to a decision. Comparison of within- and across-hemisphere trials indicated that the size of the between-hemisphere advantage increased as a function of task complexity, except for a highly lateralized rhyme decision task that can only be performed by the left hemisphere. Measures of individual differences in AHA revealed that when task demands and an individual's AHA both load on the same hemisphere, the ability to divide the processing between the hemispheres is limited. Thus, interhemispheric division of processing improves performance at higher levels of computational complexity only when the required operations can be divided between the hemispheres.

Fluid Intelligence Predicts Novel Rule Implementation in a Distributed Frontoparietal Control Network.

PubMed

Tschentscher, Nadja; Mitchell, Daniel; Duncan, John

2017-05-03

Fluid intelligence has been associated with a distributed cognitive control or multiple-demand (MD) network, comprising regions of lateral frontal, insular, dorsomedial frontal, and parietal cortex. Human fluid intelligence is also intimately linked to task complexity, and the process of solving complex problems in a sequence of simpler, more focused parts. Here, a complex target detection task included multiple independent rules, applied one at a time in successive task epochs. Although only one rule was applied at a time, increasing task complexity (i.e., the number of rules) impaired performance in participants of lower fluid intelligence. Accompanying this loss of performance was reduced response to rule-critical events across the distributed MD network. The results link fluid intelligence and MD function to a process of attentional focus on the successive parts of complex behavior. SIGNIFICANCE STATEMENT Fluid intelligence is intimately linked to the ability to structure complex problems in a sequence of simpler, more focused parts. We examine the basis for this link in the functions of a distributed frontoparietal or multiple-demand (MD) network. With increased task complexity, participants of lower fluid intelligence showed reduced responses to task-critical events. Reduced responses in the MD system were accompanied by impaired behavioral performance. Low fluid intelligence is linked to poor foregrounding of task-critical information across a distributed MD system. Copyright © 2017 Tschentscher et al.

Discerning measures of conscious brain processes associated with superior early motor performance: Capacity, coactivation, and character.

PubMed

van Duijn, Tina; Buszard, Tim; Hoskens, Merel C J; Masters, Rich S W

2017-01-01

This study explored the relationship between working memory (WM) capacity, corticocortical communication (EEG coherence), and propensity for conscious control of movement during the performance of a complex far-aiming task. We were specifically interested in the role of these variables in predicting motor performance by novices. Forty-eight participants completed (a) an assessment of WM capacity (an adapted Rotation Span task), (b) a questionnaire that assessed the propensity to consciously control movement (the Movement Specific Reinvestment Scale), and (c) a hockey push-pass task. The hockey push-pass task was performed in a single task (movement only) condition and a combined task (movement plus decision) condition. Electroencephalography (EEG) was used to examine brain activity during the single task. WM capacity best predicted single task performance. WM capacity in combination with T8-Fz coherence (between the visuospatial and motor regions of the brain) best predicted combined task performance. We discuss the implied roles of visuospatial information processing capacity, neural coactivation, and propensity for conscious processing during performance of complex motor tasks. © 2017 Elsevier B.V. All rights reserved.

Is the hand to speech what speech is to the hand?

PubMed

Mildner, V

2000-01-01

Interference between the manual and the verbal performance on two types of concurrent verbal-manual tasks was studied on a sample of 48 female right-handers. The more complex verbal task (storytelling) affected both hands significantly, the less complex (essentially phonemic) task affected only the right hand, with insignificant negative influence on the left-hand performance. No significant reciprocal effects of the motor task on verbalization were found.

Roles of Working Memory Performance and Instructional Strategy in Complex Cognitive Task Performance

ERIC Educational Resources Information Center

Cevik, V.; Altun, A.

2016-01-01

This study aims to investigate how working memory (WM) performances and instructional strategy choices affect learners' complex cognitive task performance in online environments. Three different e-learning environments were designed based on Merrill's (2006a) model of instructional strategies. The lack of experimental research on his framework is…

Syntactic Complexity, Lexical Variation and Accuracy as a Function of Task Complexity and Proficiency Level in L2 Writing and Speaking

ERIC Educational Resources Information Center

Kuiken, Folkert; Vedder, Ineke

2012-01-01

The research project reported in this chapter consists of three studies in which syntactic complexity, lexical variation and fluency appear as dependent variables. The independent variables are task complexity and proficiency level, as the three studies investigate the effect of task complexity on the written and oral performance of L2 learners of…

Intermanual transfer and bilateral cortical plasticity is maintained in older adults after skilled motor training with simple and complex tasks

PubMed Central

Dickins, Daina S. E.; Sale, Martin V.; Kamke, Marc R.

2015-01-01

Intermanual transfer refers to the phenomenon whereby unilateral motor training induces performance gains in both the trained limb and in the opposite, untrained limb. Evidence indicates that intermanual transfer is attenuated in older adults following training on a simple ballistic movement task, but not after training on a complex task. This study investigated whether differences in plasticity in bilateral motor cortices underlie these differential intermanual transfer effects in older adults. Twenty young (<35 years-old) and older adults (>65 years) trained on a simple (repeated ballistic thumb abduction) and complex (sequential finger-thumb opposition) task in separate sessions. Behavioral performance was used to quantify intermanual transfer between the dominant (trained) and non-dominant (untrained) hands. The amplitude of motor-evoked potentials induced by single pulse transcranial magnetic stimulation was used to investigate excitability changes in bilateral motor cortices. Contrary to predictions, both age groups exhibited performance improvements in both hands after unilateral skilled motor training with simple and complex tasks. These performance gains were accompanied by bilateral increases in cortical excitability in both groups for the simple but not the complex task. The findings suggest that advancing age does not necessarily influence the capacity for intermanual transfer after training with the dominant hand. PMID:25999856

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.

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 noise frequency on performance and annoyance for women and men

NASA Technical Reports Server (NTRS)

Key, K. F.; Payne, M. C., Jr.

1981-01-01

Effects of noise frequencies on both performance on a complex psychomotor task and annoyance were investigated for men (n = 30) and women (n = 30). Each subject performed a complex psychomotor task for 50 min in the presence of low-frequency noise, high-frequency noise, or ambient noise. Women and men learned the task at different rates. Little effect of noise was shown. Annoyance ratings were subsequently obtained from each subject for noises of various frequencies by the method of magnitude estimation. High-frequency noises were more annoying than low-frequency noises regardless of sex and immediate prior exposure to noise. Sex differences in annoyance did not occur. No direct relationship between learning to perform a complex task while exposed to noise and annoyance by that noise was demonstrated.

Disruption of self-organized actions in monkeys with progressive MPTP-induced parkinsonism. I. Effects of task complexity.

PubMed

Pessiglione, Mathias; Guehl, Dominique; Hirsch, Etienne C; Féger, Jean; Tremblay, Léon

2004-01-01

Parkinson's disease (PD) is characterized by motor symptoms, usually accompanied by cognitive deficits. The question addressed in this study is whether complexity of routine actions can exacerbate parkinsonian disorders that are often considered to be motor symptoms. To examine this question, we trained four vervet monkeys (Cercopithecus aethiops) to perform three multiple-choice retrieval tasks. In order of ascending complexity, rewards were freely available (task 1), covered with transparent sliding plaques (task 2), and covered with opaque sliding plaques cued by symbols (task 3). Thus, from task 1 to task 2 we added a motor difficulty--the recall of context-adapted movement; and from task 2 to task 3 we added a cognitive difficulty: the recall of symbol-reward associations. The more complex the task, the longer it took to learn, but after extensive training the performance was stable in all tasks, with similar retrieval durations. The monkeys then received systemic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) injections (0.3-0.4 mg/kg) every 4-7 days, until the first motor symptoms appeared. In the course of MPTP intoxication, the behavioural performance declined while the motor symptoms were absent or mild--the retrieval duration increased, and non-initiated choices and hesitations between choices became frequent. Interestingly, this decline was in proportion to task complexity, and was particularly pronounced with the cognitive difficulty. Furthermore, freezing appeared only with the cognitive difficulty. We therefore suggest that everyday cognitive difficulties may exacerbate hypokinesia (lack of initiation, abnormal slowness) and executive disorders (hesitations, freezing) in the early stages of human PD.

Rule induction performance in amnestic mild cognitive impairment and Alzheimer's dementia: examining the role of simple and biconditional rule learning processes.

PubMed

Oosterman, Joukje M; Heringa, Sophie M; Kessels, Roy P C; Biessels, Geert Jan; Koek, Huiberdina L; Maes, Joseph H R; van den Berg, Esther

2017-04-01

Rule induction tests such as the Wisconsin Card Sorting Test require executive control processes, but also the learning and memorization of simple stimulus-response rules. In this study, we examined the contribution of diminished learning and memorization of simple rules to complex rule induction test performance in patients with amnestic mild cognitive impairment (aMCI) or Alzheimer's dementia (AD). Twenty-six aMCI patients, 39 AD patients, and 32 control participants were included. A task was used in which the memory load and the complexity of the rules were independently manipulated. This task consisted of three conditions: a simple two-rule learning condition (Condition 1), a simple four-rule learning condition (inducing an increase in memory load, Condition 2), and a complex biconditional four-rule learning condition-inducing an increase in complexity and, hence, executive control load (Condition 3). Performance of AD patients declined disproportionately when the number of simple rules that had to be memorized increased (from Condition 1 to 2). An additional increment in complexity (from Condition 2 to 3) did not, however, disproportionately affect performance of the patients. Performance of the aMCI patients did not differ from that of the control participants. In the patient group, correlation analysis showed that memory performance correlated with Condition 1 performance, whereas executive task performance correlated with Condition 2 performance. These results indicate that the reduced learning and memorization of underlying task rules explains a significant part of the diminished complex rule induction performance commonly reported in AD, although results from the correlation analysis suggest involvement of executive control functions as well. Taken together, these findings suggest that care is needed when interpreting rule induction task performance in terms of executive function deficits in these patients.

Development and evaluation of a predictive algorithm for telerobotic task complexity

NASA Technical Reports Server (NTRS)

Gernhardt, M. L.; Hunter, R. C.; Hedgecock, J. C.; Stephenson, A. G.

1993-01-01

There is a wide range of complexity in the various telerobotic servicing tasks performed in subsea, space, and hazardous material handling environments. Experience with telerobotic servicing has evolved into a knowledge base used to design tasks to be 'telerobot friendly.' This knowledge base generally resides in a small group of people. Written documentation and requirements are limited in conveying this knowledge base to serviceable equipment designers and are subject to misinterpretation. A mathematical model of task complexity based on measurable task parameters and telerobot performance characteristics would be a valuable tool to designers and operational planners. Oceaneering Space Systems and TRW have performed an independent research and development project to develop such a tool for telerobotic orbital replacement unit (ORU) exchange. This algorithm was developed to predict an ORU exchange degree of difficulty rating (based on the Cooper-Harper rating used to assess piloted operations). It is based on measurable parameters of the ORU, attachment receptacle and quantifiable telerobotic performance characteristics (e.g., link length, joint ranges, positional accuracy, tool lengths, number of cameras, and locations). The resulting algorithm can be used to predict task complexity as the ORU parameters, receptacle parameters, and telerobotic characteristics are varied.

Automatic Assessment of Complex Task Performance in Games and Simulations. CRESST Report 775

ERIC Educational Resources Information Center

Iseli, Markus R.; Koenig, Alan D.; Lee, John J.; Wainess, Richard

2010-01-01

Assessment of complex task performance is crucial to evaluating personnel in critical job functions such as Navy damage control operations aboard ships. Games and simulations can be instrumental in this process, as they can present a broad range of complex scenarios without involving harm to people or property. However, "automatic"…

Task Complexity and Modality: Exploring Learners' Experience from the Perspective of Flow

ERIC Educational Resources Information Center

Cho, Minyoung

2018-01-01

Despite an increased awareness of language learner performance in task-based instruction, little is known about how learners perceive and respond to different task factors. This study investigates the effects of task complexity and modality on (a) learners' perception of task difficulty, skill, and its balance, and on (b) learners' task…

POPEYE: A production rule-based model of multitask supervisory control (POPCORN)

NASA Technical Reports Server (NTRS)

Townsend, James T.; Kadlec, Helena; Kantowitz, Barry H.

1988-01-01

Recent studies of relationships between subjective ratings of mental workload, performance, and human operator and task characteristics have indicated that these relationships are quite complex. In order to study the various relationships and place subjective mental workload within a theoretical framework, we developed a production system model for the performance component of the complex supervisory task called POPCORN. The production system model is represented by a hierarchial structure of goals and subgoals, and the information flow is controlled by a set of condition-action rules. The implementation of this production system, called POPEYE, generates computer simulated data under different task difficulty conditions which are comparable to those of human operators performing the task. This model is the performance aspect of an overall dynamic psychological model which we are developing to examine and quantify relationships between performance and psychological aspects in a complex environment.

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.

The composite complex span: French validation of a short working memory task.

PubMed

Gonthier, Corentin; Thomassin, Noémylle; Roulin, Jean-Luc

2016-03-01

Most studies in individual differences in the field of working memory research use complex span tasks to measure working memory capacity. Various complex span tasks based on different materials have been developed, and these tasks have proven both reliable and valid; several complex span tasks are often combined to provide a domain-general estimate of working memory capacity with even better psychometric properties. The present work sought to address two issues. Firstly, having participants perform several full-length complex span tasks in succession makes for a long and tedious procedure. Secondly, few complex span tasks have been translated and validated in French. We constructed a French working memory task labeled the Composite Complex Span (CCS). The CCS includes shortened versions of three classic complex span tasks: the reading span, symmetry span, and operation span. We assessed the psychometric properties of the CCS, including test-retest reliability and convergent validity, with Raven's Advanced Progressive Matrices and with an alpha span task; the CCS demonstrated satisfying qualities in a sample of 1,093 participants. This work provides evidence that shorter versions of classic complex span tasks can yield valid working memory estimates. The materials and normative data for the CCS are also included.

Effects of Task Planning and Rhetorical Mode of Writing on Lexical Complexity, Syntactic Complexity, and Overall Writing Quality of EFL Writers' Task Performance

ERIC Educational Resources Information Center

Yildiz, Mine; Yesilyurt, Savas

2017-01-01

Based on Robinson's Triadic Componential Framework and the definition of task planning by Ellis (2005), this study was carried out to find out the effects of task planning and rhetorical mode on lexical and syntactic complexity, and overall writing quality of writing production of EFL learners. Following a repeated-measures design, the present…

Motor performance of tongue with a computer-integrated system under different levels of background physical exertion

PubMed Central

Huo, Xueliang; Johnson-Long, Ashley N.; Ghovanloo, Maysam; Shinohara, Minoru

2015-01-01

The purpose of this study was to compare the motor performance of tongue, using Tongue Drive System, to hand operation for relatively complex tasks under different levels of background physical exertion. Thirteen young able-bodied adults performed tasks that tested the accuracy and variability in tracking a sinusoidal waveform, and the performance in playing two video games that require accurate and rapid movements with cognitive processing using tongue and hand under two levels of background physical exertion. Results show additional background physical activity did not influence rapid and accurate displacement motor performance, but compromised the slow waveform tracking and shooting performances in both hand and tongue. Slow waveform tracking performance by the tongue was compromised with an additional motor or cognitive task, but with an additional motor task only for the hand. Practitioner Summary We investigated the influence of task complexity and background physical exertion on the motor performance of tongue and hand. Results indicate the task performance degrades with an additional concurrent task or physical exertion due to the limited attentional resources available for handling both the motor task and background exertion. PMID:24003900

Deficits of long-term memory in ecstasy users are related to cognitive complexity of the task.

PubMed

Brown, John; McKone, Elinor; Ward, Jeff

2010-03-01

Despite animal evidence that methylenedioxymethamphetamine (ecstasy) causes lasting damage in brain regions related to long-term memory, results regarding human memory performance have been variable. This variability may reflect the cognitive complexity of the memory tasks. However, previous studies have tested only a limited range of cognitive complexity. Furthermore, comparisons across different studies are made difficult by regional variations in ecstasy composition and patterns of use. The objective of this study is to evaluate ecstasy-related deficits in human verbal memory over a wide range of cognitive complexity using subjects drawn from a single geographical population. Ecstasy users were compared to non-drug using controls on verbal tasks with low cognitive complexity (stem completion), moderate cognitive complexity (stem-cued recall and word list learning) and high cognitive complexity (California Verbal Learning Test, Verbal Paired Associates and a novel Verbal Triplet Associates test). Where significant differences were found, both groups were also compared to cannabis users. More cognitively complex memory tasks were associated with clearer ecstasy-related deficits than low complexity tasks. In the most cognitively demanding task, ecstasy-related deficits remained even after multiple learning opportunities, whereas the performance of cannabis users approached that of non-drug using controls. Ecstasy users also had weaker deliberate strategy use than both non-drug and cannabis controls. Results were consistent with the proposal that ecstasy-related memory deficits are more reliable on tasks with greater cognitive complexity. This could arise either because such tasks require a greater contribution from the frontal lobe or because they require greater interaction between multiple brain regions.

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...

Goal neglect and knowledge chunking in the construction of novel behaviour☆

PubMed Central

Bhandari, Apoorva; Duncan, John

2014-01-01

Task complexity is critical in cognitive efficiency and fluid intelligence. To examine functional limits in task complexity, we examine the phenomenon of goal neglect, where participants with low fluid intelligence fail to follow task rules that they otherwise understand. Though neglect is known to increase with task complexity, here we show that – in contrast to previous accounts – the critical factor is not the total complexity of all task rules. Instead, when the space of task requirements can be divided into separate sub-parts, neglect is controlled by the complexity of each component part. The data also show that neglect develops and stabilizes over the first few performance trials, i.e. as instructions are first used to generate behaviour. In all complex behaviour, a critical process is combination of task events with retrieved task requirements to create focused attentional episodes dealing with each decision in turn. In large part, we suggest, fluid intelligence may reflect this process of converting complex requirements into effective attentional episodes. PMID:24141034

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.

Individual strategy ratings improve the control for task difficulty effects in arithmetic problem solving paradigms.

PubMed

Tschentscher, Nadja; Hauk, Olaf

2015-01-01

Mental arithmetic is a powerful paradigm to study problem solving using neuroimaging methods. However, the evaluation of task complexity varies significantly across neuroimaging studies. Most studies have parameterized task complexity by objective features such as the number size. Only a few studies used subjective rating procedures. In fMRI, we provided evidence that strategy self-reports control better for task complexity across arithmetic conditions than objective features (Tschentscher and Hauk, 2014). Here, we analyzed the relative predictive value of self-reported strategies and objective features for performance in addition and multiplication tasks, by using a paradigm designed for neuroimaging research. We found a superiority of strategy ratings as predictor of performance above objective features. In a Principal Component Analysis on reaction times, the first component explained over 90 percent of variance and factor loadings reflected percentages of self-reported strategies well. In multiple regression analyses on reaction times, self-reported strategies performed equally well or better than objective features, depending on the operation type. A Receiver Operating Characteristic (ROC) analysis confirmed this result. Reaction times classified task complexity better when defined by individual ratings. This suggests that participants' strategy ratings are reliable predictors of arithmetic complexity and should be taken into account in neuroimaging research.

Individual strategy ratings improve the control for task difficulty effects in arithmetic problem solving paradigms

PubMed Central

Tschentscher, Nadja; Hauk, Olaf

2015-01-01

Mental arithmetic is a powerful paradigm to study problem solving using neuroimaging methods. However, the evaluation of task complexity varies significantly across neuroimaging studies. Most studies have parameterized task complexity by objective features such as the number size. Only a few studies used subjective rating procedures. In fMRI, we provided evidence that strategy self-reports control better for task complexity across arithmetic conditions than objective features (Tschentscher and Hauk, 2014). Here, we analyzed the relative predictive value of self-reported strategies and objective features for performance in addition and multiplication tasks, by using a paradigm designed for neuroimaging research. We found a superiority of strategy ratings as predictor of performance above objective features. In a Principal Component Analysis on reaction times, the first component explained over 90 percent of variance and factor loadings reflected percentages of self-reported strategies well. In multiple regression analyses on reaction times, self-reported strategies performed equally well or better than objective features, depending on the operation type. A Receiver Operating Characteristic (ROC) analysis confirmed this result. Reaction times classified task complexity better when defined by individual ratings. This suggests that participants’ strategy ratings are reliable predictors of arithmetic complexity and should be taken into account in neuroimaging research. PMID:26321997

Drunk, but not blind: the effects of alcohol intoxication on change blindness.

PubMed

Colflesh, Gregory J H; Wiley, Jennifer

2013-03-01

Alcohol use has long been assumed to alter cognition via attentional processes. To better understand the cognitive consequences of intoxication, the present study tested the effects of moderate intoxication (average BAC between .071 and .082) on attentional processing using complex working memory capacity (WMC) span tasks and a change blindness task. Intoxicated and sober participants were matched on baseline WMC performance, and intoxication significantly decreased performance on the complex span tasks. Surprisingly, intoxication improved performance on the change blindness task. The results are interpreted as evidence that intoxication decreases attentional control, causing either a shift towards more passive processing and/or a more diffuse attentional state. This may result in decreased performance on tasks where attentional control or focus are required, but may actually facilitate performance in some contexts. Copyright © 2013 Elsevier Inc. All rights reserved.

The effects of instructional sets on reactions to and performance on an intelligent tutoring system

NASA Technical Reports Server (NTRS)

Johnson, Debra Steele

1993-01-01

The effects of a contextual factor, i.e., task instructions, on performance on and reactions to an Intellegent Tutoring System (ITS) training Remote Manipulator System (RMS) tasks were examined. The results supported the first prediction that task instructions could be used to successfully induce a mastery versus an achievement orientation. Previous research suggests that a mastery orientation can result in beneficial effects on learning and performance of complex tasks. Furthermore, the results supported the second prediction that a mastery orientation would have beneficial effects on learning and performance as well as affective and cognitive reactions to the ITS tasks. Moreover, the results indicated that a mastery orientation was especially beneficial for the more complex ITS tasks and later in task practice, i.e., when a task was performed for the second time. A mastery orientation is posited to have its beneficial effects by focusing more effort and attention on task performance. Conclusions are drawn with some caution due to the small number of subjects, although the results for these subjects were consistent across multiple trials and multiple measures of performance. ITS designers are urged to consider contextual factors such as task instructions and feedback in terms of their potential to induce a mastery versus an achievement orientation.

Decreased cerebellar-cerebral connectivity contributes to complex task performance

PubMed Central

Knops, André

2016-01-01

The cerebellum's role in nonmotor processes is now well accepted, but cerebellar interaction with cerebral targets is not well understood. Complex cognitive tasks activate cerebellar, parietal, and frontal regions, but the effective connectivity between these regions has never been tested. To this end, we used psycho-physiological interactions (PPI) analysis to test connectivity changes of cerebellar and parietal seed regions in complex (2-digit by 1-digit multiplication, e.g., 12 × 3) vs. simple (1-digit by 1-digit multiplication, e.g., 4 × 3) task conditions (“complex − simple”). For cerebellar seed regions (lobule VI, hemisphere and vermis), we found significantly decreased cerebellar-parietal, cerebellar-cingulate, and cerebellar-frontal connectivity in complex multiplication. For parietal seed regions (PFcm, PFop, PFm) we found significantly increased parietal-parietal and parietal-frontal connectivity in complex multiplication. These results suggest that decreased cerebellar-cerebral connectivity contributes to complex task performance. Interestingly, BOLD activity contrasts revealed partially overlapping parietal areas of increased BOLD activity but decreased cerebellar-parietal PPI connectivity. PMID:27334957

Conditioned Emotional Response: Performance Decrement in Humans as a Function of Task Complexity. Final Report.

ERIC Educational Resources Information Center

Sachs, David A.; May, Jack G., Jr.

This study was designed to investigate the effects of increasing levels of task complexity on the conditioned emotional response (CER) with human subjects (Ss). Three hypotheses were proposed: (1) the CER would increase as task complexity increased, (2) there would be sex differences between Ss with respect to the interaction between the CER and…

Using virtual reality simulation to study navigation in a complex environment as a functional-cognitive task; A pilot study.

PubMed

Kizony, R; Zeilig, G; Krasovsky, T; Bondi, M; Weiss, P L; Kodesh, E; Kafri, M

2017-01-01

Navigation skills are required for performance of functional complex tasks and may decline due to aging. Investigation of navigation skills should include measurement of cognitive-executive and motor aspects, which are part of complex tasks. to compare young and older healthy adults in navigation within a simulated environment with and without a functional-cognitive task. Ten young adults (25.6±4.3 years) and seven community dwelling older men (69.9±3.8 years) were tested during a single session. After training on a self-paced treadmill to navigate in a non-functional simulation, they performed the Virtual Multiple Errands Test (VMET) in a mall simulation. Outcome measures included cognitive-executive aspects of performance and gait parameters. Younger adults' performance of the VMET was more efficient (1.8±1.0) than older adults (5.3±2.7; p < 0.05) and faster (younger 478.1±141.5 s, older 867.6±393.5 s; p < 0.05). There were no differences between groups in gait parameters. Both groups walked slower in the mall simulation. The shopping simulation provided a paradigm to assess the interplay between motor and cognitive aspects involved in the efficient performance of a complex task. The study emphasized the role of the cognitive-executive aspect of task performance in healthy older adults.

Involvement of Spearman's g in conceptualisation versus execution of complex tasks.

PubMed

Carroll, Ellen L; Bright, Peter

2016-10-01

Strong correlations between measures of fluid intelligence (or Spearman's g) and working memory are widely reported in the literature, but there is considerable controversy concerning the nature of underlying mechanisms driving this relationship. In the four experiments presented here we consider the role of response conflict and task complexity in the context of real-time task execution demands (Experiments 1-3) and also address recent evidence that g confers an advantage at the level of task conceptualisation rather than (or in addition to) task execution (Experiment 4). We observed increased sensitivity of measured fluid intelligence to task performance in the presence (vs. the absence) of response conflict, and this relationship remained when task complexity was reduced. Performance-g correlations were also observed in the absence of response conflict, but only in the context of high task complexity. Further, we present evidence that differences in conceptualisation or 'modelling' of task instructions prior to execution had an important mediating effect on observed correlations, but only when the task encompassed a strong element of response inhibition. Our results suggest that individual differences in ability reflect, in large part, variability in the efficiency with which the relational complexity of task constraints are held in mind. It follows that fluid intelligence may support successful task execution through the construction of effective action plans via optimal allocation of limited resources. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

The Influence of Relational Complexity and Strategy Selection on Children's Reasoning in the Latin Square Task

ERIC Educational Resources Information Center

Perret, Patrick; Bailleux, Christine; Dauvier, Bruno

2011-01-01

The present study focused on children's deductive reasoning when performing the Latin Square Task, an experimental task designed to explore the influence of relational complexity. Building on Birney, Halford, and Andrew's (2006) research, we created a version of the task that minimized nonrelational factors and introduced new categories of items.…

Neural Correlates Associated with Successful Working Memory Performance in Older Adults as Revealed by Spatial ICA

PubMed Central

Saliasi, Emi; Geerligs, Linda; Lorist, Monicque M.; Maurits, Natasha M.

2014-01-01

To investigate which neural correlates are associated with successful working memory performance, fMRI was recorded in healthy younger and older adults during performance on an n-back task with varying task demands. To identify functional networks supporting working memory processes, we used independent component analysis (ICA) decomposition of the fMRI data. Compared to younger adults, older adults showed a larger neural (BOLD) response in the more complex (2-back) than in the baseline (0-back) task condition, in the ventral lateral prefrontal cortex (VLPFC) and in the right fronto-parietal network (FPN). Our results indicated that a higher BOLD response in the VLPFC was associated with increased performance accuracy in older adults, in both the baseline and the more complex task condition. This ‘BOLD-performance’ relationship suggests that the neural correlates linked with successful performance in the older adults are not uniquely related to specific working memory processes present in the complex but not in the baseline task condition. Furthermore, the selective presence of this relationship in older but not in younger adults suggests that increased neural activity in the VLPFC serves a compensatory role in the aging brain which benefits task performance in the elderly. PMID:24911016

The Effect of "Massed" Task Repetitions on Complexity, Accuracy and Fluency: Does It Transfer to a New Task?

ERIC Educational Resources Information Center

Ahmadian, Mohammad Javad

2011-01-01

To date, research results suggest that task repetition positively affects oral task performance. However, researchers have not yet shown the extension of the benefits of repeating the same task to performance of a new task. This article first provides an overview of the currently available research findings on task repetition and then presents the…

An analysis of relational complexity in an air traffic control conflict detection task.

PubMed

Boag, Christine; Neal, Andrew; Loft, Shayne; Halford, Graeme S

2006-11-15

Theoretical analyses of air traffic complexity were carried out using the Method for the Analysis of Relational Complexity. Twenty-two air traffic controllers examined static air traffic displays and were required to detect and resolve conflicts. Objective measures of performance included conflict detection time and accuracy. Subjective perceptions of mental workload were assessed by a complexity-sorting task and subjective ratings of the difficulty of different aspects of the task. A metric quantifying the complexity of pair-wise relations among aircraft was able to account for a substantial portion of the variance in the perceived complexity and difficulty of conflict detection problems, as well as reaction time. Other variables that influenced performance included the mean minimum separation between aircraft pairs and the amount of time that aircraft spent in conflict.

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.

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.

Successfully Carrying out Complex Learning-Tasks through Guiding Teams' Qualitative and Quantitative Reasoning

ERIC Educational Resources Information Center

Slof, B.; Erkens, G.; Kirschner, P. A.; Janssen, J.; Jaspers, J. G. M.

2012-01-01

This study investigated whether and how scripting learners' use of representational tools in a computer supported collaborative learning (CSCL)-environment fostered their collaborative performance on a complex business-economics task. Scripting the problem-solving process sequenced and made its phase-related part-task demands explicit, namely…

Automated Instructional Monitors for Complex Operational Tasks. Final Report.

ERIC Educational Resources Information Center

Feurzeig, Wallace

A computer-based instructional system is described which incorporates diagnosis of students difficulties in acquiring complex concepts and skills. A computer automatically generated a simulated display. It then monitored and analyzed a student's work in the performance of assigned training tasks. Two major tasks were studied. The first,…

Complexity as a Reflection of the Dimensionality of a Task.

ERIC Educational Resources Information Center

Spilsbury, Georgina

1992-01-01

The hypothesis that a task that increases in complexity (increasing its correlation with a central measure of intelligence) does so by increasing its dimensionality by tapping individual differences or another variable was supported by findings from 46 adults aged 20-70 years performing a mental counting task. (SLD)

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…

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…

Task Complexity, Student Perceptions of Vocabulary Learning in EFL, and Task Performance

ERIC Educational Resources Information Center

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

2013-01-01

Background: The study deepened our understanding of how students' self-ef?cacy beliefs contribute to the context of teaching English as a foreign language in the framework of cognitive mediational paradigm at a ?ne-tuned task-speci?c level. Aim: The aim was to examine the relationship among task complexity, self-ef?cacy beliefs, domain-related…

Human Factors Tools for Improving Simulation Activities in Continuing Medical Education

ERIC Educational Resources Information Center

Seagull, F. Jacob

2012-01-01

Human factors (HF) is a discipline often drawn upon when there is a need to train people to perform complex, high-stakes tasks and effectively assess their performance. Complex tasks often present unique challenges for training and assessment. HF has developed specialized techniques that have been effective in overcoming several of these…

The Effects of Goal-Contingent Payment on the Performance of a Complex Task.

ERIC Educational Resources Information Center

Campbell, Donald J.

1984-01-01

Using a complex, computerized decision-making task, 56 university students participated in a six-week, repeated measures, goal-setting project, involving different payment systems. Results indicated that goal-contingent payment is superior to hourly payment in influencing performance, even though the perceived valence of payment and the actual…

Working memory subsystems and task complexity in young boys with Fragile X syndrome.

PubMed

Baker, S; Hooper, S; Skinner, M; Hatton, D; Schaaf, J; Ornstein, P; Bailey, D

2011-01-01

Working memory problems have been targeted as core deficits in individuals with Fragile X syndrome (FXS); however, there have been few studies that have examined working memory in young boys with FXS, and even fewer studies that have studied the working memory performance of young boys with FXS across different degrees of complexity. The purpose of this study was to investigate the phonological loop and visual-spatial working memory in young boys with FXS, in comparison to mental age-matched typical boys, and to examine the impact of complexity of the working memory tasks on performance. The performance of young boys (7 to 13-years-old) with FXS (n = 40) was compared with that of mental age and race matched typically developing boys (n = 40) on measures designed to test the phonological loop and the visuospatial sketchpad across low, moderate and high degrees of complexity. Multivariate analyses were used to examine group differences across the specific working memory systems and degrees of complexity. Results suggested that boys with FXS showed deficits in phonological loop and visual-spatial working memory tasks when compared with typically developing mental age-matched boys. For the boys with FXS, the phonological loop was significantly lower than the visual-spatial sketchpad; however, there was no significant difference in performance across the low, moderate and high degrees of complexity in the working memory tasks. Reverse tasks from both the phonological loop and visual-spatial sketchpad appeared to be the most challenging for both groups, but particularly for the boys with FXS. These findings implicate a generalised deficit in working memory in young boys with FXS, with a specific disproportionate impairment in the phonological loop. Given the lack of differentiation on the low versus high complexity tasks, simple span tasks may provide an adequate estimate of working memory until greater involvement of the central executive is achieved. © 2010 The Authors. Journal of Intellectual Disability Research © 2010 Blackwell Publishing Ltd.

Working memory subsystems and task complexity in young boys with Fragile X syndrome

PubMed Central

Baker, S.; Hooper, S.; Skinner, M.; Hatton, D.; Schaaf, J.; Ornstein, P.; Bailey, D.

2011-01-01

Background Working memory problems have been targeted as core deficits in individuals with Fragile X syndrome (FXS); however, there have been few studies that have examined working memory in young boys with FXS, and even fewer studies that have studied the working memory performance of young boys with FXS across different degrees of complexity. The purpose of this study was to investigate the phonological loop and visual–spatial working memory in young boys with FXS, in comparison to mental age-matched typical boys, and to examine the impact of complexity of the working memory tasks on performance. Methods The performance of young boys (7 to 13-years-old) with FXS (n = 40) was compared with that of mental age and race matched typically developing boys (n = 40) on measures designed to test the phonological loop and the visuospatial sketchpad across low, moderate and high degrees of complexity. Multivariate analyses were used to examine group differences across the specific working memory systems and degrees of complexity. Results Results suggested that boys with FXS showed deficits in phonological loop and visual–spatial working memory tasks when compared with typically developing mental age-matched boys. For the boys with FXS, the phonological loop was significantly lower than the visual–spatial sketchpad; however, there was no significant difference in performance across the low, moderate and high degrees of complexity in the working memory tasks. Reverse tasks from both the phonological loop and visual–spatial sketchpad appeared to be the most challenging for both groups, but particularly for the boys with FXS. Conclusions These findings implicate a generalised deficit in working memory in young boys with FXS, with a specific disproportionate impairment in the phonological loop. Given the lack of differentiation on the low versus high complexity tasks, simple span tasks may provide an adequate estimate of working memory until greater involvement of the central executive is achieved. PMID:21121991

Bingo! Externally-Supported Performance Intervention for Deficient Visual Search in Normal Aging, Parkinson’s Disease and Alzheimer’s Disease

PubMed Central

Laudate, Thomas M.; Neargarder, Sandy; Dunne, Tracy E.; Sullivan, Karen D.; Joshi, Pallavi; Gilmore, Grover C.; Riedel, Tatiana M.; Cronin-Golomb, Alice

2011-01-01

External support may improve task performance regardless of an individual’s ability to compensate for cognitive deficits through internally-generated mechanisms. We investigated if performance of a complex, familiar visual search task (the game of bingo) could be enhanced in groups with suboptimal vision by providing external support through manipulation of task stimuli. Participants were 19 younger adults, 14 individuals with probable Alzheimer’s disease (AD), 13 AD-matched healthy adults, 17 non-demented individuals with Parkinson’s disease (PD), and 20 PD-matched healthy adults. We varied stimulus contrast, size, and visual complexity during game play. The externally-supported performance interventions of increased stimulus size and decreased complexity resulted in improvements in performance by all groups. Performance improvement through increased stimulus size and decreased complexity was demonstrated by all groups. AD also obtained benefit from increasing contrast, presumably by compensating for their contrast sensitivity deficit. The general finding of improved performance across healthy and afflicted groups suggests the value of visual support as an easy-to-apply intervention to enhance cognitive performance. PMID:22066941

The organization of perception and action in complex control skills

NASA Technical Reports Server (NTRS)

Miller, Richard A.; Jagacinski, Richard J.

1989-01-01

An attempt was made to describe the perceptual, cognitive, and action processes that account for highly skilled human performance in complex task environments. In order to study such a performance in a controlled setting, a laboratory task was constructed and three experiments were performed using human subjects. A general framework was developed for describing the organization of perceptual, cognitive, and action process.

Applying Best Business Practices from Corporate Performance Management to DoD

DTIC Science & Technology

2013-01-01

leading or governing large, complex corporations and are experienced in creating reliable solutions to complex management issues guided by best business ...recommendations and effective solutions aimed at improving DoD. Defense Business Board Corporate Performance Management REPORT FY13-03 Task...Group 1 Applying Best Business Practices from Corporate Performance Management to DoD TASK The Deputy Secretary of Defense (DEPSECDEF

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

PubMed

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

2013-02-01

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

Goal neglect and knowledge chunking in the construction of novel behaviour.

PubMed

Bhandari, Apoorva; Duncan, John

2014-01-01

Task complexity is critical in cognitive efficiency and fluid intelligence. To examine functional limits in task complexity, we examine the phenomenon of goal neglect, where participants with low fluid intelligence fail to follow task rules that they otherwise understand. Though neglect is known to increase with task complexity, here we show that - in contrast to previous accounts - the critical factor is not the total complexity of all task rules. Instead, when the space of task requirements can be divided into separate sub-parts, neglect is controlled by the complexity of each component part. The data also show that neglect develops and stabilizes over the first few performance trials, i.e. as instructions are first used to generate behaviour. In all complex behaviour, a critical process is combination of task events with retrieved task requirements to create focused attentional episodes dealing with each decision in turn. In large part, we suggest, fluid intelligence may reflect this process of converting complex requirements into effective attentional episodes. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Refueling Strategies for a Team of Cooperating AUVs

DTIC Science & Technology

2011-01-01

manager, and thus the constraint a centrally managed underwater network imposes on the mission. Task management utilizing Robust Decentralized Task ...the computational complexity. A bid based approach to task management has also been studied as a possible means of decentralization of group task ...currently performing another task . In [18], ground robots perform distributed task allocation using the ASyMTRy-D algorithm, which is based on CNP

A Study on the Effects of Some Reinforcers to Improve Performance of Employees in a Retail Industry

ERIC Educational Resources Information Center

Raj, John Dilip; Nelson, John Abraham; Rao, K. S. P.

2006-01-01

Two field experiments were conducted in the Business Information Technology Department of a major retail industry to analyze the impact of positive task performance reinforcers. The employees were divided into two broad groups--those performing complex tasks and those performing relatively simpler tasks. The first group was further divided into…

Recruitment of intuitive versus analytic thinking strategies affects the role of working memory in a gambling task.

PubMed

Gozzi, Marta; Cherubini, Paolo; Papagno, Costanza; Bricolo, Emanuela

2011-05-01

Previous studies found mixed results concerning the role of working memory (WM) in the gambling task (GT). Here, we aimed at reconciling inconsistencies by showing that the standard version of the task can be solved using intuitive strategies operating automatically, while more complex versions require analytic strategies drawing on executive functions. In Study 1, where good performance on the GT could be achieved using intuitive strategies, participants performed well both with and without a concurrent WM load. In Study 2, where analytical strategies were required to solve a more complex version of the GT, participants without WM load performed well, while participants with WM load performed poorly. In Study 3, where the complexity of the GT was further increased, participants in both conditions performed poorly. In addition to the standard performance measure, we used participants' subjective expected utility, showing that it differs from the standard measure in some important aspects.

Cognitive performance modeling based on general systems performance theory.

PubMed

Kondraske, George V

2010-01-01

General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies involving two complex tasks (i.e., driving and performing laparoscopic surgery) and incorporating measures that are clearly related to cognitive performance (information processing speed and short-term memory capacity) were revisited. A GSPT-derived method of task analysis and performance prediction termed Nonlinear Causal Resource Analysis (NCRA) was employed to determine the demand on basic cognitive performance resources required to support different levels of complex task performance. This approach is presented as a means to determine a cognitive workload profile and the subsequent computation of a single number measure of cognitive workload (CW). Computation of CW may be a viable alternative to measuring it. Various possible "more basic" performance resources that contribute to cognitive system performance are discussed. It is concluded from this preliminary exploration that a GSPT-based approach can contribute to defining cognitive performance models that are useful for both individual subjects and specific groups (e.g., military pilots).

Decision Making and Ratio Processing in Patients with Mild Cognitive Impairment.

PubMed

Pertl, Marie-Theres; Benke, Thomas; Zamarian, Laura; Delazer, Margarete

2015-01-01

Making advantageous decisions is important in everyday life. This study aimed at assessing how patients with mild cognitive impairment (MCI) make decisions under risk. Additionally, it investigated the relationship between decision making, ratio processing, basic numerical abilities, and executive functions. Patients with MCI (n = 22) were compared with healthy controls (n = 29) on a complex task of decision making under risk (Game of Dice Task-Double, GDT-D), on two tasks evaluating basic decision making under risk, on a task of ratio processing, and on several neuropsychological background tests. Patients performed significantly lower than controls on the GDT-D and on ratio processing, whereas groups performed comparably on basic decision tasks. Specifically, in the GDT-D, patients obtained lower net scores and lower mean expected values, which indicate a less advantageous performance relative to that of controls. Performance on the GDT-D correlated significantly with performance in basic decision tasks, ratio processing, and executive-function measures when the analysis was performed on the whole sample. Patients with MCI make sub-optimal decisions in complex risk situations, whereas they perform at the same level as healthy adults in simple decision situations. Ratio processing and executive functions have an impact on the decision-making performance of both patients and healthy older adults. In order to facilitate advantageous decisions in complex everyday situations, information should be presented in an easily comprehensible form and cognitive training programs for patients with MCI should focus--among other abilities--on executive functions and ratio processing.

EEG Patterns Related to Cognitive Tasks of Varying Complexity.

ERIC Educational Resources Information Center

Dunn, Denise A.; And Others

A study was conducted that attempted to show changes in electroencephalographic (EEG) patterns (identified using topographic EEG mapping) when children were required to perform the relatively simple task of button pressing during an eyes-open baseline session of low cognitive demand and a complex reaction time (RT) task of high cognitive demand.…

Performance of Children with Developmental Dyslexia on High and Low Topological Entropy Artificial Grammar Learning Task

ERIC Educational Resources Information Center

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

2017-01-01

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…

Donepezil and flight simulator performance: effects on retention of complex skills.

PubMed

Yesavage, J A; Mumenthaler, M S; Taylor, J L; Friedman, L; O'Hara, R; Sheikh, J; Tinklenberg, J; Whitehouse, P J

2002-07-09

We report a randomized, double-blind, parallel group, placebo-controlled study to test the effects of the acetylcholinesterase inhibitor, donepezil (5 mg/d for 30 days), on aircraft pilot performance in 18 licensed pilots with mean age of 52 years. After 30 days of treatment, the donepezil group showed greater ability to retain the capacity to perform a set of complex simulator tasks than the placebo group, p < 0.05. Donepezil appears to have beneficial effects on retention of training on complex aviation tasks in nondemented older adults.

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.

Manual asymmetry in older adults on a complex coincidence-anticipation task.

PubMed

Rodrigues, Paula Cristina Dos Santos; Silva, João Miguel Carvalho da; Barreiros, João Manuel Pardal; Vasconcelos, Maria Olga Fernandes

2018-04-20

Age-related asymmetrical functional decline was tested in a sample of 57 right-handed volunteers between 65 and 85 years of age. Participants performed a complex coincidence-anticipation (CA) task with both preferred and non-preferred hands. Results demonstrated that the proficiency of a complex CA task was similar for the 2 age groups, but different for the 2 hands. The non-preferred hand was more proficient for temporal accuracy but not for response timing, which was similar for both hands. Moreover, the lack of interaction between age and hand both in response timing and response accuracy reveal symmetric performance across ages.

Variability and reduced performance of preschool- and early school-aged children on psychoacoustic tasks: What are the relevant factors?

NASA Astrophysics Data System (ADS)

Allen, Prudence

2003-04-01

Young children typically perform more poorly on psychoacoustic tasks than do adults, with large individual differences. When performance is averaged across children within age groups, the data suggest a gradual change in performance with increasing age. However, an examination of individual data suggests that the performance matures more rapidly, although at different times for different children. The mechanisms of development responsible for these changes are likely very complex, involving both sensory and cognitive processes. This paper will discuss some previously suggested mechanisms including attention and cue weighting, as well as possibilities suggested from more recent studies in which learning effects were examined. In one task, a simple frequency discrimination was required, while in another the listener was required to extract regularities in complex sequences of sounds that varied from trial to trial. Results suggested that the ability to select and consistently employ an effective listening strategy was especially important in the performance of the more complex task, while simple stimulus exposure and motivation contributed to the simpler task. These factors are important for understanding the perceptual development and for the subsequent application of psychoacoustic findings to clinical populations. [Work supported by the NSERC and the Canadian Language and Literacy Research Network.

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.

Modularity and hierarchical organization of action programs in children's acquisition of graphic skills.

PubMed

Manoel, Edison de J; Dantas, Luiz; Gimenez, Roberto; de Oliveira, Dalton Lustosa

2011-10-01

The organization of actions is based on modules in memory as a result of practice, easing the demand of performing more complex actions. If this modularization occurs, the elements of the module must remain invariant in new tasks. To test this hypothesis, 35 children, age 10 yr., practiced a graphic criterion task on a digital tablet and completed a complex graphic task enclosing the previous one. Total movement and pause times to draw the figure indicated skill acquisition. A module was identified by the variability of relative timing, pause time, and sequencing. Total movement to perform the criterion task did not increase significantly when it was embedded in the more complex task. Modularity was evidenced by the stability of relative timing and pause time and sequencing. The spatial position of new elements did not perturb the module, so the grammar of action may still have been forming.

Subjective rating scales as a workload

NASA Technical Reports Server (NTRS)

Bird, K. L.

1981-01-01

A multidimensional bipolar-adjective rating scale is employed as a subjective measure of operator workload in the performance of a one-axis tracking task. The rating scale addressed several dimensions of workload, including cognitive, physical, and perceptual task loading as well as fatigue and stress effects. Eight subjects performed a one-axis tracking task (with six levels of difficulty) and rated these tasks on several workload dimensions. Performance measures were tracking error RMS (root-mean square) and the standard deviation of control stick output. Significant relationships were observed between these performance measures and skill required, task complexity, attention level, task difficulty, task demands, and stress level.

Specific-Token Effects in Screening Tasks: Possible Implications for Aviation Security

ERIC Educational Resources Information Center

Smith, J. David; Redford, Joshua S.; Washburn, David A.; Taglialatela, Lauren A.

2005-01-01

Screeners at airport security checkpoints perform an important categorization task in which they search for threat items in complex x-ray images. But little is known about how the processes of categorization stand up to visual complexity. The authors filled this research gap with screening tasks in which participants searched for members of target…

Interaction between marihuana and altitude on a complex behavioral task in baboons.

DOT National Transportation Integrated Search

1975-01-01

Marihuana, or its principal active ingredient, delta-9-tetrahydrocannabinol (delta9-THC), impairs performance on complex behavioral tasks in animals and man. Although there exists some evidence that altitude-induced hypoxia potentiates the physiologi...

The Effect of Task Complexity on Functional Adequacy, Fluency and Lexical Diversity in Speaking Performances of Native and Non-Native Speakers

ERIC Educational Resources Information Center

De Jong, Nivja H.; Steinel, Margarita P.; Florijn, Arjen F.; Schoonen, Rob; Hulstijn, Jan H.

2012-01-01

This study investigated how task complexity affected native and non-native speakers' speaking performance in terms of a measure of communicative success (functional adequacy), three types of fluency (breakdown fluency, speed fluency, and repair fluency), and lexical diversity. Participants (208 non-native and 59 native speakers of Dutch) carried…

The Spectacles through Which I See the Race and IQ Debate

ERIC Educational Resources Information Center

Flynn, James R.

2010-01-01

The ranking of Wechsler subtests in terms of their "g" loadings is equivalent to ranking them in terms of the cognitive complexity of the tasks measured. Lower performing groups do not always fall behind higher performing groups the more complex the task. But that is the general rule, no matter whether the cause of the lower performance…

Enhancing Learning Performance and Adaptability for Complex Tasks

DTIC Science & Technology

2005-03-30

development of active learning interventions and techniques that influence the focus and quality of learner regulatory activity (Kozlowski Toney et al...what are the effects of these goal representations on learning strategies, performance, and adaptability? Can active learning inductions, that influence...and mindful process - active learning - are generally associated with improved skill acquisition and adaptability for complex tasks (Smith et al

Cognitive tasks promote automatization of postural control in young and older adults.

PubMed

Potvin-Desrochers, Alexandra; Richer, Natalie; Lajoie, Yves

2017-09-01

Researchers looking at the effects of performing a concurrent cognitive task on postural control in young and older adults using traditional center-of-pressure measures and complexity measures found discordant results. Results of experiments showing improvements of stability have suggested the use of strategies such as automatization of postural control or stiffening strategy. This experiment aimed to confirm in healthy young and older adults that performing a cognitive task while standing leads to improvements that are due to automaticity of sway by using sample entropy. Twenty-one young adults and twenty-five older adults were asked to stand on a force platform while performing a cognitive task. There were four cognitive tasks: simple reaction time, go/no-go reaction time, equation and occurrence of a digit in a number sequence. Results demonstrated decreased sway area and variability as well as increased sample entropy for both groups when performing a cognitive task. Results suggest that performing a concurrent cognitive task promotes the adoption of an automatic postural control in young and older adults as evidenced by an increased postural stability and postural sway complexity. Copyright © 2017 Elsevier B.V. All rights reserved.

Thinking about the weather: How display salience and knowledge affect performance in a graphic inference task.

PubMed

Hegarty, Mary; Canham, Matt S; Fabrikant, Sara I

2010-01-01

Three experiments examined how bottom-up and top-down processes interact when people view and make inferences from complex visual displays (weather maps). Bottom-up effects of display design were investigated by manipulating the relative visual salience of task-relevant and task-irrelevant information across different maps. Top-down effects of domain knowledge were investigated by examining performance and eye fixations before and after participants learned relevant meteorological principles. Map design and knowledge interacted such that salience had no effect on performance before participants learned the meteorological principles; however, after learning, participants were more accurate if they viewed maps that made task-relevant information more visually salient. Effects of display design on task performance were somewhat dissociated from effects of display design on eye fixations. The results support a model in which eye fixations are directed primarily by top-down factors (task and domain knowledge). They suggest that good display design facilitates performance not just by guiding where viewers look in a complex display but also by facilitating processing of the visual features that represent task-relevant information at a given display location. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

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.

Methodology in the assessment of complex performance : the effects of signal rate on monitoring a static process.

DOT National Transportation Integrated Search

1969-08-01

This study concerned the rate of presentation of stimuli on a task involving the monitoring of a static process of the kind represented by aircraft warning light indicators. The task was performed concurrently with various combinations of tasks requi...

Monitoring cognitive and emotional processes through pupil and cardiac response during dynamic versus logical task.

PubMed

Causse, Mickaël; Sénard, Jean-Michel; Démonet, Jean François; Pastor, Josette

2010-06-01

The paper deals with the links between physiological measurements and cognitive and emotional functioning. As long as the operator is a key agent in charge of complex systems, the definition of metrics able to predict his performance is a great challenge. The measurement of the physiological state is a very promising way but a very acute comprehension is required; in particular few studies compare autonomous nervous system reactivity according to specific cognitive processes during task performance and task related psychological stress is often ignored. We compared physiological parameters recorded on 24 healthy subjects facing two neuropsychological tasks: a dynamic task that require problem solving in a world that continually evolves over time and a logical task representative of cognitive processes performed by operators facing everyday problem solving. Results showed that the mean pupil diameter change was higher during the dynamic task; conversely, the heart rate was more elevated during the logical task. Finally, the systolic blood pressure seemed to be strongly sensitive to psychological stress. A better taking into account of the precise influence of a given cognitive activity and both workload and related task-induced psychological stress during task performance is a promising way to better monitor operators in complex working situations to detect mental overload or pejorative stress factor of error.

Working memory capacity and the scope and control of attention.

PubMed

Shipstead, Zach; Harrison, Tyler L; Engle, Randall W

2015-08-01

Complex span and visual arrays are two common measures of working memory capacity that are respectively treated as measures of attention control and storage capacity. A recent analysis of these tasks concluded that (1) complex span performance has a relatively stronger relationship to fluid intelligence and (2) this is due to the requirement that people engage control processes while performing this task. The present study examines the validity of these conclusions by examining two large data sets that include a more diverse set of visual arrays tasks and several measures of attention control. We conclude that complex span and visual arrays account for similar amounts of variance in fluid intelligence. The disparity relative to the earlier analysis is attributed to the present study involving a more complete measure of the latent ability underlying the performance of visual arrays. Moreover, we find that both types of working memory task have strong relationships to attention control. This indicates that the ability to engage attention in a controlled manner is a critical aspect of working memory capacity, regardless of the type of task that is used to measure this construct.

Working Memory and Reasoning Benefit from Different Modes of Large-scale Brain Dynamics in Healthy Older Adults.

PubMed

Lebedev, Alexander V; Nilsson, Jonna; Lövdén, Martin

2018-07-01

Researchers have proposed that solving complex reasoning problems, a key indicator of fluid intelligence, involves the same cognitive processes as solving working memory tasks. This proposal is supported by an overlap of the functional brain activations associated with the two types of tasks and by high correlations between interindividual differences in performance. We replicated these findings in 53 older participants but also showed that solving reasoning and working memory problems benefits from different configurations of the functional connectome and that this dissimilarity increases with a higher difficulty load. Specifically, superior performance in a typical working memory paradigm ( n-back) was associated with upregulation of modularity (increased between-network segregation), whereas performance in the reasoning task was associated with effective downregulation of modularity. We also showed that working memory training promotes task-invariant increases in modularity. Because superior reasoning performance is associated with downregulation of modular dynamics, training may thus have fostered an inefficient way of solving the reasoning tasks. This could help explain why working memory training does little to promote complex reasoning performance. The study concludes that complex reasoning abilities cannot be reduced to working memory and suggests the need to reconsider the feasibility of using working memory training interventions to attempt to achieve effects that transfer to broader cognition.

Neural correlates of the difference between working memory speed and simple sensorimotor speed: an fMRI study.

PubMed

Takeuchi, Hikaru; Sugiura, Motoaki; Sassa, Yuko; Sekiguchi, Atsushi; Yomogida, Yukihito; Taki, Yasuyuki; Kawashima, Ryuta

2012-01-01

The difference between the speed of simple cognitive processes and the speed of complex cognitive processes has various psychological correlates. However, the neural correlates of this difference have not yet been investigated. In this study, we focused on working memory (WM) for typical complex cognitive processes. Functional magnetic resonance imaging data were acquired during the performance of an N-back task, which is a measure of WM for typical complex cognitive processes. In our N-back task, task speed and memory load were varied to identify the neural correlates responsible for the difference between the speed of simple cognitive processes (estimated from the 0-back task) and the speed of WM. Our findings showed that this difference was characterized by the increased activation in the right dorsolateral prefrontal cortex (DLPFC) and the increased functional interaction between the right DLPFC and right superior parietal lobe. Furthermore, the local gray matter volume of the right DLPFC was correlated with participants' accuracy during fast WM tasks, which in turn correlated with a psychometric measure of participants' intelligence. Our findings indicate that the right DLPFC and its related network are responsible for the execution of the fast cognitive processes involved in WM. Identified neural bases may underlie the psychometric differences between the speed with which subjects perform simple cognitive tasks and the speed with which subjects perform more complex cognitive tasks, and explain the previous traditional psychological findings.

Hierarchical Control Using Networks Trained with Higher-Level Forward Models

PubMed Central

Wayne, Greg; Abbott, L.F.

2015-01-01

We propose and develop a hierarchical approach to network control of complex tasks. In this approach, a low-level controller directs the activity of a “plant,” the system that performs the task. However, the low-level controller may only be able to solve fairly simple problems involving the plant. To accomplish more complex tasks, we introduce a higher-level controller that controls the lower-level controller. We use this system to direct an articulated truck to a specified location through an environment filled with static or moving obstacles. The final system consists of networks that have memorized associations between the sensory data they receive and the commands they issue. These networks are trained on a set of optimal associations that are generated by minimizing cost functions. Cost function minimization requires predicting the consequences of sequences of commands, which is achieved by constructing forward models, including a model of the lower-level controller. The forward models and cost minimization are only used during training, allowing the trained networks to respond rapidly. In general, the hierarchical approach can be extended to larger numbers of levels, dividing complex tasks into more manageable sub-tasks. The optimization procedure and the construction of the forward models and controllers can be performed in similar ways at each level of the hierarchy, which allows the system to be modified to perform other tasks, or to be extended for more complex tasks without retraining lower-levels. PMID:25058706

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

PubMed

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

2014-05-01

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

A method for work modeling at complex systems: towards applying information systems in family health care units.

PubMed

Jatobá, Alessandro; de Carvalho, Paulo Victor R; da Cunha, Amauri Marques

2012-01-01

Work in organizations requires a minimum level of consensus on the understanding of the practices performed. To adopt technological devices to support the activities in environments where work is complex, characterized by the interdependence among a large number of variables, understanding about how work is done not only takes an even greater importance, but also becomes a more difficult task. Therefore, this study aims to present a method for modeling of work in complex systems, which allows improving the knowledge about the way activities are performed where these activities do not simply happen by performing procedures. Uniting techniques of Cognitive Task Analysis with the concept of Work Process, this work seeks to provide a method capable of providing a detailed and accurate vision of how people perform their tasks, in order to apply information systems for supporting work in organizations.

Acquisition and production of skilled behavior in dynamic decision-making tasks. Semiannual Status Report M.S. Thesis - Georgia Inst. of Tech., Nov. 1992

NASA Technical Reports Server (NTRS)

Kirlik, Alex; Kossack, Merrick Frank

1993-01-01

This status report consists of a thesis entitled 'Ecological Task Analysis: A Method for Display Enhancements.' Previous use of various analysis processes for the purpose of display interface design or enhancement has run the risk of failing to improve user performance due to the analysis resulting in only a sequencial listing of user tasks. Adopting an ecological approach to performing the task analysis, however, may result in the necessary modeling of an unpredictable and variable task domain required to improve user performance. Kirlik has proposed an Ecological Task Analysis framework which is designed for this purpose. It is the purpose of this research to measure this framework's effectiveness at enhancing display interfaces in order to improve user performance. Following the proposed framework, an ecological task analysis of experienced users of a complex and dynamic laboratory task, Star Cruiser, was performed. Based on this analysis, display enhancements were proposed and implemented. An experiment was then conducted to compare this new version of Star Cruiser to the original. By measuring user performance at different tasks, it was determined that during early sessions, use of the enhanced display contributed to better user performance compared to that achieved using the original display. Furthermore, the results indicate that the enhancements proposed as a result of the ecological task analysis affected user performance differently depending on whether they are enhancements which aid in the selection of a possible action or in the performance of an action. Generalizations of these findings to larger, more complex systems were avoided since the analysis was only performed on this one particular system.

The effects of syntactic complexity on the human-computer interaction

NASA Technical Reports Server (NTRS)

Chechile, R. A.; Fleischman, R. N.; Sadoski, D. M.

1986-01-01

Three divided-attention experiments were performed to evaluate the effectiveness of a syntactic analysis of the primary task of editing flight route-way-point information. For all editing conditions, a formal syntactic expression was developed for the operator's interaction with the computer. In terms of the syntactic expression, four measures of syntactic were examined. Increased syntactic complexity did increase the time to train operators, but once the operators were trained, syntactic complexity did not influence the divided-attention performance. However, the number of memory retrievals required of the operator significantly accounted for the variation in the accuracy, workload, and task completion time found on the different editing tasks under attention-sharing conditions.

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

PubMed

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

2016-09-01

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

Characterization of children's decision making: sensitivity to punishment frequency, not task complexity.

PubMed

Crone, Eveline A; Bunge, Silvia A; Latenstein, Heleen; van der Molen, Maurits W

2005-06-01

On a gambling task that models real-life decision making, children between ages 7 and 12 perform like patients with bilateral lesions of the ventromedial prefrontal cortex (VMPFC), opting for choices that yield high immediate gains in spite of higher future losses (Crone & Van der Molen, 2004). The current study set out to characterize developmental changes in decision making by varying task complexity and punishment frequency. Three age groups (7-9 years, 10-12 years, 13-15 years) performed two versions of a computerized variant of the original Iowa gambling task. Task complexity was manipulated by varying the number of choices participants could make. Punishment frequency was manipulated by varying the frequency of delayed punishment. Results showed a developmental increase in the sensitivity to future consequences, which was present only when the punishment was presented infrequently. These results could not be explained by differential sensitivity to task complexity, hypersensitivity to reward, or failure to switch response set after receiving punishment. There was a general pattern of boys outperforming girls by making more advantageous choices over the course of the task. In conclusion, 7-12-year-old children--like VMPFC patients--appear myopic about the future except when the potential for future punishment is high.

Number line estimation and complex mental calculation: Is there a shared cognitive process driving the two tasks?

PubMed

Montefinese, Maria; Semenza, Carlo

2018-05-17

It is widely accepted that different number-related tasks, including solving simple addition and subtraction, may induce attentional shifts on the so-called mental number line, which represents larger numbers on the right and smaller numbers on the left. Recently, it has been shown that different number-related tasks also employ spatial attention shifts along with general cognitive processes. Here we investigated for the first time whether number line estimation and complex mental arithmetic recruit a common mechanism in healthy adults. Participants' performance in two-digit mental additions and subtractions using visual stimuli was compared with their performance in a mental bisection task using auditory numerical intervals. Results showed significant correlations between participants' performance in number line bisection and that in two-digit mental arithmetic operations, especially in additions, providing a first proof of a shared cognitive mechanism (or multiple shared cognitive mechanisms) between auditory number bisection and complex mental calculation.

Enhanced and diminished visuo-spatial information processing in autism depends on stimulus complexity.

PubMed

Bertone, Armando; Mottron, Laurent; Jelenic, Patricia; Faubert, Jocelyn

2005-10-01

Visuo-perceptual processing in autism is characterized by intact or enhanced performance on static spatial tasks and inferior performance on dynamic tasks, suggesting a deficit of dorsal visual stream processing in autism. However, previous findings by Bertone et al. indicate that neuro-integrative mechanisms used to detect complex motion, rather than motion perception per se, may be impaired in autism. We present here the first demonstration of concurrent enhanced and decreased performance in autism on the same visuo-spatial static task, wherein the only factor dichotomizing performance was the neural complexity required to discriminate grating orientation. The ability of persons with autism was found to be superior for identifying the orientation of simple, luminance-defined (or first-order) gratings but inferior for complex, texture-defined (or second-order) gratings. Using a flicker contrast sensitivity task, we demonstrated that this finding is probably not due to abnormal information processing at a sub-cortical level (magnocellular and parvocellular functioning). Together, these findings are interpreted as a clear indication of altered low-level perceptual information processing in autism, and confirm that the deficits and assets observed in autistic visual perception are contingent on the complexity of the neural network required to process a given type of visual stimulus. We suggest that atypical neural connectivity, resulting in enhanced lateral inhibition, may account for both enhanced and decreased low-level information processing in autism.

Hyperbaric Oxygen Environment Can Enhance Brain Activity and Multitasking Performance

PubMed Central

Vadas, Dor; Kalichman, Leonid; Hadanny, Amir; Efrati, Shai

2017-01-01

Background: The Brain uses 20% of the total oxygen supply consumed by the entire body. Even though, <10% of the brain is active at any given time, it utilizes almost all the oxygen delivered. In order to perform complex tasks or more than one task (multitasking), the oxygen supply is shifted from one brain region to another, via blood perfusion modulation. The aim of the present study was to evaluate whether a hyperbaric oxygen (HBO) environment, with increased oxygen supply to the brain, will enhance the performance of complex and/or multiple activities. Methods: A prospective, double-blind randomized control, crossover trial including 22 healthy volunteers. Participants were asked to perform a cognitive task, a motor task and a simultaneous cognitive-motor task (multitasking). Participants were randomized to perform the tasks in two environments: (a) normobaric air (1 ATA 21% oxygen) (b) HBO (2 ATA 100% oxygen). Two weeks later participants were crossed to the alternative environment. Blinding of the normobaric environment was achieved in the same chamber with masks on while hyperbaric sensation was simulated by increasing pressure in the first minute and gradually decreasing to normobaric environment prior to tasks performance. Results: Compared to the performance at normobaric conditions, both cognitive and motor single tasks scores were significantly enhanced by HBO environment (p < 0.001 for both). Multitasking performance was also significantly enhanced in HBO environment (p = 0.006 for the cognitive part and p = 0.02 for the motor part). Conclusions: The improvement in performance of both single and multi-tasking while in an HBO environment supports the hypothesis which according to, oxygen is indeed a rate limiting factor for brain activity. Hyperbaric oxygenation can serve as an environment for brain performance. Further studies are needed to evaluate the optimal oxygen levels for maximal brain performance. PMID:29021747

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.

Hyperbaric Oxygen Environment Can Enhance Brain Activity and Multitasking Performance.

PubMed

Vadas, Dor; Kalichman, Leonid; Hadanny, Amir; Efrati, Shai

2017-01-01

Background: The Brain uses 20% of the total oxygen supply consumed by the entire body. Even though, <10% of the brain is active at any given time, it utilizes almost all the oxygen delivered. In order to perform complex tasks or more than one task (multitasking), the oxygen supply is shifted from one brain region to another, via blood perfusion modulation. The aim of the present study was to evaluate whether a hyperbaric oxygen (HBO) environment, with increased oxygen supply to the brain, will enhance the performance of complex and/or multiple activities. Methods: A prospective, double-blind randomized control, crossover trial including 22 healthy volunteers. Participants were asked to perform a cognitive task, a motor task and a simultaneous cognitive-motor task (multitasking). Participants were randomized to perform the tasks in two environments: (a) normobaric air (1 ATA 21% oxygen) (b) HBO (2 ATA 100% oxygen). Two weeks later participants were crossed to the alternative environment. Blinding of the normobaric environment was achieved in the same chamber with masks on while hyperbaric sensation was simulated by increasing pressure in the first minute and gradually decreasing to normobaric environment prior to tasks performance. Results: Compared to the performance at normobaric conditions, both cognitive and motor single tasks scores were significantly enhanced by HBO environment ( p < 0.001 for both). Multitasking performance was also significantly enhanced in HBO environment ( p = 0.006 for the cognitive part and p = 0.02 for the motor part). Conclusions: The improvement in performance of both single and multi-tasking while in an HBO environment supports the hypothesis which according to, oxygen is indeed a rate limiting factor for brain activity. Hyperbaric oxygenation can serve as an environment for brain performance. Further studies are needed to evaluate the optimal oxygen levels for maximal brain performance.

Autistic traits and social anxiety predict differential performance on social cognitive tasks in typically developing young adults

PubMed Central

Burk, Joshua A.; Fleckenstein, Katarina; Kozikowski, C. Teal

2018-01-01

The current work examined the unique contribution that autistic traits and social anxiety have on tasks examining attention and emotion processing. In Study 1, 119 typically-developing college students completed a flanker task assessing the control of attention to target faces and away from distracting faces during emotion identification. In Study 2, 208 typically-developing college students performed a visual search task which required identification of whether a series of 8 or 16 emotional faces depicted the same or different emotions. Participants with more self-reported autistic traits performed more slowly on the flanker task in Study 1 than those with fewer autistic traits when stimuli depicted complex emotions. In Study 2, participants higher in social anxiety performed less accurately on trials showing all complex faces; participants with autistic traits showed no differences. These studies suggest that traits related to autism and to social anxiety differentially impact social cognitive processing. PMID:29596523

The Effects of Pre-Task, On-Line, and Both Pre-Task and On-Line Planning on Fluency, Complexity, and Accuracy--The Case of Iranian EFL Learners' Written Production

ERIC Educational Resources Information Center

Piri, Faramarz; Barati, Hossein; Ketabi, Saeed

2012-01-01

Previous studies on the effect of planning on language production have revealed that planning does have a positive effect on language performance in terms of fluency, complexity, and accuracy. The present study was an attempt to investigate the effects of pre-task, on-line, and both pre-task and on-line planning on fluency, accuracy, and…

Why are You Late?: Investigating the Role of Time Management in Time-Based Prospective Memory

PubMed Central

Waldum, Emily R; McDaniel, Mark A.

2016-01-01

Time-based prospective memory tasks (TBPM) are those that are to be performed at a specific future time. Contrary to typical laboratory TBPM tasks (e.g., “hit the “z” key every 5 minutes”), many real-world TBPM tasks require more complex time-management processes. For instance to attend an appointment on time, one must estimate the duration of the drive to the appointment and then utilize this estimate to create and execute a secondary TBPM intention (e.g., “I need to start driving by 1:30 to make my 2:00 appointment on time”). Future under- and overestimates of drive time can lead to inefficient TBPM performance with the former lending to missed appointments and the latter to long stints in the waiting room. Despite the common occurrence of complex TBPM tasks in everyday life, to date, no studies have investigated how components of time management, including time estimation, affect behavior in such complex TBPM tasks. Therefore, the current study aimed to investigate timing biases in both older and younger adults and further to determine how such biases along with additional time management components including planning and plan fidelity influence complex TBPM performance. Results suggest for the first time that younger and older adults do not always utilize similar timing strategies, and as a result, can produce differential timing biases under the exact same environmental conditions. These timing biases, in turn, play a vital role in how efficiently both younger and older adults perform a later TBPM task that requires them to utilize their earlier time estimate. PMID:27336325

Reconfiguration of Brain Network Architectures between Resting-State and Complexity-Dependent Cognitive Reasoning.

PubMed

Hearne, Luke J; Cocchi, Luca; Zalesky, Andrew; Mattingley, Jason B

2017-08-30

Our capacity for higher cognitive reasoning has a measurable limit. This limit is thought to arise from the brain's capacity to flexibly reconfigure interactions between spatially distributed networks. Recent work, however, has suggested that reconfigurations of task-related networks are modest when compared with intrinsic "resting-state" network architecture. Here we combined resting-state and task-driven functional magnetic resonance imaging to examine how flexible, task-specific reconfigurations associated with increasing reasoning demands are integrated within a stable intrinsic brain topology. Human participants (21 males and 28 females) underwent an initial resting-state scan, followed by a cognitive reasoning task involving different levels of complexity, followed by a second resting-state scan. The reasoning task required participants to deduce the identity of a missing element in a 4 × 4 matrix, and item difficulty was scaled parametrically as determined by relational complexity theory. Analyses revealed that external task engagement was characterized by a significant change in functional brain modules. Specifically, resting-state and null-task demand conditions were associated with more segregated brain-network topology, whereas increases in reasoning complexity resulted in merging of resting-state modules. Further increments in task complexity did not change the established modular architecture, but affected selective patterns of connectivity between frontoparietal, subcortical, cingulo-opercular, and default-mode networks. Larger increases in network efficiency within the newly established task modules were associated with higher reasoning accuracy. Our results shed light on the network architectures that underlie external task engagement, and highlight selective changes in brain connectivity supporting increases in task complexity. SIGNIFICANCE STATEMENT Humans have clear limits in their ability to solve complex reasoning problems. It is thought that such limitations arise from flexible, moment-to-moment reconfigurations of functional brain networks. It is less clear how such task-driven adaptive changes in connectivity relate to stable, intrinsic networks of the brain and behavioral performance. We found that increased reasoning demands rely on selective patterns of connectivity within cortical networks that emerged in addition to a more general, task-induced modular architecture. This task-driven architecture reverted to a more segregated resting-state architecture both immediately before and after the task. These findings reveal how flexibility in human brain networks is integral to achieving successful reasoning performance across different levels of cognitive demand. Copyright © 2017 the authors 0270-6474/17/378399-13$15.00/0.

Perceptual Visual Grouping under Inattention: Electrophysiological Functional Imaging

ERIC Educational Resources Information Center

Razpurker-Apfeld, Irene; Pratt, Hillel

2008-01-01

Two types of perceptual visual grouping, differing in complexity of shape formation, were examined under inattention. Fourteen participants performed a similarity judgment task concerning two successive briefly presented central targets surrounded by task-irrelevant simple and complex grouping patterns. Event-related potentials (ERPs) were…

Information Processing by Schizophrenics When Task Complexity Increases

ERIC Educational Resources Information Center

Hirt, Michael; And Others

1977-01-01

The performance of hospitalized paranoid schizophrenics, nonparanoids, and hospitalized controls was compared on motor, perceptual, and cognitive tasks of increasing complexity. The data were examined within the context of comparing differential predictions made by input and central processing theories of information-processing deficit. (Editor)

Electroencephalogram complexity analysis in children with attention-deficit/hyperactivity disorder during a visual cognitive task.

PubMed

Zarafshan, Hadi; Khaleghi, Ali; Mohammadi, Mohammad Reza; Moeini, Mahdi; Malmir, Nastaran

2016-01-01

The aim of this study was to investigate electroencephalogram (EEG) dynamics using complexity analysis in children with attention-deficit/hyperactivity disorder (ADHD) compared with healthy control children when performing a cognitive task. Thirty 7-12-year-old children meeting Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5) criteria for ADHD and 30 healthy control children underwent an EEG evaluation during a cognitive task, and Lempel-Ziv complexity (LZC) values were computed. There were no significant differences between ADHD and control groups on age and gender. The mean LZC of the ADHD children was significantly larger than healthy children over the right anterior and right posterior regions during the cognitive performance. In the ADHD group, complexity of the right hemisphere was higher than that of the left hemisphere, but the complexity of the left hemisphere was higher than that of the right hemisphere in the normal group. Although fronto-striatal dysfunction is considered conclusive evidence for the pathophysiology of ADHD, our arithmetic mental task has provided evidence of structural and functional changes in the posterior regions and probably cerebellum in ADHD.

Chasing the silver bullet: measuring driver fatigue using simple and complex tasks.

PubMed

Baulk, S D; Biggs, S N; Reid, K J; van den Heuvel, C J; Dawson, D

2008-01-01

Driver fatigue remains a significant cause of motor-vehicle accidents worldwide. New technologies are increasingly utilised to improve road safety, but there are no effective on-road measures for fatigue. While simulated driving tasks are sensitive, and simple performance tasks have been used in industrial fatigue management systems (FMS) to quantify risk, little is known about the relationship between such measures. Establishing a simple, on-road measure of fatigue, as a fitness-to-drive tool, is an important issue for road safety and accident prevention, particularly as many fatigue related accidents are preventable. This study aimed to measure fatigue-related performance decrements using a simple task (reaction time - RT) and a complex task (driving simulation), and to determine the potential for a link between such measures, thus improving FMS success. Fifteen volunteer participants (7 m, 8 f) aged 22-56 years (mean 33.6 years), underwent 26 h of supervised wakefulness before an 8h recovery sleep opportunity. Participants were tested using a 30-min interactive driving simulation test, bracketed by a 10-min psychomotor vigilance task (PVT) at 4, 8, 18 and 24h of wakefulness, and following recovery sleep. Extended wakefulness caused significant decrements in PVT and driving performance. Although these measures are clearly linked, our analyses suggest that driving simulation cannot be replaced by a simple PVT. Further research is needed to closely examine links between performance measures, and to facilitate accurate management of fitness to drive, which requires more complex assessments of performance than RT alone.

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

PubMed

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

2012-01-01

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

Multiple-Task Performance: A Critical Review of the Literature and a Cognitive Neuroscience Framework

DTIC Science & Technology

1994-03-10

determine capacity variations as shown in dual-task performance. In addition, neurobiology and psychological evidence shows that the nervous system is...do we perform complex tasks requiring two or more activities in a short period of time and what determines the quality of performance? Psychological ...definition for these kinds of entities. Introduction of the computer metaphor in cognitive psychology , ascribing behavioral capacity limitations to a kind

Cooperating Expert Systems For Space Station Power Distribution Management

NASA Astrophysics Data System (ADS)

Nguyen, T. A.; Chiou, W. C.

1987-02-01

In a complex system such as the manned Space Station, it is deem necessary that many expert systems must perform tasks in a concurrent and cooperative manner. An important question arise is: what cooperative-task-performing models are appropriate for multiple expert systems to jointly perform tasks. The solution to this question will provide a crucial automation design criteria for the Space Station complex systems architecture. Based on a client/server model for performing tasks, we have developed a system that acts as a front-end to support loosely-coupled communications between expert systems running on multiple Symbolics machines. As an example, we use two ART*-based expert systems to demonstrate the concept of parallel symbolic manipulation for power distribution management and dynamic load planner/scheduler in the simulated Space Station environment. This on-going work will also explore other cooperative-task-performing models as alternatives which can evaluate inter and intra expert system communication mechanisms. It will be served as a testbed and a bench-marking tool for other Space Station expert subsystem communication and information exchange.

Complex Sentence Comprehension and Working Memory in Children With Specific Language Impairment

PubMed Central

Montgomery, James W.; Evans, Julia L.

2015-01-01

Purpose This study investigated the association of 2 mechanisms of working memory (phonological short-term memory [PSTM], attentional resource capacity/allocation) with the sentence comprehension of school-age children with specific language impairment (SLI) and 2 groups of control children. Method Twenty-four children with SLI, 18 age-matched (CA) children, and 16 language- and memory-matched (LMM) children completed a nonword repetition task (PSTM), the competing language processing task (CLPT; resource capacity/allocation), and a sentence comprehension task comprising complex and simple sentences. Results (1) The SLI group performed worse than the CA group on each memory task; (2) all 3 groups showed comparable simple sentence comprehension, but for complex sentences, the SLI and LMM groups performed worse than the CA group; (3) for the SLI group, (a) CLPT correlated with complex sentence comprehension, and (b) nonword repetition correlated with simple sentence comprehension; (4) for CA children, neither memory variable correlated with either sentence type; and (5) for LMM children, only CLPT correlated with complex sentences. Conclusions Comprehension of both complex and simple grammar by school-age children with SLI is a mentally demanding activity, requiring significant working memory resources. PMID:18723601

Quantifying the Physiological Stress Response to Simulated Maritime Pilotage Tasks: The Influence of Task Complexity and Pilot Experience.

PubMed

Main, Luana C; Wolkow, Alexander; Chambers, Timothy P

2017-11-01

The aim of this study was to quantify the stress associated with performing maritime pilotage tasks in a high-fidelity simulator. Eight trainee and 13 maritime pilots completed two simulated pilotage tasks of varying complexity. Salivary cortisol samples were collected pre- and post-simulation for both trials. Heart rate was measured continuously throughout the study. Significant changes in salivary cortisol (P = 0.000, η = 0.139), average (P = 0.006, η = 0.087), and peak heart rate (P = 0.013, η = 0.077) from pre- to postsimulation were found. Varying task complexity did partially influence stress response; average (P = 0.016, η = 0.026) and peak heart rate (P = 0.034, η = 0.020) were higher in the experimental condition. Trainees also recorded higher average (P = 0.000, η = 0.054) and peak heart rates (P = 0.027, η = 0.022). Performing simulated pilotage tasks evoked a measurable stress response in both trainee and expert maritime pilots.

Making Student Online Teams Work

ERIC Educational Resources Information Center

Olsen, Joel; Kalinski, Ray

2017-01-01

Online professors typically assign teams based on time zones, performance, or alphabet, but are these the best ways to position student virtual teams for success? Personality and task complexity could provide additional direction. Personality and task complexity were used as independent variables related to the depended variable of team…

Effects of training on short- and long-term skill retention in a complex multiple-task environment.

PubMed

Sauer, J; Hockey, G R; Wastell, D G

2000-12-01

The paper reports the results of an experiment on the performance and retention of a complex task. This was a computer-based simulation of the essential elements of a spacecraft's life support system. It allowed the authors to take a range of measures, including primary and secondary task performance, system intervention and information sampling strategies, mental model structure, and subjective operator state. The study compared the effectiveness of two methods of training, based on low level (procedure-based) and high level (system-based) understanding. Twenty-five participants were trained extensively on the task, then given a 1-h testing session. A second testing session was carried out 8 months after the first (with no intervening practice) with 17 of the original participants. While training had little effect on control performance, there were considerable effects on system management strategies, as well as in structure of operator's mental model. In the second testing session, the anticipated general performance decrement did not occur, though for complex faults there was an increase in selectivity towards the primary control task. The relevance of the findings for training and skill retention in real work environments is discussed in the context of a model of compensatory control.

Structured analysis and modeling of complex systems

NASA Technical Reports Server (NTRS)

Strome, David R.; Dalrymple, Mathieu A.

1992-01-01

The Aircrew Evaluation Sustained Operations Performance (AESOP) facility at Brooks AFB, Texas, combines the realism of an operational environment with the control of a research laboratory. In recent studies we collected extensive data from the Airborne Warning and Control Systems (AWACS) Weapons Directors subjected to high and low workload Defensive Counter Air Scenarios. A critical and complex task in this environment involves committing a friendly fighter against a hostile fighter. Structured Analysis and Design techniques and computer modeling systems were applied to this task as tools for analyzing subject performance and workload. This technology is being transferred to the Man-Systems Division of NASA Johnson Space Center for application to complex mission related tasks, such as manipulating the Shuttle grappler arm.

Measuring information processing in a client with extreme agitation following traumatic brain injury using the Perceive, Recall, Plan and Perform System of Task Analysis.

PubMed

Nott, Melissa T; Chapparo, Christine

2008-09-01

Agitation following traumatic brain injury is characterised by a heightened state of activity with disorganised information processing that interferes with learning and achieving functional goals. This study aimed to identify information processing problems during task performance of a severely agitated adult using the Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis. Second, this study aimed to examine the sensitivity of the PRPP System to changes in task performance over a short period of rehabilitation, and third, to evaluate the guidance provided by the PRPP in directing intervention. A case study research design was employed. The PRPP System of Task Analysis was used to assess changes in task embedded information processing capacity during occupational therapy intervention with a severely agitated adult in a rehabilitation context. Performance is assessed on three selected tasks over a one-month period. Information processing difficulties during task performance can be clearly identified when observing a severely agitated adult following a traumatic brain injury. Processing skills involving attention, sensory processing and planning were most affected at this stage of rehabilitation. These processing difficulties are linked to established descriptions of agitated behaviour. Fluctuations in performance across three tasks of differing processing complexity were evident, leading to hypothesised relationships between task complexity, environment and novelty with information processing errors. Changes in specific information processing capacity over time were evident based on repeated measures using the PRPP System of Task Analysis. This lends preliminary support for its utility as an outcome measure, and raises hypotheses about the type of therapy required to enhance information processing in people with severe agitation. The PRPP System is sensitive to information processing changes in severely agitated adults when used to reassess performance over short intervals and can provide direct guidance to occupational therapy intervention to improve task embedded information processing by categorising errors under four stages of an information processing model: Perceive, Recall, Plan and Perform.

Effects of Strategy Instruction on the Learning, Use, and Vertical Transfer of Strategies.

ERIC Educational Resources Information Center

Finley, Fred N.; Smith, Edward L.

1980-01-01

Compares group differences in strategy learning, use, and transfer to a more complex task for two groups of elementary students (N=48). Asked to perform three tasks in classifying igneous rocks, the groups differed in whether they received advice on the use of a specific strategy for performing each task. (CS)

The Endurance of Children's Working Memory: A Recall Time Analysis

ERIC Educational Resources Information Center

Towse, John N.; Hitch, Graham J.; Hamilton, Z.; Pirrie, Sarah

2008-01-01

We analyze the timing of recall as a source of information about children's performance in complex working memory tasks. A group of 8-year-olds performed a traditional operation span task in which sequence length increased across trials and an operation period task in which processing requirements were extended across trials of constant sequence…

Supporting interruption management and multimodal interface design: three meta-analyses of task performance as a function of interrupting task modality.

PubMed

Lu, Sara A; Wickens, Christopher D; Prinet, Julie C; Hutchins, Shaun D; Sarter, Nadine; Sebok, Angelia

2013-08-01

The aim of this study was to integrate empirical data showing the effects of interrupting task modality on the performance of an ongoing visual-manual task and the interrupting task itself. The goal is to support interruption management and the design of multimodal interfaces. Multimodal interfaces have been proposed as a promising means to support interruption management.To ensure the effectiveness of this approach, their design needs to be based on an analysis of empirical data concerning the effectiveness of individual and redundant channels of information presentation. Three meta-analyses were conducted to contrast performance on an ongoing visual task and interrupting tasks as a function of interrupting task modality (auditory vs. tactile, auditory vs. visual, and single modality vs. redundant auditory-visual). In total, 68 studies were included and six moderator variables were considered. The main findings from the meta-analyses are that response times are faster for tactile interrupting tasks in case of low-urgency messages.Accuracy is higher with tactile interrupting tasks for low-complexity signals but higher with auditory interrupting tasks for high-complexity signals. Redundant auditory-visual combinations are preferable for communication tasks during high workload and with a small visual angle of separation. The three meta-analyses contribute to the knowledge base in multimodal information processing and design. They highlight the importance of moderator variables in predicting the effects of interruption task modality on ongoing and interrupting task performance. The findings from this research will help inform the design of multimodal interfaces in data-rich, event-driven domains.

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.

Speech Perception in MRI Scanner Noise by Persons with Aphasia

ERIC Educational Resources Information Center

Healy, Eric W.; Moser, Dana C.; Morrow-Odom, K. Leigh; Hall, Deborah A.; Fridriksson, Julius

2007-01-01

Purpose: To examine reductions in performance on auditory tasks by aphasic and neurologically intact individuals as a result of concomitant magnetic resonance imaging (MRI) scanner noise. Method: Four tasks together forming a continuum of linguistic complexity were developed. They included complex-tone pitch discrimination, same-different…

Some effects of alcohol and simulated altitude on complex performance scores and Breathalyzer readings.

DOT National Transportation Integrated Search

1985-07-01

This study assessed possible interactive effects of alcohol and a simulated altitude of 12,500 ft. Each of 17 men was trained on the various tasks that comprise the Multiple Task Performance Battery and then performed over a 2-week period in four exp...

Learning and inference using complex generative models in a spatial localization task.

PubMed

Bejjanki, Vikranth R; Knill, David C; Aslin, Richard N

2016-01-01

A large body of research has established that, under relatively simple task conditions, human observers integrate uncertain sensory information with learned prior knowledge in an approximately Bayes-optimal manner. However, in many natural tasks, observers must perform this sensory-plus-prior integration when the underlying generative model of the environment consists of multiple causes. Here we ask if the Bayes-optimal integration seen with simple tasks also applies to such natural tasks when the generative model is more complex, or whether observers rely instead on a less efficient set of heuristics that approximate ideal performance. Participants localized a "hidden" target whose position on a touch screen was sampled from a location-contingent bimodal generative model with different variances around each mode. Over repeated exposure to this task, participants learned the a priori locations of the target (i.e., the bimodal generative model), and integrated this learned knowledge with uncertain sensory information on a trial-by-trial basis in a manner consistent with the predictions of Bayes-optimal behavior. In particular, participants rapidly learned the locations of the two modes of the generative model, but the relative variances of the modes were learned much more slowly. Taken together, our results suggest that human performance in a more complex localization task, which requires the integration of sensory information with learned knowledge of a bimodal generative model, is consistent with the predictions of Bayes-optimal behavior, but involves a much longer time-course than in simpler tasks.

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 and 80 completed the study. There was a main effect for accuracy such that older adults made more accurate decisions in the color info-vis condition than the table condition. In the low difficulty condition, participants were more successful at choosing the correct answer when the question was about the gap coverage attribute in the info-vis condition. Participants also made significantly faster decisions in the info-vis condition than in the table condition. Reducing the working memory demand of the task through the use of an ES can improve decision accuracy, especially when selection criteria is only focused on a single attribute of the insurance plan.

Hemodynamic Response Alteration As a Function of Task Complexity and Expertise—An fNIRS Study in Jugglers

PubMed Central

Carius, Daniel; Andrä, Christian; Clauß, Martina; Ragert, Patrick; Bunk, Michael; Mehnert, Jan

2016-01-01

Detailed knowledge about online brain processing during the execution of complex motor tasks with a high motion range still remains elusive. The aim of the present study was to investigate the hemodynamic responses within sensorimotor networks as well as in visual motion area during the execution of a complex visuomotor task such as juggling. More specifically, we were interested in how far the hemodynamic response as measured with functional near infrared spectroscopy (fNIRS) adapts as a function of task complexity and the level of the juggling expertise. We asked expert jugglers to perform different juggling tasks with different levels of complexity such as a 2-ball juggling, 3- and 5-ball juggling cascades. We here demonstrate that expert jugglers show an altered neurovascular response with increasing task complexity, since a 5-ball juggling cascade showed enhanced hemodynamic responses for oxygenated hemoglobin as compared to less complex tasks such as a 3- or 2-ball juggling pattern. Moreover, correlations between the hemodynamic response and the level of the juggling expertise during the 5-ball juggling cascade, acquired by cinematographic video analysis, revealed only a non-significant trend in primary motor cortex, indicating that a higher level of expertise might be associated with lower hemodynamic responses. PMID:27064925

The stability of working memory: do previous tasks influence complex span?

PubMed

Healey, M Karl; Hasher, Lynn; Danilova, Elena

2011-11-01

Schmeichel (2007) reported that performing an initial task before completing a working memory span task can lower span scores and suggested that the effect was due to depleted cognitive resources. We showed that the detrimental effect of prior tasks depends on a match between the stimuli used in the span task and the preceding task. A task requiring participants to ignore words reduced performance on a subsequent word-based verbal span task but not on an arrow-based spatial span task. Ignoring arrows had the opposite pattern of effects: reducing performance on the spatial span task but not on the word-based span task. Finally, we showed that antisaccade, a nonverbal task that taxes domain-general processes implicated in working memory, did not influence subsequent performance of either a verbal or a spatial span task. Together these results suggest that while span is sensitive to prior tasks, that sensitivity does not stem from depleted resources. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

Sleep Consolidates Motor Learning of Complex Movement Sequences in Mice.

PubMed

Nagai, Hirotaka; de Vivo, Luisa; Bellesi, Michele; Ghilardi, Maria Felice; Tononi, Giulio; Cirelli, Chiara

2017-02-01

Sleep-dependent consolidation of motor learning has been extensively studied in humans, but it remains unclear why some, but not all, learned skills benefit from sleep. Here, we compared 2 different motor tasks, both requiring the mice to run on an accelerating device. In the rotarod task, mice learn to maintain balance while running on a small rod, while in the complex wheel task, mice run on an accelerating wheel with an irregular rung pattern. In the rotarod task, performance improved to the same extent after sleep or after sleep deprivation (SD). Overall, using 7 different experimental protocols (41 sleep deprived mice, 26 sleeping controls), we found large interindividual differences in the learning and consolidation of the rotarod task, but sleep before/after training did not account for this variability. By contrast, using the complex wheel, we found that sleep after training, relative to SD, led to better performance from the beginning of the retest session, and longer sleep was correlated with greater subsequent performance. As in humans, the effects of sleep showed large interindividual variability and varied between fast and slow learners, with sleep favoring the preservation of learned skills in fast learners and leading to a net offline gain in the performance in slow learners. Using Fos expression as a proxy for neuronal activation, we also found that complex wheel training engaged motor cortex and hippocampus more than the rotarod training. Sleep specifically consolidates a motor skill that requires complex movement sequences and strongly engages both motor cortex and hippocampus. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Why are you late? Investigating the role of time management in time-based prospective memory.

PubMed

Waldum, Emily R; McDaniel, Mark A

2016-08-01

Time-based prospective memory tasks (TBPM) are those that are to be performed at a specific future time. Contrary to typical laboratory TBPM tasks (e.g., hit the Z key every 5 min), many real-world TBPM tasks require more complex time-management processes. For instance, to attend an appointment on time, one must estimate the duration of the drive to the appointment and then use this estimate to create and execute a secondary TBPM intention (e.g., "I need to start driving by 1:30 to make my 2:00 appointment on time"). Future under- and overestimates of drive time can lead to inefficient TBPM performance with the former lending to missed appointments and the latter to long stints in the waiting room. Despite the common occurrence of complex TBPM tasks in everyday life, to date, no studies have investigated how components of time management, including time estimation, affect behavior in such complex TBPM tasks. Therefore, the current study aimed to investigate timing biases in both older and younger adults and, further, to determine how such biases along with additional time management components including planning and plan fidelity influence complex TBPM performance. Results suggest for the first time that younger and older adults do not always utilize similar timing strategies, and as a result, can produce differential timing biases under the exact same environmental conditions. These timing biases, in turn, play a vital role in how efficiently both younger and older adults perform a later TBPM task that requires them to utilize their earlier time estimate. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Non-visual spatial tasks reveal increased interactions with stance postural control.

PubMed

Woollacott, Marjorie; Vander Velde, Timothy

2008-05-07

The current investigation aimed to contrast the level and quality of dual-task interactions resulting from the combined performance of a challenging primary postural task and three specific, yet categorically dissociated, secondary central executive tasks. Experiments determined the extent to which modality (visual vs. auditory) and code (non-spatial vs. spatial) specific cognitive resources contributed to postural interference in young adults (n=9) in a dual-task setting. We hypothesized that the different forms of executive n-back task processing employed (visual-object, auditory-object and auditory-spatial) would display contrasting levels of interactions with tandem Romberg stance postural control, and that interactions within the spatial domain would be revealed as most vulnerable to dual-task interactions. Across all cognitive tasks employed, including auditory-object (aOBJ), auditory-spatial (aSPA), and visual-object (vOBJ) tasks, increasing n-back task complexity produced correlated increases in verbal reaction time measures. Increasing cognitive task complexity also resulted in consistent decreases in judgment accuracy. Postural performance was significantly influenced by the type of cognitive loading delivered. At comparable levels of cognitive task difficulty (n-back demands and accuracy judgments) the performance of challenging auditory-spatial tasks produced significantly greater levels of postural sway than either the auditory-object or visual-object based tasks. These results suggest that it is the employment of limited non-visual spatially based coding resources that may underlie previously observed visual dual-task interference effects with stance postural control in healthy young adults.

Learning to multitask: effects of video game practice on electrophysiological indices of attention and resource allocation.

PubMed

Maclin, Edward L; Mathewson, Kyle E; Low, Kathy A; Boot, Walter R; Kramer, Arthur F; Fabiani, Monica; Gratton, Gabriele

2011-09-01

Changes in attention allocation with complex task learning reflect processing automatization and more efficient control. We studied these changes using ERP and EEG spectral analyses in subjects playing Space Fortress, a complex video game comprising standard cognitive task components. We hypothesized that training would free up attentional resources for a secondary auditory oddball task. Both P3 and delta EEG showed a processing trade-off between game and oddball tasks, but only some game events showed reduced attention requirements with practice. Training magnified a transient increase in alpha power following both primary and secondary task events. This contrasted with alpha suppression observed when the oddball task was performed alone, suggesting that alpha may be related to attention switching. Hence, P3 and EEG spectral data are differentially sensitive to changes in attentional processing occurring with complex task training. Copyright © 2011 Society for Psychophysiological Research.

The effects of legacy organization culture on post-merger integration.

PubMed

Frantz, Terrill L; Carley, Kathleen M

2013-01-01

We explore the relationship between the characteristics of pre-existing organization cultures and post-merger integration dynamics; this study involves examining data produced by computer simulation. Two characteristics of organization culture, its characteristic complexity and its propensity for members' to share information, are controlled in computational experiments. To characterize post-merger integration dynamics, we measure the transfer of information with respect to two types: (a) that which is necessary in performing work tasks, and (b) that which underlies the features of a group's culture. The extent to which this information is common in a group is indicative of task performance and the cultural cohesiveness of its members; leading to the level of performance for the group. We consider cultural knowledge as it pertains to both that of the entire organization and at the work-team level; often times, these can be dissimilar. We find that cultural complexity and exchange motivation vary in their influence on the diffusion of task and cultural knowledge: the more complex the culture, the longer for post-merger integration to complete, while simultaneously task performance suffers. However, the inclination for an organization to energetically share their culture with another group does not immensely impact the diffusion of cultural or task knowledge; moreover, high levels of task focus in a culture can hinder cultural diffusion, though performance is positively correlated with this characteristic. This study has relevance to post-merger integration research and practice by providing a theoretically grounded, quantitative model useful for estimating the post-merger dynamics of cultural awareness and knowledge diffusion for a specific merger situation.

Modeling the Psychometric Properties of Complex Performance Assessment Tasks Using Confirmatory Factor Analysis: A Multistage Model for Calibrating Tasks

ERIC Educational Resources Information Center

Kahraman, Nilufer; De Champlain, Andre; Raymond, Mark

2012-01-01

Item-level information, such as difficulty and discrimination are invaluable to the test assembly, equating, and scoring practices. Estimating these parameters within the context of large-scale performance assessments is often hindered by the use of unbalanced designs for assigning examinees to tasks and raters because such designs result in very…

Error framing effects on performance: cognitive, motivational, and affective pathways.

PubMed

Steele-Johnson, Debra; Kalinoski, Zachary T

2014-01-01

Our purpose was to examine whether positive error framing, that is, making errors salient and cuing individuals to see errors as useful, can benefit learning when task exploration is constrained. Recent research has demonstrated the benefits of a newer approach to training, that is, error management training, that includes the opportunity to actively explore the task and framing errors as beneficial to learning complex tasks (Keith & Frese, 2008). Other research has highlighted the important role of errors in on-the-job learning in complex domains (Hutchins, 1995). Participants (N = 168) from a large undergraduate university performed a class scheduling task. Results provided support for a hypothesized path model in which error framing influenced cognitive, motivational, and affective factors which in turn differentially affected performance quantity and quality. Within this model, error framing had significant direct effects on metacognition and self-efficacy. Our results suggest that positive error framing can have beneficial effects even when tasks cannot be structured to support extensive exploration. Whereas future research can expand our understanding of error framing effects on outcomes, results from the current study suggest that positive error framing can facilitate learning from errors in real-time performance of tasks.

From Brown-Peterson to continual distractor via operation span: A SIMPLE account of complex span.

PubMed

Neath, Ian; VanWormer, Lisa A; Bireta, Tamra J; Surprenant, Aimée M

2014-09-01

Three memory tasks-Brown-Peterson, complex span, and continual distractor-all alternate presentation of a to-be-remembered item and a distractor activity, but each task is associated with a different memory system, short-term memory, working memory, and long-term memory, respectively. SIMPLE, a relative local distinctiveness model, has previously been fit to data from both the Brown-Peterson and continual distractor tasks; here we use the same version of the model to fit data from a complex span task. Despite the many differences between the tasks, including unpredictable list length, SIMPLE fit the data well. Because SIMPLE posits a single memory system, these results constitute yet another demonstration that performance on tasks originally thought to tap different memory systems can be explained without invoking multiple memory systems.

Lesions of the rat nucleus basalis magnocellularis disrupt appetitive-to-aversive transfer learning.

PubMed

Butt, A E; Schultz, J A; Arnold, L L; Garman, E E; George, C L; Garraghty, P E

2003-01-01

Rats with selective lesions of the nucleus basalis magnocellularis (NBM) and sham-lesion control animals were tested in an operant appetitive-to-aversive transfer task. We hypothesized that NBM lesions would not affect performance in the appetitive phase, but that performance would be impaired during subsequent transfer to the aversive phase of the task. Additional groups of NBM lesion and control rats were tested in the avoidance condition only, where we hypothesized that NBM lesions would not disrupt performance. These hypotheses were based on the argument that the NBM is not necessary for simple association learning that does not tax attention. Both the appetitive phase of the transfer task and the avoidance only task depend only on simple associative learning and are argued not to tax attention. Consequently, performance in these tasks was predicted to be spared following NBM lesions. Complex, attention-demanding associative learning, however, is argued to depend on the NBM. Performance in the aversive phase of the transfer task is both attentionally demanding and associatively more complex than in either the appetitive or aversive tasks alone; thus, avoidance performance in the NBM lesion group was predicted to be impaired following transfer from prior appetitive conditioning. Results supported our hypotheses, with the NBM lesion group acquiring the appetitive response normally, but showing impaired performance following transfer to the aversive conditioning phase of the transfer task. Impairments were not attributable to disrupted avoidance learning per se, as avoidance behavior was normal in the NBM lesion group tested in the avoidance condition only.

Proactive and coactive interference in age-related performance in a recognition-based operation span task.

PubMed

Zeintl, Melanie; Kliegel, Matthias

2010-01-01

Generally, older adults perform worse than younger adults in complex working memory span tasks. So far, it is unclear which processes mainly contribute to age-related differences in working memory span. The aim of the present study was to investigate age effects and the roles of proactive and coactive interference in a recognition-based version of the operation span task. Younger and older adults performed standard versions and distracter versions of the operation span task. At retrieval, participants had to recognize target words in word lists containing targets as well as proactive and/or coactive interference-related lures. Results show that, overall, younger adults outperformed older adults in the recognition of target words. Furthermore, analyses of error types indicate that, while younger adults were only affected by simultaneously presented distracter words, older adults had difficulties with both proactive and coactive interference. Results suggest that age effects in complex span tasks may not be mainly due to retrieval deficits in old age. Copyright 2009 S. Karger AG, Basel.

A "spoon full of sugar" helps the medicine go down: How a participant friendly version of a psychophysics task significantly improves task engagement, performance and data quality in a typical adult sample.

PubMed

Smith, Marie L; Cesana, M Letizia; Farran, Emily K; Karmiloff-Smith, Annette; Ewing, Louise

2018-06-01

Few would argue that the unique insights brought by studying the typical and atypical development of psychological processes are essential to building a comprehensive understanding of the brain. Often, however, the associated challenges of working with non-standard adult populations results in the more complex psychophysical paradigms being rejected as too complex. Recently we created a child- (and clinical group) friendly implementation of one such technique - the reverse-correlation Bubbles approach - and noted an associated performance boost in adult participants. Here, we compare the administration of three different versions of this participant-friendly task in the same adult participants to empirically confirm that introducing elements in the experiment with the sole purpose of improving the participant experience, not only boosts the participant's engagement and motivation for the task but results in a significantly improved objective task performance and stronger statistical results.

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

PubMed

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

2017-10-01

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

The Hebb repetition effect in simple and complex memory span.

PubMed

Oberauer, Klaus; Jones, Timothy; Lewandowsky, Stephan

2015-08-01

The Hebb repetition effect refers to the finding that immediate serial recall is improved over trials for memory lists that are surreptitiously repeated across trials, relative to new lists. We show in four experiments that the Hebb repetition effect is also observed with a complex-span task, in which encoding or retrieval of list items alternates with an unrelated processing task. The interruption of encoding or retrieval by the processing task did not reduce the size of the Hebb effect, demonstrating that incidental long-term learning forms integrated representations of lists, excluding the interleaved processing events. Contrary to the assumption that complex-span performance relies more on long-term memory than standard immediate serial recall (simple span), the Hebb effect was not larger in complex-span than in simple-span performance. The Hebb effect in complex span was also not modulated by the opportunity for refreshing list items, questioning a role of refreshing for the acquisition of the long-term memory representations underlying the effect.

Efficient Symbolic Task Planning for Multiple Mobile Robots

DTIC Science & Technology

2016-12-13

Efficient Symbolic Task Planning for Multiple Mobile Robots Yuqian Jiang December 13, 2016 Abstract Symbolic task planning enables a robot to make...high-level deci- sions toward a complex goal by computing a sequence of actions with minimum expected costs. This thesis builds on a single- robot ...time complexity of optimal planning for multiple mobile robots . In this thesis we first investigate the performance of the state-of-the-art solvers of

Efficient estimation of ideal-observer performance in classification tasks involving high-dimensional complex backgrounds

PubMed Central

Park, Subok; Clarkson, Eric

2010-01-01

The Bayesian ideal observer is optimal among all observers and sets an absolute upper bound for the performance of any observer in classification tasks [Van Trees, Detection, Estimation, and Modulation Theory, Part I (Academic, 1968).]. Therefore, the ideal observer should be used for objective image quality assessment whenever possible. However, computation of ideal-observer performance is difficult in practice because this observer requires the full description of unknown, statistical properties of high-dimensional, complex data arising in real life problems. Previously, Markov-chain Monte Carlo (MCMC) methods were developed by Kupinski et al. [J. Opt. Soc. Am. A 20, 430(2003) ] and by Park et al. [J. Opt. Soc. Am. A 24, B136 (2007) and IEEE Trans. Med. Imaging 28, 657 (2009) ] to estimate the performance of the ideal observer and the channelized ideal observer (CIO), respectively, in classification tasks involving non-Gaussian random backgrounds. However, both algorithms had the disadvantage of long computation times. We propose a fast MCMC for real-time estimation of the likelihood ratio for the CIO. Our simulation results show that our method has the potential to speed up ideal-observer performance in tasks involving complex data when efficient channels are used for the CIO. PMID:19884916

Face and Construct Validity of a Novel Virtual Reality-Based Bimanual Laparoscopic Force-Skills Trainer With Haptics Feedback.

PubMed

Prasad, Raghu; Muniyandi, Manivannan; Manoharan, Govindan; Chandramohan, Servarayan M

2018-05-01

The purpose of this study was to examine the face and construct validity of a custom-developed bimanual laparoscopic force-skills trainer with haptics feedback. The study also examined the effect of handedness on fundamental and complex tasks. Residents (n = 25) and surgeons (n = 25) performed virtual reality-based bimanual fundamental and complex tasks. Tool-tissue reaction forces were summed, recorded, and analysed. Seven different force-based measures and a 1-time measure were used as metrics. Subsequently, participants filled out face validity and demographic questionnaires. Residents and surgeons were positive on the design, workspace, and usefulness of the simulator. Construct validity results showed significant differences between residents and experts during the execution of fundamental and complex tasks. In both tasks, residents applied large forces with higher coefficient of variation and force jerks (P < .001). Experts, with their dominant hand, applied lower forces in complex tasks and higher forces in fundamental tasks (P < .001). The coefficients of force variation (CoV) of residents and experts were higher in complex tasks (P < .001). Strong correlations were observed between CoV and task time for fundamental (r = 0.70) and complex tasks (r = 0.85). Range of smoothness of force was higher for the non-dominant hand in both fundamental and complex tasks. The simulator was able to differentiate the force-skills of residents and surgeons, and objectively evaluate the effects of handedness on laparoscopic force-skills. Competency-based laparoscopic skills assessment curriculum should be updated to meet the requirements of bimanual force-based training.

Effects of task complexity on activation of language areas in a semantic decision fMRI protocol.

PubMed

Lopes, Tátila Martins; Yasuda, Clarissa Lin; de Campos, Brunno Machado; Balthazar, Marcio L F; Binder, Jeffrey R; Cendes, Fernando

2016-01-29

Language tasks used for clinical fMRI studies may be too complex for some patients with cognitive impairments, and "easier" versions are sometimes substituted, though the effects on brain activity of such changes in task complexity are largely unknown. To investigate these differences, we compared two versions of an fMRI language comprehension protocol, with different levels of difficulty, in 24 healthy right-handed adults. The protocol contrasted an auditory word comprehension task (semantic decision) with a nonspeech control task using tone sequences (tone decision). In the "complex" version (CV), the semantic decision task required two complex semantic decisions for each word, and the tone decision task required the participant to count the number of target tones in each sequence. In the "easy" version (EV), the semantic task required only a single easier decision, and the tone task required only detection of the presence or absence of a target tone in each sequence. The protocols were adapted for a Brazilian population. Typical left hemisphere language lateralization was observed in 92% of participants for both CV and EV using the whole-brain lateralization index, and typical language lateralization was also observed for others regions of interest. Task performance was superior on the EV compared to the CV (p=0.014). There were many common areas of activation across the two version; however, the CV produced greater activation in the left superior and middle frontal giri, angular gyrus, and left posterior cingulate gyrus compared to the EV, the majority of which are areas previously identified with language and semantic processing. The EV produced stronger activation only in a small area in the posterior middle temporal gyrus. These results reveal differences between two versions of the protocol and provide evidence that both are useful for language lateralization and worked well for Brazilian population. The complex version produces stronger activation in several nodes of the semantic network and therefore is elected for participants who can perform well these tasks. Copyright © 2015 Elsevier Ltd. All rights reserved.

Selecting Learning Tasks: Effects of Adaptation and Shared Control on Learning Efficiency and Task Involvement

ERIC Educational Resources Information Center

Corbalan, Gemma; Kester, Liesbeth; van Merrienboer, Jeroen J. G.

2008-01-01

Complex skill acquisition by performing authentic learning tasks is constrained by limited working memory capacity [Baddeley, A. D. (1992). Working memory. "Science, 255", 556-559]. To prevent cognitive overload, task difficulty and support of each newly selected learning task can be adapted to the learner's competence level and perceived task…

Sentence Production in Parkinson Disease: Effects of Conceptual and Task Complexity

ERIC Educational Resources Information Center

Troche, Michelle S.; Altmann, Lori J. P.

2012-01-01

Experimental studies of sentence production in Parkinson disease (PD) are rare. This study examined the relationship between cognitive abilities and performance on two sentence production tasks, sentence repetition, and sentence generation, in which complexity was manipulated. Thirty-eight older adults aged 60 to 85, half with PD, completed the…

Time-Accuracy Functions for Determining Process and Person Differences: An Application to Cognitive Aging.

ERIC Educational Resources Information Center

Kliegl, Reinhold; And Others

1994-01-01

Tests with 2 pairs of tasks differing in cognitive complexity performed by 20 young and 20 old adults support a model for the determination of time-accuracy functions (TAFs) for individual participants. Findings replicate the established interactions between age and task complexity in the context of TAFs. (SLD)

Human behavioral complexity peaks at age 25

PubMed Central

Brugger, Peter

2017-01-01

Random Item Generation tasks (RIG) are commonly used to assess high cognitive abilities such as inhibition or sustained attention. They also draw upon our approximate sense of complexity. A detrimental effect of aging on pseudo-random productions has been demonstrated for some tasks, but little is as yet known about the developmental curve of cognitive complexity over the lifespan. We investigate the complexity trajectory across the lifespan of human responses to five common RIG tasks, using a large sample (n = 3429). Our main finding is that the developmental curve of the estimated algorithmic complexity of responses is similar to what may be expected of a measure of higher cognitive abilities, with a performance peak around 25 and a decline starting around 60, suggesting that RIG tasks yield good estimates of such cognitive abilities. Our study illustrates that very short strings of, i.e., 10 items, are sufficient to have their complexity reliably estimated and to allow the documentation of an age-dependent decline in the approximate sense of complexity. PMID:28406953

Evaluating stereoscopic displays: both efficiency measures and perceived workload sensitive to manipulations in binocular disparity

NASA Astrophysics Data System (ADS)

van Beurden, Maurice H. P. H.; Ijsselsteijn, Wijnand A.; de Kort, Yvonne A. W.

2011-03-01

Stereoscopic displays are known to offer a number of key advantages in visualizing complex 3D structures or datasets. The large majority of studies that focus on evaluating stereoscopic displays for professional applications use completion time and/or the percentage of correct answers to measure potential performance advantages. However, completion time and accuracy may not fully reflect all the benefits of stereoscopic displays. In this paper, we argue that perceived workload is an additional valuable indicator reflecting the extent to which users can benefit from using stereoscopic displays. We performed an experiment in which participants were asked to perform a visual path-tracing task within a convoluted 3D wireframe structure, varying in level of complexity of the visualised structure and level of disparity of the visualisation. The results showed that an optimal performance (completion time, accuracy and workload), depend both on task difficulty and disparity level. Stereoscopic disparity revealed a faster and more accurate task performance, whereas we observed a trend that performance on difficult tasks stands to benefit more from higher levels of disparity than performance on easy tasks. Perceived workload (as measured using the NASA-TLX) showed a similar response pattern, providing evidence that perceived workload is sensitive to variations in disparity as well as task difficulty. This suggests that perceived workload could be a useful concept, in addition to standard performance indicators, in characterising and measuring human performance advantages when using stereoscopic displays.

Linking clinician interaction and coordination to clinical performance in Patient-Aligned Care Teams.

PubMed

Hysong, Sylvia J; Thomas, Candice L; Spitzmüller, Christiane; Amspoker, Amber B; Woodard, LeChauncy; Modi, Varsha; Naik, Aanand D

2016-01-15

Team coordination within clinical care settings is a critical component of effective patient care. Less is known about the extent, effectiveness, and impact of coordination activities among professionals within VA Patient-Aligned Care Teams (PACTs). This study will address these gaps by describing the specific, fundamental tasks and practices involved in PACT coordination, their impact on performance measures, and the role of coordination task complexity. First, we will use a web-based survey of coordination practices among 1600 PACTs in the national VHA. Survey findings will characterize PACT coordination practices and assess their association with clinical performance measures. Functional job analysis, using 6-8 subject matter experts who are 3rd and 4th year residents in VA Primary Care rotations, will be utilized to identify the tasks involved in completing clinical performance measures to standard. From this, expert ratings of coordination complexity will be used to determine the level of coordinative complexity required for each of the clinical performance measures drawn from the VA External Peer Review Program (EPRP). For objective 3, data collected from the first two methods will evaluate the effect of clinical complexity on the relationships between measures of PACT coordination and their ratings on the clinical performance measures. Results from this study will support successful implementation of coordinated team-based work in clinical settings by providing knowledge regarding which aspects of care require the most complex levels of coordination and how specific coordination practices impact clinical performance.

Rhythms of Mental Performance

ERIC Educational Resources Information Center

Valdez, Pablo; Reilly, Thomas; Waterhouse, Jim

2008-01-01

Cognitive performance is affected by an individual's characteristics and the environment, as well as by the nature of the task and the amount of practice at it. Mental performance tests range in complexity and include subjective estimates of mood, simple objective tests (reaction time), and measures of complex performance that require decisions to…

Human interaction with robotic systems: performance and workload evaluations.

PubMed

Reinerman-Jones, L; Barber, D J; Szalma, J L; Hancock, P A

2017-10-01

We first tested the effect of differing tactile informational forms (i.e. directional cues vs. static cues vs. dynamic cues) on objective performance and perceived workload in a collaborative human-robot task. A second experiment evaluated the influence of task load and informational message type (i.e. single words vs. grouped phrases) on that same collaborative task. In both experiments, the relationship of personal characteristics (attentional control and spatial ability) to performance and workload was also measured. In addition to objective performance and self-report of cognitive load, we evaluated different physiological responses in each experiment. Results showed a performance-workload association for directional cues, message type and task load. EEG measures however, proved generally insensitive to such task load manipulations. Where significant EEG effects were observed, right hemisphere amplitude differences predominated, although unexpectedly these latter relationships were negative. Although EEG measures were partially associated with performance, they appear to possess limited utility as measures of workload in association with tactile displays. Practitioner Summary: As practitioners look to take advantage of innovative tactile displays in complex operational realms like human-robotic interaction, associated performance effects are mediated by cognitive workload. Despite some patterns of association, reliable reflections of operator state can be difficult to discern and employ as the number, complexity and sophistication of these respective measures themselves increase.

Do individual differences in Iowa Gambling Task performance predict adaptive decision making for risky gains and losses?

PubMed

Weller, Joshua A; Levin, Irwin P; Bechara, Antoine

2010-02-01

We relate performance on the Iowa Gambling Task (IGT), a widely used, but complex, neuropsychological task of executive function in which mixed outcomes (gains and losses) are experienced together, to performance on a relatively simpler descriptive task, the Cups task, which isolates adaptive decision making for achieving gains and avoiding losses. We found that poor IGT performance was associated with suboptimal decision making on Cups, especially for risky losses, suggesting that losses are weighted more than gains in the IGT. These findings were significant beyond several notable gender differences in which men outperformed women. Implications for the neuropsychological study of risk are discussed.

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.

Ability/Motivation Interactions in Complex Skill Acquisition

DTIC Science & Technology

1988-04-28

attentional resources. Finally, in the declarative knowledge phase, performance is slow and error prone. Once the learner has come to an adequate cognitive...mediation by the learner. After a substantial amount of consistent task practice, skilled performance becomes fast , accurate, and the task can often be

Normal Aging of the Attentional Control Functions That Underlie Working Memory.

PubMed

Sylvain-Roy, Stéphanie; Lungu, Ovidiu; Belleville, Sylvie

2015-09-01

This study assessed the effect of aging on 3 attentional control functions (ACFs)--shifting, inhibition, and updating--and on their contribution to working memory (WM) tasks. Complex WM tasks (the Brown-Peterson procedure, the reading span, and the alpha span) and tasks used to derive composite measures of the ACFs were administered to 75 younger and 75 older adults. Of the 3 ACFs, only inhibition was impaired in aging after controlling for processing speed. Furthermore, the effect of aging on WM tasks was not pervasive, as older adults showed impaired performance on the Brown-Peterson procedure and the reading span but not on the alpha span. When examining the contribution of ACFs to WM in older adults, updating accounted for performance on the Brown-Peterson and reading span tasks, and inhibition was involved in performance on the alpha span task. In younger adults, it was processing speed that contributed the most to WM. This pattern of results suggests that complex WM tasks reflect different ACFs and that this varies as a function of age. © The Author 2014. 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.

Psycho acoustical Measures in Individuals with Congenital Visual Impairment.

PubMed

Kumar, Kaushlendra; Thomas, Teenu; Bhat, Jayashree S; Ranjan, Rajesh

2017-12-01

In congenital visual impaired individuals one modality is impaired (visual modality) this impairment is compensated by other sensory modalities. There is evidence that visual impaired performed better in different auditory task like localization, auditory memory, verbal memory, auditory attention, and other behavioural tasks when compare to normal sighted individuals. The current study was aimed to compare the temporal resolution, frequency resolution and speech perception in noise ability in individuals with congenital visual impaired and normal sighted. Temporal resolution, frequency resolution, and speech perception in noise were measured using MDT, GDT, DDT, SRDT, and SNR50 respectively. Twelve congenital visual impaired participants with age range of 18 to 40 years were taken and equal in number with normal sighted participants. All the participants had normal hearing sensitivity with normal middle ear functioning. Individual with visual impairment showed superior threshold in MDT, SRDT and SNR50 as compared to normal sighted individuals. This may be due to complexity of the tasks; MDT, SRDT and SNR50 are complex tasks than GDT and DDT. Visual impairment showed superior performance in auditory processing and speech perception with complex auditory perceptual tasks.

Team Creative Environment as a Mediator Between CWX and R&D Team Performance and Moderating Boundary Conditions.

PubMed

Bornay-Barrachina, Mar; Herrero, Inés

2018-01-01

The purpose of this study was to investigate how high-quality dyadic co-worker relationships (CWXs) favour or hinder team performance. Specifically, we examine the role played by CWX, team creative environment, job complexity and task interdependence to achieve higher levels of team performance. We analyse data from 410 individuals belonging to 81 R&D teams in technology sciences to examine the quality of the dyadic relationships between team members under the same supervisor (co-workers) and team performance measured by the number of publications as their research output. Higher levels of team average CWX relationships are positively related to the establishment of a favourable creative team environment, ending into higher levels of team performance. Specifically, the role played by team average CWX in such relationship is stronger when job complexity and task interdependence are also high. Team's output not only depends on the leader and his/her relationships with subordinates but also on quality relationships among team members. CWXs contribute to creative team environments, but they are essential where jobs are complex and tasks are highly dependent. This study provides evidence of the important role played by CWXs in determining a creative environment, irrespective of their leaders. Previous research has provided information about how leader's role affects team outcomes, but the role of dyadic co-worker relationships in a team remains still relatively unknown. Considering job complexity and task interdependence variables, the study provides with a better understanding about how and when high-quality CWXs should be promoted to achieve higher team performance.

Auditory Attention and Comprehension During a Simulated Night Shift: Effects of Task Characteristics.

PubMed

Pilcher, June J; Jennings, Kristen S; Phillips, Ginger E; McCubbin, James A

2016-11-01

The current study investigated performance on a dual auditory task during a simulated night shift. Night shifts and sleep deprivation negatively affect performance on vigilance-based tasks, but less is known about the effects on complex tasks. Because language processing is necessary for successful work performance, it is important to understand how it is affected by night work and sleep deprivation. Sixty-two participants completed a simulated night shift resulting in 28 hr of total sleep deprivation. Performance on a vigilance task and a dual auditory language task was examined across four testing sessions. The results indicate that working at night negatively impacts vigilance, auditory attention, and comprehension. The effects on the auditory task varied based on the content of the auditory material. When the material was interesting and easy, the participants performed better. Night work had a greater negative effect when the auditory material was less interesting and more difficult. These findings support research that vigilance decreases during the night. The results suggest that auditory comprehension suffers when individuals are required to work at night. Maintaining attention and controlling effort especially on passages that are less interesting or more difficult could improve performance during night shifts. The results from the current study apply to many work environments where decision making is necessary in response to complex auditory information. Better predicting the effects of night work on language processing is important for developing improved means of coping with shiftwork. © 2016, Human Factors and Ergonomics Society.

Anaerobic power and muscle strength characteristics of 11 years old elite and non-elite boys and girls from gymnastics, team handball, tennis and swimming.

PubMed

Bencke, J; Damsgaard, R; Saekmose, A; Jørgensen, P; Jørgensen, K; Klausen, K

2002-06-01

The aim of the present investigation was to study the possible effects of specificity of training on muscle strength and anaerobic power in children from different sports and at different performance levels in relation to growth and maturation status. Hundred and eighty-four children of both gender participating either in swimming, tennis, team handball or gymnastics were recruited from the best clubs in Denmark. Within each sport, the coach had divided the children into an elite (E) and non-elite (NE) group according to performance level and talent. Tanner stage assessment and body weight and height measurements were performed by a physician. The anaerobic performances were assessed by Wingate tests and jumping performance in squat jump (SJ), countermovement jump (CMJ) and drop jump (DJ) from two heights. Most of the differences between groups in Wingate performance disappeared when the data were normalised to body mass. The gymnasts were the best jumpers and their superiority were increased in the more complex motor coordination tasks like DJ. The results may indicate some influence of training specificity, especially on the more complex motor tasks as DJ and there may be an effect of training before puberty. The performance in the less complex motor tasks like cycling and SJ and CMJ may also be influenced by specific training, but not to the same extent, and heritance may be an important factor for performance in these anaerobic tasks.

Are There Detrimental Effects From Proficiency-Based Training in Fundamentals of Laparoscopic Surgery Among Novices? An Exploration of Goal Theory.

PubMed

Stoller, Jeremy; Joseph, Jeremy; Parodi, Nicholas; Gardner, Aimee

2016-01-01

Goal theory states that novices may experience unintended, detrimental learning effects, with decreased performance, when given performance goals on complex tasks. In these situations, it may be more appropriate to give novices learning goals to help avoid these negative consequences. The purpose of this study was to see whether this tenant of goal theory applied to novices learning 2 tasks of fundamentals of laparoscopic surgery (FLS). Medical and physician assistant students were randomized to a performance goals group and a learning goals group. The performance goals consisted of the published proficiency standards of FLS. Both groups were pretested on perception of surgery, self-efficacy, and general affect. Each group underwent a practice session for the peg transfer task. They were tested and scored per the published standards of FLS. The participants completed NASA Task Load Index, task complexity, and postaffect questionnaires related to the peg transfer task. This was repeated with the suture with intracorporeal knot task. Posttest perception of surgery and self-efficacy questionnaires were completed. In total, 48 students participated in the study: 23 in the performance goals group and 25 in the learning goals group. Most of the participants (n = 40) were first-year medical and physician assistant students. There were no significant differences between the groups in perception of surgery, affect, goal commitment, subjective task complexity, subjective workload, and self-efficacy. There were no differences between the groups concerning overall FLS score for both the peg transfer and suturing tasks. Both groups exhibited significant increases in self-efficacy and perception of surgery (p < 0.05). FLS skills can be given to novice learners without concern for detrimental effects as might be expected by other work on goal theory. Given that performance was the same for both groups, surgical educators may have multiple pathways to educational success when incorporating goals into training programs for basic surgical skills. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

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 Impact of Different Environmental Conditions on Cognitive Function: A Focused Review

PubMed Central

Taylor, Lee; Watkins, Samuel L.; Marshall, Hannah; Dascombe, Ben J.; Foster, Josh

2016-01-01

Cognitive function defines performance in objective tasks that require conscious mental effort. Extreme environments, namely heat, hypoxia, and cold can all alter human cognitive function due to a variety of psychological and/or biological processes. The aims of this Focused Review were to discuss; (1) the current state of knowledge on the effects of heat, hypoxic and cold stress on cognitive function, (2) the potential mechanisms underpinning these alterations, and (3) plausible interventions that may maintain cognitive function upon exposure to each of these environmental stressors. The available evidence suggests that the effects of heat, hypoxia, and cold stress on cognitive function are both task and severity dependent. Complex tasks are particularly vulnerable to extreme heat stress, whereas both simple and complex task performance appear to be vulnerable at even at moderate altitudes. Cold stress also appears to negatively impact both simple and complex task performance, however, the research in this area is sparse in comparison to heat and hypoxia. In summary, this focused review provides updated knowledge regarding the effects of extreme environmental stressors on cognitive function and their biological underpinnings. Tyrosine supplementation may help individuals maintain cognitive function in very hot, hypoxic, and/or cold conditions. However, more research is needed to clarify these and other postulated interventions. PMID:26779029

Exploring Gender Differences in Solving Open-Ended Mathematical Problems.

ERIC Educational Resources Information Center

Cai, Jinfa

Open-ended tasks were used to examine gender differences in complex mathematical problem solving. The results of this study suggest that, overall, males perform better than females, but the gender differences vary from task to task. A qualitative analysis of student responses to those tasks with gender differences showed that male and female…

Queueing Network Models for Parallel Processing of Task Systems: an Operational Approach

NASA Technical Reports Server (NTRS)

Mak, Victor W. K.

1986-01-01

Computer performance modeling of possibly complex computations running on highly concurrent systems is considered. Earlier works in this area either dealt with a very simple program structure or resulted in methods with exponential complexity. An efficient procedure is developed to compute the performance measures for series-parallel-reducible task systems using queueing network models. The procedure is based on the concept of hierarchical decomposition and a new operational approach. Numerical results for three test cases are presented and compared to those of simulations.

Seeking Information Online: The Influence of Menu Type, Navigation Path Complexity and Spatial Ability on Information Gathering Tasks

ERIC Educational Resources Information Center

Puerta Melguizo, Mari Carmen; Vidya, Uti; van Oostendorp, Herre

2012-01-01

We studied the effects of menu type, navigation path complexity and spatial ability on information retrieval performance and web disorientation or lostness. Two innovative aspects were included: (a) navigation path relevance and (b) information gathering tasks. As expected we found that, when measuring aspects directly related to navigation…

Scaffolding a Complex Task of Experimental Design in Chemistry with a Computer Environment

ERIC Educational Resources Information Center

Girault, Isabelle; d'Ham, Cédric

2014-01-01

When solving a scientific problem through experimentation, students may have the responsibility to design the experiment. When students work in a conventional condition, with paper and pencil, the designed procedures stay at a very general level. There is a need for additional scaffolds to help the students perform this complex task. We propose a…

Transfer of Training from Predictor to Conventional Displays. Interim Report.

ERIC Educational Resources Information Center

Wulfeck, J. W.

Use of a predictor display has been shown to virtually transform the difficulty of a variety of complex, manual control pursuit tracking tasks to the level of those having relatively simple control requirements. With 15-minutes practice, naive operators are able to perform some complex tasks with a predictor display at accuracy levels previously…

A Comparative Study of the Variables Used to Measure Syntactic Complexity and Accuracy in Task-Based Research

ERIC Educational Resources Information Center

Inoue, Chihiro

2016-01-01

The constructs of complexity, accuracy and fluency (CAF) have been used extensively to investigate learner performance on second language tasks. However, a serious concern is that the variables used to measure these constructs are sometimes used conventionally without any empirical justification. It is crucial for researchers to understand how…

How Stimulus and Task Complexity Affect Monitoring in High-Functioning Adults with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Koolen, Sophieke; Vissers, Constance Th. W. M.; Egger, Jos I. M.; Verhoeven, Ludo

2014-01-01

The present study examined whether individuals with autism spectrum disorder (ASD) are able to update and monitor working memory representations of visual input, and whether performance is influenced by stimulus and task complexity. 15 high-functioning adults with ASD and 15 controls were asked to allocate either elements of abstract figures or…

Cognitive Task Complexity Effects on L2 Writing Performance: An Application of Mixed-Methods Approaches

ERIC Educational Resources Information Center

Abdi Tabari, Mahmoud; Ivey, Toni A.

2015-01-01

This paper provides a methodological review of previous research on cognitive task complexity, since the term emerged in 1995, and investigates why much research was more quantitative rather than qualitative. Moreover, it sheds light onto the studies which used the mixed-methods approach and determines which version of the mixed-methods designs…

The neural substrates associated with attentional resources and difficulty of concurrent processing of the two verbal tasks.

PubMed

Mizuno, Kei; Tanaka, Masaaki; Tanabe, Hiroki C; Sadato, Norihiro; Watanabe, Yasuyoshi

2012-07-01

The kana pick-out test has been widely used in Japan to evaluate the ability to divide attention in both adult and pediatric patients. However, the neural substrates underlying the ability to divide attention using the kana pick-out test, which requires participants to pick out individual letters (vowels) in a story while also reading for comprehension, thus requiring simultaneous allocation of attention to both activities, are still unclear. Moreover, outside of the clinical area, neuroimaging studies focused on the mechanisms of divided attention during complex story comprehension are rare. Thus, the purpose of the present study, to clarify the neural substrates of kana pick-out test, improves our current understanding of the basic neural mechanisms of dual task performance in verbal memory function. We compared patterns of activation in the brain obtained during performance of the individual tasks of vowel identification and story comprehension, to levels of activation when participants performed the two tasks simultaneously during the kana pick-out test. We found that activations of the left dorsal inferior frontal gyrus and superior parietal lobule increase in functional connectivity to a greater extent during the dual task condition compared to the two single task conditions. In contrast, activations of the left fusiform gyrus and middle temporal gyrus, which are significantly involved in picking out letters and complex sentences during story comprehension, respectively, were reduced in the dual task condition compared to during the two single task conditions. These results suggest that increased activations of the dorsal inferior frontal gyrus and superior parietal lobule during dual task performance may be associated with the capacity for attentional resources, and reduced activations of the left fusiform gyrus and middle temporal gyrus may reflect the difficulty of concurrent processing of the two tasks. In addition, the increase in synchronization between the left dorsal inferior frontal gyrus and superior parietal lobule in the dual task condition may induce effective communication between these brain regions and contribute to more attentional processing than in the single task condition, due to greater and more complex demands on voluntary attentional resources. Copyright © 2012 Elsevier Ltd. All rights reserved.

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-three older adults between the ages of 66 and 80 completed the study. There was a main effect for accuracy such that older adults made more accurate decisions in the color info-vis condition than the table condition. In the low difficulty condition, participants were more successful at choosing the correct answer when the question was about the gap coverage attribute in the info-vis condition. Participants also made significantly faster decisions in the info-vis condition than in the table condition. Conclusions Reducing the working memory demand of the task through the use of an ES can improve decision accuracy, especially when selection criteria is only focused on a single attribute of the insurance plan. PMID:27251110

The Effect of Visual Information on the Manual Approach and Landing

NASA Technical Reports Server (NTRS)

Wewerinke, P. H.

1982-01-01

The effect of visual information in combination with basic display information on the approach performance. A pre-experimental model analysis was performed in terms of the optimal control model. The resulting aircraft approach performance predictions were compared with the results of a moving base simulator program. The results illustrate that the model provides a meaningful description of the visual (scene) perception process involved in the complex (multi-variable, time varying) manual approach task with a useful predictive capability. The theoretical framework was shown to allow a straight-forward investigation of the complex interaction of a variety of task variables.

[Influence of mental rotation of objects on psychophysiological functions of women].

PubMed

Chikina, L V; Fedorchuk, S V; Trushina, V A; Ianchuk, P I; Makarchuk, M Iu

2012-01-01

An integral part of activity of modern human beings is an involvement to work with the computer systems which, in turn, produces a nervous - emotional tension. Hence, a problem of control of the psychophysiological state of workmen with the purpose of health preservation and success of their activity and the problem of application of rehabilitational actions are actual. At present it is known that the efficiency of rehabilitational procedures rises following application of the complex of regenerative programs. Previously performed by us investigation showed that mental rotation is capable to compensate the consequences of a nervous - emotional tension. Therefore, in the present work we investigated how the complex of spatial tasks developed by us influences psychophysiological performances of tested women for which the psycho-emotional tension with the usage of computer technologies is more essential, and the procedure of mental rotation is more complex task for them, than for men. The complex of spatial tasks applied in the given work included: mental rotation of simple objects (letters and digits), mental rotation of complex objects (geometrical figures) and mental rotation of complex objects with the usage of a short-term memory. Execution of the complex of spatial tasks reduces the time of simple and complex sensomotor response, raises parameters of a short-term memory, brain work capacity and improves nervous processes. Collectively, mental rotation of objects can be recommended as a rehabilitational resource for compensation of consequences of any psycho-emotional strain, both for men, and for women.

The Complexity of Standing Postural Sway Associates with Future Falls in Community-Dwelling Older Adults: The MOBILIZE Boston Study.

PubMed

Zhou, Junhong; Habtemariam, Daniel; Iloputaife, Ikechukwu; Lipsitz, Lewis A; Manor, Brad

2017-06-07

Standing postural control is complex, meaning that it is dependent upon numerous inputs interacting across multiple temporal-spatial scales. Diminished physiologic complexity of postural sway has been linked to reduced ability to adapt to stressors. We hypothesized that older adults with lower postural sway complexity would experience more falls in the future. 738 adults aged ≥70 years completed the Short Physical Performance Battery test (SPPB) test and assessments of single and dual-task standing postural control. Postural sway complexity was quantified using multiscale entropy. Falls were subsequently tracked for 48 months. Negative binomial regression demonstrated that older adults with lower postural sway complexity in both single and dual-task conditions had higher future fall rate (incident rate ratio (IRR) = 0.98, p = 0.02, 95% Confidence Limits (CL) = 0.96-0.99). Notably, participants in the lowest quintile of complexity during dual-task standing suffered 48% more falls during the four-year follow-up as compared to those in the highest quintile (IRR = 1.48, p = 0.01, 95% CL = 1.09-1.99). Conversely, traditional postural sway metrics or SPPB performance did not associate with future falls. As compared to traditional metrics, the degree of multi-scale complexity contained within standing postural sway-particularly during dual task conditions- appears to be a better predictor of future falls in older adults.

The hard fall effect: high working memory capacity leads to a higher, but less robust short-term memory performance.

PubMed

Thomassin, Noémylle; Gonthier, Corentin; Guerraz, Michel; Roulin, Jean-Luc

2015-01-01

Participants with a high working memory span tend to perform better than low spans in a variety of tasks. However, their performance is paradoxically more impaired when they have to perform two tasks at once, a phenomenon that could be labeled the "hard fall effect." The present study tested whether this effect exists in a short-term memory task, and investigated the proposal that the effect is due to high spans using efficient facilitative strategies under simple task conditions. Ninety-eight participants performed a spatial short-term memory task under simple and dual task conditions; stimuli presentation times either allowed for the use of complex facilitative strategies or not. High spans outperformed low spans only under simple task conditions when presentation times allowed for the use of facilitative strategies. These results indicate that the hard fall effect exists on a short-term memory task and may be caused by individual differences in strategy use.

How Students Process Equations in Solving Quantitative Synthesis Problems? Role of Mathematical Complexity in Students' Mathematical Performance

ERIC Educational Resources Information Center

Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

2017-01-01

We examine students' mathematical performance on quantitative "synthesis problems" with varying mathematical complexity. Synthesis problems are tasks comprising multiple concepts typically taught in different chapters. Mathematical performance refers to the formulation, combination, and simplification of equations. Generally speaking,…

Deficits in complex motor functions, despite no evidence of procedural learning deficits, among HIV+ individuals with history of substance dependence

PubMed Central

Gonzalez, Raul; Jacobus, Joanna; Amatya, Anup K.; Quartana, Phillip J.; Vassileva, Jasmin; Martin, Eileen M.

2008-01-01

HIV and drugs of abuse affect common neural systems underlying procedural memory, including the striatum. We compared performance of 48 HIV seropositive (HIV+) and 48 HIV seronegative (HIV−) participants with history of cocaine and/or heroin dependence across multiple Trial Blocks of three procedural learning (PL) tasks: Rotary Pursuit (RPT), Mirror Star Tracing (MST), and Weather Prediction (WPT). Groups were well matched on demographic, psychiatric, and substance use parameters, and all participants were verified abstinent from drugs. Mixed model ANOVAs revealed that the HIV+ group performed more poorly across all tasks, with a significant main effect of HIV serostatus observed on the MST and a trend toward significance obtained for the RPT. No significant differences were observed on the WPT. Both groups demonstrated significant improvements in performance across all three PL tasks. Importantly, no significant Serostatus X Trial Block interactions were observed on any task. Thus, the HIV+ group tended to perform worse than the HIV− group across all trial blocks of PL tasks with motor demands, but showed no differences in their rate of improvement across all tasks. These findings are consistent with HIV-associated deficits in complex motor skills, but not in procedural learning. PMID:18999351

An exploratory investigation of various assessment instruments as correlates of complex visual monitoring performance.

DOT National Transportation Integrated Search

1980-10-01

The present study examined a variety of possible predictors of complex monitoring performance. The criterion task was designed to resemble that of a highly automated air traffic control radar system containing computer-generated alphanumeric displays...

Development and Application of a Multi-Modal Task Analysis to Support Intelligent Tutoring of Complex Skills

ERIC Educational Resources Information Center

Skinner, Anna; Diller, David; Kumar, Rohit; Cannon-Bowers, Jan; Smith, Roger; Tanaka, Alyssa; Julian, Danielle; Perez, Ray

2018-01-01

Background: Contemporary work in the design and development of intelligent training systems employs task analysis (TA) methods for gathering knowledge that is subsequently encoded into task models. These task models form the basis of intelligent interpretation of student performance within education and training systems. Also referred to as expert…

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

NASA Technical Reports Server (NTRS)

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

1987-01-01

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

Interhemispheric Control of Unilateral Movement

PubMed Central

Beaulé, Vincent; Tremblay, Sara; Théoret, Hugo

2012-01-01

To perform strictly unilateral movements, the brain relies on a large cortical and subcortical network. This network enables healthy adults to perform complex unimanual motor tasks without the activation of contralateral muscles. However, mirror movements (involuntary movements in ipsilateral muscles that can accompany intended movement) can be seen in healthy individuals if a task is complex or fatiguing, in childhood, and with increasing age. Lateralization of movement depends on complex interhemispheric communication between cortical (i.e., dorsal premotor cortex, supplementary motor area) and subcortical (i.e., basal ganglia) areas, probably coursing through the corpus callosum (CC). Here, we will focus on transcallosal interhemispheric inhibition (IHI), which facilitates complex unilateral movements and appears to play an important role in handedness, pathological conditions such as Parkinson's disease, and stroke recovery. PMID:23304559

Wolves, dogs, rearing and reinforcement: complex interactions underlying species differences in training and problem-solving performance.

PubMed

Frank, Harry

2011-11-01

Frank and Frank et al. (1982-1987) administered a series of age-graded training and problem-solving tasks to samples of Eastern timber wolf (C. lupus lycaon) and Alaskan Malamute (C. familiaris) pups to test Frank's (Zeitschrift für Tierpsychologie 53:389-399, 1980) model of the evolution of information processing under conditions of natural and artificial selection. Results confirmed the model's prediction that wolves should perform better than dogs on problem-solving tasks and that dogs should perform better than wolves on training tasks. Further data collected at the University of Connecticut in 1983 revealed a more complex and refined picture, indicating that species differences can be mediated by a number of factors influencing wolf performance, including socialization regimen (hand-rearing vs. mother-rearing), interactive effects of socialization on the efficacy of both rewards and punishments, and the flexibility to select learning strategies that experimenters might not anticipate.

Effects of orientation on Rey complex figure performance.

PubMed

Ferraro, F Richard; Grossman, Jennifer; Bren, Amy; Hoverson, Allysa

2002-10-01

An experiment was performed that examined the impact of stimulus orientation on performance on the Rey complex figure. A total of 48 undergraduates (24 men, 24 women) were randomly assigned to one of four Rey figure orientation groups (0 degrees, 90 degrees, 180 degrees, and 270 degrees ). Participants followed standard procedures for the Rey figure, initially copying it in whatever orientation group they were assigned to. Next, all participants performed a 15-20 min lexical decision experiment, used as a filler task. Finally, and unbeknownest to them, participants were asked to recall as much of the figure as they could. As expected, results revealed a main effect of Task (F = 83.92, p < .01), in which copy performance was superior to recall performance. However, the main effect for orientation was not significant, nor did orientation interact with task (Fs < .68, ps > .57). The results are important from an applied setting, especially if testing conditions are less than optimal and a fixed stimulus position is not possible (e.g., testing at the bedside).

Regional Differences in Brain Volume Predict the Acquisition of Skill in a Complex Real-Time Strategy Videogame

PubMed Central

Basak, Chandramallika; Voss, Michelle W.; Erickson, Kirk I.; Boot, Walter R.; Kramer, Arthur F.

2015-01-01

Previous studies have found that differences in brain volume among older adults predict performance in laboratory tasks of executive control, memory, and motor learning. In the present study we asked whether regional differences in brain volume as assessed by the application of a voxel-based morphometry technique on high resolution MRI would also be useful in predicting the acquisition of skill in complex tasks, such as strategy-based video games. Twenty older adults were trained for over 20 hours to play Rise of Nations, a complex real-time strategy game. These adults showed substantial improvements over the training period in game performance. MRI scans obtained prior to training revealed that the volume of a number of brain regions, which have been previously associated with subsets of the trained skills, predicted a substantial amount of variance in learning on the complex game. Thus, regional differences in brain volume can predict learning in complex tasks that entail the use of a variety of perceptual, cognitive and motor processes. PMID:21546146

Regional differences in brain volume predict the acquisition of skill in a complex real-time strategy videogame.

PubMed

Basak, Chandramallika; Voss, Michelle W; Erickson, Kirk I; Boot, Walter R; Kramer, Arthur F

2011-08-01

Previous studies have found that differences in brain volume among older adults predict performance in laboratory tasks of executive control, memory, and motor learning. In the present study we asked whether regional differences in brain volume as assessed by the application of a voxel-based morphometry technique on high resolution MRI would also be useful in predicting the acquisition of skill in complex tasks, such as strategy-based video games. Twenty older adults were trained for over 20 h to play Rise of Nations, a complex real-time strategy game. These adults showed substantial improvements over the training period in game performance. MRI scans obtained prior to training revealed that the volume of a number of brain regions, which have been previously associated with subsets of the trained skills, predicted a substantial amount of variance in learning on the complex game. Thus, regional differences in brain volume can predict learning in complex tasks that entail the use of a variety of perceptual, cognitive and motor processes. Copyright © 2011 Elsevier Inc. All rights reserved.

Promoting the experimental dialogue between working memory and chunking: Behavioral data and simulation.

PubMed

Portrat, Sophie; Guida, Alessandro; Phénix, Thierry; Lemaire, Benoît

2016-04-01

Working memory (WM) is a cognitive system allowing short-term maintenance and processing of information. Maintaining information in WM consists, classically, in rehearsing or refreshing it. Chunking could also be considered as a maintenance mechanism. However, in the literature, it is more often used to explain performance than explicitly investigated within WM paradigms. Hence, the aim of the present paper was (1) to strengthen the experimental dialogue between WM and chunking, by studying the effect of acronyms in a computer-paced complex span task paradigm and (2) to formalize explicitly this dialogue within a computational model. Young adults performed a WM complex span task in which they had to maintain series of 7 letters for further recall while performing a concurrent location judgment task. The series to be remembered were either random strings of letters or strings containing a 3-letter acronym that appeared in position 1, 3, or 5 in the series. Together, the data and simulations provide a better understanding of the maintenance mechanisms taking place in WM and its interplay with long-term memory. Indeed, the behavioral WM performance lends evidence to the functional characteristics of chunking that seems to be, especially in a WM complex span task, an attentional time-based mechanism that certainly enhances WM performance but also competes with other processes at hand in WM. Computational simulations support and delineate such a conception by showing that searching for a chunk in long-term memory involves attentionally demanding subprocesses that essentially take place during the encoding phases of the task.

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 differences in intrinsic load arising from variations in the physical complexity of a simulation task. The complementary nature of these subjective and objective measures suggests their combined use is advantageous in simulation instructional design research. © 2015 John Wiley & Sons Ltd.

Does strategy instruction on the Rey-Osterrieth Complex Figure task lead to transferred performance improvement on the Modified Taylor Complex Figure task? A randomized controlled trial in school-aged children.

PubMed

Resch, Christine; Keulers, Esther; Martens, Rosa; van Heugten, Caroline; Hurks, Petra

2018-04-05

Providing children with organizational strategy instruction on the Rey Osterrieth Complex Figure (ROCF) has previously been found to improve organizational and accuracy performance on this task. It is unknown whether strategy instruction on the ROCF would also transfer to performance improvement on copying and the recall of another complex figure. Participants were 98 typically developing children (aged 9.5-12.6 years, M = 10.6). Children completed the ROCF (copy and recall) as a pretest. Approximately a month later, they were randomized to complete the ROCF with strategy instruction in the form of a stepwise administration of the ROCF or again in the standard format. All children then copied and recalled the Modified Taylor Complex Figure (MTCF). All productions were assessed in terms of organization, accuracy and completion time. Organization scores for the MTCF did not differ for the two groups for the copy production, but did differ for the recall production, indicating transfer. Accuracy and completion times did not differ between groups. Performance on all measures, except copy accuracy, improved between pretest ROCF and posttest MTCF production for both groups, suggesting practice effects. Findings indicate that transfer of strategy instruction from one complex figure to another is only present for organization of recalled information. The increase in RCF-OSS scores did not lead to a higher accuracy or a faster copy or recall.

Clutter in electronic medical records: examining its performance and attentional costs using eye tracking.

PubMed

Moacdieh, Nadine; Sarter, Nadine

2015-06-01

The objective was to use eye tracking to trace the underlying changes in attention allocation associated with the performance effects of clutter, stress, and task difficulty in visual search and noticing tasks. Clutter can degrade performance in complex domains, yet more needs to be known about the associated changes in attention allocation, particularly in the presence of stress and for different tasks. Frequently used and relatively simple eye tracking metrics do not effectively capture the various effects of clutter, which is critical for comprehensively analyzing clutter and developing targeted, real-time countermeasures. Electronic medical records (EMRs) were chosen as the application domain for this research. Clutter, stress, and task difficulty were manipulated, and physicians' performance on search and noticing tasks was recorded. Several eye tracking metrics were used to trace attention allocation throughout those tasks, and subjective data were gathered via a debriefing questionnaire. Clutter degraded performance in terms of response time and noticing accuracy. These decrements were largely accentuated by high stress and task difficulty. Eye tracking revealed the underlying attentional mechanisms, and several display-independent metrics were shown to be significant indicators of the effects of clutter. Eye tracking provides a promising means to understand in detail (offline) and prevent (in real time) major performance breakdowns due to clutter. Display designers need to be aware of the risks of clutter in EMRs and other complex displays and can use the identified eye tracking metrics to evaluate and/or adjust their display. © 2015, Human Factors and Ergonomics Society.

An ICAI architecture for troubleshooting in complex, dynamic systems

NASA Technical Reports Server (NTRS)

Fath, Janet L.; Mitchell, Christine M.; Govindaraj, T.

1990-01-01

Ahab, an intelligent computer-aided instruction (ICAI) program, illustrates an architecture for simulator-based ICAI programs to teach troubleshooting in complex, dynamic environments. The architecture posits three elements of a computerized instructor: the task model, the student model, and the instructional module. The task model is a prescriptive model of expert performance that uses symptomatic and topographic search strategies to provide students with directed problem-solving aids. The student model is a descriptive model of student performance in the context of the task model. This student model compares the student and task models, critiques student performance, and provides interactive performance feedback. The instructional module coordinates information presented by the instructional media, the task model, and the student model so that each student receives individualized instruction. Concept and metaconcept knowledge that supports these elements is contained in frames and production rules, respectively. The results of an experimental evaluation are discussed. They support the hypothesis that training with an adaptive online system built using the Ahab architecture produces better performance than training using simulator practice alone, at least with unfamiliar problems. It is not sufficient to develop an expert strategy and present it to students using offline materials. The training is most effective if it adapts to individual student needs.

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

Examining the locus of age effects on complex span tasks.

PubMed

McCabe, Jennifer; Hartman, Marilyn

2003-09-01

To investigate the locus of age effects on complex span tasks, the authors evaluated the contributions of working memory functions and processing speed. Age differences were found in measures of storage capacity, language processing speed, and lower level speed. Statistically controlling for each of these in hierarchical regressions substantially reduced, but did not eliminate, the complex span age effect. Accounting for lower level speed and storage, however, removed essentially the entire age effect, suggesting that both functions play important and independent roles. Additional evidence for the role of storage capacity was the absence of complex span age differences with span size calibrated to individual word span performance. Explanations for age differences based on inhibition and concurrent task performamce were not supported.

Working memory deficits in children with reading difficulties: memory span and dual task coordination.

PubMed

Wang, Shinmin; Gathercole, Susan E

2013-05-01

The current study investigated the cause of the reported problems in working memory in children with reading difficulties. Verbal and visuospatial simple and complex span tasks, and digit span and reaction times tasks performed singly and in combination, were administered to 46 children with single word reading difficulties and 45 typically developing children matched for age and nonverbal ability. Children with reading difficulties had pervasive deficits in the simple and complex span tasks and had poorer abilities to coordinate two cognitive demanding tasks. These findings indicate that working memory problems in children with reading difficulties may reflect a core deficit in the central executive. Copyright © 2012 Elsevier Inc. All rights reserved.

Brain and effort: brain activation and effort-related working memory in healthy participants and patients with working memory deficits.

PubMed

Engström, Maria; Landtblom, Anne-Marie; Karlsson, Thomas

2013-01-01

Despite the interest in the neuroimaging of working memory, little is still known about the neurobiology of complex working memory in tasks that require simultaneous manipulation and storage of information. In addition to the central executive network, we assumed that the recently described salience network [involving the anterior insular cortex (AIC) and the anterior cingulate cortex (ACC)] might be of particular importance to working memory tasks that require complex, effortful processing. Healthy participants (n = 26) and participants suffering from working memory problems related to the Kleine-Levin syndrome (KLS) (a specific form of periodic idiopathic hypersomnia; n = 18) participated in the study. Participants were further divided into a high- and low-capacity group, according to performance on a working memory task (listening span). In a functional magnetic resonance imaging (fMRI) study, participants were administered the reading span complex working memory task tapping cognitive effort. The fMRI-derived blood oxygen level dependent (BOLD) signal was modulated by (1) effort in both the central executive and the salience network and (2) capacity in the salience network in that high performers evidenced a weaker BOLD signal than low performers. In the salience network there was a dichotomy between the left and the right hemisphere; the right hemisphere elicited a steeper increase of the BOLD signal as a function of increasing effort. There was also a stronger functional connectivity within the central executive network because of increased task difficulty. The ability to allocate cognitive effort in complex working memory is contingent upon focused resources in the executive and in particular the salience network. Individual capacity during the complex working memory task is related to activity in the salience (but not the executive) network so that high-capacity participants evidence a lower signal and possibly hence a larger dynamic response.

Brain and effort: brain activation and effort-related working memory in healthy participants and patients with working memory deficits

PubMed Central

Engström, Maria; Landtblom, Anne-Marie; Karlsson, Thomas

2013-01-01

Despite the interest in the neuroimaging of working memory, little is still known about the neurobiology of complex working memory in tasks that require simultaneous manipulation and storage of information. In addition to the central executive network, we assumed that the recently described salience network [involving the anterior insular cortex (AIC) and the anterior cingulate cortex (ACC)] might be of particular importance to working memory tasks that require complex, effortful processing. Method: Healthy participants (n = 26) and participants suffering from working memory problems related to the Kleine–Levin syndrome (KLS) (a specific form of periodic idiopathic hypersomnia; n = 18) participated in the study. Participants were further divided into a high- and low-capacity group, according to performance on a working memory task (listening span). In a functional magnetic resonance imaging (fMRI) study, participants were administered the reading span complex working memory task tapping cognitive effort. Principal findings: The fMRI-derived blood oxygen level dependent (BOLD) signal was modulated by (1) effort in both the central executive and the salience network and (2) capacity in the salience network in that high performers evidenced a weaker BOLD signal than low performers. In the salience network there was a dichotomy between the left and the right hemisphere; the right hemisphere elicited a steeper increase of the BOLD signal as a function of increasing effort. There was also a stronger functional connectivity within the central executive network because of increased task difficulty. Conclusion: The ability to allocate cognitive effort in complex working memory is contingent upon focused resources in the executive and in particular the salience network. Individual capacity during the complex working memory task is related to activity in the salience (but not the executive) network so that high-capacity participants evidence a lower signal and possibly hence a larger dynamic response. PMID:23616756

Hierarchical Task Analysis and Training Decisions.

ERIC Educational Resources Information Center

Shepherd, A.

1985-01-01

Hierarchical task analysis (HTA), which requires description of a task in terms of a hierarchy of operations and plans, is reviewed and examined as a basis for making training decisions. Benefits of HTA in terms of economy of analysis and as a means of accounting for complex performance are outlined. (Author/MBR)

A Multitasking General Executive for Compound Continuous Tasks

ERIC Educational Resources Information Center

Salvucci, Dario D.

2005-01-01

As cognitive architectures move to account for increasingly complex real-world tasks, one of the most pressing challenges involves understanding and modeling human multitasking. Although a number of existing models now perform multitasking in real-world scenarios, these models typically employ customized executives that schedule tasks for the…

The Role of Training, Individual Differences and Knowledge Representation in Cognitive-Oriented Task Performance.

ERIC Educational Resources Information Center

Koubek, Richard J.

The roles of training, problem representation, and individual differences on performance of both automated (simple) and controlled (complex) process tasks were studied. The following hypotheses were tested: (1) training and cognitive style affect the representation developed; (2) training and cognitive style affect the development and performance…

Affect Response to Simulated Information Attack during Complex Task Performance

DTIC Science & Technology

2014-12-02

AND FRUSTRATION ........................ 42 FIGURE 27. TASK LOAD INDEX OF MENTAL DEMAND, TEMPORAL DEMAND, AND PHYSICAL DEMAND...situational awareness, affect, and trait characteristics interact with human performance during cyberspace attacks in the physical and information...Operator state was manipulated using emotional stimulation portrayed through the presentation of video segments. The effect of emotions on

Editorial: Cognitive Architectures, Model Comparison and AGI

NASA Astrophysics Data System (ADS)

Lebiere, Christian; Gonzalez, Cleotilde; Warwick, Walter

2010-12-01

Cognitive Science and Artificial Intelligence share compatible goals of understanding and possibly generating broadly intelligent behavior. In order to determine if progress is made, it is essential to be able to evaluate the behavior of complex computational models, especially those built on general cognitive architectures, and compare it to benchmarks of intelligent behavior such as human performance. Significant methodological challenges arise, however, when trying to extend approaches used to compare model and human performance from tightly controlled laboratory tasks to complex tasks involving more open-ended behavior. This paper describes a model comparison challenge built around a dynamic control task, the Dynamic Stocks and Flows. We present and discuss distinct approaches to evaluating performance and comparing models. Lessons drawn from this challenge are discussed in light of the challenge of using cognitive architectures to achieve Artificial General Intelligence.

Effects of Planning on Task Load, Knowledge, and Tool Preference: A Comparison of Two Tools

ERIC Educational Resources Information Center

Bonestroo, Wilco J.; de Jong, Ton

2012-01-01

Self-regulated learners are expected to plan their own learning. Because planning is a complex task, it is not self-evident that all learners can perform this task successfully. In this study, we examined the effects of two planning support tools on the quality of created plans, planning behavior, task load, and acquired knowledge. Sixty-five…

PANORAMA: An approach to performance modeling and diagnosis of extreme-scale workflows

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

Deelman, Ewa; Carothers, Christopher; Mandal, Anirban

Here we report that computational science is well established as the third pillar of scientific discovery and is on par with experimentation and theory. However, as we move closer toward the ability to execute exascale calculations and process the ensuing extreme-scale amounts of data produced by both experiments and computations alike, the complexity of managing the compute and data analysis tasks has grown beyond the capabilities of domain scientists. Therefore, workflow management systems are absolutely necessary to ensure current and future scientific discoveries. A key research question for these workflow management systems concerns the performance optimization of complex calculation andmore » data analysis tasks. The central contribution of this article is a description of the PANORAMA approach for modeling and diagnosing the run-time performance of complex scientific workflows. This approach integrates extreme-scale systems testbed experimentation, structured analytical modeling, and parallel systems simulation into a comprehensive workflow framework called Pegasus for understanding and improving the overall performance of complex scientific workflows.« less

PANORAMA: An approach to performance modeling and diagnosis of extreme-scale workflows

DOE PAGES

Deelman, Ewa; Carothers, Christopher; Mandal, Anirban; ...

2015-07-14

Here we report that computational science is well established as the third pillar of scientific discovery and is on par with experimentation and theory. However, as we move closer toward the ability to execute exascale calculations and process the ensuing extreme-scale amounts of data produced by both experiments and computations alike, the complexity of managing the compute and data analysis tasks has grown beyond the capabilities of domain scientists. Therefore, workflow management systems are absolutely necessary to ensure current and future scientific discoveries. A key research question for these workflow management systems concerns the performance optimization of complex calculation andmore » data analysis tasks. The central contribution of this article is a description of the PANORAMA approach for modeling and diagnosing the run-time performance of complex scientific workflows. This approach integrates extreme-scale systems testbed experimentation, structured analytical modeling, and parallel systems simulation into a comprehensive workflow framework called Pegasus for understanding and improving the overall performance of complex scientific workflows.« less

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

PubMed Central

Charles, Lauren M.; Ricketts, Todd A.

2017-01-01

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

N-back versus Complex Span Working Memory Training.

PubMed

Blacker, Kara J; Negoita, Serban; Ewen, Joshua B; Courtney, Susan M

2017-12-01

Working memory (WM) is the ability to maintain and manipulate task-relevant information in the absence of sensory input. While its improvement through training is of great interest, the degree to which WM training transfers to untrained WM tasks (near transfer) and other untrained cognitive skills (far transfer) remains debated and the mechanism(s) underlying transfer are unclear. Here we hypothesized that a critical feature of dual n-back training is its reliance on maintaining relational information in WM. In Experiment 1, using an individual differences approach, we found evidence that performance on an n-back task was predicted by performance on a measure of relational WM (i.e., WM for vertical spatial relationships independent of absolute spatial locations); whereas the same was not true for a complex span WM task. In Experiment 2, we tested the idea that reliance on relational WM is critical to produce transfer from n-back but not complex span task training. Participants completed adaptive training on either a dual n-back task, a symmetry span task, or on a non-WM active control task. We found evidence of near transfer for the dual n-back group; however, far transfer to a measure of fluid intelligence did not emerge. Recording EEG during a separate WM transfer task, we examined group-specific, training-related changes in alpha power, which are proposed to be sensitive to WM demands and top-down modulation of WM. Results indicated that the dual n-back group showed significantly greater frontal alpha power after training compared to before training, more so than both other groups. However, we found no evidence of improvement on measures of relational WM for the dual n-back group, suggesting that near transfer may not be dependent on relational WM. These results suggest that dual n-back and complex span task training may differ in their effectiveness to elicit near transfer as well as in the underlying neural changes they facilitate.

A quantitative measure for degree of automation and its relation to system performance and mental load.

PubMed

Wei, Z G; Macwan, A P; Wieringa, P A

1998-06-01

In this paper we quantitatively model degree of automation (DofA) in supervisory control as a function of the number and nature of tasks to be performed by the operator and automation. This model uses a task weighting scheme in which weighting factors are obtained from task demand load, task mental load, and task effect on system performance. The computation of DofA is demonstrated using an experimental system. Based on controlled experiments using operators, analyses of the task effect on system performance, the prediction and assessment of task demand load, and the prediction of mental load were performed. Each experiment had a different DofA. The effect of a change in DofA on system performance and mental load was investigated. It was found that system performance became less sensitive to changes in DofA at higher levels of DofA. The experimental data showed that when the operator controlled a partly automated system, perceived mental load could be predicted from the task mental load for each task component, as calculated by analyzing a situation in which all tasks were manually controlled. Actual or potential applications of this research include a methodology to balance and optimize the automation of complex industrial systems.

Phonological similarity effect in complex span task.

PubMed

Camos, Valérie; Mora, Gérôme; Barrouillet, Pierre

2013-01-01

The aim of our study was to test the hypothesis that two systems are involved in verbal working memory; one is specifically dedicated to the maintenance of phonological representations through verbal rehearsal while the other would maintain multimodal representations through attentional refreshing. This theoretical framework predicts that phonologically related phenomena such as the phonological similarity effect (PSE) should occur when the domain-specific system is involved in maintenance, but should disappear when concurrent articulation hinders its use. Impeding maintenance in the domain-general system by a concurrent attentional demand should impair recall performance without affecting PSE. In three experiments, we manipulated the concurrent articulation and the attentional demand induced by the processing component of complex span tasks in which participants had to maintain lists of either similar or dissimilar words. Confirming our predictions, PSE affected recall performance in complex span tasks. Although both the attentional demand and the articulatory requirement of the concurrent task impaired recall, only the induction of an articulatory suppression during maintenance made the PSE disappear. These results suggest a duality in the systems devoted to verbal maintenance in the short term, constraining models of working memory.

Secondary task for full flight simulation incorporating tasks that commonly cause pilot error: Time estimation

NASA Technical Reports Server (NTRS)

Rosch, E.

1975-01-01

The task of time estimation, an activity occasionally performed by pilots during actual flight, was investigated with the objective of providing human factors investigators with an unobtrusive and minimally loading additional task that is sensitive to differences in flying conditions and flight instrumentation associated with the main task of piloting an aircraft simulator. Previous research indicated that the duration and consistency of time estimates is associated with the cognitive, perceptual, and motor loads imposed by concurrent simple tasks. The relationships between the length and variability of time estimates and concurrent task variables under a more complex situation involving simulated flight were clarified. The wrap-around effect with respect to baseline duration, a consequence of mode switching at intermediate levels of concurrent task distraction, should contribute substantially to estimate variability and have a complex effect on the shape of the resulting distribution of estimates.

Cross-cultural differences for three visual memory tasks in Brazilian children.

PubMed

Santos, F H; Mello, C B; Bueno, O F A; Dellatolas, G

2005-10-01

Norms for three visual memory tasks, including Corsi's block tapping test and the BEM 144 complex figures and visual recognition, were developed for neuropsychological assessment in Brazilian children. The tasks were measured in 127 children ages 7 to 10 years from rural and urban areas of the States of São Paulo and Minas Gerais. Analysis indicated age-related but not sex-related differences. A cross-cultural effect was observed in relation to copying and recall of Complex pictures. Different performances between rural and urban children were noted.

Effects of task complexity on rhythmic reproduction performance in adults.

PubMed

Iannarilli, Flora; Vannozzi, Giuseppe; Iosa, Marco; Pesce, Caterina; Capranica, Laura

2013-02-01

The aim of the present study was to investigate the effect of task complexity on the capability to reproduce rhythmic patterns. Sedentary musically illiterate individuals (age: 34.8±4.2 yrs; M±SD) were administered a rhythmic test including three rhythmic patterns to be reproduced by means of finger-tapping, foot-tapping and walking. For the quantification of subjects' ability in the reproduction of rhythmic patterns, qualitative and quantitative parameters were submitted to analysis. A stereophotogrammetric system was used to reconstruct and evaluate individual performances. The findings indicated a good internal stability of the rhythmic reproduction, suggesting that the present experimental design is suitable to discriminate the participants' rhythmic ability. Qualitative aspects of rhythmic reproduction (i.e., speed of execution and temporal ratios between events) varied as a function of the perceptual-motor requirements of the rhythmic reproduction task, with larger reproduction deviations in the walking task. Copyright © 2013 Elsevier B.V. All rights reserved.

The Impact of Automation Reliability and Operator Fatigue on Performance and Reliance

DTIC Science & Technology

2016-09-23

Matthews1 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER H0HJ (53290813) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8... performance . Reliability Reliability of automation is a key factor in an operator’s reliance on automation. Previous work has shown that... Performance in a complex multiple-task environment during a laboratory-based simulation of occasional night work . Human Factors: The Journal of the

Computerized assessment of sustained attention: interactive effects of task demand, noise, and anxiety.

PubMed

Ballard, J C

1996-12-01

In a sample of 163 college undergraduates, the effects of task demand, noise, and anxiety on Continuous Performance Test (CPT) errors were evaluated with multiple regression and multivariate analysis of variance. Results indicated significantly more omission errors on the difficult task. Complex interaction effects of noise and self-reported anxiety yielded more omissions in quiet intermittent white noise, particularly for high-anxious subjects performing the difficult task. Anxiety levels tended to increase from pretest to posttest, particularly for low-anxious subjects in the quiet, difficult-task condition, while a decrease was seen for high-anxious subjects in the loud, easy-task condition. Commission errors were unrelated to any predictor variables, suggesting that "attention" cannot be considered a unitary phenomenon. The variety of direct and interactive effects on vigilance performance underscore the need for clinicians to use a variety of measures to assess attentional skills, to avoid diagnosis of attention deficits on the basis of a single computerized task performance, and to rule out anxiety and other contributors to poor vigilance task performance.

Relations between Short-term Memory Deficits, Semantic Processing, and Executive Function

PubMed Central

Allen, Corinne M.; Martin, Randi C.; Martin, Nadine

2012-01-01

Background Previous research has suggested separable short-term memory (STM) buffers for the maintenance of phonological and lexical-semantic information, as some patients with aphasia show better ability to retain semantic than phonological information and others show the reverse. Recently, researchers have proposed that deficits to the maintenance of semantic information in STM are related to executive control abilities. Aims The present study investigated the relationship of executive function abilities with semantic and phonological short-term memory (STM) and semantic processing in such patients, as some previous research has suggested that semantic STM deficits and semantic processing abilities are critically related to specific or general executive function deficits. Method and Procedures 20 patients with aphasia and STM deficits were tested on measures of short-term retention, semantic processing, and both complex and simple executive function tasks. Outcome and Results In correlational analyses, we found no relation between semantic STM and performance on simple or complex executive function tasks. In contrast, phonological STM was related to executive function performance in tasks that had a verbal component, suggesting that performance in some executive function tasks depends on maintaining or rehearsing phonological codes. Although semantic STM was not related to executive function ability, performance on semantic processing tasks was related to executive function, perhaps due to similar executive task requirements in both semantic processing and executive function tasks. Conclusions Implications for treatment and interpretations of executive deficits are discussed. PMID:22736889

Evaluating Multiple Perspectives: Approaching the Synthesis Task through Assessing Credibility

ERIC Educational Resources Information Center

Lafferty, Karen Elizabeth; Summers, Amy; Tanaka, Stephanie; Cavanagh, Jeanne

2016-01-01

Introduction of the Common Core State Standards and assessments like the synthesis performance task pose new challenges for secondary English teachers. As students of all ability levels engage with complex text and in tasks that target higher level cognitive skills, teachers need strategies to support their understanding. This article describes…

Text Characteristics of Task Input and Difficulty in Second Language Listening Comprehension

ERIC Educational Resources Information Center

Revesz, Andrea; Brunfaut, Tineke

2013-01-01

This study investigated the effects of a group of task factors on advanced English as a second language learners' actual and perceived listening performance. We examined whether the speed, linguistic complexity, and explicitness of the listening text along with characteristics of the text necessary for task completion influenced comprehension. We…

Decision paths in complex tasks

NASA Technical Reports Server (NTRS)

Galanter, Eugene

1991-01-01

Complex real world action and its prediction and control has escaped analysis by the classical methods of psychological research. The reason is that psychologists have no procedures to parse complex tasks into their constituents. Where such a division can be made, based say on expert judgment, there is no natural scale to measure the positive or negative values of the components. Even if we could assign numbers to task parts, we lack rules i.e., a theory, to combine them into a total task representation. We compare here two plausible theories for the amalgamation of the value of task components. Both of these theories require a numerical representation of motivation, for motivation is the primary variable that guides choice and action in well-learned tasks. We address this problem of motivational quantification and performance prediction by developing psychophysical scales of the desireability or aversiveness of task components based on utility scaling methods (Galanter 1990). We modify methods used originally to scale sensory magnitudes (Stevens and Galanter 1957), and that have been applied recently to the measure of task 'workload' by Gopher and Braune (1984). Our modification uses utility comparison scaling techniques which avoid the unnecessary assumptions made by Gopher and Braune. Formula for the utility of complex tasks based on the theoretical models are used to predict decision and choice of alternate paths to the same goal.

Robust Multimodal Cognitive Load Measurement

DTIC Science & Technology

2014-03-26

dimension, Hurst exponent ) of electroencephalogram (EEG) signals to evaluate changes in working memory load during the performance of a cognitive task...dimension, Hurst exponent ) of electroencephalogram (EEG) signals to evaluate changes in working memory load during the performance of a cognitive task with...approximate entropies, wavelet-based complexity measures, correlation dimension, Hurst exponent ) of electroencephalogram (EEG) signals to evaluate changes

Dribble Files: Methodologies to Evaluate Learning and Performance in Complex Environments

ERIC Educational Resources Information Center

Schrader, P. G.; Lawless, Kimberly A.

2007-01-01

Research in the area of technology learning environments is tremendously complex. Tasks performed in these contexts are highly cognitive and mostly invisible to the observer. The nature of performance in these contexts is explained not only by the outcome but also by the process. However, evaluating the learning process with respect to tasks…

Transfer of Complex Skill Learning from Virtual to Real Rowing

PubMed Central

Rauter, Georg; Sigrist, Roland; Koch, Claudio; Crivelli, Francesco; van Raai, Mark; Riener, Robert; Wolf, Peter

2013-01-01

Simulators are commonly used to train complex tasks. In particular, simulators are applied to train dangerous tasks, to save costs, and to investigate the impact of different factors on task performance. However, in most cases, the transfer of simulator training to the real task has not been investigated. Without a proof for successful skill transfer, simulators might not be helpful at all or even counter-productive for learning the real task. In this paper, the skill transfer of complex technical aspects trained on a scull rowing simulator to sculling on water was investigated. We assume if a simulator provides high fidelity rendering of the interactions with the environment even without augmented feedback, training on such a realistic simulator would allow similar skill gains as training in the real environment. These learned skills were expected to transfer to the real environment. Two groups of four recreational rowers participated. One group trained on water, the other group trained on a simulator. Within two weeks, both groups performed four training sessions with the same licensed rowing trainer. The development in performance was assessed by quantitative biomechanical performance measures and by a qualitative video evaluation of an independent, blinded trainer. In general, both groups could improve their performance on water. The used biomechanical measures seem to allow only a limited insight into the rowers' development, while the independent trainer could also rate the rowers' overall impression. The simulator quality and naturalism was confirmed by the participants in a questionnaire. In conclusion, realistic simulator training fostered skill gains to a similar extent as training in the real environment and enabled skill transfer to the real environment. In combination with augmented feedback, simulator training can be further exploited to foster motor learning even to a higher extent, which is subject to future work. PMID:24376518

Nonuniform Changes in the Distribution of Visual Attention from Visual Complexity and Action: A Driving Simulation Study.

PubMed

Park, George D; Reed, Catherine L

2015-02-01

Researchers acknowledge the interplay between action and attention, but typically consider action as a response to successful attentional selection or the correlation of performance on separate action and attention tasks. We investigated how concurrent action with spatial monitoring affects the distribution of attention across the visual field. We embedded a functional field of view (FFOV) paradigm with concurrent central object recognition and peripheral target localization tasks in a simulated driving environment. Peripheral targets varied across 20-60 deg eccentricity at 11 radial spokes. Three conditions assessed the effects of visual complexity and concurrent action on the size and shape of the FFOV: (1) with no background, (2) with driving background, and (3) with driving background and vehicle steering. The addition of visual complexity slowed task performance and reduced the FFOV size but did not change the baseline shape. In contrast, the addition of steering produced not only shrinkage of the FFOV, but also changes in the FFOV shape. Nonuniform performance decrements occurred in proximal regions used for the central task and for steering, independent of interference from context elements. Multifocal attention models should consider the role of action and account for nonhomogeneities in the distribution of attention. © 2015 SAGE Publications.

Neuropsychological study of FASD in a sample of American Indian children: processing simple versus complex information.

PubMed

Aragón, Alfredo S; Kalberg, Wendy O; Buckley, David; Barela-Scott, Lindsey M; Tabachnick, Barbara G; May, Philip A

2008-12-01

Although a large body of literature exists on cognitive functioning in alcohol-exposed children, it is unclear if there is a signature neuropsychological profile in children with Fetal Alcohol Spectrum Disorders (FASD). This study assesses cognitive functioning in children with FASD from several American Indian reservations in the Northern Plains States, and it applies a hierarchical model of simple versus complex information processing to further examine cognitive function. We hypothesized that complex tests would discriminate between children with FASD and culturally similar controls, while children with FASD would perform similar to controls on relatively simple tests. Our sample includes 32 control children and 24 children with a form of FASD [fetal alcohol syndrome (FAS) = 10, partial fetal alcohol syndrome (PFAS) = 14]. The test battery measures general cognitive ability, verbal fluency, executive functioning, memory, and fine-motor skills. Many of the neuropsychological tests produced results consistent with a hierarchical model of simple versus complex processing. The complexity of the tests was determined "a priori" based on the number of cognitive processes involved in them. Multidimensional scaling was used to statistically analyze the accuracy of classifying the neurocognitive tests into a simple versus complex dichotomy. Hierarchical logistic regression models were then used to define the contribution made by complex versus simple tests in predicting the significant differences between children with FASD and controls. Complex test items discriminated better than simple test items. The tests that conformed well to the model were the Verbal Fluency, Progressive Planning Test (PPT), the Lhermitte memory tasks, and the Grooved Pegboard Test (GPT). The FASD-grouped children, when compared with controls, demonstrated impaired performance on letter fluency, while their performance was similar on category fluency. On the more complex PPT trials (problems 5 to 8), as well as the Lhermitte logical tasks, the FASD group performed the worst. The differential performance between children with FASD and controls was evident across various neuropsychological measures. The children with FASD performed significantly more poorly on the complex tasks than did the controls. The identification of a neurobehavioral profile in children with prenatal alcohol exposure will help clinicians identify and diagnose children with FASD.

Broad attention to multiple individual objects may facilitate change detection with complex auditory scenes.

PubMed

Irsik, Vanessa C; Vanden Bosch der Nederlanden, Christina M; Snyder, Joel S

2016-11-01

Attention and other processing constraints limit the perception of objects in complex scenes, which has been studied extensively in the visual sense. We used a change deafness paradigm to examine how attention to particular objects helps and hurts the ability to notice changes within complex auditory scenes. In a counterbalanced design, we examined how cueing attention to particular objects affected performance in an auditory change-detection task through the use of valid or invalid cues and trials without cues (Experiment 1). We further examined how successful encoding predicted change-detection performance using an object-encoding task and we addressed whether performing the object-encoding task along with the change-detection task affected performance overall (Experiment 2). Participants had more error for invalid compared to valid and uncued trials, but this effect was reduced in Experiment 2 compared to Experiment 1. When the object-encoding task was present, listeners who completed the uncued condition first had less overall error than those who completed the cued condition first. All participants showed less change deafness when they successfully encoded change-relevant compared to irrelevant objects during valid and uncued trials. However, only participants who completed the uncued condition first also showed this effect during invalid cue trials, suggesting a broader scope of attention. These findings provide converging evidence that attention to change-relevant objects is crucial for successful detection of acoustic changes and that encouraging broad attention to multiple objects is the best way to reduce change deafness. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

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.

The effects of interaction with the device described by procedural text on recall, true/false, and task performance.

PubMed

Diehl, V A; Mills, C B

1995-11-01

In two experiments, subjects interacted to different extents with relevant devices while reading two complex multistep procedural texts and were then tested with task performance time, true/false, and recall measures. While reading, subjects performed the task (read and do), saw the experimenter perform the task (read and see experimenter do), imagined doing the task (read and imagine), looked at the device while reading (read and see), or only read (read only). Van Dijk and Kintsch's (1983) text representation theory led to the prediction that exposure to the task device (in the read-and-do, read-and-see, and read-and-see-experimenter-do conditions) would lead to the development of a stronger situation model and therefore faster task performance, whereas the read-only and read-and-see conditions would lead to a better textbase, and therefore better performance on the true/false and recall tasks. Paivio's (1991) dual coding theory led to the opposite prediction for recall. The results supported the text representation theory with task performance and recall. The read-and-see condition produced consistently good performance on the true/false measure. Amount of text study time contributed to recall performance. These findings support the notion that information available while reading leads to differential development of representations in memory, which, in turn, causes differences in performance on various measures.

Time for actions in lucid dreams: effects of task modality, length, and complexity

PubMed Central

Erlacher, Daniel; Schädlich, Melanie; Stumbrys, Tadas; Schredl, Michael

2014-01-01

The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (LaBerge, 1985; Erlacher and Schredl, 2004), but Erlacher and Schredl (2004) found that performing squats required about 40% more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted. In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20, and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for the second condition where eight lucid dreamers had to walk 10, 20, or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps. Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics). However, no difference was found for relative times (no disproportional time effects) and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations. PMID:24474942

Time for actions in lucid dreams: effects of task modality, length, and complexity.

PubMed

Erlacher, Daniel; Schädlich, Melanie; Stumbrys, Tadas; Schredl, Michael

2013-01-01

The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (LaBerge, 1985; Erlacher and Schredl, 2004), but Erlacher and Schredl (2004) found that performing squats required about 40% more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted. In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20, and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for the second condition where eight lucid dreamers had to walk 10, 20, or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps. Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics). However, no difference was found for relative times (no disproportional time effects) and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations.

Complexity quantification of dense array EEG using sample entropy analysis.

PubMed

Ramanand, Pravitha; Nampoori, V P N; Sreenivasan, R

2004-09-01

In this paper, a time series complexity analysis of dense array electroencephalogram signals is carried out using the recently introduced Sample Entropy (SampEn) measure. This statistic quantifies the regularity in signals recorded from systems that can vary from the purely deterministic to purely stochastic realm. The present analysis is conducted with an objective of gaining insight into complexity variations related to changing brain dynamics for EEG recorded from the three cases of passive, eyes closed condition, a mental arithmetic task and the same mental task carried out after a physical exertion task. It is observed that the statistic is a robust quantifier of complexity suited for short physiological signals such as the EEG and it points to the specific brain regions that exhibit lowered complexity during the mental task state as compared to a passive, relaxed state. In the case of mental tasks carried out before and after the performance of a physical exercise, the statistic can detect the variations brought in by the intermediate fatigue inducing exercise period. This enhances its utility in detecting subtle changes in the brain state that can find wider scope for applications in EEG based brain studies.

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.

POPCORN: a Supervisory Control Simulation for Workload and Performance Research

NASA Technical Reports Server (NTRS)

Hart, S. G.; Battiste, V.; Lester, P. T.

1984-01-01

A multi-task simulation of a semi-automatic supervisory control system was developed to provide an environment in which training, operator strategy development, failure detection and resolution, levels of automation, and operator workload can be investigated. The goal was to develop a well-defined, but realistically complex, task that would lend itself to model-based analysis. The name of the task (POPCORN) reflects the visual display that depicts different task elements milling around waiting to be released and pop out to be performed. The operator's task was to complete each of 100 task elements that ere represented by different symbols, by selecting a target task and entering the desired a command. The simulated automatic system then completed the selected function automatically. Highly significant differences in performance, strategy, and rated workload were found as a function of all experimental manipulations (except reward/penalty).

An analysis of the processing requirements of a complex perceptual-motor task

NASA Technical Reports Server (NTRS)

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

1983-01-01

Current concerns in the assessment of mental workload are discussed, and the event-related brain potential (ERP) is introduced as a promising mental-workload index. Subjects participated in a series of studies in which they were required to perform a target acquisition task while also covertly counting either auditory or visual probes. The effects of several task-difficulty manipulations on the P300 component of the ERP elicited by the counted stimulus probes were investigated. With sufficiently practiced subjects the amplitude of the P300 was found to decrease with increases in task difficulty. The second experiment also provided evidence that the P300 is selectively sensitive to task-relevant attributes. A third experiment demonstrated a convergence in the amplitude of the P300s elicited in the simple and difficult versions of the tracking task. The amplitude of the P300 was also found to covary with the measures of tracking performance. The results of the series of three experiments illustrate the sensitivity of the P300 to the processing requirements of a complex target acquisition task. The findings are discussed in terms of the multidimensional nature of processing resources.

College Should Be an Intellectual Workout

ERIC Educational Resources Information Center

Malesic, Jonathan

2013-01-01

The physical fitness required to perform complex athletic feats has a parallel in the intellectual fitness it takes to perform complex mental tasks. At the heart of liberal education sits the idea that moderate training in several disciplines is better than intensive training in just one. Through exercising students' abilities in interpreting…

L2 Performance in Text-Chat and Spoken Discourse

ERIC Educational Resources Information Center

Sauro, Shannon

2012-01-01

The present study builds upon research in the CAF (complexity, accuracy, fluency) framework for examining learner performance to compare the lexical and syntactic complexity of learner output in spoken discourse and synchronous computer-mediated communication (SCMC) during completion of narrative tasks. Data were generated from transcripts and…

The 'Reading the Mind in Films' Task [child version]: complex emotion and mental state recognition in children with and without autism spectrum conditions.

PubMed

Golan, Ofer; Baron-Cohen, Simon; Golan, Yael

2008-09-01

Children with autism spectrum conditions (ASC) have difficulties recognizing others' emotions. Research has mostly focused on basic emotion recognition, devoid of context. This study reports the results of a new task, assessing recognition of complex emotions and mental states in social contexts. An ASC group (n = 23) was compared to a general population control group (n = 24). Children with ASC performed lower than controls on the task. Using task scores, more than 87% of the participants were allocated to their group. This new test quantifies complex emotion and mental state recognition in life-like situations. Our findings reveal that children with ASC have residual difficulties in this aspect of empathy. The use of language-based compensatory strategies for emotion recognition is discussed.

Patterns of physiological activity accompanying performance on a perceptual-motor task.

DOT National Transportation Integrated Search

1969-04-01

Air traffic controllers are required to spend considerable periods of time observing radar displays. Yet, information regarding physiological measures which best reflect the attentional process in complex vigilance tasks is generally lacking. As an i...

Dissociation between facial and bodily expressions in emotion recognition: A case study.

PubMed

Leiva, Samanta; Margulis, Laura; Micciulli, Andrea; Ferreres, Aldo

2017-12-21

Existing single-case studies have reported deficit in recognizing basic emotions through facial expression and unaffected performance with body expressions, but not the opposite pattern. The aim of this paper is to present a case study with impaired emotion recognition through body expressions and intact performance with facial expressions. In this single-case study we assessed a 30-year-old patient with autism spectrum disorder, without intellectual disability, and a healthy control group (n = 30) with four tasks of basic and complex emotion recognition through face and body movements, and two non-emotional control tasks. To analyze the dissociation between facial and body expressions, we used Crawford and Garthwaite's operational criteria, and we compared the patient and the control group performance with a modified one-tailed t-test designed specifically for single-case studies. There were no statistically significant differences between the patient's and the control group's performances on the non-emotional body movement task or the facial perception task. For both kinds of emotions (basic and complex) when the patient's performance was compared to the control group's, statistically significant differences were only observed for the recognition of body expressions. There were no significant differences between the patient's and the control group's correct answers for emotional facial stimuli. Our results showed a profile of impaired emotion recognition through body expressions and intact performance with facial expressions. This is the first case study that describes the existence of this kind of dissociation pattern between facial and body expressions of basic and complex emotions.

Evaluating mepindolol in a test model of examination anxiety in students.

PubMed

Krope, P; Kohrs, A; Ott, H; Wagner, W; Fichte, K

1982-03-01

The effect of a single dose of beta-blocker (5 or 10 mg mepindolol) during a written examination was investigated in two double-blind studies (N : 49 and 55 students, respectively). The question was whether the beta-blocker would in comparison to placebo diminish examination anxiety and improve the performance of highly complex tasks, while leaving the performance of less complex tasks unchanged. A reduction in examination anxiety after beta-blocker intake could not be demonstrated with a multi-level test model (which included the parameters self-rated anxiety, motor behaviour, task performance and physiology), although pulse rates were lowered significantly. An improvement in performance could not be observed, while - by the same token - the performance was not impaired by the beta-blocker. A hypothesis according to which a beta-blocker has an anxiolytic effect and improves performance, dependent on the level of habitual examination anxiety, was tested post hoc, but could not be confirmed. Ten of the subjects treated with 10 mg mepindolol, complained of different side effects, including dizziness, fatigue and headache.

Optimizing the number of steps in learning tasks for complex skills.

PubMed

Nadolski, Rob J; Kirschner, Paul A; van Merriënboer, Jeroen J G

2005-06-01

Carrying out whole tasks is often too difficult for novice learners attempting to acquire complex skills. The common solution is to split up the tasks into a number of smaller steps. The number of steps must be optimized for efficient and effective learning. The aim of the study is to investigate the relation between the number of steps provided to learners and the quality of their learning of complex skills. It is hypothesized that students receiving an optimized number of steps will learn better than those receiving either the whole task in only one step or those receiving a large number of steps. Participants were 35 sophomore law students studying at Dutch universities, mean age=22.8 years (SD=3.5), 63% were female. Participants were randomly assigned to 1 of 3 computer-delivered versions of a multimedia programme on how to prepare and carry out a law plea. The versions differed only in the number of learning steps provided. Videotaped plea-performance results were determined, various related learning measures were acquired and all computer actions were logged and analyzed. Participants exposed to an intermediate (i.e. optimized) number of steps outperformed all others on the compulsory learning task. No differences in performance on a transfer task were found. A high number of steps proved to be less efficient for carrying out the learning task. An intermediate number of steps is the most effective, proving that the number of steps can be optimized for improving learning.

Effects of Load, Cognitive Complexity and Type A on Satisfaction.

DTIC Science & Technology

1983-06-01

load, performance , style, cognitive style, Type A, cognitive complexity, stress, satisfaction , visual motor tasks 20. ABSTRAC (Continue on reverse side...1982) and Ewen (1973) have pointed toward pressure to perform as a condition which modifies the satisfaction - performance relationship. Other moderator...1975; Mehrabian and West, 1977) are much more rare than theory and research focused on, for example, the performance - satisfaction relationship

Attention in aviation. [to aircraft design and pilot performance

NASA Technical Reports Server (NTRS)

Wickens, Christopher D.

1987-01-01

The relevance of four principles or mechanisms of human attention to the design of aviation systems and the performance of pilots in multitask environments, including workload prediction and measurement, control-display integration, and the use of voice and head-up displays is discussed. The principles are: the mental energy that supplies task performance (resources), the resulting cross-talk between tasks as they are made more similar (confusion), the combination of different task elements (integration), and the way in which one task is processed and another is ignored (selection or tunneling). The introduction of greater levels of complexity into the validation of attentional theories in order to approach the demands of the cockpit or ATC console is proposed.

Child care and parenting issues for the young stroke survivor.

PubMed

Culler, Kathleen Hilko; Jasch, Christine; Scanlan, Susan

1994-03-01

Parenting is a complex and challenging task for any parent and it becomes even more complicated for an individual who experiences a disability. Literature addressing the parenting role for individuals who have experienced a stroke is limited. This article provides information on evaluation tools available for assessing an individual's ability to perform child care tasks and intervention strategies such as adaptive techniques and equipment for maximizing ability and promoting safe performance of child care tasks by the individual who has experienced a stroke. Product and literature resources that can be used by either the health professional or the parent with a stroke to facilitate parenting and child care task performance are included.

Influence of social presence on eye movements in visual search tasks.

PubMed

Liu, Na; Yu, Ruifeng

2017-12-01

This study employed an eye-tracking technique to investigate the influence of social presence on eye movements in visual search tasks. A total of 20 male subjects performed visual search tasks in a 2 (target presence: present vs. absent) × 2 (task complexity: complex vs. simple) × 2 (social presence: alone vs. a human audience) within-subject experiment. Results indicated that the presence of an audience could evoke a social facilitation effect on response time in visual search tasks. Compared with working alone, the participants made fewer and shorter fixations, larger saccades and shorter scan path in simple search tasks and more and longer fixations, smaller saccades and longer scan path in complex search tasks when working with an audience. The saccade velocity and pupil diameter in the audience-present condition were larger than those in the working-alone condition. No significant change in target fixation number was observed between two social presence conditions. Practitioner Summary: This study employed an eye-tracking technique to examine the influence of social presence on eye movements in visual search tasks. Results clarified the variation mechanism and characteristics of oculomotor scanning induced by social presence in visual search.

Embedded interruptions and task complexity influence schema-related cognitive load progression in an abstract learning task.

PubMed

Wirzberger, Maria; Esmaeili Bijarsari, Shirin; Rey, Günter Daniel

2017-09-01

Cognitive processes related to schema acquisition comprise an essential source of demands in learning situations. Since the related amount of cognitive load is supposed to change over time, plausible temporal models of load progression based on different theoretical backgrounds are inspected in this study. A total of 116 student participants completed a basal symbol sequence learning task, which provided insights into underlying cognitive dynamics. Two levels of task complexity were determined by the amount of elements within the symbol sequence. In addition, interruptions due to an embedded secondary task occurred at five predefined stages over the task. Within the resulting 2x5-factorial mixed between-within design, the continuous monitoring of efficiency in learning performance enabled assumptions on relevant resource investment. From the obtained results, a nonlinear change of learning efficiency over time seems most plausible in terms of cognitive load progression. Moreover, different effects of the induced interruptions show up in conditions of task complexity, which indicate the activation of distinct cognitive mechanisms related to structural aspects of the task. Findings are discussed in the light of evidence from research on memory and information processing. Copyright © 2017 Elsevier B.V. All rights reserved.

Cognitive Task Analysis: Implications for the Theory and Practice of Instructional Design.

ERIC Educational Resources Information Center

Dehoney, Joanne

Cognitive task analysis grew out of efforts by cognitive psychologists to understand problem-solving in a lab setting. It has proved a useful tool for describing expert performance in complex problem solving domains. This review considers two general models of cognitive task analysis and examines the procedures and results of analyses in three…

Students transcribing tasks: Noticing Fluency, Accuracy, and Complexity

ERIC Educational Resources Information Center

Stillwell, Christopher; Curabba, Brad; Alexander, Kamsin; Kidd, Andrew; Kim, Euna; Stone, Paul; Wyle, Christopher

2010-01-01

Student self-transcription can greatly enhance the power of tasks to promote language learning, for it allows students to re-examine their experience freed from the pressure of performing the task itself, so they can notice and reflect on the language used and encountered. This is a powerful step in language development because it allows for…

Item Mass and Complexity and the Arithmetic Computation of Students with Learning Disabilities.

ERIC Educational Resources Information Center

Cawley, John F.; Shepard, Teri; Smith, Maureen; Parmar, Rene S.

1997-01-01

The performance of 76 students (ages 10 to 15) with learning disabilities on four tasks of arithmetic computation within each of the four basic operations was examined. Tasks varied in difficulty level and number of strokes needed to complete all items. Intercorrelations between task sets and operations were examined as was the use of…

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

ERIC Educational Resources Information Center

Wang, Shinmin; Gathercole, Susan E.

2013-01-01

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

Visuospatial Working Memory in Intuitive Geometry, and in Academic Achievement in Geometry

ERIC Educational Resources Information Center

Giofre, David; Mammarella, Irene C.; Ronconi, Lucia; Cornoldi, Cesare

2013-01-01

A study was conducted on the involvement of visuospatial working memory (VSWM) in intuitive geometry and in school performance in geometry at secondary school. A total of 166 pupils were administered: (1) six VSWM tasks, comprising simple storage and complex span tasks; and (2) the intuitive geometry task devised by Dehaene, Izard, Pica, and…

Thinking about the Weather: How Display Salience and Knowledge Affect Performance in a Graphic Inference Task

ERIC Educational Resources Information Center

Hegarty, Mary; Canham, Matt S.; Fabrikant, Sara I.

2010-01-01

Three experiments examined how bottom-up and top-down processes interact when people view and make inferences from complex visual displays (weather maps). Bottom-up effects of display design were investigated by manipulating the relative visual salience of task-relevant and task-irrelevant information across different maps. Top-down effects of…

Effects of Peer-Tutor Competences on Learner Cognitive Load and Learning Performance during Knowledge Sharing

ERIC Educational Resources Information Center

Hsiao, Ya-Ping; Brouns, Francis; van Bruggen, Jan; Sloep, Peter B.

2012-01-01

In Learning Networks, learners need to share knowledge with others to build knowledge. In particular, when working on complex tasks, they often need to acquire extra cognitive resources from others to process a high task load. However, without support high task load and organizing knowledge sharing themselves might easily overload learners'…

Next Generation Real-Time Systems: Investigating the Potential of Partial-Solution Tasks.

DTIC Science & Technology

1994-12-01

insufficient for dealing with the complexities of next-generation real - time systems . New methods of intelligent control must be developed for guaranteeing...on-time task completion for real - time systems that are faced with unpredictable and dynamically changing requirements. Implementing real-time...tasks by experimentally measuring the change in performance of 11 simulated real - time systems when converted from all-or-nothing tasks to partial

A study on the effects of some reinforcers to improve performance of employees in a retail industry.

PubMed

Raj, John Dilip; Nelson, John Abraham; Rao, K S P

2006-11-01

Two field experiments were conducted in the Business Information Technology Department of a major retail industry to analyze the impact of positive task performance reinforcers. The employees were divided into two broad groups - those performing complex tasks and those performing relatively simpler tasks. The first group was further divided into two subgroups, one being reinforced with money and paid leave and the other with feedback. Both the subgroups showed a significant improvement in performance behavior. However, feedback had a stronger effect on task performance even after the reinforcement was withdrawn. The second group of employees was allowed to choose reinforcers of their liking. Two simple techniques, a casual dress code and flexible working hours chosen by them, had a positive effect on their performance, which continued even after 6 months into the intervention. Besides, the procedure for the second group required no monetary or work-time loss to the employer.

Assessing performance in complex team environments.

PubMed

Whitmore, Jeffrey N

2005-07-01

This paper provides a brief introduction to team performance assessment. It highlights some critical aspects leading to the successful measurement of team performance in realistic console operations; discusses the idea of process and outcome measures; presents two types of team data collection systems; and provides an example of team performance assessment. Team performance assessment is a complicated endeavor relative to assessing individual performance. Assessing team performance necessitates a clear understanding of each operator's task, both at the individual and team level, and requires planning for efficient data capture and analysis. Though team performance assessment requires considerable effort, the results can be very worthwhile. Most tasks performed in Command and Control environments are team tasks, and understanding this type of performance is becoming increasingly important to the evaluation of mission success and for overall system optimization.

Material-specific difficulties in episodic memory tasks in mild traumatic brain injury.

PubMed

Tsirka, Vassiliki; Simos, Panagiotis; Vakis, Antonios; Vourkas, Michael; Arzoglou, Vasileios; Syrmos, Nikolaos; Stavropoulos, Stavros; Micheloyannis, Sifis

2010-03-01

The study examines acute, material-specific secondary memory performance in 26 patients with mild traumatic brain injury (MTBI) and 26 healthy controls, matched on demographic variables and indexes of crystallized intelligence. Neuropsychological tests were used to evaluate primary and secondary memory, executive functions, and verbal fluency. Participants were also tested on episodic memory tasks involving words, pseudowords, pictures of common objects, and abstract kaleidoscopic images. Patients showed reduced performance on episodic memory measures, and on tasks associated with visuospatial processing and executive function (Trail Making Test part B, semantic fluency). Significant differences between groups were also noted for correct rejections and response bias on the kaleidoscope task. MTBI patients' reduced performance on memory tasks for complex, abstract stimuli can be attributed to a dysfunction in the strategic component of memory process.

A Verbal-Instruction System to Help Persons with Multiple Disabilities Perform Complex Food- and Drink-Preparation Tasks Independently

ERIC Educational Resources Information Center

Lancioni, Giulio E.; Singh, Nirbhay N.; O'Reilly, Mark F.; Sigafoos, Jeff; Oliva, Doretta; Smaldone, Angela; La Martire, Maria L.; Alberti, Gloria; Scigliuzzo, Francesca

2011-01-01

In a recent single-case study, we showed that a new verbal-instruction system, ensuring the automatic presentation of step instructions, was beneficial for promoting the task performance of a woman with multiple disabilities (including blindness). The present study was aimed at replicating and extending the aforementioned investigation with three…

Anticipating a Post-Task Activity: The Effects on Accuracy, Complexity, and Fluency of Second Language Performance

ERIC Educational Resources Information Center

Foster, Pauline; Skehan, Peter

2013-01-01

The concept of focus on form has been influential in second language (L2) acquisition and pedagogy. One example of the implementation of focus on form is a post-task activity (e.g., anticipation of a public performance) that can selectively orient learners toward increased levels of accuracy. The present research proposes a new operationalization…

Brain regions engaged by part- and whole-task performance in a video game: a model-based test of the decomposition hypothesis.

PubMed

Anderson, John R; Bothell, Daniel; Fincham, Jon M; Anderson, Abraham R; Poole, Ben; Qin, Yulin

2011-12-01

Part- and whole-task conditions were created by manipulating the presence of certain components of the Space Fortress video game. A cognitive model was created for two-part games that could be combined into a model that performed the whole game. The model generated predictions both for behavioral patterns and activation patterns in various brain regions. The activation predictions concerned both tonic activation that was constant in these regions during performance of the game and phasic activation that occurred when there was resource competition. The model's predictions were confirmed about how tonic and phasic activation in different regions would vary with condition. These results support the Decomposition Hypothesis that the execution of a complex task can be decomposed into a set of information-processing components and that these components combine unchanged in different task conditions. In addition, individual differences in learning gains were predicted by individual differences in phasic activation in those regions that displayed highest tonic activity. This individual difference pattern suggests that the rate of learning of a complex skill is determined by capacity limits.

Auditory memory for timbre.

PubMed

McKeown, Denis; Wellsted, David

2009-06-01

Psychophysical studies are reported examining how the context of recent auditory stimulation may modulate the processing of new sounds. The question posed is how recent tone stimulation may affect ongoing performance in a discrimination task. In the task, two complex sounds occurred in successive intervals. A single target component of one complex was decreased (Experiments 1 and 2) or increased (Experiments 3, 4, and 5) in intensity on half of trials: The task was simply to identify those trials. Prior to each trial, a pure tone inducer was introduced either at the same frequency as the target component or at the frequency of a different component of the complex. Consistent with a frequency-specific form of disruption, discrimination performance was impaired when the inducing tone matched the frequency of the following decrement or increment. A timbre memory model (TMM) is proposed incorporating channel-specific interference allied to inhibition of attending in the coding of sounds in the context of memory traces of recent sounds. (c) 2009 APA, all rights reserved.

A neurobehavioral examination of individuals with high-functioning autism and Asperger's disorder using a fronto-striatal model of dysfunction.

PubMed

Rinehart, Nicole J; Bradshaw, John L; Tonge, Bruce J; Brereton, Avril V; Bellgrove, Mark A

2002-06-01

The repetitive, stereotyped, and obsessive behaviors that characterize autism may in part be attributable to disruption of the region of the fronto-striatal system, which mediates executive abilities. Neuropsychological testing has shown that children with autism exhibit set-shifting deficiencies on tests such as the Wisconsin Card Sorting task but show normal inhibitory ability on variants of the Stroop color-word test. According to Minshew and Goldstein's multiple primary deficit theory, the complexity of the executive functioning task is important in determining the performance of individuals with autism. This study employed a visual-spatial task (with a Stroop-type component) to examine the integrity of executive functioning, in particular inhibition, in autism (n = 12) and Asperger's disorder (n = 12) under increasing levels of cognitive complexity. Whereas the Asperger's disorder group performed similarly to age- and IQ-matched control participants, even at the higher levels of cognitive complexity, the high-functioning autism group displayed inhibitory deficits specifically associated with increasing cognitive load.

Working memory training may increase working memory capacity but not fluid intelligence.

PubMed

Harrison, Tyler L; Shipstead, Zach; Hicks, Kenny L; Hambrick, David Z; Redick, Thomas S; Engle, Randall W

2013-12-01

Working memory is a critical element of complex cognition, particularly under conditions of distraction and interference. Measures of working memory capacity correlate positively with many measures of real-world cognition, including fluid intelligence. There have been numerous attempts to use training procedures to increase working memory capacity and thereby performance on the real-world tasks that rely on working memory capacity. In the study reported here, we demonstrated that training on complex working memory span tasks leads to improvement on similar tasks with different materials but that such training does not generalize to measures of fluid intelligence.

The N2-P3 complex of the evoked potential and human performance

NASA Technical Reports Server (NTRS)

Odonnell, Brian F.; Cohen, Ronald A.

1988-01-01

The N2-P3 complex and other endogenous components of human evoked potential provide a set of tools for the investigation of human perceptual and cognitive processes. These multidimensional measures of central nervous system bioelectrical activity respond to a variety of environmental and internal factors which have been experimentally characterized. Their application to the analysis of human performance in naturalistic task environments is just beginning. Converging evidence suggests that the N2-P3 complex reflects processes of stimulus evaluation, perceptual resource allocation, and decision making that proceed in parallel, rather than in series, with response generation. Utilization of these EP components may provide insights into the central nervous system mechanisms modulating task performance unavailable from behavioral measures alone. The sensitivity of the N2-P3 complex to neuropathology, psychopathology, and pharmacological manipulation suggests that these components might provide sensitive markers for the effects of environmental stressors on the human central nervous system.

Complex Tasks Force Hand Laterality and Technological Behaviour in Naturalistically Housed Chimpanzees: Inferences in Hominin Evolution

PubMed Central

Mosquera, M.; Geribàs, N.; Bargalló, A.; Llorente, M.; Riba, D.

2012-01-01

Clear hand laterality patterns in humans are widely accepted. However, humans only elicit a significant hand laterality pattern when performing complementary role differentiation (CRD) tasks. Meanwhile, hand laterality in chimpanzees is weaker and controversial. Here we have reevaluated our results on hand laterality in chimpanzees housed in naturalistic environments at Fundació Mona (Spain) and Chimfunshi Wild Orphanage (Zambia). Our results show that the difference between hand laterality in humans and chimpanzees is not as great as once thought. Furthermore, we found a link between hand laterality and task complexity and also an even more interesting connection: CRD tasks elicited not only the hand laterality but also the use of tools. This paper aims to turn attention to the importance of this threefold connection in human evolution: the link between CRD tasks, hand laterality, and tool use, which has important evolutionary implications that may explain the development of complex behaviour in early hominins. PMID:22550466

Complex tasks force hand laterality and technological behaviour in naturalistically housed chimpanzees: inferences in hominin evolution.

PubMed

Mosquera, M; Geribàs, N; Bargalló, A; Llorente, M; Riba, D

2012-01-01

Clear hand laterality patterns in humans are widely accepted. However, humans only elicit a significant hand laterality pattern when performing complementary role differentiation (CRD) tasks. Meanwhile, hand laterality in chimpanzees is weaker and controversial. Here we have reevaluated our results on hand laterality in chimpanzees housed in naturalistic environments at Fundació Mona (Spain) and Chimfunshi Wild Orphanage (Zambia). Our results show that the difference between hand laterality in humans and chimpanzees is not as great as once thought. Furthermore, we found a link between hand laterality and task complexity and also an even more interesting connection: CRD tasks elicited not only the hand laterality but also the use of tools. This paper aims to turn attention to the importance of this threefold connection in human evolution: the link between CRD tasks, hand laterality, and tool use, which has important evolutionary implications that may explain the development of complex behaviour in early hominins.

The Effect of a Six-Month Dancing Program on Motor-Cognitive Dual-Task Performance in Older Adults.

PubMed

Hamacher, Dennis; Hamacher, Daniel; Rehfeld, Kathrin; Hökelmann, Anita; Schega, Lutz

2015-10-01

Dancing is a complex sensorimotor activity involving physical and mental elements which have positive effects on cognitive functions and motor control. The present randomized controlled trial aims to analyze the effects of a dancing program on the performance on a motor-cognitive dual task. Data of 35 older adults, who were assigned to a dancing group or a health-related exercise group, are presented in the study. In pretest and posttest, we assessed cognitive performance and variability of minimum foot clearance, stride time, and stride length while walking. Regarding the cognitive performance and the stride-to-stride variability of minimum foot clearance, interaction effects have been found, indicating that dancing lowers gait variability to a higher extent than conventional health-related exercise. The data show that dancing improves minimum foot clearance variability and cognitive performance in a dual-task situation. Multi-task exercises (like dancing) might be a powerful tool to improve motor-cognitive dual-task performance.

Make Your Workflows Smarter

NASA Technical Reports Server (NTRS)

Jones, Corey; Kapatos, Dennis; Skradski, Cory

2012-01-01

Do you have workflows with many manual tasks that slow down your business? Or, do you scale back workflows because there are simply too many manual tasks? Basic workflow robots can automate some common tasks, but not everything. This presentation will show how advanced robots called "expression robots" can be set up to perform everything from simple tasks such as: moving, creating folders, renaming, changing or creating an attribute, and revising, to more complex tasks like: creating a pdf, or even launching a session of Creo Parametric and performing a specific modeling task. Expression robots are able to utilize the Java API and Info*Engine to do almost anything you can imagine! Best of all, these tools are supported by PTC and will work with later releases of Windchill. Limited knowledge of Java, Info*Engine, and XML are required. The attendee will learn what task expression robots are capable of performing. The attendee will learn what is involved in setting up an expression robot. The attendee will gain a basic understanding of simple Info*Engine tasks

AstroGrid: Taverna in the Virtual Observatory .

NASA Astrophysics Data System (ADS)

Benson, K. M.; Walton, N. A.

This paper reports on the implementation of the Taverna workbench by AstroGrid, a tool for designing and executing workflows of tasks in the Virtual Observatory. The workflow approach helps astronomers perform complex task sequences with little technical effort. Visual approach to workflow construction streamlines highly complex analysis over public and private data and uses computational resources as minimal as a desktop computer. Some integration issues and future work are discussed in this article.

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

PubMed

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

2015-09-01

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

Virtual reality for gait training: can it induce motor learning to enhance complex walking and reduce fall risk in patients with Parkinson's disease?

PubMed

Mirelman, Anat; Maidan, Inbal; Herman, Talia; Deutsch, Judith E; Giladi, Nir; Hausdorff, Jeffrey M

2011-02-01

Gait and cognitive disturbances are common in Parkinson's disease (PD). These deficits exacerbate fall risk and difficulties with mobility, especially during complex or dual-task walking. Traditional gait training generally fails to fully address these complex gait activities. Virtual reality (VR) incorporates principles of motor learning while delivering engaging and challenging training in complex environments. We hypothesized that VR may be applied to address the multifaceted deficits associated with fall risk in PD. Twenty patients received 18 sessions (3 per week) of progressive intensive treadmill training with virtual obstacles (TT + VR). Outcome measures included gait under usual-walking and dual-task conditions and while negotiating physical obstacles. Cognitive function and functional performance were also assessed. Patients were 67.1 ± 6.5 years and had a mean disease duration of 9.8 ± 5.6 years. Posttraining, gait speed significantly improved during usual walking, during dual task, and while negotiating overground obstacles. Dual-task gait variability decreased (ie, improved) and Trail Making Test times (parts A and B) improved. Gains in functional performance measures and retention effects, 1 month later, were also observed. To our knowledge, this is the first time that TT + VR has been used for gait training in PD. The results indicate that TT + VR is viable in PD and may significantly improve physical performance, gait during complex challenging conditions, and even certain aspects of cognitive function. These findings have important implications for understanding motor learning in the presence of PD and for treating fall risk in PD, aging, and others who share a heightened risk of falls.

Integrating Markets to Bridge Supply and Demand for Knowledge Intensive Tasks

NASA Astrophysics Data System (ADS)

Overbeek, Sietse; Janssen, Marijn; van Bommel, Patrick

The advent of the knowledge-based economy has underlined the importance of intellectual capital that is possessed by knowledge intensive organizations. Three general observations of knowledge intensive work produced by actors working in such organizations served as the basis for the initiation of this research. First, knowledge intensive tasks become increasingly complex. Second, actors that perform such tasks experience an increase in cognitive load. Third, the desired quality of task performance and the produced task results are at stake due to the aforementioned two developments. In this research we investigate how supply and demand of intangible assets such as knowledge, cognitive characteristics, and quality factors can be matched based on market mechanisms.

Robot-assisted surgery: an emerging platform for human neuroscience research

PubMed Central

Jarc, Anthony M.; Nisky, Ilana

2015-01-01

Classic studies in human sensorimotor control use simplified tasks to uncover fundamental control strategies employed by the nervous system. Such simple tasks are critical for isolating specific features of motor, sensory, or cognitive processes, and for inferring causality between these features and observed behavioral changes. However, it remains unclear how these theories translate to complex sensorimotor tasks or to natural behaviors. Part of the difficulty in performing such experiments has been the lack of appropriate tools for measuring complex motor skills in real-world contexts. Robot-assisted surgery (RAS) provides an opportunity to overcome these challenges by enabling unobtrusive measurements of user behavior. In addition, a continuum of tasks with varying complexity—from simple tasks such as those in classic studies to highly complex tasks such as a surgical procedure—can be studied using RAS platforms. Finally, RAS includes a diverse participant population of inexperienced users all the way to expert surgeons. In this perspective, we illustrate how the characteristics of RAS systems make them compelling platforms to extend many theories in human neuroscience, as well as, to develop new theories altogether. PMID:26089785

Objective Assessment of Laparoscopic Force and Psychomotor Skills in a Novel Virtual Reality-Based Haptic Simulator.

PubMed

Prasad, M S Raghu; Manivannan, Muniyandi; Manoharan, Govindan; Chandramohan, S M

2016-01-01

Most of the commercially available virtual reality-based laparoscopic simulators do not effectively evaluate combined psychomotor and force-based laparoscopic skills. Consequently, the lack of training on these critical skills leads to intraoperative errors. To assess the effectiveness of the novel virtual reality-based simulator, this study analyzed the combined psychomotor (i.e., motion or movement) and force skills of residents and expert surgeons. The study also examined the effectiveness of real-time visual force feedback and tool motion during training. Bimanual fundamental (i.e., probing, pulling, sweeping, grasping, and twisting) and complex tasks (i.e., tissue dissection) were evaluated. In both tasks, visual feedback on applied force and tool motion were provided. The skills of the participants while performing the early tasks were assessed with and without visual feedback. Participants performed 5 repetitions of fundamental and complex tasks. Reaction force and instrument acceleration were used as metrics. Surgical Gastroenterology, Government Stanley Medical College and Hospital; Institute of Surgical Gastroenterology, Madras Medical College and Rajiv Gandhi Government General Hospital. Residents (N = 25; postgraduates and surgeons with <2 years of laparoscopic surgery) and expert surgeons (N = 25; surgeons with >4 and ≤10 years of laparoscopic surgery). Residents applied large forces compared with expert surgeons and performed abrupt tool movements (p < 0.001). However, visual + haptic feedback improved the performance of residents (p < 0.001). In complex tasks, visual + haptic feedback did not influence the applied force of expert surgeons, but influenced their tool motion (p < 0.001). Furthermore, in complex tissue sweeping task, expert surgeons applied more force, but were within the tissue damage limits. In both groups, exertion of large forces and abrupt tool motion were observed during grasping, probing or pulling, and tissue sweeping maneuvers (p < 0.001). Modern day curriculum-based training should evaluate the skills of residents with robust force and psychomotor-based exercises for proficient laparoscopy. Visual feedback on force and motion during training has the potential to enhance the learning curve of residents. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Come to think of it: Contributions of reasoning abilities and training schedule to skill acquisition in a virtual throwing task.

PubMed

Frömer, Romy; Stürmer, Birgit; Sommer, Werner

2016-10-01

According to Schmidt's schema theory skill acquisition is based on schema formation where multiple learning incidents with varying task features are abstracted to a unifying pattern, the schema. Practice can be scheduled block-wise, with low contextual interference (CI) or randomly, with high CI. The greater effort during high CI training usually results in reduced training success but enhanced retention and transfer performance. In contrast to well-established CI effects for simple tasks, findings for complex tasks are heterogeneous, supposedly due to the detrimental accumulation of task demands. We assumed that in complex tasks, cognitive reasoning abilities might impose a limit upon schema formation and hence the effectiveness of CI. In a virtual overarm-throwing experiment participants practiced target positions at center, left, or right and were retested for retention - at the center position - and transfer with a larger target distance. Although there was no main effect of CI on performance, either in training, retention or transfer, under high CI, training performance was better for participants with higher reasoning ability, as measured with the Raven matrices. This advantage persisted across retention and transfer. Under low CI, reasoning was positively related to performance improvement only in the last third of training. We argue, that variability of practice is a necessary prerequisite for beneficial effects of reasoning abilities. Based on previous findings, we discuss feedback evaluation as a possible locus of the relationship between reasoning and performance in motor skill acquisition. Copyright © 2016 Elsevier B.V. All rights reserved.

Music is as distracting as noise: the differential distraction of background music and noise on the cognitive test performance of introverts and extraverts.

PubMed

Furnham, Adrian; Strbac, Lisa

2002-02-20

Previous research has found that introverts' performance on complex cognitive tasks is more negatively affected by distracters, e.g. music and background television, than extraverts' performance. This study extended previous research by examining whether background noise would be as distracting as music. In the presence of silence, background garage music and office noise, 38 introverts and 38 extraverts carried out a reading comprehension task, a prose recall task and a mental arithmetic task. It was predicted that there would be an interaction between personality and background sound on all three tasks: introverts would do less well on all of the tasks than extraverts in the presence of music and noise but in silence performance would be the same. A significant interaction was found on the reading comprehension task only, although a trend for this effect was clearly present on the other two tasks. It was also predicted that there would be a main effect for background sound: performance would be worse in the presence of music and noise than silence. Results confirmed this prediction. These findings support the Eysenckian hypothesis of the difference in optimum cortical arousal in introverts and extraverts.

Blinks, saccades, and fixation pauses during vigilance task performance. I., Time on task.

DOT National Transportation Integrated Search

1994-12-01

In the future, operators of complex equipment will spend more time monitoring computer controlled devices rather than having hands on control of such equipment. The operator intervenes in system operation under "unusual" conditions or when there is a...

Goal orientation: effects on backing up behavior, performance, efficacy, and commitment in teams.

PubMed

Porter, Christopher O L H

2005-07-01

The author examined the predictive validity of goal orientation in teams on both team process and outcome variables. Results indicate that when mean goal orientation scores were used as a way of describing team members' inputs, learning orientation was related to backing up behavior, efficacy, and commitment. The relationships between performance orientation and efficacy and commitment, however, were more complex and were clarified when task performance was also taken into account. Performance orientation had a negative effect on efficacy when task performance was low and a positive effect on commitment when task performance was high. The implications of these findings for theory and research on goal orientation in teams and team staffing are discussed. Copyright 2005 APA, all rights reserved.

Characterizing and Mitigating Work Time Inflation in Task Parallel Programs

DOE PAGES

Olivier, Stephen L.; de Supinski, Bronis R.; Schulz, Martin; ...

2013-01-01

Task parallelism raises the level of abstraction in shared memory parallel programming to simplify the development of complex applications. However, task parallel applications can exhibit poor performance due to thread idleness, scheduling overheads, and work time inflation – additional time spent by threads in a multithreaded computation beyond the time required to perform the same work in a sequential computation. We identify the contributions of each factor to lost efficiency in various task parallel OpenMP applications and diagnose the causes of work time inflation in those applications. Increased data access latency can cause significant work time inflation in NUMA systems.more » Our locality framework for task parallel OpenMP programs mitigates this cause of work time inflation. Our extensions to the Qthreads library demonstrate that locality-aware scheduling can improve performance up to 3X compared to the Intel OpenMP task scheduler.« less

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory.

PubMed

Meier, Beat; Zimmermann, Thomas D

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory

PubMed Central

Meier, Beat; Zimmermann, Thomas D.

2015-01-01

In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially. PMID:26082709

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.

Nominal and functional task difficulty in skill acquisition: Effects on performance in two tests of transfer.

PubMed

Sanli, Elizabeth A; Lee, Timothy D

2015-06-01

The influence of nominal and functional task difficulty during the acquisition of a motor skill was examined in two tests of transfer of learning. The task involved a ballistic, target-directed, finger action. Nominal task difficulty was defined as the distance of the target from the home position. Functional task difficulty was created by manipulating the progression of target distances during practice. Based on the challenge point framework (Guadagnoli & Lee, 2004), we predicted that practice with a set of targets farther away from the performer would benefit from less functional task difficulty, while practice with a closer set of targets would benefit from more functional task difficulty. In single-task transfer tests, learners who practiced using the high nominal task difficulty targets benefitted in terms of persistence of performance over time. In dual-task transfer tests, groups with an intermediate combined (nominal and functional) task difficulty performed with greater persistence over time on tests of transfer than those who practiced with the highest or lowest combined difficulty. Together these findings suggest that the influences of nominal and functional task difficulty during acquisition are weighted differentially depending upon the transfer test context. The challenge point framework does not accurately capture this complex relationship in its current form. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of music engagement on responses to painful stimulation.

PubMed

Bradshaw, David H; Chapman, C Richard; Jacobson, Robert C; Donaldson, Gary W

2012-06-01

We propose a theoretical framework for the behavioral modulation of pain based on constructivism, positing that task engagement, such as listening for errors in a musical passage, can establish a construction of reality that effectively replaces pain as a competing construction. Graded engagement produces graded reductions in pain as indicated by reduced psychophysiological arousal and subjective pain report. Fifty-three healthy volunteers having normal hearing participated in 4 music listening conditions consisting of passive listening (no task) or performing an error detection task varying in signal complexity and task difficulty. During all conditions, participants received normally painful fingertip shocks varying in intensity while stimulus-evoked potentials (SEP), pupil dilation responses (PDR), and retrospective pain reports were obtained. SEP and PDR increased with increasing stimulus intensity. Task performance decreased with increasing task difficulty. Mixed model analyses, adjusted for habituation/sensitization and repeated measures within person, revealed significant quadratic trends for SEP and pain report (Pchange<0.001) with large reductions from no task to easy task and smaller graded reductions corresponding to increasing task difficulty/complexity. PDR decreased linearly (Pchange<0.001) with graded task condition. We infer that these graded reductions in indicators of central and peripheral arousal and in reported pain correspond to graded increases in engagement in the music listening task. Engaging activities may prevent pain by creating competing constructions of reality that draw on the same processing resources as pain. Better understanding of these processes will advance the development of more effective pain modulation through improved manipulation of engagement strategies.

Tracking reading: dual task costs of oral reading for young versus older adults.

PubMed

Kemper, Susan; Bontempo, Daniel; Schmalzried, RaLynn; McKedy, Whitney; Tagliaferri, Bruno; Kieweg, Doug

2014-02-01

A digital pursuit rotor was used to monitor oral reading costs by time-locking tracking performance to the auditory wave form produced as young and older adults were reading out short paragraphs. Multilevel modeling was used to determine how paragraph-level predictors of length, grammatical complexity, and readability and person-level predictors such as speaker age or working memory capacity predicted reading and tracking performance. In addition, sentence-by-sentence variation in tracking performance was examined during the production of individual sentences and during the pauses before upcoming sentences. The results suggest that dual tasking has a greater impact on older adults' reading comprehension and tracking performance. At the level of individual sentences, young and older adults adopt different strategies to deal with grammatically complex and propositionally dense sentences.

Dual Task Costs of Oral Reading for Young versus Older Adults

PubMed Central

Kemper, Susan; Bontempo, Daniel; Schmalzried, RaLynn; McKedy, Whitney; Tagliaferri, Bruno; Kieweg, Doug

2013-01-01

A digital pursuit rotor was used to monitor oral reading costs by time-locking tracking performance to the auditory wave form produced as young and older adults were reading out short paragraphs. Multilevel modeling was used to determine how paragraph-level predictors of length, grammatical complexity, and readability and person-level predictors such as speaker age or working memory capacity predicted reading and tracking performance. In addition, sentence-by-sentence variation in tracking performance was examined during the production of individual sentences and during the pauses before upcoming sentences. The results suggest that dual tasking has a greater impact on older adults’ reading comprehension and tracking performance. At the level of individual sentences, young and older adults adopt different strategies to deal with grammatically complex and propositionally dense sentences. PMID:23463405

Emotional and cognitive influences in air traffic controller tasks: An investigation using a virtual environment?

PubMed

Truschzinski, Martina; Betella, Alberto; Brunnett, Guido; Verschure, Paul F M J

2018-05-01

Air traffic controllers are required to perform complex tasks which require attention and high precision. This study investigates how the difficulty of such tasks influences emotional states, cognitive workload and task performance. We use quantitative and qualitative measurements, including the recording of pupil dilation and changes in affect using questionnaires. Participants were required to perform a number of air traffic control tasks using the immersive human accessible Virtual Reality space in the "eXperience Induction Machine". Based on the data collected, we developed and validated a model which integrates personality, workload and affective theories. Our results indicate that the difficulty of an air traffic control task has a direct influence on cognitive workload as well as on the self-reported mood; whereas both mood and workload seem to change independently. In addition, we show that personality, in particular neuroticism, affects both mood and performance of the participants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Activities of daily living measured by the Harvard Automated Phone Task track with cognitive decline over time in non-demented elderly.

PubMed

Marshall, Gad A; Aghjayan, Sarah L; Dekhtyar, Maria; Locascio, Joseph J; Jethwani, Kamal; Amariglio, Rebecca E; Johnson, Keith A; Sperling, Reisa A; Rentz, Dorene M

2017-01-01

Impairment in activities of daily living is a major burden to both patients and caregivers. Mild impairment in instrumental activities of daily living is often seen at the stage of mild cognitive impairment. The field of Alzheimer's disease is moving toward earlier diagnosis and intervention and more sensitive and ecologically valid assessments of instrumental or complex activities of daily living are needed. The Harvard Automated Phone Task, a novel performance-based activities of daily living instrument, has the potential to fill this gap. To further validate the Harvard Automated Phone Task by assessing its longitudinal relationship to global cognition and specific cognitive domains in clinically normal elderly and individuals with mild cognitive impairment. In a longitudinal study, the Harvard Automated Phone Task was associated with cognitive measures using mixed effects models. The Harvard Automated Phone Task's ability to discriminate across diagnostic groups at baseline was also assessed. Academic clinical research center. Two hundred and seven participants (45 young normal, 141 clinically normal elderly, and 21 mild cognitive impairment) were recruited from the community and the memory disorders clinics at Brigham and Women's Hospital and Massachusetts General Hospital. Participants performed the three tasks of the Harvard Automated Phone Task, which consist of navigating an interactive voice response system to refill a prescription (APT-Script), select a new primary care physician (APT-PCP), and make a bank account transfer and payment (APT-Bank). The 3 tasks were scored based on time, errors, repetitions, and correct completion of the task. The primary outcome measure used for each of the tasks was total time adjusted for correct completion. The Harvard Automated Phone Task discriminated well between young normal, clinically normal elderly, and mild cognitive impairment participants (APT-Script: p<0.001; APT-PCP: p<0.001; APT-Bank: p=0.04). Worse baseline Harvard Automated Phone Task performance or worsening Harvard Automated Phone Task performance over time tracked with overall worse performance or worsening performance over time in global cognition, processing speed, executive function, and episodic memory. Prior cross-sectional and current longitudinal analyses have demonstrated the utility of the Harvard Automated Phone Task, a new performance-based activities of daily living instrument, in the assessment of early changes in complex activities of daily living in non-demented elderly at risk for Alzheimer's disease. Future studies will focus on cross-validation with other sensitive activities of daily living tests and Alzheimer's disease biomarkers.

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

PubMed

Picou, Erin M; Ricketts, Todd A

2014-01-01

The purpose of this study was to evaluate the effect of changing the secondary task in dual-task paradigms that measure listening effort. Specifically, the effects of increasing the secondary task complexity or the depth of processing on a paradigm's sensitivity to changes in listening effort were quantified in a series of two experiments. Specific factors investigated within each experiment were background noise and visual cues. Participants in Experiment 1 were adults with normal hearing (mean age 23 years) and participants in Experiment 2 were adults with mild sloping to moderately severe sensorineural hearing loss (mean age 60.1 years). In both experiments, participants were tested using three dual-task paradigms. These paradigms had identical primary tasks, which were always monosyllable word recognition. The secondary tasks were all physical reaction time measures. The stimulus for the secondary task varied by paradigm and was a (1) simple visual probe, (2) a complex visual probe, or (3) the category of word presented. In this way, the secondary tasks mainly varied from the simple paradigm by either complexity or depth of speech processing. Using all three paradigms, participants were tested in four conditions, (1) auditory-only stimuli in quiet, (2) auditory-only stimuli in noise, (3) auditory-visual stimuli in quiet, and (4) auditory-visual stimuli in noise. During auditory-visual conditions, the talker's face was visible. Signal-to-noise ratios used during conditions with background noise were set individually so word recognition performance was matched in auditory-only and auditory-visual conditions. In noise, word recognition performance was approximately 80% and 65% for Experiments 1 and 2, respectively. For both experiments, word recognition performance was stable across the three paradigms, confirming that none of the secondary tasks interfered with the primary task. In Experiment 1 (listeners with normal hearing), analysis of median reaction times revealed a significant main effect of background noise on listening effort only with the paradigm that required deep processing. Visual cues did not change listening effort as measured with any of the three dual-task paradigms. In Experiment 2 (listeners with hearing loss), analysis of median reaction times revealed expected significant effects of background noise using all three paradigms, but no significant effects of visual cues. None of the dual-task paradigms were sensitive to the effects of visual cues. Furthermore, changing the complexity of the secondary task did not change dual-task paradigm sensitivity to the effects of background noise on listening effort for either group of listeners. However, the paradigm whose secondary task involved deeper processing was more sensitive to the effects of background noise for both groups of listeners. While this paradigm differed from the others in several respects, depth of processing may be partially responsible for the increased sensitivity. Therefore, this paradigm may be a valuable tool for evaluating other factors that affect listening effort.

Effect of feedback mode and task difficulty on quality of timing decisions in a zero-sum game.

PubMed

Tikuisis, Peter; Vartanian, Oshin; Mandel, David R

2014-09-01

The objective was to investigate the interaction between the mode of performance outcome feedback and task difficulty on timing decisions (i.e., when to act). Feedback is widely acknowledged to affect task performance. However, the extent to which feedback display mode and its impact on timing decisions is moderated by task difficulty remains largely unknown. Participants repeatedly engaged a zero-sum game involving silent duels with a computerized opponent and were given visual performance feedback after each engagement. They were sequentially tested on three different levels of task difficulty (low, intermediate, and high) in counterbalanced order. Half received relatively simple "inside view" binary outcome feedback, and the other half received complex "outside view" hit rate probability feedback. The key dependent variables were response time (i.e., time taken to make a decision) and survival outcome. When task difficulty was low to moderate, participants were more likely to learn and perform better from hit rate probability feedback than binary outcome feedback. However, better performance with hit rate feedback exacted a higher cognitive cost manifested by higher decision response time. The beneficial effect of hit rate probability feedback on timing decisions is partially moderated by task difficulty. Performance feedback mode should be judiciously chosen in relation to task difficulty for optimal performance in tasks involving timing decisions.

Non-Interfering Effects of Active Post-Encoding Tasks on Episodic Memory Consolidation in Humans

PubMed Central

Varma, Samarth; Takashima, Atsuko; Krewinkel, Sander; van Kooten, Maaike; Fu, Lily; Medendorp, W. Pieter; Kessels, Roy P. C.; Daselaar, Sander M.

2017-01-01

So far, studies that investigated interference effects of post-learning processes on episodic memory consolidation in humans have used tasks involving only complex and meaningful information. Such tasks require reallocation of general or encoding-specific resources away from consolidation-relevant activities. The possibility that interference can be elicited using a task that heavily taxes our limited brain resources, but has low semantic and hippocampal related long-term memory processing demands, has never been tested. We address this question by investigating whether consolidation could persist in parallel with an active, encoding-irrelevant, minimally semantic task, regardless of its high resource demands for cognitive processing. We distinguish the impact of such a task on consolidation based on whether it engages resources that are: (1) general/executive, or (2) specific/overlapping with the encoding modality. Our experiments compared subsequent memory performance across two post-encoding consolidation periods: quiet wakeful rest and a cognitively demanding n-Back task. Across six different experiments (total N = 176), we carefully manipulated the design of the n-Back task to target general or specific resources engaged in the ongoing consolidation process. In contrast to previous studies that employed interference tasks involving conceptual stimuli and complex processing demands, we did not find any differences between n-Back and rest conditions on memory performance at delayed test, using both recall and recognition tests. Our results indicate that: (1) quiet, wakeful rest is not a necessary prerequisite for episodic memory consolidation; and (2) post-encoding cognitive engagement does not interfere with memory consolidation when task-performance has minimal semantic and hippocampally-based episodic memory processing demands. We discuss our findings with reference to resource and reactivation-led interference theories. PMID:28424596

Non-Interfering Effects of Active Post-Encoding Tasks on Episodic Memory Consolidation in Humans.

PubMed

Varma, Samarth; Takashima, Atsuko; Krewinkel, Sander; van Kooten, Maaike; Fu, Lily; Medendorp, W Pieter; Kessels, Roy P C; Daselaar, Sander M

2017-01-01

So far, studies that investigated interference effects of post-learning processes on episodic memory consolidation in humans have used tasks involving only complex and meaningful information. Such tasks require reallocation of general or encoding-specific resources away from consolidation-relevant activities. The possibility that interference can be elicited using a task that heavily taxes our limited brain resources, but has low semantic and hippocampal related long-term memory processing demands, has never been tested. We address this question by investigating whether consolidation could persist in parallel with an active, encoding-irrelevant, minimally semantic task, regardless of its high resource demands for cognitive processing. We distinguish the impact of such a task on consolidation based on whether it engages resources that are: (1) general/executive, or (2) specific/overlapping with the encoding modality. Our experiments compared subsequent memory performance across two post-encoding consolidation periods: quiet wakeful rest and a cognitively demanding n-Back task. Across six different experiments (total N = 176), we carefully manipulated the design of the n-Back task to target general or specific resources engaged in the ongoing consolidation process. In contrast to previous studies that employed interference tasks involving conceptual stimuli and complex processing demands, we did not find any differences between n-Back and rest conditions on memory performance at delayed test, using both recall and recognition tests. Our results indicate that: (1) quiet, wakeful rest is not a necessary prerequisite for episodic memory consolidation; and (2) post-encoding cognitive engagement does not interfere with memory consolidation when task-performance has minimal semantic and hippocampally-based episodic memory processing demands. We discuss our findings with reference to resource and reactivation-led interference theories.

Neuropsychological Investigation of Motor Impairments in Autism

PubMed Central

Duffield, Tyler; Trontel, Haley; Bigler, Erin D.; Froehlich, Alyson; Prigge, Molly B.; Travers, Brittany; Green, Ryan R.; Cariello, Annahir N.; Cooperrider, Jason; Nielsen, Jared; Alexander, Andrew; Anderson, Jeffrey; Fletcher, P. Thomas; Lange, Nicholas; Zielinski, Brandon; Lainhart, Janet

2013-01-01

It is unclear how standardized neuropsychological measures of motor function relate to brain volumes of motor regions in autism spectrum disorder (ASD). An all male sample composed of 59 ASD and 30 controls (ages 5–33 years) completed three measures of motor function: strength of grip (SOG), finger tapping test (FTT), and grooved peg-board test (GPT). Likewise, all participants underwent magnetic resonance imaging with region of interest (ROI) volumes obtained to include the following regions: motor cortex (pre-central gyrus), somatosensory cortex (post-central gyrus), thalamus, basal ganglia, cerebellum and caudal middle frontal gyrus. These traditional neuropsychological measures of motor function are assumed to differ in motor complexity with GPT requiring the most followed by FTT and SOG. Performance by ASD participants on the GPT and FTT differed significantly from controls, with the largest effect size differences observed on the more complex GPT task. Differences on the SOG task between the two groups were non-significant. Since more complex motor tasks tap more complex networks, poorer GPT performance by those with ASD may reflect less efficient motor networks. There was no gross pathology observed in classic motor areas of the brain in ASD, as region of interest (ROI) volumes did not differ, but FTT was negatively related to motor cortex volume in ASD. The results suggest a hierarchical motor disruption in ASD, with difficulties evident only in more complex tasks as well as a potential anomalous size-function relation in motor cortex in ASD. PMID:23985036

A framework for characterizing eHealth literacy demands and barriers.

PubMed

Chan, Connie V; Kaufman, David R

2011-11-17

Consumer eHealth interventions are of a growing importance in the individual management of health and health behaviors. However, a range of access, resources, and skills barriers prevent health care consumers from fully engaging in and benefiting from the spectrum of eHealth interventions. Consumers may engage in a range of eHealth tasks, such as participating in health discussion forums and entering information into a personal health record. eHealth literacy names a set of skills and knowledge that are essential for productive interactions with technology-based health tools, such as proficiency in information retrieval strategies, and communicating health concepts effectively. We propose a theoretical and methodological framework for characterizing complexity of eHealth tasks, which can be used to diagnose and describe literacy barriers and inform the development of solution strategies. We adapted and integrated two existing theoretical models relevant to the analysis of eHealth literacy into a single framework to systematically categorize and describe task demands and user performance on tasks needed by health care consumers in the information age. The method derived from the framework is applied to (1) code task demands using a cognitive task analysis, and (2) code user performance on tasks. The framework and method are applied to the analysis of a Web-based consumer eHealth task with information-seeking and decision-making demands. We present the results from the in-depth analysis of the task performance of a single user as well as of 20 users on the same task to illustrate both the detailed analysis and the aggregate measures obtained and potential analyses that can be performed using this method. The analysis shows that the framework can be used to classify task demands as well as the barriers encountered in user performance of the tasks. Our approach can be used to (1) characterize the challenges confronted by participants in performing the tasks, (2) determine the extent to which application of the framework to the cognitive task analysis can predict and explain the problems encountered by participants, and (3) inform revisions to the framework to increase accuracy of predictions. The results of this illustrative application suggest that the framework is useful for characterizing task complexity and for diagnosing and explaining barriers encountered in task completion. The framework and analytic approach can be a potentially powerful generative research platform to inform development of rigorous eHealth examination and design instruments, such as to assess eHealth competence, to design and evaluate consumer eHealth tools, and to develop an eHealth curriculum.

A Framework for Characterizing eHealth Literacy Demands and Barriers

PubMed Central

Chan, Connie V

2011-01-01

Background Consumer eHealth interventions are of a growing importance in the individual management of health and health behaviors. However, a range of access, resources, and skills barriers prevent health care consumers from fully engaging in and benefiting from the spectrum of eHealth interventions. Consumers may engage in a range of eHealth tasks, such as participating in health discussion forums and entering information into a personal health record. eHealth literacy names a set of skills and knowledge that are essential for productive interactions with technology-based health tools, such as proficiency in information retrieval strategies, and communicating health concepts effectively. Objective We propose a theoretical and methodological framework for characterizing complexity of eHealth tasks, which can be used to diagnose and describe literacy barriers and inform the development of solution strategies. Methods We adapted and integrated two existing theoretical models relevant to the analysis of eHealth literacy into a single framework to systematically categorize and describe task demands and user performance on tasks needed by health care consumers in the information age. The method derived from the framework is applied to (1) code task demands using a cognitive task analysis, and (2) code user performance on tasks. The framework and method are applied to the analysis of a Web-based consumer eHealth task with information-seeking and decision-making demands. We present the results from the in-depth analysis of the task performance of a single user as well as of 20 users on the same task to illustrate both the detailed analysis and the aggregate measures obtained and potential analyses that can be performed using this method. Results The analysis shows that the framework can be used to classify task demands as well as the barriers encountered in user performance of the tasks. Our approach can be used to (1) characterize the challenges confronted by participants in performing the tasks, (2) determine the extent to which application of the framework to the cognitive task analysis can predict and explain the problems encountered by participants, and (3) inform revisions to the framework to increase accuracy of predictions. Conclusions The results of this illustrative application suggest that the framework is useful for characterizing task complexity and for diagnosing and explaining barriers encountered in task completion. The framework and analytic approach can be a potentially powerful generative research platform to inform development of rigorous eHealth examination and design instruments, such as to assess eHealth competence, to design and evaluate consumer eHealth tools, and to develop an eHealth curriculum. PMID:22094891

Visual Search Performance in the Autism Spectrum II: The Radial Frequency Search Task with Additional Segmentation Cues

ERIC Educational Resources Information Center

Almeida, Renita A.; Dickinson, J. Edwin; Maybery, Murray T.; Badcock, Johanna C.; Badcock, David R.

2010-01-01

The Embedded Figures Test (EFT) requires detecting a shape within a complex background and individuals with autism or high Autism-spectrum Quotient (AQ) scores are faster and more accurate on this task than controls. This research aimed to uncover the visual processes producing this difference. Previously we developed a search task using radial…

Repeating a Monologue under Increasing Time Pressure: Effects on Fluency, Complexity, and Accuracy

ERIC Educational Resources Information Center

Thai, Chau; Boers, Frank

2016-01-01

Studies have shown that learners' task performance improves when they have the opportunity to repeat the task. Conditions for task repetition vary, however. In the 4/3/2 activity, learners repeat a monologue under increasing time pressure. The purpose is to foster fluency, but it has been suggested in the literature that it also benefits other…

A Cognition Analysis of QUASAR's Mathematics Performance Assessment Tasks and Their Sensitivity to Measuring Changes in Middle School Students' Thinking and Reasoning.

ERIC Educational Resources Information Center

Cai, Jinfa, And Others

1996-01-01

Presents a conceptual framework for analyzing students' mathematical understanding, reasoning, problem solving, and communication. Analyses of student responses indicated that the tasks appear to measure the complex thinking and reasoning processes that they were designed to assess. Concludes that the QUASAR assessment tasks can capture changes in…

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.

Cognitive Performance Effects of Bilastine 20 mg During 6 Hours at 8000 ft Cabin Altitude.

PubMed

Valk, Pierre J L; Simons, Ries; Jetten, Andrea M; Valiente, Román; Labeaga, Luis

2016-07-01

Bilastine is a new oral, second generation antihistamine used in the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. It is considered a nonsedating antihistamine and might be recommended for use in pilots, pending research on the effects on flying-related performance under hypobaric conditions that prevail in an airliner. We assessed the effects of a single dose of bilastine 20 mg on alertness and complex task performance of healthy volunteers in a hypobaric chamber at 75.2 kPa (8000 ft/2438 m cabin altitude). In a randomized, double-blind, crossover study, 24 volunteers received a single dose of bilastine 20 mg, hydroxyzine 50 mg (active control), and placebo. Using the Vigilance and Tracking Task, Multi-Attribute Task Battery, and Stanford Sleepiness Scale, assessments were made before and up to 6 h after intake of the study medication. Bilastine 20 mg had no impairing effects on sleepiness levels, vigilance, or complex task performance for up to 6 h post-dose. Hydroxyzine 50 mg (active control) was associated with significant sleepiness and impaired performance across this time period, confirming the sensitivity of the tests. Bilastine 20 mg did not cause sleepiness or impaired performance on tasks related to flying. It is anticipated that a single dose of bilastine 20 mg will not affect flying performance. Bilastine may provide a safe therapeutic alternative for pilots suffering from allergic rhinitis or urticaria. Our findings might also have implications for the treatment of allergic disorders of personnel involved in other safety-sensitive jobs. Valk PJL, Simons R, Jetten AM, Valiente R, Labeaga L. Cognitive performance effects of bilastine 20 mg during 6 hours at 8000 ft cabin altitude. Aerosp Med Hum Perform. 2016; 87(7):622-627.

Training complexity is not decisive factor for improving adaptation to visual sensory conflict.

PubMed

Yang, Yang; Pu, Fang; Li, Shuyu; Li, Yan; Li, Deyu; Fan, Yubo

2012-01-01

Ground-based preflight training utilizing unusual visual stimuli is useful for decreasing the susceptibility to space motion sickness (SMS). The effectiveness of the sensorimotor adaptation training is affected by the training tasks, but what kind of task is more effective remains unknown. Whether the complexity is the decisive factor to consider for designing the training and if other factors are more important need to be analyzed. The results from the analysis can help to optimize the preflight training tasks for astronauts. Twenty right-handed subjects were asked to draw the right path of 45° rotated maze before and after 30 min training. Subjects wore an up-down reversing prism spectacle in test and training sessions. Two training tasks were performed: drawing the right path of the horizontal maze (complex task but with different orientation feature) and drawing the L-shape lines (easy task with same orientation feature). The error rate and the executing time were measured during the test. Paired samples t test was used to compare the effects of the two training tasks. After each training, the error rate and the executing time were significantly decreased. However, the training effectiveness of the easy task was better as the test was finished more quickly and accurately. The complexity is not always the decisive factor for designing the adaptation training task, e.g. the orientation feature is more important in this study. In order to accelerate the adaptation and to counter SMS, the task for astronauts preflight adaptation training could be simple activities with the key features.

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 experience levels for some laparoscopic tasks, but no benefit in the speed of task performance. Robotic assistance may provide some benefit in precision of surgical task performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Telerobot control system

NASA Technical Reports Server (NTRS)

Backes, Paul G. (Inventor); Tso, Kam S. (Inventor)

1993-01-01

This invention relates to an operator interface for controlling a telerobot to perform tasks in a poorly modeled environment and/or within unplanned scenarios. The telerobot control system includes a remote robot manipulator linked to an operator interface. The operator interface includes a setup terminal, simulation terminal, and execution terminal for the control of the graphics simulator and local robot actuator as well as the remote robot actuator. These terminals may be combined in a single terminal. Complex tasks are developed from sequential combinations of parameterized task primitives and recorded teleoperations, and are tested by execution on a graphics simulator and/or local robot actuator, together with adjustable time delays. The novel features of this invention include the shared and supervisory control of the remote robot manipulator via operator interface by pretested complex tasks sequences based on sequences of parameterized task primitives combined with further teleoperation and run-time binding of parameters based on task context.

An Investigation of the Use of Real-time Image Mosaicing for Facilitating Global Spatial Awareness in Visual Search

NASA Astrophysics Data System (ADS)

Soung Yee, Anthony

Three experiments have been completed to investigate whether and how a software technique called real-time image mosaicing applied to a restricted field of view (FOV) might influence target detection and path integration performance in simulated aerial search scenarios, representing local and global spatial awareness tasks respectively. The mosaiced FOV (mFOV) was compared to single FOV (sFOV) and one with double the single size (dFOV). In addition to advancing our understanding of visual information in mosaicing, the present study examines the advantages and limitations of a number of metrics used to evaluate performance in path integration tasks, with particular attention paid to measuring performance in identifying complex routes. The highlights of the results are summarized as follows, according to Experiments 1 through 3 respectively. 1. A novel response method for evaluating route identification performance was developed. The surmised benefits of the mFOV relative to sFOV and dFOV revealed no significant differences in performance for the relatively simple route shapes tested. Compared to the mFOV and dFOV conditions, target detection performance in the local task was found to be superior in the sFOV condition. 2. In order to appropriately quantify the observed differences in complex route selections made by the participants, a novel analysis method was developed using the Thurstonian Paired Comparisons Method. 3. To investigate the effect of display size and elevation angle (EA) in a complex route environment, a 2x3 experiment was conducted for the two spatial tasks, at a height selected from Experiment 2. Although no significant differences were found in the target detection task, contrasts in the Paired Comparisons Method results revealed that route identification performance were as hypothesised: mFOV > dFOV > sFOV for EA = 90°. Results were similar for EA = 45°, but with mFOV being no different than dFOV. As hypothesised, EA was found to have an effect on route selection performance, with a top down view performing better than an angled view for the mFOV and sFOV conditions.

Effect of Chunk Strength on the Performance of Children with Developmental Dyslexia on Artificial Grammar Learning Task May Be Related to Complexity

ERIC Educational Resources Information Center

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

2017-01-01

There is a long held view that chunks play a crucial role in artificial grammar learning performance. We compared chunk strength influences on performance, in high and low topological entropy (a measure of complexity) grammar systems, with dyslexic children, age-matched and reading-level-matched control participants. Findings show that age-matched…

Good distractions: Testing the effects of listening to an audiobook on driving performance in simple and complex road environments.

PubMed

Nowosielski, Robert J; Trick, Lana M; Toxopeus, Ryan

2018-02-01

Distracted driving (driving while performing a secondary task) causes many collisions. Most research on distracted driving has focused on operating a cell-phone, but distracted driving can include eating while driving, conversing with passengers or listening to music or audiobooks. Although the research has focused on the deleterious effects of distraction, there may be situations where distraction improves driving performance. Fatigue and boredom are also associated with collision risk and it is possible that secondary tasks can help alleviate the effects of fatigue and boredom. Furthermore, it has been found that individuals with high levels of executive functioning as measured by the OSPAN (Operation Span) task show better driving while multitasking. In this study, licensed drivers were tested in a driving simulator (a car body surrounded by screens) that simulated simple or complex roads. Road complexity was manipulated by increasing traffic, scenery, and the number of curves in the drive. Participants either drove, or drove while listening to an audiobook. Driving performance was measured in terms of braking response time to hazards (HRT): the time required to brake in response to pedestrians or vehicles that suddenly emerged from the periphery into the path of the vehicle, speed, standard deviation of speed, standard deviation of lateral position (SDLP). Overall, braking times to hazards were higher on the complex drive than the simple one, though the effects of secondary tasks such as audiobooks were especially deleterious on the complex drive. In contrast, on the simple drive, driving while listening to an audiobook lead to faster HRT. We found evidence that individuals with high OSPAN scores had faster HRTs when listening to an audiobook. These results suggest that there are environmental and individual factors behind difference in the allocation of attention while listening to audiobooks while driving. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of continuous positive airway pressure treatment on short-term memory performance over 24 h of sustained wakefulness in patients with obstructive sleep apnea-hypopnea syndrome.

PubMed

Grenèche, Jérôme; Krieger, Jean; Bertrand, Frédéric; Erhardt, Christine; Maumy, Myriam; Tassi, Patricia

2013-10-01

Few studies have examined the impact of continuous positive airway pressure (CPAP) therapy on short-term memory (STM) over sustained wakefulness in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS). We have investigated if impaired STM can be reversed by CPAP treatment in a 24-h sustained wakefulness paradigm. Our follow-up study was conducted with repeated-memory tasks within 12 OSAHS patients and 10 healthy controls who underwent three 32-h sessions, one before CPAP (T0) and the second (T3) and the third (T6), after 3 and 6 months of treatment, respectively, for OSAHS patients. Each session included one night of sleep followed by 24h of sustained wakefulness, during which both groups performed STM tasks including both digit span (DS) and Sternberg tasks. Untreated OSAHS patients had no deficit in the forward DS task measuring immediate memory but were impaired in STM, especially working memory assessed by the complex Sternberg task and the backward DS. However, only performance in the latter was improved after 6 months of CPAP treatment. Because the high level of memory scanning required high speed in information processing, persistent impairment on the complex Sternberg task may be attributable to working memory slowing, possibly enhanced by sustained wakefulness. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Team performance in networked supervisory control of unmanned air vehicles: effects of automation, working memory, and communication content.

PubMed

McKendrick, Ryan; Shaw, Tyler; de Visser, Ewart; Saqer, Haneen; Kidwell, Brian; Parasuraman, Raja

2014-05-01

Assess team performance within a net-worked supervisory control setting while manipulating automated decision aids and monitoring team communication and working memory ability. Networked systems such as multi-unmanned air vehicle (UAV) supervision have complex properties that make prediction of human-system performance difficult. Automated decision aid can provide valuable information to operators, individual abilities can limit or facilitate team performance, and team communication patterns can alter how effectively individuals work together. We hypothesized that reliable automation, higher working memory capacity, and increased communication rates of task-relevant information would offset performance decrements attributed to high task load. Two-person teams performed a simulated air defense task with two levels of task load and three levels of automated aid reliability. Teams communicated and received decision aid messages via chat window text messages. Task Load x Automation effects were significant across all performance measures. Reliable automation limited the decline in team performance with increasing task load. Average team spatial working memory was a stronger predictor than other measures of team working memory. Frequency of team rapport and enemy location communications positively related to team performance, and word count was negatively related to team performance. Reliable decision aiding mitigated team performance decline during increased task load during multi-UAV supervisory control. Team spatial working memory, communication of spatial information, and team rapport predicted team success. An automated decision aid can improve team performance under high task load. Assessment of spatial working memory and the communication of task-relevant information can help in operator and team selection in supervisory control systems.

Aging and the Vulnerability of Speech to Dual Task Demands

PubMed Central

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

2010-01-01

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

Profiles of Motor Laterality in Young Athletes' Performance of Complex Movements: Merging the MOTORLAT and PATHoops Tools

PubMed Central

Castañer, Marta; Andueza, Juan; Hileno, Raúl; Puigarnau, Silvia; Prat, Queralt; Camerino, Oleguer

2018-01-01

Laterality is a key aspect of the analysis of basic and specific motor skills. It is relevant to sports because it involves motor laterality profiles beyond left-right preference and spatial orientation of the body. The aim of this study was to obtain the laterality profiles of young athletes, taking into account the synergies between the support and precision functions of limbs and body parts in the performance of complex motor skills. We applied two instruments: (a) MOTORLAT, a motor laterality inventory comprising 30 items of basic, specific, and combined motor skills, and (b) the Precision and Agility Tapping over Hoops (PATHoops) task, in which participants had to perform a path by stepping in each of 14 hoops arranged on the floor, allowing the observation of their feet, left-right preference and spatial orientation. A total of 96 young athletes performed the PATHoops task and the 30 MOTORLAT items, allowing us to obtain data about limb dominance and spatial orientation of the body in the performance of complex motor skills. Laterality profiles were obtained by means of a cluster analysis and a correlational analysis and a contingency analysis were applied between the motor skills and spatial orientation actions performed. The results obtained using MOTORLAT show that the combined motor skills criterion (for example, turning while jumping) differentiates athletes' uses of laterality, showing a clear tendency toward mixed laterality profiles in the performance of complex movements. In the PATHoops task, the best spatial orientation strategy was “same way” (same foot and spatial wing) followed by “opposite way” (opposite foot and spatial wing), in keeping with the research assumption that actions unfolding in a horizontal direction in front of an observer's eyes are common in a variety of sports. PMID:29930527

Development of phonological awareness in bilingual chinese children.

PubMed

Chen, Xi; Ku, Yu-Min; Koyama, Emiko; Anderson, Richard C; Li, Wenling

2008-11-01

This study investigated the phonological awareness of 219 first, second, and fourth grade Cantonese-speaking children from the south of China, who received immersion Mandarin instruction beginning in the first grade. Children received onset, rime and tone awareness tasks in Cantonese and Mandarin. Children performed better on the Cantonese onset awareness task in grade one, but the difference disappeared in higher grades. However, their performance on the rime and tone awareness tasks was better in Mandarin. These results reflect the phonological structure of the two languages: Mandarin has a more complex onset system, whereas Cantonese has more complex tone and rime systems. Moreover, children's phonological awareness increased faster in Mandarin, which likely resulted from Mandarin instruction. Confirmatory factor analysis suggested that onset-rime awareness is a universal construct, whereas tone awareness is a language-specific construct.

Knowledge representation system for assembly using robots

NASA Technical Reports Server (NTRS)

Jain, A.; Donath, M.

1987-01-01

Assembly robots combine the benefits of speed and accuracy with the capability of adaptation to changes in the work environment. However, an impediment to the use of robots is the complexity of the man-machine interface. This interface can be improved by providing a means of using a priori-knowledge and reasoning capabilities for controlling and monitoring the tasks performed by robots. Robots ought to be able to perform complex assembly tasks with the help of only supervisory guidance from human operators. For such supervisory quidance, it is important to express the commands in terms of the effects desired, rather than in terms of the motion the robot must undertake in order to achieve these effects. A suitable knowledge representation can facilitate the conversion of task level descriptions into explicit instructions to the robot. Such a system would use symbolic relationships describing the a priori information about the robot, its environment, and the tasks specified by the operator to generate the commands for the robot.

Effects of visual and verbal interference tasks on olfactory memory: the role of task complexity.

PubMed

Annett, J M; Leslie, J C

1996-08-01

Recent studies have demonstrated that visual and verbal suppression tasks interfere with olfactory memory in a manner which is partially consistent with a dual coding interpretation. However, it has been suggested that total task complexity rather than modality specificity of the suppression tasks might account for the observed pattern of results. This study addressed the issue of whether or not the level of difficulty and complexity of suppression tasks could explain the apparent modality effects noted in earlier experiments. A total of 608 participants were each allocated to one of 19 experimental conditions involving interference tasks which varied suppression type (visual or verbal), nature of complexity (single, double or mixed) and level of difficulty (easy, optimal or difficult) and presented with 13 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Both recognition and recall performance showed an overall effect for suppression nature, suppression level and time of testing with no effect for suppression type. The results lend only limited support to Paivio's (1986) dual coding theory, but have a number of characteristics which suggest that an adequate account of olfactory memory may be broadly similar to current theories of face and object recognition. All of these phenomena might be dealt with by an appropriately modified version of dual coding theory.

Processing complex pseudo-words in mild cognitive impairment: The interaction of preserved morphological rule knowledge with compromised cognitive ability.

PubMed

Manouilidou, Christina; Dolenc, Barbara; Marvin, Tatjana; Pirtošek, Zvezdan

2016-01-01

Mild cognitive impairment (MCI) affects the cognitive performance of elderly adults. However, the level of severity is not high enough to be diagnosed with dementia. Previous research reports subtle language impairments in individuals with MCI specifically in domains related to lexical meaning. The present study used both off-line (grammaticality judgment) and on-line (lexical decision) tasks to examine aspects of lexical processing and how they are affected by MCI. 21 healthy older adults and 23 individuals with MCI saw complex pseudo-words that violated various principles of word formation in Slovenian and decided if each letter string was an actual word of their language. The pseudo-words ranged in their degree of violability. A task effect was found, with MCI performance to be similar to that of healthy controls in the off-line task but different in the on-line task. Overall, the MCI group responded slower than the elderly controls. No significant differences were observed in the off-line task, while the on-line task revealed a main effect of Violation type, a main effect of Group and a significant Violation × Group interaction reflecting a difficulty for the MCI group to process pseudo-words in real time. That is, while individuals with MCI seem to preserve morphological rule knowledge, they experience additional difficulties while processing complex pseudo-words. This was attributed to an executive dysfunction associated with MCI that delays the recognition of ungrammatical formations.

Age-related differences in reaction time task performance in young children.

PubMed

Kiselev, Sergey; Espy, Kimberly Andrews; Sheffield, Tiffany

2009-02-01

Performance of reaction time (RT) tasks was investigated in young children and adults to test the hypothesis that age-related differences in processing speed supersede a "global" mechanism and are a function of specific differences in task demands and processing requirements. The sample consisted of 54 4-year-olds, 53 5-year-olds, 59 6-year-olds, and 35 adults from Russia. Using the regression approach pioneered by Brinley and the transformation method proposed by Madden and colleagues and Ridderinkhoff and van der Molen, age-related differences in processing speed differed among RT tasks with varying demands. In particular, RTs differed between children and adults on tasks that required response suppression, discrimination of color or spatial orientation, reversal of contingencies of previously learned stimulus-response rules, and greater stimulus-response complexity. Relative costs of these RT task differences were larger than predicted by the global difference hypothesis except for response suppression. Among young children, age-related differences larger than predicted by the global difference hypothesis were evident when tasks required color or spatial orientation discrimination and stimulus-response rule complexity, but not for response suppression or reversal of stimulus-response contingencies. Process-specific, age-related differences in processing speed that support heterochronicity of brain development during childhood were revealed.

Modeling and simulation of dynamic ant colony's labor division for task allocation of UAV swarm

NASA Astrophysics Data System (ADS)

Wu, Husheng; Li, Hao; Xiao, Renbin; Liu, Jie

2018-02-01

The problem of unmanned aerial vehicle (UAV) task allocation not only has the intrinsic attribute of complexity, such as highly nonlinear, dynamic, highly adversarial and multi-modal, but also has a better practicability in various multi-agent systems, which makes it more and more attractive recently. In this paper, based on the classic fixed response threshold model (FRTM), under the idea of "problem centered + evolutionary solution" and by a bottom-up way, the new dynamic environmental stimulus, response threshold and transition probability are designed, and a dynamic ant colony's labor division (DACLD) model is proposed. DACLD allows a swarm of agents with a relatively low-level of intelligence to perform complex tasks, and has the characteristic of distributed framework, multi-tasks with execution order, multi-state, adaptive response threshold and multi-individual response. With the proposed model, numerical simulations are performed to illustrate the effectiveness of the distributed task allocation scheme in two situations of UAV swarm combat (dynamic task allocation with a certain number of enemy targets and task re-allocation due to unexpected threats). Results show that our model can get both the heterogeneous UAVs' real-time positions and states at the same time, and has high degree of self-organization, flexibility and real-time response to dynamic environments.

Extending the limits of complex learning in organic amnesia: computer training in a vocational domain.

PubMed

Glisky, E L; Schacter, D L

1989-01-01

This study explored the limits of learning that could be achieved by an amnesic patient in a complex real-world domain. Using a cuing procedure known as the method of vanishing cues, a severely amnesic encephalitic patient was taught over 250 discrete pieces of new information concerning the rules and procedures for performing a task involving data entry into a computer. Subsequently, she was able to use this acquired knowledge to perform the task accurately and efficiently in the workplace. These results suggest that amnesic patients' preserved learning abilities can be extended well beyond what has been reported previously.

Encoding vs. retention: differential effects of cue manipulation on working memory performance in schizophrenia.

PubMed

Javitt, Daniel C; Rabinowicz, Esther; Silipo, Gail; Dias, Elisa C

2007-03-01

Deficits in working memory performance are among the most widely replicated findings in schizophrenia. Roles of encoding vs. memory retention in working memory remain unresolved. The present study evaluated working memory performance in schizophrenia using an AX-type continuous performance test (AX-CPT) paradigm. Participants included 48 subjects with schizophrenia and 27 comparison subjects. Behavior was obtained in 3 versions of the task, which differed based upon ease of cue interoperability. In a simple cue version of the task, cue letters were replaced with red or green circles. In the complex cue version, letter/color conjunctions served as cues. In the base version of the task, patients showed increased rates of false alarms to invalidly cued targets, similar to prior reports. However, when the cue stimuli were replaced with green or red circles to ease interpretation, patients showed similar false alarm rates to controls. When feature conjunction cues were used, patients were also disproportionately affected relative to controls. No significant group by interstimulus interval interaction effects were observed in either the simple or complex cue conditions, suggesting normal retention of information even in the presence of overall performance decrements. These findings suggest first, that cue manipulation disproportionately affects AX-CPT performance in schizophrenia and, second, that substantial behavioral deficits may be observed on working memory tasks even in the absence of disturbances in mnemonic retention.

Because difficulty is not the same for everyone: the impact of complexity in working memory is associated with cannabinoid 1 receptor genetic variation in young adults.

PubMed

Ruiz-Contreras, Alejandra E; Román-López, Talía V; Caballero-Sánchez, Ulises; Rosas-Escobar, Cintia B; Ortega-Mora, E Ivett; Barrera-Tlapa, Miguel A; Romero-Hidalgo, Sandra; Carrillo-Sánchez, Karol; Hernández-Morales, Salvador; Vadillo-Ortega, Felipe; González-Barrios, Juan Antonio; Méndez-Díaz, Mónica; Prospéro-García, Oscar

2017-03-01

Individual differences in working memory ability are mainly revealed when a demanding challenge is imposed. Here, we have associated cannabinoid 1 (CB1) receptor genetic variation rs2180619 (AA, AG, GG), which is located in a potential CNR1 regulatory sequence, with performance in working memory. Two-hundred and nine Mexican-mestizo healthy young participants (89 women, 120 men, mean age: 23.26 years, SD = 2.85) were challenged to solve a medium (2-back) vs. a high (3-back) difficulty N-back tasks. All subjects responded as expected, performance was better with the medium than the high demand task version, but no differences were found among genotypes while performing each working memory (WM) task. However, the cost of the level of complexity in N-back paradigm was double for GG subjects than for AA subjects. It is noteworthy that an additive-dosage allele relation was found for G allele in terms of cost of level of complexity. These genetic variation results support that the endocannabinoid system, evaluated by rs2180619 polymorphism, is involved in WM ability in humans.

Task complexity modulates pilot electroencephalographic activity during real flights.

PubMed

Di Stasi, Leandro L; Diaz-Piedra, Carolina; Suárez, Juan; McCamy, Michael B; Martinez-Conde, Susana; Roca-Dorda, Joaquín; Catena, Andrés

2015-07-01

Most research connecting task performance and neural activity to date has been conducted in laboratory conditions. Thus, field studies remain scarce, especially in extreme conditions such as during real flights. Here, we investigated the effects of flight procedures of varied complexity on the in-flight EEG activity of military helicopter pilots. Flight procedural complexity modulated the EEG power spectrum: highly demanding procedures (i.e., takeoff and landing) were associated with higher EEG power in the higher frequency bands, whereas less demanding procedures (i.e., flight exercises) were associated with lower EEG power over the same frequency bands. These results suggest that EEG recordings may help to evaluate an operator's cognitive performance in challenging real-life scenarios, and thus could aid in the prevention of catastrophic events. © 2015 Society for Psychophysiological Research.

Distributed computation of graphics primitives on a transputer network

NASA Technical Reports Server (NTRS)

Ellis, Graham K.

1988-01-01

A method is developed for distributing the computation of graphics primitives on a parallel processing network. Off-the-shelf transputer boards are used to perform the graphics transformations and scan-conversion tasks that would normally be assigned to a single transputer based display processor. Each node in the network performs a single graphics primitive computation. Frequently requested tasks can be duplicated on several nodes. The results indicate that the current distribution of commands on the graphics network shows a performance degradation when compared to the graphics display board alone. A change to more computation per node for every communication (perform more complex tasks on each node) may cause the desired increase in throughput.

Action observation versus motor imagery in learning a complex motor task: a short review of literature and a kinematics study.

PubMed

Gatti, R; Tettamanti, A; Gough, P M; Riboldi, E; Marinoni, L; Buccino, G

2013-04-12

Both motor imagery and action observation have been shown to play a role in learning or re-learning complex motor tasks. According to a well accepted view they share a common neurophysiological basis in the mirror neuron system. Neurons within this system discharge when individuals perform a specific action and when they look at another individual performing the same or a motorically related action. In the present paper, after a short review of literature on the role of action observation and motor imagery in motor learning, we report the results of a kinematics study where we directly compared motor imagery and action observation in learning a novel complex motor task. This involved movement of the right hand and foot in the same angular direction (in-phase movement), while at the same time moving the left hand and foot in an opposite angular direction (anti-phase movement), all at a frequency of 1Hz. Motor learning was assessed through kinematics recording of wrists and ankles. The results showed that action observation is better than motor imagery as a strategy for learning a novel complex motor task, at least in the fast early phase of motor learning. We forward that these results may have important implications in educational activities, sport training and neurorehabilitation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Pitch discrimination by ferrets for simple and complex sounds.

PubMed

Walker, Kerry M M; Schnupp, Jan W H; Hart-Schnupp, Sheelah M B; King, Andrew J; Bizley, Jennifer K

2009-09-01

Although many studies have examined the performance of animals in detecting a frequency change in a sequence of tones, few have measured animals' discrimination of the fundamental frequency (F0) of complex, naturalistic stimuli. Additionally, it is not yet clear if animals perceive the pitch of complex sounds along a continuous, low-to-high scale. Here, four ferrets (Mustela putorius) were trained on a two-alternative forced choice task to discriminate sounds that were higher or lower in F0 than a reference sound using pure tones and artificial vowels as stimuli. Average Weber fractions for ferrets on this task varied from approximately 20% to 80% across references (200-1200 Hz), and these fractions were similar for pure tones and vowels. These thresholds are approximately ten times higher than those typically reported for other mammals on frequency change detection tasks that use go/no-go designs. Naive human listeners outperformed ferrets on the present task, but they showed similar effects of stimulus type and reference F0. These results suggest that while non-human animals can be trained to label complex sounds as high or low in pitch, this task may be much more difficult for animals than simply detecting a frequency change.

Sex and cultural differences in spatial performance between Japanese and North Americans.

PubMed

Sakamoto, Maiko; Spiers, Mary V

2014-04-01

Previous studies have suggested that Asians perform better than North Americans on spatial tasks but show smaller sex differences. In this study, we evaluated the relationship between long-term experience with a pictorial written language and spatial performance. It was hypothesized that native Japanese Kanji (a complex pictorial written language) educated adults would show smaller sex differences on spatial tasks than Japanese Americans or North Americans without Kanji education. A total of 80 young healthy participants (20 native Japanese speakers, 20 Japanese Americans-non Japanese speaking, and 40 North Americans-non Japanese speaking) completed the Rey Complex Figure Test (RCFT), the Mental Rotations Test (MRT), and customized 2D and 3D spatial object location memory tests. As predicted, main effects revealed men performed better on the MRT and RCFT and women performed better on the spatial object location memory tests. Also, as predicted, native Japanese performed better on all tests than the other groups. In contrast to the other groups, native Japanese showed a decreased magnitude of sex differences on aspects of the RCFT (immediate and delayed recall) and no significant sex difference on the efficiency of the strategy used to copy and encode the RCFT figure. This study lends support to the idea that intensive experience over time with a pictorial written language (i.e., Japanese Kanji) may contribute to increased spatial performance on some spatial tasks as well as diminish sex differences in performance on tasks that most resemble Kanji.

The impact of reward and punishment on skill learning depends on task demands

PubMed Central

Steel, Adam; Silson, Edward H.; Stagg, Charlotte J.; Baker, Chris I.

2016-01-01

Reward and punishment motivate behavior, but it is unclear exactly how they impact skill performance and whether the effect varies across skills. The present study investigated the effect of reward and punishment in both a sequencing skill and a motor skill context. Participants trained on either a sequencing skill (serial reaction time task) or a motor skill (force-tracking task). Skill knowledge was tested immediately after training, and again 1 hour, 24–48 hours, and 30 days after training. We found a dissociation of the effects of reward and punishment on the tasks, primarily reflecting the impact of punishment. While punishment improved serial reaction time task performance, it impaired force-tracking task performance. In contrast to prior literature, neither reward nor punishment benefitted memory retention, arguing against the common assumption that reward ubiquitously benefits skill retention. Collectively, these results suggest that punishment impacts skilled behavior more than reward in a complex, task dependent fashion. PMID:27786302

The impact of reward and punishment on skill learning depends on task demands.

PubMed

Steel, Adam; Silson, Edward H; Stagg, Charlotte J; Baker, Chris I

2016-10-27

Reward and punishment motivate behavior, but it is unclear exactly how they impact skill performance and whether the effect varies across skills. The present study investigated the effect of reward and punishment in both a sequencing skill and a motor skill context. Participants trained on either a sequencing skill (serial reaction time task) or a motor skill (force-tracking task). Skill knowledge was tested immediately after training, and again 1 hour, 24-48 hours, and 30 days after training. We found a dissociation of the effects of reward and punishment on the tasks, primarily reflecting the impact of punishment. While punishment improved serial reaction time task performance, it impaired force-tracking task performance. In contrast to prior literature, neither reward nor punishment benefitted memory retention, arguing against the common assumption that reward ubiquitously benefits skill retention. Collectively, these results suggest that punishment impacts skilled behavior more than reward in a complex, task dependent fashion.

A resource management architecture based on complex network theory in cloud computing federation

NASA Astrophysics Data System (ADS)

Zhang, Zehua; Zhang, Xuejie

2011-10-01

Cloud Computing Federation is a main trend of Cloud Computing. Resource Management has significant effect on the design, realization, and efficiency of Cloud Computing Federation. Cloud Computing Federation has the typical characteristic of the Complex System, therefore, we propose a resource management architecture based on complex network theory for Cloud Computing Federation (abbreviated as RMABC) in this paper, with the detailed design of the resource discovery and resource announcement mechanisms. Compare with the existing resource management mechanisms in distributed computing systems, a Task Manager in RMABC can use the historical information and current state data get from other Task Managers for the evolution of the complex network which is composed of Task Managers, thus has the advantages in resource discovery speed, fault tolerance and adaptive ability. The result of the model experiment confirmed the advantage of RMABC in resource discovery performance.

Augmenting team cognition in human-automation teams performing in complex operational environments.

PubMed

Cuevas, Haydee M; Fiore, Stephen M; Caldwell, Barrett S; Strater, Laura

2007-05-01

There is a growing reliance on automation (e.g., intelligent agents, semi-autonomous robotic systems) to effectively execute increasingly cognitively complex tasks. Successful team performance for such tasks has become even more dependent on team cognition, addressing both human-human and human-automation teams. Team cognition can be viewed as the binding mechanism that produces coordinated behavior within experienced teams, emerging from the interplay between each team member's individual cognition and team process behaviors (e.g., coordination, communication). In order to better understand team cognition in human-automation teams, team performance models need to address issues surrounding the effect of human-agent and human-robot interaction on critical team processes such as coordination and communication. Toward this end, we present a preliminary theoretical framework illustrating how the design and implementation of automation technology may influence team cognition and team coordination in complex operational environments. Integrating constructs from organizational and cognitive science, our proposed framework outlines how information exchange and updating between humans and automation technology may affect lower-level (e.g., working memory) and higher-level (e.g., sense making) cognitive processes as well as teams' higher-order "metacognitive" processes (e.g., performance monitoring). Issues surrounding human-automation interaction are discussed and implications are presented within the context of designing automation technology to improve task performance in human-automation teams.

Performing Complex Tasks by Users With Upper-Extremity Disabilities Using a 6-DOF Robotic Arm: A Study.

PubMed

Al-Halimi, Reem K; Moussa, Medhat

2017-06-01

In this paper, we report on the results of a study that was conducted to examine how users suffering from severe upper-extremity disabilities can control a 6 degrees-of-freedom (DOF) robotics arm to complete complex activities of daily living. The focus of the study is not on assessing the robot arm but on examining the human-robot interaction patterns. Three participants were recruited. Each participant was asked to perform three tasks: eating three pieces of pre-cut bread from a plate, drinking three sips of soup from a bowl, and opening a right-handed door with lever handle. Each of these tasks was repeated three times. The arm was mounted on the participant's wheelchair, and the participants were free to move the arm as they wish to complete these tasks. Each task consisted of a sequence of modes where a mode is defined as arm movement in one DOF. Results show that participants used a total of 938 mode movements with an average of 75.5 (std 10.2) modes for the eating task, 70 (std 8.8) modes for the soup task, and 18.7 (std 4.5) modes for the door opening task. Tasks were then segmented into smaller subtasks. It was found that there are patterns of usage per participant and per subtask. These patterns can potentially allow a robot to learn from user's demonstration what is the task being executed and by whom and respond accordingly to reduce user effort.

Activities of daily living measured by the Harvard Automated Phone Task track with cognitive decline over time in non-demented elderly

PubMed Central

Marshall, Gad A.; Aghjayan, Sarah L.; Dekhtyar, Maria; Locascio, Joseph J.; Jethwani, Kamal; Amariglio, Rebecca E.; Johnson, Keith A.; Sperling, Reisa A.; Rentz, Dorene M.

2017-01-01

Background Impairment in activities of daily living is a major burden to both patients and caregivers. Mild impairment in instrumental activities of daily living is often seen at the stage of mild cognitive impairment. The field of Alzheimer’s disease is moving toward earlier diagnosis and intervention and more sensitive and ecologically valid assessments of instrumental or complex activities of daily living are needed. The Harvard Automated Phone Task, a novel performance-based activities of daily living instrument, has the potential to fill this gap. Objective To further validate the Harvard Automated Phone Task by assessing its longitudinal relationship to global cognition and specific cognitive domains in clinically normal elderly and individuals with mild cognitive impairment. Design In a longitudinal study, the Harvard Automated Phone Task was associated with cognitive measures using mixed effects models. The Harvard Automated Phone Task’s ability to discriminate across diagnostic groups at baseline was also assessed. Setting Academic clinical research center. Participants Two hundred and seven participants (45 young normal, 141 clinically normal elderly, and 21 mild cognitive impairment) were recruited from the community and the memory disorders clinics at Brigham and Women’s Hospital and Massachusetts General Hospital. Measurements Participants performed the three tasks of the Harvard Automated Phone Task, which consist of navigating an interactive voice response system to refill a prescription (APT-Script), select a new primary care physician (APT-PCP), and make a bank account transfer and payment (APT-Bank). The 3 tasks were scored based on time, errors, repetitions, and correct completion of the task. The primary outcome measure used for each of the tasks was total time adjusted for correct completion. Results The Harvard Automated Phone Task discriminated well between young normal, clinically normal elderly, and mild cognitive impairment participants (APT-Script: p<0.001; APT-PCP: p<0.001; APT-Bank: p=0.04). Worse baseline Harvard Automated Phone Task performance or worsening Harvard Automated Phone Task performance over time tracked with overall worse performance or worsening performance over time in global cognition, processing speed, executive function, and episodic memory. Conclusions Prior cross-sectional and current longitudinal analyses have demonstrated the utility of the Harvard Automated Phone Task, a new performance-based activities of daily living instrument, in the assessment of early changes in complex activities of daily living in non-demented elderly at risk for Alzheimer’s disease. Future studies will focus on cross-validation with other sensitive activities of daily living tests and Alzheimer’s disease biomarkers. PMID:29124043

Ecological Virtual Reality Evaluation of Neglect Symptoms (EVENS): Effects of Virtual Scene Complexity in the Assessment of Poststroke Unilateral Spatial Neglect.

PubMed

Ogourtsova, Tatiana; Archambault, Philippe; Sangani, Samir; Lamontagne, Anouk

2018-01-01

Unilateral spatial neglect (USN) is a highly prevalent and disabling poststroke impairment. USN is traditionally assessed with paper-and-pencil tests that lack ecological validity, generalization to real-life situations and are easily compensated for in chronic stages. Virtual reality (VR) can, however, counteract these limitations. We aimed to examine the feasibility of a novel assessment of USN symptoms in a functional shopping activity, the Ecological VR-based Evaluation of Neglect Symptoms (EVENS). EVENS is immersive and consists of simple and complex 3-dimensional scenes depicting grocery shopping shelves, where joystick-based object detection and navigation tasks are performed while seated. Effects of virtual scene complexity on navigational and detection abilities in patients with (USN+, n = 12) and without (USN-, n = 15) USN following a right hemisphere stroke and in age-matched healthy controls (HC, n = 9) were determined. Longer detection times, larger mediolateral deviations from ideal paths and longer navigation times were found in USN+ versus USN- and HC groups, particularly in the complex scene. EVENS detected lateralized and nonlateralized USN-related deficits, performance alterations that were dependent or independent of USN severity, and performance alterations in 3 USN- subjects versus HC. EVENS' environmental changing complexity, along with the functional tasks of far space detection and navigation can potentially be clinically relevant and warrant further empirical investigation. Findings are discussed in terms of attentional models, lateralized versus nonlateralized deficits in USN, and tasks-specific mechanisms.

Cortical grey matter content is associated with both age and bimanual performance, but is not observed to mediate age-related behavioural decline.

PubMed

van Ruitenbeek, Peter; Serbruyns, Leen; Solesio-Jofre, Elena; Meesen, Raf; Cuypers, Koen; Swinnen, Stephan P

2017-01-01

Declines in both cortical grey matter and bimanual coordination performance are evident in healthy ageing. However, the relationship between ageing, bimanual performance, and grey matter loss remains unclear, particularly across the whole adult lifespan. Therefore, participants (N = 93, range 20-80 years) performed a complex Bimanual Tracking Task, and structural brain images were obtained using magnetic resonance imaging. Analyses revealed that age correlated negatively with task performance. Voxel-based morphometry analysis revealed that age was associated with grey matter declines in task-relevant cortical areas and that grey matter in these areas was negatively associated with task performance. However, no evidence for a mediating effect of grey matter in age-related bimanual performance decline was observed. We propose a new hypothesis that functional compensation may account for the observed absence of mediation, which is in line with the observed pattern of increased inter-individual variance in performance with age.

Memory for product sounds: the effect of sound and label type.

PubMed

Ozcan, Elif; van Egmond, René

2007-11-01

The (mnemonic) interactions between auditory, visual, and the semantic systems have been investigated using structurally complex auditory stimuli (i.e., product sounds). Six types of product sounds (air, alarm, cyclic, impact, liquid, mechanical) that vary in spectral-temporal structure were presented in four label type conditions: self-generated text, text, image, and pictogram. A memory paradigm that incorporated free recall, recognition, and matching tasks was employed. The results for the sound type suggest that the amount of spectral-temporal structure in a sound can be indicative for memory performance. Findings related to label type suggest that 'self' creates a strong bias for the retrieval and the recognition of sounds that were self-labeled; the density and the complexity of the visual information (i.e., pictograms) hinders the memory performance ('visual' overshadowing effect); and image labeling has an additive effect on the recall and matching tasks (dual coding). Thus, the findings suggest that the memory performances for product sounds are task-dependent.

Mission planning for autonomous systems

NASA Technical Reports Server (NTRS)

Pearson, G.

1987-01-01

Planning is a necessary task for intelligent, adaptive systems operating independently of human controllers. A mission planning system that performs task planning by decomposing a high-level mission objective into subtasks and synthesizing a plan for those tasks at varying levels of abstraction is discussed. Researchers use a blackboard architecture to partition the search space and direct the focus of attention of the planner. Using advanced planning techniques, they can control plan synthesis for the complex planning tasks involved in mission planning.

A comparison of the vigilance performance of men and women using a simulated radar task.

DOT National Transportation Integrated Search

1978-03-01

The present study examined the question of possible sex differences in the ability to sustain attention to a complex monitoring task requiring only a detection response to critical stimulus changes. The visual display was designed to approximate a fu...

Check It Out! Using Checklists to Support Student Learning

ERIC Educational Resources Information Center

Rowlands, Kathleen Dudden

2007-01-01

Kathleen Dudden Rowlands recommends using checklists to support student learning and performance. Well-designed checklists identify steps students can take to complete complex tasks, which scaffolds students' metacognitive development and fosters the confidence and independence needed for internalizing these steps for future tasks. (Contains 7…

Effects of noise exposure on performance of a simulated radar task.

DOT National Transportation Integrated Search

1979-11-01

The present study examined the effect of noise (radar control room sounds, 80 dBA) on the ability to sustain attention to a complex monitoring task. The visual display was designed to resemble that of a highly automated air traffic control radar syst...

Learnable Interfaces--Leveraging Navigation by Design

ERIC Educational Resources Information Center

Swanson, Kari Gunvaldson

2012-01-01

Complex productivity applications that integrate tasks in the workplace are becoming more common. Usability typically focuses on short-term, immediate measures of task performance. This study incorporates a long-term goal of more durable learning, focusing on implicit learning (spontaneous, unplanned, usually unconscious learning as a result of…

A virtual work space for both hands manipulation with coherency between kinesthetic and visual sensation

NASA Technical Reports Server (NTRS)

Ishii, Masahiro; Sukanya, P.; Sato, Makoto

1994-01-01

This paper describes the construction of a virtual work space for tasks performed by two handed manipulation. We intend to provide a virtual environment that encourages users to accomplish tasks as they usually act in a real environment. Our approach uses a three dimensional spatial interface device that allows the user to handle virtual objects by hand and be able to feel some physical properties such as contact, weight, etc. We investigated suitable conditions for constructing our virtual work space by simulating some basic assembly work, a face and fit task. We then selected the conditions under which the subjects felt most comfortable in performing this task and set up our virtual work space. Finally, we verified the possibility of performing more complex tasks in this virtual work space by providing simple virtual models and then let the subjects create new models by assembling these components. The subjects can naturally perform assembly operations and accomplish the task. Our evaluation shows that this virtual work space has the potential to be used for performing tasks that require two-handed manipulation or cooperation between both hands in a natural manner.

Age-related differences in complex monitoring performance.

DOT National Transportation Integrated Search

1981-04-01

The present study examined the effect of age on the ability to sustain attention to a complex monitoring task. The visual display was designed to resemble an air traffic control radar display containing alphanumeric symbols. Subjects in age groups 18...

An evaluation of the effects of high visual taskload on the separate behaviors involved in complex monitoring performance.

DOT National Transportation Integrated Search

1988-01-01

Operational monitoring situations, in contrast to typical laboratory vigilance tasks, generally involve more than just stimulus detection and recognition. They frequently involve complex multidimensional discriminations, interpretations of significan...

Training in Goal-Oriented Attentional Self-Regulation Improves Executive Functioning in Veterans with Chronic TBI.

PubMed

Novakovic-Agopian, Tatjana; Kornblith, Erica S; Abrams, Gary; Burciaga-Rosales, Joaquin; Loya, Fred; D'Esposito, Mark; Chen, Anthony J-W

2018-05-02

Deficits in executive control functions are some of the most common and disabling consequences of both military and civilian brain injury. However, effective interventions are scant. The goal of this study was to assess whether cognitive rehabilitation training that was successfully applied in chronic civilian brain injury would be effective for military Veterans with TBI. In a prior study, participants with chronic acquired brain injury significantly improved after training in goal-oriented attentional self-regulation (GOALS) on measures of attention/executive function, functional task performance, and goal-directed control over neural processing on fMRI. The objective of this study was to assess effects of GOALS training in Veterans with chronic TBI. 33 Veterans with chronic TBI and executive difficulties in their daily life completed either five weeks of manualized Goal-Oriented Attentional Self-Regulation (GOALS) training or Brain-Health Education (BHE) matched in time and intensity. Evaluator-blinded assessments at baseline and post training included neuropsychological and complex functional task performance and self-report measures of emotional regulation. After GOALS, but not BHE training, participants significantly improved from baseline on primary outcome measures of: Overall Complex Attention/Executive Function composite neuropsychological performance score [F = 7.10, p =.01; partial 2 = .19], and on overall complex functional task performance (Goal Processing Scale Overall Performance) [F=6.92, p=.01, partial 2 =.20]. Additionally, post-GOALS participants indicated significant improvement on emotional regulation self-report measures [POMS Confusion Score F=6.05, p=.02, partial2=.20]. Training in attentional self-regulation applied to participant defined goals may improve cognitive functioning in Veterans with chronic TBI. Attention regulation training may not only impact executive control functioning in real world complex tasks, but may also improve emotional regulation and functioning. Implications for treatment of Veterans with TBI are discussed.

Influence of Procedural Learning on Iowa Gambling Task Performance Among HIV+ Individuals with History of Substance Dependence

PubMed Central

Gonzalez, Raul; Wardle, Margaret; Jacobus, Joanna; Vassileva, Jasmin; Martin-Thormeyer, Eileen M.

2010-01-01

HIV+ individuals have been shown to demonstrate deficits on the Iowa Gambling Task (IGT), a complex measure of “decision-making.” Little remains known about what other neurocognitive processes may account for variability in IGT performance among HIV+ samples or the role of procedural learning (PL) in IGT performance. A sample of 49 HIV+ individuals with a history of substance use disorders was examined to explore the relationship between IGT performance and three measures of PL: The Rotary Pursuit, Mirror Star Tracing, and Weather Prediction tasks. We found no statistically significant relationships between IGT performance and any of the PL tasks, despite finding significant correlations among the PL tasks. This pattern of results persisted when analyzing IGT performance in various ways (e.g., performance on earlier trial blocks or impairment classifications). Although other nondeclarative processes (e.g., somatic markers) may be important for IGT performance, these findings do not support PL as an important component neurocognitive process for the IGT. Similarly, these results suggest that differences in PL performance does not account for the decision-making deficits or variability in performances observed on the IGT among HIV+ individuals with a history of substance dependence. PMID:19939850

Visuoperceptual functioning differs in 9- to 12-year olds prenatally exposed to cigarettes and marihuana.

PubMed

Fried, P A; Watkinson, B

2000-01-01

Visuoperceptual performance was examined in 146 9- to 12-year old children for whom prenatal exposure to marihuana and cigarettes had been ascertained. The subjects, participants in an ongoing longitudinal study, were from a low-risk, predominantly middle class sample. The tasks ranged in complexity from those that required basic visuoperceptual skills to those that required considerable integration and cognitive manipulation of such skills. Trend analysis revealed a dose dependent negative association between prenatal cigarette exposure and an overall score reflecting basic visuoperceptual functioning. This association remained after consideration of potential prenatal confounds, pre- and postnatal secondhand smoke exposure, and the nonperceptual demands of the tasks. This poorer performance in the basic visuoperceptual domain underlay a poorer performance in more complex visuoperceptual tasks among the offspring of cigarette smokers. In contrast, prenatal marihuana exposure was not associated with basic visuoperceptual functioning but was negatively associated with performance in visual problem solving situations. The interpretation of the marihuana findings is discussed in relation to a "top-down" integrative ability associated with executive function, the extant prefrontal literature, and earlier observations of this sample.

Human Performance in Continuous Operations. Volume 3. Technical Documentation

DTIC Science & Technology

1980-03-01

completed for the U. S. Commander, V Corps. Artillery, by Manning (1978). Manning collected information which bears on the following three questions: 0 Can...performance data were not collected in these pre- liminary studies. Field Studies of Continuous Tank OperationsLI __ _ _ __ _ _ _ To simulate a combat...on routine, monotonous tasks tends A show rapid and severe decrement after peri- odk of more than 24 hours without sleep. I Increasing task complexity

Understanding neuromotor strategy during functional upper extremity tasks using symbolic dynamics.

PubMed

Nathan, Dominic E; Guastello, Stephen J; Prost, Robert W; Jeutter, Dean C

2012-01-01

The ability to model and quantify brain activation patterns that pertain to natural neuromotor strategy of the upper extremities during functional task performance is critical to the development of therapeutic interventions such as neuroprosthetic devices. The mechanisms of information flow, activation sequence and patterns, and the interaction between anatomical regions of the brain that are specific to movement planning, intention and execution of voluntary upper extremity motor tasks were investigated here. This paper presents a novel method using symbolic dynamics (orbital decomposition) and nonlinear dynamic tools of entropy, self-organization and chaos to describe the underlying structure of activation shifts in regions of the brain that are involved with the cognitive aspects of functional upper extremity task performance. Several questions were addressed: (a) How is it possible to distinguish deterministic or causal patterns of activity in brain fMRI from those that are really random or non-contributory to the neuromotor control process? (b) Can the complexity of activation patterns over time be quantified? (c) What are the optimal ways of organizing fMRI data to preserve patterns of activation, activation levels, and extract meaningful temporal patterns as they evolve over time? Analysis was performed using data from a custom developed time resolved fMRI paradigm involving human subjects (N=18) who performed functional upper extremity motor tasks with varying time delays between the onset of intention and onset of actual movements. The results indicate that there is structure in the data that can be quantified through entropy and dimensional complexity metrics and statistical inference, and furthermore, orbital decomposition is sensitive in capturing the transition of states that correlate with the cognitive aspects of functional task performance.

The influence of cue-task association and location on switch cost and alternating-switch cost.

PubMed

Arbuthnott, Katherine D; Woodward, Todd S

2002-03-01

Task-switching performance is strongly influenced by whether the imperative stimulus uniquely specifies which task to perform: Switch cost is substantial with bivalent stimuli but is greatly reduced with univalent stimuli, suggesting that available contextual information influences processing in task-switching situations. The present study examined whether task-relevant information provided by task cues influences the magnitude of switch cost in a parallel manner. Cues presented 500 ms prior to a trivalent stimulus indicated which of three tasks to perform. These cues either had a preexisting association with the to-be-performed task (verbal cues), or a recently learned association with the task (spatial and shape cues). The results paralleled the effects of stimulus bivalence: substantial switch cost with recently learned cue-task associations and greatly reduced switch cost with preexisting cue-task associations. This suggests that both stimulus-based and cue-based information can activate the relevant task set, possibly providing external support to endogenous control processes. Alternating-switch cost, a greater cost for switching back to a recently abandoned task, was also observed with both preexisting and recently learned cue-task associations, but only when all tasks were presented in a consistent spatial location. When spatial location was used to cue the to-be-performed tasks, no alternating-switch cost was observed, suggesting that different processes may be involved when tasks are uniquely located in space. Specification of the nature of these processes may prove to be complex, as post-hoc inspection of the data suggested that for the spatial cue condition, the alternating-switch cost may oscillate between cost and benefit, depending on the relevant task.

Control of complex physically simulated robot groups

NASA Astrophysics Data System (ADS)

Brogan, David C.

2001-10-01

Actuated systems such as robots take many forms and sizes but each requires solving the difficult task of utilizing available control inputs to accomplish desired system performance. Coordinated groups of robots provide the opportunity to accomplish more complex tasks, to adapt to changing environmental conditions, and to survive individual failures. Similarly, groups of simulated robots, represented as graphical characters, can test the design of experimental scenarios and provide autonomous interactive counterparts for video games. The complexity of writing control algorithms for these groups currently hinders their use. A combination of biologically inspired heuristics, search strategies, and optimization techniques serve to reduce the complexity of controlling these real and simulated characters and to provide computationally feasible solutions.

Brain Regions Engaged by Part- and Whole-task Performance in a Video Game: A Model-based Test of the Decomposition Hypothesis

PubMed Central

Anderson, John R.; Bothell, Daniel; Fincham, Jon M.; Anderson, Abraham R.; Poole, Ben; Qin, Yulin

2013-01-01

Part- and whole-task conditions were created by manipulating the presence of certain components of the Space Fortress video game. A cognitive model was created for two-part games that could be combined into a model that performed the whole game. The model generated predictions both for behavioral patterns and activation patterns in various brain regions. The activation predictions concerned both tonic activation that was constant in these regions during performance of the game and phasic activation that occurred when there was resource competition. The model’s predictions were confirmed about how tonic and phasic activation in different regions would vary with condition. These results support the Decomposition Hypothesis that the execution of a complex task can be decomposed into a set of information-processing components and that these components combine unchanged in different task conditions. In addition, individual differences in learning gains were predicted by individual differences in phasic activation in those regions that displayed highest tonic activity. This individual difference pattern suggests that the rate of learning of a complex skill is determined by capacity limits. PMID:21557648

Use of a Tracing Task to Assess Visuomotor Performance: Effects of Age, Sex, and Handedness

PubMed Central

2013-01-01

Background. Visuomotor abnormalities are common in aging and age-related disease, yet difficult to quantify. This study investigated the effects of healthy aging, sex, and handedness on the performance of a tracing task. Participants (n = 150, aged 21–95 years, 75 females) used a stylus to follow a moving target around a circle on a tablet computer with their dominant and nondominant hands. Participants also performed the Trail Making Test (a measure of executive function). Methods. Deviations from the circular path were computed to derive an “error” time series. For each time series, absolute mean, variance, and complexity index (a proposed measure of system functionality and adaptability) were calculated. Using the moving target and stylus coordinates, the percentage of task time within the target region and the cumulative micropause duration (a measure of motion continuity) were computed. Results. All measures showed significant effects of aging (p < .0005). Post hoc age group comparisons showed that with increasing age, the absolute mean and variance of the error increased, complexity index decreased, percentage of time within the target region decreased, and cumulative micropause duration increased. Only complexity index showed a significant difference between dominant versus nondominant hands within each age group (p < .0005). All measures showed relationships to the Trail Making Test (p < .05). Conclusions. Measures derived from a tracing task identified performance differences in healthy individuals as a function of age, sex, and handedness. Studies in populations with specific neuromotor syndromes are warranted to test the utility of measures based on the dynamics of tracking a target as a clinical assessment tool. PMID:23388876

Functional brain imaging of a complex navigation task following one night of total sleep deprivation

NASA Technical Reports Server (NTRS)

Strangman, Gary; Thompson, John H.; Strauss, Monica M.; Marshburn, Thomas H.; Sutton, Jeffrey P.

2006-01-01

Study Objectives: To assess the cerebral effects associated with sleep deprivation in a simulation of a complex, real-world, high-risk task. Design and Interventions: A two-week, repeated measures, cross-over experimental protocol, with counterbalanced orders of normal sleep (NS) and total sleep deprivation (TSD). Setting: Each subject underwent functional magnetic resonance imaging (fMRI) while performing a dual-joystick, 3D sensorimotor navigation task (simulated orbital docking). Scanning was performed twice per subject, once following a night of normal sleep (NS), and once following a single night of total sleep deprivation (TSD). Five runs (eight 24s docking trials each) were performed during each scanning session. Participants: Six healthy, young, right-handed volunteers (2 women; mean age 20) participated. Measurements and Results: Behavioral performance on multiple measures was comparable in the two sleep conditions. Neuroimaging results within sleep conditions revealed similar locations of peak activity for NS and TSD, including left sensorimotor cortex, left precuneus (BA 7), and right visual areas (BA 18/19). However, cerebral activation following TSD was substantially larger and exhibited higher amplitude modulations from baseline. When directly comparing NS and TSD, most regions exhibited TSD>NS activity, including multiple prefrontal cortical areas (BA 8/9,44/45,47), lateral parieto-occipital areas (BA 19/39, 40), superior temporal cortex (BA 22), and bilateral thalamus and amygdala. Only left parietal cortex (BA 7) demonstrated NS>TSD activity. Conclusions: The large network of cerebral differences between the two conditions, even with comparable behavioral performance, suggests the possibility of detecting TSD-induced stress via functional brain imaging techniques on complex tasks before stress-induced failures.

Cold-Blooded Attention: Finger Temperature Predicts Attentional Performance.

PubMed

Vergara, Rodrigo C; Moënne-Loccoz, Cristóbal; Maldonado, Pedro E

2017-01-01

Thermal stress has been shown to increase the chances of unsafe behavior during industrial and driving performances due to reductions in mental and attentional resources. Nonetheless, establishing appropriate safety standards regarding environmental temperature has been a major problem, as modulations are also be affected by the task type, complexity, workload, duration, and previous experience with the task. To bypass this attentional and thermoregulatory problem, we focused on the body rather than environmental temperature. Specifically, we measured tympanic, forehead, finger and environmental temperatures accompanied by a battery of attentional tasks. We considered a 10 min baseline period wherein subjects were instructed to sit and relax, followed by three attentional tasks: a continuous performance task (CPT), a flanker task (FT) and a counting task (CT). Using multiple linear regression models, we evaluated which variable(s) were the best predictors of performance. The results showed a decrement in finger temperature due to instruction and task engagement that was absent when the subject was instructed to relax. No changes were observed in tympanic or forehead temperatures, while the environmental temperature remained almost constant for each subject. Specifically, the magnitude of the change in finger temperature was the best predictor of performance in all three attentional tasks. The results presented here suggest that finger temperature can be used as a predictor of alertness, as it predicted performance in attentional tasks better than environmental temperature. These findings strongly support that peripheral temperature can be used as a tool to prevent unsafe behaviors and accidents.

The Fleeting Nature of Sex Differences in Spatial Ability.

ERIC Educational Resources Information Center

Alderton, David L.

Gender differences were examined on three computer-administered spatial processing tasks: (1) the Intercept task, requiring processing dynamic or moving figures; (2) the mental rotation test, employing rotated asymmetric polygons; and (3) the integrating details test, in which subjects performed a complex visual synthesis. Participants were about…

Auditory Memory for Timbre

ERIC Educational Resources Information Center

McKeown, Denis; Wellsted, David

2009-01-01

Psychophysical studies are reported examining how the context of recent auditory stimulation may modulate the processing of new sounds. The question posed is how recent tone stimulation may affect ongoing performance in a discrimination task. In the task, two complex sounds occurred in successive intervals. A single target component of one complex…

When Higher Working Memory Capacity Hinders Insight

ERIC Educational Resources Information Center

DeCaro, Marci S.; Van Stockum, Charles A., Jr.; Wieth, Mareike B.

2016-01-01

Higher working memory capacity (WMC) improves performance on a range of cognitive and academic tasks. However, a greater ability to control attention sometimes leads individuals with higher WMC to persist in using complex, attention-demanding approaches that are suboptimal for a given task. We examined whether higher WMC would hinder insight…

Sleep-Dependent Learning and Motor-Skill Complexity

ERIC Educational Resources Information Center

Kuriyama, Kenichi; Stickgold, Robert; Walker, Matthew P.

2004-01-01

Learning of a procedural motor-skill task is known to progress through a series of unique memory stages. Performance initially improves during training, and continues to improve, without further rehearsal, across subsequent periods of sleep. Here, we investigate how this delayed sleep-dependent learning is affected when the task characteristics…

Autonomic Physiological Response Patterns Related to Intelligence

ERIC Educational Resources Information Center

Melis, Cor; van Boxtel, Anton

2007-01-01

We examined autonomic physiological responses induced by six different cognitive ability tasks, varying in complexity, that were selected on the basis of on Guilford's Structure of Intellect model. In a group of 52 participants, task performance was measured together with nine different autonomic response measures and respiration rate. Weighted…

The Structure of Visuospatial Memory in Adulthood

ERIC Educational Resources Information Center

Mammarella, Irene C.; Borella, Erika; Pastore, Massimiliano; Pazzaglia, Francesca

2013-01-01

The present study aimed to investigate the structure of visuospatial memory in adulthood. Adults 40-89 years of age (n = 160) performed simple storage and complex visuospatial span tasks. Simple storage tasks were distinguished into three presentation formats: (i) visual, which involved maintaining shapes and textures; (ii) spatial-sequential,…

Assessing Pragmatics: DCTS and Retrospective Verbal Reports

ERIC Educational Resources Information Center

Beltrán-Palanques, Vicente

2016-01-01

Assessing pragmatic knowledge in the instructed setting is seen as a complex but necessary task, which requires the design of appropriate research methodologies to examine pragmatic performance. This study discusses the use of two different research methodologies, namely those of Discourse Completion Tests/Tasks (DCTs) and verbal reports. Research…

Enhancing Automaticity through Task-Based Language Learning

ERIC Educational Resources Information Center

De Ridder, Isabelle; Vangehuchten, Lieve; Gomez, Marta Sesena

2007-01-01

In general terms automaticity could be defined as the subconscious condition wherein "we perform a complex series of tasks very quickly and efficiently, without having to think about the various components and subcomponents of action involved" (DeKeyser 2001: 125). For language learning, Segalowitz (2003) characterised automaticity as a…

Working memory costs of task switching.

PubMed

Liefooghe, Baptist; Barrouillet, Pierre; Vandierendonck, André; Camos, Valérie

2008-05-01

Although many accounts of task switching emphasize the importance of working memory as a substantial source of the switch cost, there is a lack of evidence demonstrating that task switching actually places additional demands on working memory. The present study addressed this issue by implementing task switching in continuous complex span tasks with strictly controlled time parameters. A series of 4 experiments demonstrate that recall performance decreased as a function of the number of task switches and that the concurrent load of item maintenance had no influence on task switching. These results indicate that task switching induces a cost on working memory functioning. Implications for theories of task switching, working memory, and resource sharing are addressed.

The Association of Clinic-Based Mobility Tasks and Measures of Community Performance and Risk.

PubMed

Callisaya, Michele L; Verghese, Joe

2018-01-10

Gait speed is recognized as an important predictor of adverse outcomes in older people. However, it is unknown whether other more complex mobility tasks are better predictors of such outcomes. To examine a range of clinic-based mobility tests and determine which were most strongly associated with measures of community performance and risk (CP&R). Cross-sectional study. Central Control Mobility and Aging Study, Westchester County, New York. Aged ≥65 years (n = 424). Clinic-based mobility measures included gait speed measured during normal and dual-task conditions, the Floor Maze Immediate and Delay tasks, and stair ascending and descending. CP&R measures were self-reported by the use of standardized questionnaires and classified into measures of performance (distance walked, travel outside one's home [life space], activities of daily living, and participation in cognitive leisure activities) or risk (balance confidence, fear of falling, and past falls). Linear and logistic regression were used to examine associations between the clinic-based mobility measures and CP&R measures adjusting for covariates. The mean age of the sample was 77.8 (SD 6.4) years, and 55.2% (n = 234) were female. In final models, faster normal walking speed was most strongly associated with 5 of the 7 community measures (greater distance walked, greater life space, better activities of daily living function, higher balance confidence, and less fear of falling; all P < .05). More complex tasks (walking while talking and maze immediate) were associated with cognitive leisure activity (P < .05), and ascending stairs was the only measure associated with a history of falls (P < .05). Normal walking speed is a simple and inexpensive clinic-based mobility test that is associated with a wide range of CP&R measures. In addition, poorer performance ascending stairs may assist in identifying those at risk of falls. Poorer performance in more complex mobility tasks (walking while talking and maze immediate) may suggest inability to participate in cognitive leisure activities. III. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Disengagement from tasks as a function of cognitive load and depressive symptom severity.

PubMed

Bowie, Christopher R; Milanovic, Melissa; Tran, Tanya; Cassidy, Sarah

2017-01-01

Depression is associated with impairment in cognition and everyday functioning. Mechanisms of cognitive dysfunction in depression and the factors that influence strategic deployment of cognitive abilities in complex environments remain elusive. In this study we investigated whether depression symptom severity is associated with disengagement from a working memory task (Paced Auditory Serial Addition Task; PASAT) with parametric adjustment of task difficulty. 235 participants completed the Beck Depression Inventory, low and high cognitive load conditions of the PASAT, and quality of life. Cognitive disengagement was the sum of consecutive items in which participants did not proffer a response to the trial. Individuals with higher depression severity showed more cognitive disengagement on the high but not low cognitive load trial of the PASAT; they did not differ in number of correct responses. Increased disengagement from the low to high cognitive load was associated with more impaired quality of life. Depression severity is associated with increased disengagement from tasks as difficulty increases. These findings suggest the importance of measuring how cognitive skills are avoided in complex environments in addition to considering performance accuracy. Individuals with depressive symptoms might preferentially avoid cognitive tasks that are perceived as more complex in spite of intact ability.

Working Memory, Language Skills, and Autism Symptomatology

PubMed Central

Schuh, Jillian M.; Eigsti, Inge-Marie

2012-01-01

While many studies have reported working memory (WM) impairments in autism spectrum disorders, others do not. Sample characteristics, WM domain, and task complexity likely contribute to these discrepancies. Although deficits in visuospatial WM have been more consistently documented, there is much controversy regarding verbal WM in autism. The goal of the current study was to explore visuospatial and verbal WM in a well-controlled sample of children with high-functioning autism (HFA) and typical development. Individuals ages 9–17 with HFA (n = 18) and typical development (n = 18), were carefully matched on gender, age, IQ, and language, and were administered a series of standardized visuospatial and verbal WM tasks. The HFA group displayed significant impairment across WM domains. No differences in performance were noted across WM tasks for either the HFA or typically developing groups. Over and above nonverbal cognition, WM abilities accounted for significant variance in language skills and symptom severity. The current study suggests broad WM limitations in HFA. We further suggest that deficits in verbal WM are observed in more complex tasks, as well as in simpler tasks, such as phonological WM. Increased task complexity and linguistic demands may influence WM abilities. PMID:25379222

Complex motor-cognitive factors processed in the anterior nucleus of the thalamus: an intracerebral recording study.

PubMed

Bočková, Martina; Chládek, Jan; Jurák, Pavel; Halámek, Josef; Štillová, Klára; Baláž, Marek; Chrastina, Jan; Rektor, Ivan

2015-03-01

Cognitive adverse effects were reported after the deep brain stimulation (DBS) of the anterior nucleus of the thalamus (AN) in epilepsy. As the AN may have an influence on widespread neocortical networks, we hypothesized that the AN, in addition to its participation in memory processing, may also participate in cognitive activities linked with the frontal neocortical structures. The aim of this study was to investigate whether the AN might participate in complex motor-cognitive activities. Three pharmacoresistant epilepsy patients implanted with AN-DBS electrodes performed two tasks involving the writing of single letters: (1) copying letters from a monitor; and (2) writing of any letter other than that appearing on the monitor. The cognitive load of the second task was increased. The task-related oscillatory changes and evoked potentials were assessed. Local event-related alpha and beta desynchronization were more expressed during the second task while the lower gamma synchronization decreased. The local field event-related potentials were elicited by the two tasks without any specific differences. The AN participates in cognitive networks processing complex motor-cognitive tasks. Attention should be paid to executive functions in subjects undergoing AN-DBS.

Geometric and Algebraic Approaches in the Concept of Complex Numbers

ERIC Educational Resources Information Center

Panaoura, A.; Elia, I.; Gagatsis, A.; Giatilis, G.-P.

2006-01-01

This study explores pupils' performance and processes in tasks involving equations and inequalities of complex numbers requiring conversions from a geometric representation to an algebraic representation and conversions in the reverse direction, and also in complex numbers problem solving. Data were collected from 95 pupils of the final grade from…

Real-Time Performance Feedback for the Manual Control of Spacecraft

NASA Astrophysics Data System (ADS)

Karasinski, John Austin

Real-time performance metrics were developed to quantify workload, situational awareness, and manual task performance for use as visual feedback to pilots of aerospace vehicles. Results from prior lunar lander experiments with variable levels of automation were replicated and extended to provide insights for the development of real-time metrics. Increased levels of automation resulted in increased flight performance, lower workload, and increased situational awareness. Automated Speech Recognition (ASR) was employed to detect verbal callouts as a limited measure of subjects' situational awareness. A one-dimensional manual tracking task and simple instructor-model visual feedback scheme was developed. This feedback was indicated to the operator by changing the color of a guidance element on the primary flight display, similar to how a flight instructor points out elements of a display to a student pilot. Experiments showed that for this low-complexity task, visual feedback did not change subject performance, but did increase the subjects' measured workload. Insights gained from these experiments were applied to a Simplified Aid for EVA Rescue (SAFER) inspection task. The effects of variations of an instructor-model performance-feedback strategy on human performance in a novel SAFER inspection task were investigated. Real-time feedback was found to have a statistically significant effect of improving subject performance and decreasing workload in this complicated four degree of freedom manual control task with two secondary tasks.

Automated Cognitive Health Assessment Using Smart Home Monitoring of Complex Tasks

PubMed Central

Dawadi, Prafulla N.; Cook, Diane J.; Schmitter-Edgecombe, Maureen

2014-01-01

One of the many services that intelligent systems can provide is the automated assessment of resident well-being. We hypothesize that the functional health of individuals, or ability of individuals to perform activities independently without assistance, can be estimated by tracking their activities using smart home technologies. In this paper, we introduce a machine learning-based method for assessing activity quality in smart homes. To validate our approach we quantify activity quality for 179 volunteer participants who performed a complex, interweaved set of activities in our smart home apartment. We observed a statistically significant correlation (r=0.79) between automated assessment of task quality and direct observation scores. Using machine learning techniques to predict the cognitive health of the participants based on task quality is accomplished with an AUC value of 0.64. We believe that this capability is an important step in understanding everyday functional health of individuals in their home environments. PMID:25530925

Automated Cognitive Health Assessment Using Smart Home Monitoring of Complex Tasks.

PubMed

Dawadi, Prafulla N; Cook, Diane J; Schmitter-Edgecombe, Maureen

2013-11-01

One of the many services that intelligent systems can provide is the automated assessment of resident well-being. We hypothesize that the functional health of individuals, or ability of individuals to perform activities independently without assistance, can be estimated by tracking their activities using smart home technologies. In this paper, we introduce a machine learning-based method for assessing activity quality in smart homes. To validate our approach we quantify activity quality for 179 volunteer participants who performed a complex, interweaved set of activities in our smart home apartment. We observed a statistically significant correlation (r=0.79) between automated assessment of task quality and direct observation scores. Using machine learning techniques to predict the cognitive health of the participants based on task quality is accomplished with an AUC value of 0.64. We believe that this capability is an important step in understanding everyday functional health of individuals in their home environments.

Non-linguistic learning in aphasia: Effects of training method and stimulus characteristics

PubMed Central

Vallila-Rohter, Sofia; Kiran, Swathi

2013-01-01

Purpose The purpose of the current study was to explore non-linguistic learning ability in patients with aphasia, examining the impact of stimulus typicality and feedback on success with learning. Method Eighteen patients with aphasia and eight healthy controls participated in this study. All participants completed four computerized, non-linguistic category-learning tasks. We probed learning ability under two methods of instruction: feedback-based (FB) and paired-associate (PA). We also examined the impact of task complexity on learning ability, comparing two stimulus conditions: typical (Typ) and atypical (Atyp). Performance was compared between groups and across conditions. Results Results demonstrated that healthy controls were able to successfully learn categories under all conditions. For our patients with aphasia, two patterns of performance arose. One subgroup of patients was able to maintain learning across task manipulations and conditions. The other subgroup of patients demonstrated a sensitivity to task complexity, learning successfully only in the typical training conditions. Conclusions Results support the hypothesis that impairments of general learning are present in aphasia. Some patients demonstrated the ability to extract category information under complex training conditions, while others learned only under conditions that were simplified and emphasized salient category features. Overall, the typical training condition facilitated learning for all participants. Findings have implications for therapy, which are discussed. PMID:23695914

Mental workload while driving: effects on visual search, discrimination, and decision making.

PubMed

Recarte, Miguel A; Nunes, Luis M

2003-06-01

The effects of mental workload on visual search and decision making were studied in real traffic conditions with 12 participants who drove an instrumented car. Mental workload was manipulated by having participants perform several mental tasks while driving. A simultaneous visual-detection and discrimination test was used as performance criteria. Mental tasks produced spatial gaze concentration and visual-detection impairment, although no tunnel vision occurred. According to ocular behavior analysis, this impairment was due to late detection and poor identification more than to response selection. Verbal acquisition tasks were innocuous compared with production tasks, and complex conversations, whether by phone or with a passenger, are dangerous for road safety.

Operator strategies under varying conditions of workload

NASA Technical Reports Server (NTRS)

Arnegard, Ruth J.

1991-01-01

An attempt was made to operationally define and measure strategic behavior in a complex multiple task environment. The Multi-Attribute Task battery was developed to simulate various aspects of flight and consisted of an auditory communication task, monitoring tasks, a tracking tasks, a resource management task which allowed a wide range of responding patterns, and a scheduling window which allowed operators to predict changes in workload. This battery was validated for its sensitivity to strategic behavior, and baseline measures for each individual task were collected. Twenty-four undergraduate and graduate students then performed the battery for four 64 minute sessions which took place over a period of 2 days. Each subject performed the task battery under four levels of workload, which were presented for equal lengths of time during all four sessions. Results indicated that in general, performance improves as a function of experience with the battery, but that performance decreased as workload level increased. The data also showed that subjects developed strategies for responding to the resource management task which allowed them to manage the high workload levels more efficiently. This particular strategy developed over time but was also associated with errors of complacency. These results are presented along with implications for the aviation field and areas of future research.

The atomic simulation environment-a Python library for working with atoms.

PubMed

Hjorth Larsen, Ask; Jørgen Mortensen, Jens; Blomqvist, Jakob; Castelli, Ivano E; Christensen, Rune; Dułak, Marcin; Friis, Jesper; Groves, Michael N; Hammer, Bjørk; Hargus, Cory; Hermes, Eric D; Jennings, Paul C; Bjerre Jensen, Peter; Kermode, James; Kitchin, John R; Leonhard Kolsbjerg, Esben; Kubal, Joseph; Kaasbjerg, Kristen; Lysgaard, Steen; Bergmann Maronsson, Jón; Maxson, Tristan; Olsen, Thomas; Pastewka, Lars; Peterson, Andrew; Rostgaard, Carsten; Schiøtz, Jakob; Schütt, Ole; Strange, Mikkel; Thygesen, Kristian S; Vegge, Tejs; Vilhelmsen, Lasse; Walter, Michael; Zeng, Zhenhua; Jacobsen, Karsten W

2017-07-12

The atomic simulation environment (ASE) is a software package written in the Python programming language with the aim of setting up, steering, and analyzing atomistic simulations. In ASE, tasks are fully scripted in Python. The powerful syntax of Python combined with the NumPy array library make it possible to perform very complex simulation tasks. For example, a sequence of calculations may be performed with the use of a simple 'for-loop' construction. Calculations of energy, forces, stresses and other quantities are performed through interfaces to many external electronic structure codes or force fields using a uniform interface. On top of this calculator interface, ASE provides modules for performing many standard simulation tasks such as structure optimization, molecular dynamics, handling of constraints and performing nudged elastic band calculations.

The atomic simulation environment—a Python library for working with atoms

NASA Astrophysics Data System (ADS)

Hjorth Larsen, Ask; Jørgen Mortensen, Jens; Blomqvist, Jakob; Castelli, Ivano E.; Christensen, Rune; Dułak, Marcin; Friis, Jesper; Groves, Michael N.; Hammer, Bjørk; Hargus, Cory; Hermes, Eric D.; Jennings, Paul C.; Bjerre Jensen, Peter; Kermode, James; Kitchin, John R.; Leonhard Kolsbjerg, Esben; Kubal, Joseph; Kaasbjerg, Kristen; Lysgaard, Steen; Bergmann Maronsson, Jón; Maxson, Tristan; Olsen, Thomas; Pastewka, Lars; Peterson, Andrew; Rostgaard, Carsten; Schiøtz, Jakob; Schütt, Ole; Strange, Mikkel; Thygesen, Kristian S.; Vegge, Tejs; Vilhelmsen, Lasse; Walter, Michael; Zeng, Zhenhua; Jacobsen, Karsten W.

2017-07-01

The atomic simulation environment (ASE) is a software package written in the Python programming language with the aim of setting up, steering, and analyzing atomistic simulations. In ASE, tasks are fully scripted in Python. The powerful syntax of Python combined with the NumPy array library make it possible to perform very complex simulation tasks. For example, a sequence of calculations may be performed with the use of a simple ‘for-loop’ construction. Calculations of energy, forces, stresses and other quantities are performed through interfaces to many external electronic structure codes or force fields using a uniform interface. On top of this calculator interface, ASE provides modules for performing many standard simulation tasks such as structure optimization, molecular dynamics, handling of constraints and performing nudged elastic band calculations.

Cognitive-motor dual-task ability of athletes with and without intellectual impairment.

PubMed

Van Biesen, Debbie; Jacobs, Lore; McCulloch, Katina; Janssens, Luc; Vanlandewijck, Yves C

2018-03-01

Cognition is important in many sports, for example, making split-second-decisions under pressure, or memorising complex movement sequences. The dual-task (DT) paradigm is an ecologically valid approach for the assessment of cognitive function in conjunction with motor demands. This study aimed to determine the impact of impaired intelligence on DT performance. The motor task required balancing on one leg on a beam, and the cognitive task was a multiple-object-tracking (MOT) task assessing dynamic visual-search capacity. The sample included 206 well-trained athletes with and without intellectual impairment (II), matched for sport, age and training volume (140 males, 66 females, M age = 23.2 ± 4.1 years, M training experience = 12.3 ± 5.7 years). In the single-task condition, II-athletes showed reduced balance control (F = 55.9, P < .001, η 2  = .23) and reduced MOT (F = 86.3, P < .001, η 2  = .32) compared to the control group. A mixed-model ANCOVA revealed significant differences in DT performance for the balance and the MOT task between both groups. The DT costs were significantly larger for the II-athletes (-8.28% versus -1.34% for MOT and -33.13% versus -12.89% for balance). The assessment of MOT in a DT paradigm provided insight in how impaired intelligence constrains the ability of II-athletes to successfully perform at the highest levels in the complex and dynamical sport-environment.

Cognitive task load in a naval ship control centre: from identification to prediction.

PubMed

Grootjen, M; Neerincx, M A; Veltman, J A

Deployment of information and communication technology will lead to further automation of control centre tasks and an increasing amount of information to be processed. A method for establishing adequate levels of cognitive task load for the operators in such complex environments has been developed. It is based on a model distinguishing three load factors: time occupied, task-set switching, and level of information processing. Application of the method resulted in eight scenarios for eight extremes of task load (i.e. low and high values for each load factor). These scenarios were performed by 13 teams in a high-fidelity control centre simulator of the Royal Netherlands Navy. The results show that the method provides good prediction of the task load that will actually appear in the simulator. The model allowed identification of under- and overload situations showing negative effects on operator performance corresponding to controlled experiments in a less realistic task environment. Tools proposed to keep the operator at an optimum task load are (adaptive) task allocation and interface support.

Culture & Cognition Laboratory

DTIC Science & Technology

2011-05-01

life: Real world social-interaction cooperative tasks are inherently unequal in difficulty. Re-scoring performance on unequal tasks in order to enable...real- world situations to which this model is intended to apply, it is possible for calls for help to not be heard, or for a potential help-provider to...not have clear, well-defined objectives. Since many complex real- worlds tasks are not well-defined, defining a realistic objective can be considered a

Analysis of the pen pressure and grip force signal during basic drawing tasks: The timing and speed changes impact drawing characteristics.

PubMed

Gatouillat, Arthur; Dumortier, Antoine; Perera, Subashan; Badr, Youakim; Gehin, Claudine; Sejdić, Ervin

2017-08-01

Writing is a complex fine and trained motor skill, involving complex biomechanical and cognitive processes. In this paper, we propose the study of writing kinetics using three angles: the pen-tip normal force, the total grip force signal and eventually writing quality assessment. In order to collect writing kinetics data, we designed a sensor collecting these characteristics simultaneously. Ten healthy right-handed adults were recruited and were asked to perform four tasks: first, they were instructed to draw circles at a speed they considered comfortable; they then were instructed to draw circles at a speed they regarded as fast; afterwards, they repeated the comfortable task compelled to follow the rhythm of a metronome; and eventually they performed the fast task under the same timing constraints. Statistical differences between the tasks were computed, and while pen-tip normal force and total grip force signal were not impacted by the changes introduced in each task, writing quality features were affected by both the speed changes and timing constraint changes. This verifies the already-studied speed-accuracy trade-off and suggest the existence of a timing constraints-accuracy trade-off. Copyright © 2017 Elsevier Ltd. All rights reserved.

Levels of Information Processing in a Fitts law task (LIPFitts)

NASA Technical Reports Server (NTRS)

Mosier, K. L.; Hart, S. G.

1986-01-01

State-of-the-art flight technology has restructured the task of human operators, decreasing the need for physical and sensory resources, and increasing the quantity of cognitive effort required, changing it qualitatively. Recent technological advances have the most potential for impacting a pilot in two areas: performance and mental workload. In an environment in which timing is critical, additional cognitive processing can cause performance decrements, and increase a pilot's perception of the mental workload involved. The effects of stimulus processing demands on motor response performance and subjective mental workload are examined, using different combinations of response selection and target acquisition tasks. The information processing demands of the response selection were varied (e.g., Sternberg memory set tasks, math equations, pattern matching), as was the difficulty of the response execution. Response latency as well as subjective workload ratings varied in accordance with the cognitive complexity of the task. Movement times varied according to the difficulty of the response execution task. Implications in terms of real-world flight situations are discussed.

Acute effects of caffeine on several operant behaviors in rhesus monkeys.

PubMed

Buffalo, E A; Gillam, M P; Allen, R R; Paule, M G

1993-11-01

The acute effects of 1,3-trimethylxanthine (caffeine) were assessed using an operant test battery (OTB) of complex food-reinforced tasks that are thought to depend upon relatively specific brain functions, such as motivation to work for food (progressive ratio, PR), learning (incremental repeated acquisition, IRA), color and position discrimination (conditioned position responding, CPR), time estimation (temporal response differentiation, TRD), and short-term memory and attention (delayed matching-to-sample, DMTS). Endpoints included response rates (RR), accuracies (ACC), and percent task completed (PTC). Caffeine sulfate (0.175-20.0 mg/kg, IV), given 15 min pretesting, produced significant dose-dependent decreases in TRD percent task completed and accuracy at doses > or = 5.6 mg/kg. Caffeine produced no systematic effects on either DMTS or PR responding, but low doses tended to enhance performance in both IRA and CPR tasks. Thus, in monkeys, performance of an operant task designed to model time estimation is more sensitive to the disruptive effects of caffeine than is performance of the other tasks in the OTB.

Quantifying the Physiological Stress Response to Simulated Maritime Pilotage Tasks

PubMed Central

Main, Luana C.; Wolkow, Alexander; Chambers, Timothy P.

2017-01-01

Objective: The aim of this study was to quantify the stress associated with performing maritime pilotage tasks in a high-fidelity simulator. Methods: Eight trainee and 13 maritime pilots completed two simulated pilotage tasks of varying complexity. Salivary cortisol samples were collected pre- and post-simulation for both trials. Heart rate was measured continuously throughout the study. Results: Significant changes in salivary cortisol (P = 0.000, η2 = 0.139), average (P = 0.006, η2 = 0.087), and peak heart rate (P = 0.013, η2 = 0.077) from pre- to postsimulation were found. Varying task complexity did partially influence stress response; average (P = 0.016, η2 = 0.026) and peak heart rate (P = 0.034, η2 = 0.020) were higher in the experimental condition. Trainees also recorded higher average (P = 0.000, η2 = 0.054) and peak heart rates (P = 0.027, η2 = 0.022). Conclusion: Performing simulated pilotage tasks evoked a measurable stress response in both trainee and expert maritime pilots. PMID:28922309

Sex differences in event-related potential components during the solution of complex mental rotation tasks.

PubMed

Jaušovec, Norbert

2012-04-18

The objective of the study was to evaluate the factor of sex in terms of its influence on event-related potential components during the solution of a complex mental rotation task. To evaluate the factor of sex, independent of differences in ability levels and hormonal changes, women and men were equalized with respect to general intelligence and spatial ability. In addition, all women were tested during the low-estrogen phase of the menstrual cycle. The event-related potential analysis indicated that men showed shorter P3 and longer P1 latencies, as well as lower N1 amplitudes. These results suggest that men devoted more time to the analysis of irrelevant information presented in the rotation tasks, which resulted in mental rotation taking place earlier in men than in women. It can be concluded that, even though men and women showed similar performances on complex rotation tasks, they differed in their solution processes.

Emotional reactivity and cognitive performance in aversively motivated tasks: a comparison between four rat strains.

PubMed

van der Staay, F Josef; Schuurman, Teun; van Reenen, Cornelis G; Korte, S Mechiel

2009-12-15

Cognitive function might be affected by the subjects' emotional reactivity. We assessed whether behavior in different tests of emotional reactivity is correlated with performance in aversively motivated learning tasks, using four strains of rats generally considered to have a different emotional reactivity. The performance of male Brown Norway, Lewis, Fischer 344, and Wistar Kyoto rats in open field (OF), elevated plus-maze (EPM), and circular light-dark preference box (cLDB) tasks, which are believed to provide measures of emotional reactivity, was evaluated. Spatial working and reference memory were assessed in two aversively motivated learning and memory tasks: the standard and the "repeated acquisition" versions of the Morris water maze escape task, respectively. All rats were also tested in a passive avoidance task. At the end of the study, levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid, and 5-HT turnover in the hippocampus and frontal cortex were determined. Strain differences showed a complex pattern across behavioral tests and serotonergic measures. Fischer 344 rats had the poorest performance in both versions of the Morris water escape task, whereas Brown Norway rats performed these tasks very well but the passive avoidance task poorly. Neither correlation analysis nor principal component analysis provided convincing support for the notion that OF, EPM, and cLDB tasks measure the same underlying trait. Our findings do not support the hypothesis that the level of emotional reactivity modulates cognitive performance in aversively motivated tasks. Concepts such as "emotional reactivity" and "learning and memory" cannot adequately be tapped with only one behavioral test. Our results emphasize the need for multiple testing.

General mental ability and two types of adaptation to unforeseen change: applying discontinuous growth models to the task-change paradigm.

PubMed

Lang, Jonas W B; Bliese, Paul D

2009-03-01

The present research provides new insights into the relationship between general mental ability (GMA) and adaptive performance by applying a discontinuous growth modeling framework to a study of unforeseen change on a complex decision-making task. The proposed framework provides a way to distinguish 2 types of adaptation (transition adaptation and reacquisition adaptation) from 2 common performance components (skill acquisition and basal task performance). Transition adaptation refers to an immediate loss of performance following a change, whereas reacquisition adaptation refers to the ability to relearn a changed task over time. Analyses revealed that GMA was negatively related to transition adaptation and found no evidence for a relationship between GMA and reacquisition adaptation. The results are integrated within the context of adaptability research, and implications of using the described discontinuous growth modeling framework to study adaptability are discussed. (c) 2009 APA, all rights reserved.

The reaction times of drivers aged 20 to 80 during a divided attention driving.

PubMed

Svetina, Matija

2016-11-16

Many studies addressing age-related changes in driving performance focus on comparing young vs. older drivers, which might lead to the biased conclusion that driving performance decreases only after the age of 65. The main aim of the study was to show that changes in driving performance are progressive throughout the adult years. A sample of 351 drivers aged 20 to 80 was assessed for their reaction times while driving between road cones. The drivers were exposed to 2 conditions varying according to task complexity. In single task conditions, the drivers performed a full stopping maneuver at a given signal; in dual task conditions, the drivers were distracted before the signal for stopping maneuver was triggered. Reaction times were compared across conditions and age groups. The results showed that both reaction times and variability of driving performance increased progressively between the ages of 20 and 80. The increase in both reaction times and variability was greater in the complex task condition. The high-performing quarter of elderly drivers performed equally well or better than younger drivers did. The data clearly supported the claim that driving performance changes steadily across age groups: both mean reaction time and interindividual variability progressively increase with age. In addition, a significant group of older drivers was identified who did not show the expected age-related decrease in performance. The findings have important implications, suggesting that in relation to driving, aging is a progressive phenomenon and may lead to variety of driving performance; age-related studies of driving performance should put more emphasis on investigating changes across the whole driver age range rather than only comparing younger and older drivers.

Enhanced visual performance in obsessive compulsive personality disorder.

PubMed

Ansari, Zohreh; Fadardi, Javad Salehi

2016-12-01

Visual performance is considered as commanding modality in human perception. We tested whether Obsessive-compulsive personality disorder (OCPD) people do differently in visual performance tasks than people without OCPD. One hundred ten students of Ferdowsi University of Mashhad and non-student participants were tested by Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II), among whom 18 (mean age = 29.55; SD = 5.26; 84% female) met the criteria for OCPD classification; controls were 20 persons (mean age = 27.85; SD = 5.26; female = 84%), who did not met the OCPD criteria. Both groups were tested on a modified Flicker task for two dimensions of visual performance (i.e., visual acuity: detecting the location of change, complexity, and size; and visual contrast sensitivity). The OCPD group had responded more accurately on pairs related to size, complexity, and contrast, but spent more time to detect a change on pairs related to complexity and contrast. The OCPD individuals seem to have more accurate visual performance than non-OCPD controls. The findings support the relationship between personality characteristics and visual performance within the framework of top-down processing model. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

How to use MPI communication in highly parallel climate simulations more easily and more efficiently.

NASA Astrophysics Data System (ADS)

Behrens, Jörg; Hanke, Moritz; Jahns, Thomas

2014-05-01

In this talk we present a way to facilitate efficient use of MPI communication for developers of climate models. Exploitation of the performance potential of today's highly parallel supercomputers with real world simulations is a complex task. This is partly caused by the low level nature of the MPI communication library which is the dominant communication tool at least for inter-node communication. In order to manage the complexity of the task, climate simulations with non-trivial communication patterns often use an internal abstraction layer above MPI without exploiting the benefits of communication aggregation or MPI-datatypes. The solution for the complexity and performance problem we propose is the communication library YAXT. This library is built on top of MPI and takes high level descriptions of arbitrary domain decompositions and automatically derives an efficient collective data exchange. Several exchanges can be aggregated in order to reduce latency costs. Examples are given which demonstrate the simplicity and the performance gains for selected climate applications.

Validation of inertial measurement units with an optoelectronic system for whole-body motion analysis.

PubMed

Robert-Lachaine, Xavier; Mecheri, Hakim; Larue, Christian; Plamondon, André

2017-04-01

The potential of inertial measurement units (IMUs) for ergonomics applications appears promising. However, previous IMUs validation studies have been incomplete regarding aspects of joints analysed, complexity of movements and duration of trials. The objective was to determine the technological error and biomechanical model differences between IMUs and an optoelectronic system and evaluate the effect of task complexity and duration. Whole-body kinematics from 12 participants was recorded simultaneously with a full-body Xsens system where an Optotrak cluster was fixed on every IMU. Short functional movements and long manual material handling tasks were performed and joint angles were compared between the two systems. The differences attributed to the biomechanical model showed significantly greater (P ≤ .001) RMSE than the technological error. RMSE was systematically higher (P ≤ .001) for the long complex task with a mean on all joints of 2.8° compared to 1.2° during short functional movements. Definition of local coordinate systems based on anatomical landmarks or single posture was the most influent difference between the two systems. Additionally, IMUs accuracy was affected by the complexity and duration of the tasks. Nevertheless, technological error remained under 5° RMSE during handling tasks, which shows potential to track workers during their daily labour.

Mind wandering and the attention network system.

PubMed

Gonçalves, Óscar F; Rêgo, Gabriel; Oliveira-Silva, Patrícia; Leite, Jorge; Carvalho, Sandra; Fregni, Felipe; Amaro, Edson; Boggio, Paulo S

2017-01-01

Attention and mind wandering are often seen as anticorrelated. However, both attention and mind wandering are multi-component processes, and their relationship may be more complex than previously thought. In this study, we tested the interference of different types of thoughts as measured by a Thought Identification Task - TIT (on task thoughts, task related interference thoughts, external distractions, stimulus independent and task unrelated thoughts) on different components of the attention network system - ANT (alerting, orienting, executive). Results show that, during the ANT, individuals were predominantly involved in task related interference thoughts which, along with external distractors, significantly impaired their performance accuracy. However, mind wandering (i.e., stimulus independent and task unrelated thoughts) did not significantly interfere with accuracy in the ANT. No significant relationship was found between type of thoughts and alerting, orienting, or executive effects in the ANT. While task related interference thoughts and external distractions seemed to impair performance on the attention task, mind wandering was still compatible with satisfactory performance in the ANT. The present results confirmed the importance of differentiating type of "out of task" thoughts in studying the relationship between though distractors and attention. Copyright © 2016 Elsevier B.V. All rights reserved.

Biologically plausible learning in recurrent neural networks reproduces neural dynamics observed during cognitive tasks

PubMed Central

Miconi, Thomas

2017-01-01

Neural activity during cognitive tasks exhibits complex dynamics that flexibly encode task-relevant variables. Chaotic recurrent networks, which spontaneously generate rich dynamics, have been proposed as a model of cortical computation during cognitive tasks. However, existing methods for training these networks are either biologically implausible, and/or require a continuous, real-time error signal to guide learning. Here we show that a biologically plausible learning rule can train such recurrent networks, guided solely by delayed, phasic rewards at the end of each trial. Networks endowed with this learning rule can successfully learn nontrivial tasks requiring flexible (context-dependent) associations, memory maintenance, nonlinear mixed selectivities, and coordination among multiple outputs. The resulting networks replicate complex dynamics previously observed in animal cortex, such as dynamic encoding of task features and selective integration of sensory inputs. We conclude that recurrent neural networks offer a plausible model of cortical dynamics during both learning and performance of flexible behavior. DOI: http://dx.doi.org/10.7554/eLife.20899.001 PMID:28230528

Biologically plausible learning in recurrent neural networks reproduces neural dynamics observed during cognitive tasks.

PubMed

Miconi, Thomas

2017-02-23

Neural activity during cognitive tasks exhibits complex dynamics that flexibly encode task-relevant variables. Chaotic recurrent networks, which spontaneously generate rich dynamics, have been proposed as a model of cortical computation during cognitive tasks. However, existing methods for training these networks are either biologically implausible, and/or require a continuous, real-time error signal to guide learning. Here we show that a biologically plausible learning rule can train such recurrent networks, guided solely by delayed, phasic rewards at the end of each trial. Networks endowed with this learning rule can successfully learn nontrivial tasks requiring flexible (context-dependent) associations, memory maintenance, nonlinear mixed selectivities, and coordination among multiple outputs. The resulting networks replicate complex dynamics previously observed in animal cortex, such as dynamic encoding of task features and selective integration of sensory inputs. We conclude that recurrent neural networks offer a plausible model of cortical dynamics during both learning and performance of flexible behavior.

Do absorption and realistic distraction influence performance of component task surgical procedure?

PubMed

Pluyter, Jon R; Buzink, Sonja N; Rutkowski, Anne-F; Jakimowicz, Jack J

2010-04-01

Surgeons perform complex tasks while exposed to multiple distracting sources that may increase stress in the operating room (e.g., music, conversation, and unadapted use of sophisticated technologies). This study aimed to examine whether such realistic social and technological distracting conditions may influence surgical performance. Twelve medical interns performed a laparoscopic cholecystectomy task with the Xitact LC 3.0 virtual reality simulator under distracting conditions (exposure to music, conversation, and nonoptimal handling of the laparoscope) versus nondistracting conditions (control condition) as part of a 2 x 2 within-subject experimental design. Under distracting conditions, the medical interns showed a significant decline in task performance (overall task score, task errors, and operating time) and significantly increased levels of irritation toward both the assistant handling the laparoscope in a nonoptimal way and the sources of social distraction. Furthermore, individual differences in cognitive style (i.e., cognitive absorption and need for cognition) significantly influenced the levels of irritation experienced by the medical interns. The results suggest careful evaluation of the social and technological sources of distraction in the operation room to reduce irritation for the surgeon and provision of proper preclinical laparoscope navigation training to increase security for the patient.

Visual and skill effects on soccer passing performance, kinematics, and outcome estimations

PubMed Central

Basevitch, Itay; Tenenbaum, Gershon; Land, William M.; Ward, Paul

2015-01-01

The role of visual information and action representations in executing a motor task was examined from a mental representations approach. High-skill (n = 20) and low-skill (n = 20) soccer players performed a passing task to two targets at distances of 9.14 and 18.29 m, under three visual conditions: normal, occluded, and distorted vision (i.e., +4.0 corrective lenses, a visual acuity of approximately 6/75) without knowledge of results. Following each pass, participants estimated the relative horizontal distance from the target as the ball crossed the target plane. Kinematic data during each pass were also recorded for the shorter distance. Results revealed that performance on the motor task decreased as a function of visual information and task complexity (i.e., distance from target) regardless of skill level. High-skill players performed significantly better than low-skill players on both the actual passing and estimation tasks, at each target distance and visual condition. In addition, kinematic data indicated that high-skill participants were more consistent and had different kinematic movement patterns than low-skill participants. Findings contribute to the understanding of the underlying mechanisms required for successful performance in a self-paced, discrete and closed motor task. PMID:25784886

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

Task-Dependent Behavioral Dynamics Make the Case for Temporal Integration in Multiple Strategies during Odor Processing

PubMed Central

Brown, Austin; Mehta, Nisarg; Vujovic, Mark; Amina, Tasneem; Fixsen, Bethany

2017-01-01

Differing results in olfactory-based decision-making research regarding the amount of time that rats and mice use to identify odors have led to some disagreements about odor-processing mechanics, including whether or not rodents use temporal integration (i.e., sniffing longer to identify odors better). Reported differences in behavioral strategies may be due to the different types of tasks used in different laboratories. Some researchers have reported that animals performing two-alternative choice (TAC) tasks need only 1–2 sniffs and do not increase performance with longer sampling. Others have reported that animals performing go/no-go (GNG) tasks increase sampling times and performance for difficult discriminations, arguing for temporal integration. We present results from four experiments comparing GNG and TAC tasks over several behavioral variables (e.g., performance, sampling duration). When rats know only one task, they perform better in GNG than in TAC. However, performance was not statistically different when rats learned and were tested in both tasks. Rats sample odors longer in GNG than in TAC, even when they know both tasks and perform them in the same or different sessions. Longer sampling is associated with better performance for both tasks in difficult discriminations, which supports the case for temporal integration over ≥2–6 sniffs in both tasks. These results illustrate that generalizations from a single task about behavioral or cognitive abilities (e.g., processing, perception) do not capture the full range of complexity and can significantly impact inferences about general abilities in sensory perception. SIGNIFICANCE STATEMENT Behavioral tasks and training and testing history affect measured outcomes in cognitive tests. Rats sample odors longer in a go/no-go (GNG) than in a two-alternative choice (TAC) task, performing better in GNG unless they know both tasks. Odor-sampling time is extended in both tasks when the odors to be discriminated are very similar. Rats may extend sampling time to integrate odor information up to ∼0.5 s (2–6 sniffs). Such factors as task, task parameters, and training history affect decision times and performance, making it important to use multiple tasks when making inferences about sensory or cognitive processing. PMID:28336570

The effects of age, sleep deprivation, and altitude on complex performance.

DOT National Transportation Integrated Search

1985-05-01

Little research has been concerned with the combined effects on performance of age, sleep deprivation, and altitude. This study examined their potential interaction with laboratory tasks measuring aviation-related psychological functions. : Healthy m...

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

PubMed

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

2009-04-01

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

Parietal neural prosthetic control of a computer cursor in a graphical-user-interface task

NASA Astrophysics Data System (ADS)

Revechkis, Boris; Aflalo, Tyson NS; Kellis, Spencer; Pouratian, Nader; Andersen, Richard A.

2014-12-01

Objective. To date, the majority of Brain-Machine Interfaces have been used to perform simple tasks with sequences of individual targets in otherwise blank environments. In this study we developed a more practical and clinically relevant task that approximated modern computers and graphical user interfaces (GUIs). This task could be problematic given the known sensitivity of areas typically used for BMIs to visual stimuli, eye movements, decision-making, and attentional control. Consequently, we sought to assess the effect of a complex, GUI-like task on the quality of neural decoding. Approach. A male rhesus macaque monkey was implanted with two 96-channel electrode arrays in area 5d of the superior parietal lobule. The animal was trained to perform a GUI-like ‘Face in a Crowd’ task on a computer screen that required selecting one cued, icon-like, face image from a group of alternatives (the ‘Crowd’) using a neurally controlled cursor. We assessed whether the crowd affected decodes of intended cursor movements by comparing it to a ‘Crowd Off’ condition in which only the matching target appeared without alternatives. We also examined if training a neural decoder with the Crowd On rather than Off had any effect on subsequent decode quality. Main results. Despite the additional demands of working with the Crowd On, the animal was able to robustly perform the task under Brain Control. The presence of the crowd did not itself affect decode quality. Training the decoder with the Crowd On relative to Off had no negative influence on subsequent decoding performance. Additionally, the subject was able to gaze around freely without influencing cursor position. Significance. Our results demonstrate that area 5d recordings can be used for decoding in a complex, GUI-like task with free gaze. Thus, this area is a promising source of signals for neural prosthetics that utilize computing devices with GUI interfaces, e.g. personal computers, mobile devices, and tablet computers.

Parietal neural prosthetic control of a computer cursor in a graphical-user-interface task.

PubMed

Revechkis, Boris; Aflalo, Tyson N S; Kellis, Spencer; Pouratian, Nader; Andersen, Richard A

2014-12-01

To date, the majority of Brain-Machine Interfaces have been used to perform simple tasks with sequences of individual targets in otherwise blank environments. In this study we developed a more practical and clinically relevant task that approximated modern computers and graphical user interfaces (GUIs). This task could be problematic given the known sensitivity of areas typically used for BMIs to visual stimuli, eye movements, decision-making, and attentional control. Consequently, we sought to assess the effect of a complex, GUI-like task on the quality of neural decoding. A male rhesus macaque monkey was implanted with two 96-channel electrode arrays in area 5d of the superior parietal lobule. The animal was trained to perform a GUI-like 'Face in a Crowd' task on a computer screen that required selecting one cued, icon-like, face image from a group of alternatives (the 'Crowd') using a neurally controlled cursor. We assessed whether the crowd affected decodes of intended cursor movements by comparing it to a 'Crowd Off' condition in which only the matching target appeared without alternatives. We also examined if training a neural decoder with the Crowd On rather than Off had any effect on subsequent decode quality. Despite the additional demands of working with the Crowd On, the animal was able to robustly perform the task under Brain Control. The presence of the crowd did not itself affect decode quality. Training the decoder with the Crowd On relative to Off had no negative influence on subsequent decoding performance. Additionally, the subject was able to gaze around freely without influencing cursor position. Our results demonstrate that area 5d recordings can be used for decoding in a complex, GUI-like task with free gaze. Thus, this area is a promising source of signals for neural prosthetics that utilize computing devices with GUI interfaces, e.g. personal computers, mobile devices, and tablet computers.

Designing Effective Web Forms for Older Web Users

ERIC Educational Resources Information Center

Li, Hui; Rau, Pei-Luen Patrick; Fujimura, Kaori; Gao, Qin; Wang, Lin

2012-01-01

This research aims to provide insight for web form design for older users. The effects of task complexity and information structure of web forms on older users' performance were examined. Forty-eight older participants with abundant computer and web experience were recruited. The results showed significant differences in task time and error rate…

Common EEG features for behavioral estimation in disparate, real-world tasks.

PubMed

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

2016-02-01

In this study we explored the potential for capturing the behavioral dynamics observed in real-world tasks from concurrent measures of EEG. In doing so, we sought to develop models of behavior that would enable the identification of common cross-participant and cross-task EEG features. To accomplish this we had participants perform both simulated driving and guard duty tasks while we recorded their EEG. For each participant we developed models to estimate their behavioral performance during both tasks. Sequential forward floating selection was used to identify the montage of independent components for each model. Linear regression was then used on the combined power spectra from these independent components to generate a continuous estimate of behavior. Our results show that oscillatory processes, evidenced in EEG, can be used to successfully capture slow fluctuations in behavior in complex, multi-faceted tasks. The average correlation coefficients between the actual and estimated behavior was 0.548 ± 0.117 and 0.701 ± 0.154 for the driving and guard duty tasks respectively. Interestingly, through a simple clustering approach we were able to identify a number of common components, both neural and eye-movement related, across participants and tasks. We used these component clusters to quantify the relative influence of common versus participant-specific features in the models of behavior. These findings illustrate the potential for estimating complex behavioral dynamics from concurrent measures from EEG using a finite library of universal features. Published by Elsevier B.V.

Working Memory Integration Processes in Benign Childhood Epilepsy with Centrotemporal Spikes.

PubMed

Kárpáti, Judit; Donauer, Nándor; Somogyi, Eszter; Kónya, Anikó

2015-12-01

Benign epilepsy of childhood with centrotemporal spikes (BECTS) is the most frequent focal epilepsy in children; however, the pattern of affected memory processes remains controversial. Previous studies in BECTS imply deficits in complex working memory tasks, but not in simple modality-specific tasks. We studied working memory processes in children with BECTS by comparing performance in memory binding tasks of different complexities. We compared 17 children with BECTS (aged 6 to 13 years) to 17 healthy children matched for age, sex, and intelligence quotient. We measured spatial and verbal memory components separately and jointly on three single-binding tasks (binding of what and where; what and when; and where and when) and a combined-binding task (integration of what, where, and when). We also evaluated basic visuospatial memory functions with subtests of the Children's Memory Scale, and intellectual abilities with verbal tasks of the Wechsler Intelligence Scale for Children-Fourth Edition and the Raven Progressive Matrices. We found no difference between the BECTS and control groups in single-binding tasks; however, the children with BECTS performed significantly worse on the combined task, which included integration of spatial, verbal, and temporal information. We found no deficits in their intellectual abilities or basic visuospatial memory functions. Children with BECTS may have intact simple maintenance processes of working memory, but difficulty with high-level functions requiring attentional and executive resources. Our findings imply no specific memory dysfunction in BECTS, but suggest difficulties in integrating information within working memory, and possible frontal lobe disturbances.

How similar are nut-cracking and stone-flaking? A functional approach to percussive technology

PubMed Central

Bril, Blandine; Parry, Ross; Dietrich, Gilles

2015-01-01

Various authors have suggested similarities between tool use in early hominins and chimpanzees. This has been particularly evident in studies of nut-cracking which is considered to be the most complex skill exhibited by wild apes, and has also been interpreted as a precursor of more complex stone-flaking abilities. It has been argued that there is no major qualitative difference between what the chimpanzee does when he cracks a nut and what early hominins did when they detached a flake from a core. In this paper, similarities and differences between skills involved in stone-flaking and nut-cracking are explored through an experimental protocol with human subjects performing both tasks. We suggest that a ‘functional’ approach to percussive action, based on the distinction between functional parameters that characterize each task and parameters that characterize the agent's actions and movements, is a fruitful method for understanding those constraints which need to be mastered to perform each task successfully, and subsequently, the nature of skill involved in both tasks. PMID:26483533

Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs.

PubMed

Müller, Corsin A; Riemer, Stefanie; Virányi, Zsófia; Huber, Ludwig; Range, Friederike

2016-01-01

Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject's level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance.

Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs

PubMed Central

Müller, Corsin A.; Riemer, Stefanie; Virányi, Zsófia; Huber, Ludwig; Range, Friederike

2016-01-01

Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject’s level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance. PMID:26863141

A Methodology for Assessing Learning in Complex and Ill-Structured Task Domains

ERIC Educational Resources Information Center

Spector, J. Michael

2006-01-01

New information and communications technologies and research in cognitive science have led to new ways to think about and implement learning environments. Among these new approaches to instruction and new methods to support learning and performance is an interest in and emphasis on complex subject matter (e.g., complex and dynamic systems…

Complexity and Hemispheric Abilities: Evidence for a Differential Impact on Semantics and Phonology

ERIC Educational Resources Information Center

Tremblay, Tania; Monetta, Laura; Joanette, Yves

2009-01-01

The main goal of this study was to determine whether the phonological and semantic processing of words are similarly influenced by an increase in processing complexity. Thirty-six French-speaking young adults performed both semantic and phonological word judgment tasks, using a divided visual field procedure. The phonological complexity of words…

Learner-Learner Interaction during Collaborative Pragmatic Tasks: The Role of Cognitive and Pragmatic Task Demands

ERIC Educational Resources Information Center

Kim, YouJin; Taguchi, Naoko

2016-01-01

Previous task complexity studies have suggested that learners produce more negotiation of meaning opportunities during complex tasks than simple tasks (Robinson, 2011). The present study builds on the existing task complexity literature by examining the impact of task complexity and pragmatic situational demands on the number of learning…

Crew workload strategies in advanced cockpits

NASA Technical Reports Server (NTRS)

Hart, Sandra G.

1990-01-01

Many methods of measuring and predicting operator workload have been developed that provide useful information in the design, evaluation, and operation of complex systems and which aid in developing models of human attention and performance. However, the relationships between such measures, imposed task demands, and measures of performance remain complex and even contradictory. It appears that we have ignored an important factor: people do not passively translate task demands into performance. Rather, they actively manage their time, resources, and effort to achieve an acceptable level of performance while maintaining a comfortable level of workload. While such adaptive, creative, and strategic behaviors are the primary reason that human operators remain an essential component of all advanced man-machine systems, they also result in individual differences in the way people respond to the same task demands and inconsistent relationships among measures. Finally, we are able to measure workload and performance, but interpreting such measures remains difficult; it is still not clear how much workload is too much or too little nor the consequences of suboptimal workload on system performance and the mental, physical, and emotional well-being of the human operators. The rationale and philosophy of a program of research developed to address these issues will be reviewed and contrasted to traditional methods of defining, measuring, and predicting human operator workload. Viewgraphs are given.

Fit for the frontline? A focus group exploration of auditory tasks carried out by infantry and combat support personnel.

PubMed

Bevis, Zoe L; Semeraro, Hannah D; van Besouw, Rachel M; Rowan, Daniel; Lineton, Ben; Allsopp, Adrian J

2014-01-01

In order to preserve their operational effectiveness and ultimately their survival, military personnel must be able to detect important acoustic signals and maintain situational awareness. The possession of sufficient hearing ability to perform job-specific auditory tasks is defined as auditory fitness for duty (AFFD). Pure tone audiometry (PTA) is used to assess AFFD in the UK military; however, it is unclear whether PTA is able to accurately predict performance on job-specific auditory tasks. The aim of the current study was to gather information about auditory tasks carried out by infantry personnel on the frontline and the environment these tasks are performed in. The study consisted of 16 focus group interviews with an average of five participants per group. Eighty British army personnel were recruited from five infantry regiments. The focus group guideline included seven open-ended questions designed to elicit information about the auditory tasks performed on operational duty. Content analysis of the data resulted in two main themes: (1) the auditory tasks personnel are expected to perform and (2) situations where personnel felt their hearing ability was reduced. Auditory tasks were divided into subthemes of sound detection, speech communication and sound localization. Reasons for reduced performance included background noise, hearing protection and attention difficulties. The current study provided an important and novel insight to the complex auditory environment experienced by British infantry personnel and identified 17 auditory tasks carried out by personnel on operational duties. These auditory tasks will be used to inform the development of a functional AFFD test for infantry personnel.

Cognitive-motor interference during fine and gross motor tasks in children with Developmental Coordination Disorder (DCD).

PubMed

Schott, Nadja; El-Rajab, Inaam; Klotzbier, Thomas

2016-10-01

While typically developing children produce relatively automatized postural control processes, children with DCD seem to exhibit an automatization deficit. Dual tasks with various cognitive loads seem to be an effective way to assess the automatic deficit hypothesis. The aims of the study were: (1) to examine the effect of a concurrent cognitive task on fine and gross motor tasks in children with DCD, and (2) to determine whether the effect varied with different difficulty levels of the concurrent task. We examined dual-task performance (Trail-Making-Test, Trail-Walking-Test) in 20 children with DCD and 39 typically developing children. Based on the idea of the Trail-Making-Test, participants walked along a fixed pathway, following a prescribed path, delineated by target markers of (1) increasing sequential numbers, and (2) increasing sequential numbers and letters. The motor and cognitive dual-task effects (DTE) were calculated for each task. Regardless of the cognitive task, children with DCD performed equally well in fine and gross motor tasks, and were slower in the dual task conditions than under single task-conditions, compared with children without DCD. Increased cognitive task complexity resulted in slow trail walking as well as slower trail tracing. The motor interference for the gross motor tasks was least for the simplest conditions and greatest for the complex conditions and was more pronounced in children with DCD. Cognitive interference was low irrespective of the motor task. Children with DCD show a different approach to allocation of cognitive resources, and have difficulties making motor skills automatic. The latter notion is consistent with impaired cerebellar function and the "automatization deficit hypothesis", suggesting that any deficit in the automatization process will appear if conscious monitoring of the motor skill is made more difficult by integrating another task requiring attentional resources. Copyright © 2016 Elsevier Ltd. All rights reserved.

Motor learning from virtual reality to natural environments in individuals with Duchenne muscular dystrophy.

PubMed

Quadrado, Virgínia Helena; Silva, Talita Dias da; Favero, Francis Meire; Tonks, James; Massetti, Thais; Monteiro, Carlos Bandeira de Mello

2017-11-10

To examine whether performance improvements in the virtual environment generalize to the natural environment. we had 64 individuals, 32 of which were individuals with DMD and 32 were typically developing individuals. The groups practiced two coincidence timing tasks. In the more tangible button-press task, the individuals were required to 'intercept' a falling virtual object at the moment it reached the interception point by pressing a key on the computer. In the more abstract task, they were instructed to 'intercept' the virtual object by making a hand movement in a virtual environment using a webcam. For individuals with DMD, conducting a coincidence timing task in a virtual environment facilitated transfer to the real environment. However, we emphasize that a task practiced in a virtual environment should have higher rates of difficulties than a task practiced in a real environment. IMPLICATIONS FOR REHABILITATION Virtual environments can be used to promote improved performance in ?real-world? environments. Virtual environments offer the opportunity to create paradigms similar ?real-life? tasks, however task complexity and difficulty levels can be manipulated, graded and enhanced to increase likelihood of success in transfer of learning and performance. Individuals with DMD, in particular, showed immediate performance benefits after using virtual reality.

Effects of age and the use of hands-free cellular phones on driving behavior and task performance.

PubMed

Liu, Yung-Ching; Ou, Yang-Kun

2011-12-01

This study used a driving simulator to investigate the effect of using a Bluetooth hands-free cellular phone earpiece on the driving behavior of two age groups. Forty-eight participants (24 aged 20-26 and 24 aged 65-73) were examined to assess their performance on the following divided-attention tasks under 2 driving load conditions (high and low): (1) attempting to maintain the speed limit and (2) using a cellular phone while driving. The length of the call conversation (long vs. short) and the conversational content (complex vs. simple) were manipulated as within-subject independent variables. The driving behavior of the participants, their task reaction times and accuracy, and subjective ratings were collected as dependent variables. The results indicate that under low driving loads, short talk times, and simple conversational content, the driving behavior of the participants showed low variance in the vehicle's mean speed. In contrast, complex conversation had a significantly negative impact on driving behavior. Notably, under a low driving load, motorists' driving behaviors, measured in lateral acceleration, caused significantly smaller variance in complex conversations compared to no call and simple conversations. The use of a hands-free cellular phone affected the performance (acceleration, lane deviation, reaction time, and accuracy) of older drivers significantly more than younger drivers. While performing divided attention tasks, the accuracy of the older drivers was 66.3 percent and that of the younger drivers was 96.3 percent. Although this study did not find a clear impact of cellular phone use on the driving behavior of younger drivers, their divided-attention task reaction times and accuracy were better under no-call than calling conditions. This study indicates that the use of hands-free cellular phones could significantly affect the safety of driving among the older and present risks, although lesser, for younger drivers.

Linguistic and auditory temporal processing in children with specific language impairment.

PubMed

Fortunato-Tavares, Talita; Rocha, Caroline Nunes; Andrade, Claudia Regina Furquim de; Befi-Lopes, Débora Maria; Schochat, Eliane; Hestvik, Arild; Schwartz, Richard G

2009-01-01

Several studies suggest the association of specific language impairment (SLI) to deficits in auditory processing. It has been evidenced that children with SLI present deficit in brief stimuli discrimination. Such deficit would lead to difficulties in developing phonological abilities necessary to map phonemes and to effectively and automatically code and decode words and sentences. However, the correlation between temporal processing (TP) and specific deficits in language disorders--such as syntactic comprehension abilities--has received little or no attention. To analyze the correlation between: TP (through the Frequency Pattern Test--FPT) and Syntactic Complexity Comprehension (through a Sentence Comprehension Task). Sixteen children with typical language development (8;9 +/- 1;1 years) and seven children with SLI (8;1 +/- 1;2 years) participated on the study. Accuracy of both groups decreased with the increase on syntactic complexity (both p < 0.01). On the between groups comparison, performance difference on the Test of Syntactic Complexity Comprehension (TSCC) was statistically significant (p = 0.02).As expected, children with SLI presented FPT performance outside reference values. On the SLI group, correlations between TSCC and FPT were positive and higher for high syntactic complexity (r = 0.97) than for low syntactic complexity (r = 0.51). Results suggest that FPT is positively correlated to syntactic complexity comprehension abilities.The low performance on FPT could serve as an additional indicator of deficits in complex linguistic processing. Future studies should consider, besides the increase of the sample, longitudinal studies that investigate the effect of frequency pattern auditory training on performance in high syntactic complexity comprehension tasks.

Neuromapping: Inflight Evaluation of Cognition and Adaptability

NASA Technical Reports Server (NTRS)

Kofman, I. S.; De Dios, Y. E.; Lawrence, K.; Schade, A.; Reschke, M. F.; Bloomberg, J. J.; Wood, S. J.; Mulavara, A. P.; Seidle, R. D.

2016-01-01

In consideration of the health and performance of crewmembers during flight and postflight, we are conducting a controlled prospective longitudinal study to investigate the effects of spaceflight on the extent, longevity and neural bases of sensorimotor, cognitive, and neural changes. Previous studies investigating sensorimotor adaptation to the microgravity environment longitudinally inflight have shown reduction in the ability to perform complex dual tasks. In this study we perform a series of tests investigating the longitudinal effects of adaptation to the microgravity environment and how it affects spatial cognition, manual visuo-motor adaption and dual tasking.

Single-trial classification of motor imagery differing in task complexity: a functional near-infrared spectroscopy study

PubMed Central

2011-01-01

Background For brain computer interfaces (BCIs), which may be valuable in neurorehabilitation, brain signals derived from mental activation can be monitored by non-invasive methods, such as functional near-infrared spectroscopy (fNIRS). Single-trial classification is important for this purpose and this was the aim of the presented study. In particular, we aimed to investigate a combined approach: 1) offline single-trial classification of brain signals derived from a novel wireless fNIRS instrument; 2) to use motor imagery (MI) as mental task thereby discriminating between MI signals in response to different tasks complexities, i.e. simple and complex MI tasks. Methods 12 subjects were asked to imagine either a simple finger-tapping task using their right thumb or a complex sequential finger-tapping task using all fingers of their right hand. fNIRS was recorded over secondary motor areas of the contralateral hemisphere. Using Fisher's linear discriminant analysis (FLDA) and cross validation, we selected for each subject a best-performing feature combination consisting of 1) one out of three channel, 2) an analysis time interval ranging from 5-15 s after stimulation onset and 3) up to four Δ[O2Hb] signal features (Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis). Results The results of our single-trial classification showed that using the simple combination set of channels, time intervals and up to four Δ[O2Hb] signal features comprising Δ[O2Hb] mean signal amplitudes, variance, skewness and kurtosis, it was possible to discriminate single-trials of MI tasks differing in complexity, i.e. simple versus complex tasks (inter-task paired t-test p ≤ 0.001), over secondary motor areas with an average classification accuracy of 81%. Conclusions Although the classification accuracies look promising they are nevertheless subject of considerable subject-to-subject variability. In the discussion we address each of these aspects, their limitations for future approaches in single-trial classification and their relevance for neurorehabilitation. PMID:21682906

HERMIES-3: A step toward autonomous mobility, manipulation, and perception

NASA Technical Reports Server (NTRS)

Weisbin, C. R.; Burks, B. L.; Einstein, J. R.; Feezell, R. R.; Manges, W. W.; Thompson, D. H.

1989-01-01

HERMIES-III is an autonomous robot comprised of a seven degree-of-freedom (DOF) manipulator designed for human scale tasks, a laser range finder, a sonar array, an omni-directional wheel-driven chassis, multiple cameras, and a dual computer system containing a 16-node hypercube expandable to 128 nodes. The current experimental program involves performance of human-scale tasks (e.g., valve manipulation, use of tools), integration of a dexterous manipulator and platform motion in geometrically complex environments, and effective use of multiple cooperating robots (HERMIES-IIB and HERMIES-III). The environment in which the robots operate has been designed to include multiple valves, pipes, meters, obstacles on the floor, valves occluded from view, and multiple paths of differing navigation complexity. The ongoing research program supports the development of autonomous capability for HERMIES-IIB and III to perform complex navigation and manipulation under time constraints, while dealing with imprecise sensory information.

Can stereotype threat affect motor performance in the absence of explicit monitoring processes? Evidence using a strength task.

PubMed

Chalabaev, Aïna; Brisswalter, Jeanick; Radel, Rémi; Coombes, Stephen A; Easthope, Christopher; Clément-Guillotin, Corentin

2013-04-01

Previous evidence shows that stereotype threat impairs complex motor skills through increased conscious monitoring of task performance. Given that one-step motor skills may not be susceptible to these processes, we examined whether performance on a simple strength task may be reduced under stereotype threat. Forty females and males performed maximum voluntary contractions under stereotypical or nullified-stereotype conditions. Results showed that the velocity of force production within the first milliseconds of the contraction decreased in females when the negative stereotype was induced, whereas maximal force did not change. In males, the stereotype induction only increased maximal force. These findings suggest that stereotype threat may impair motor skills in the absence of explicit monitoring processes, by influencing the planning stage of force production.

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

PubMed

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

2010-09-01

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

High-performance execution of psychophysical tasks with complex visual stimuli in MATLAB

PubMed Central

Asaad, Wael F.; Santhanam, Navaneethan; McClellan, Steven

2013-01-01

Behavioral, psychological, and physiological experiments often require the ability to present sensory stimuli, monitor and record subjects' responses, interface with a wide range of devices, and precisely control the timing of events within a behavioral task. Here, we describe our recent progress developing an accessible and full-featured software system for controlling such studies using the MATLAB environment. Compared with earlier reports on this software, key new features have been implemented to allow the presentation of more complex visual stimuli, increase temporal precision, and enhance user interaction. These features greatly improve the performance of the system and broaden its applicability to a wider range of possible experiments. This report describes these new features and improvements, current limitations, and quantifies the performance of the system in a real-world experimental setting. PMID:23034363

The effect of marihuana dosage on driver performance

DOT National Transportation Integrated Search

1973-10-01

Performance in a complex driving simulator under 4 marihuan dose levels was examined. Car control and tracking appeared to be uninfluenced, but significant dose-related impairment was found on a visual recognition task simulating the search-and-recog...

Biomechanical Analyses of Stair-climbing while Dual-tasking

PubMed Central

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

2015-01-01

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

Formulation of the age-education index: measuring age and education effects in neuropsychological performance.

PubMed

Lam, Max; Eng, Goi Khia; Rapisarda, Attilio; Subramaniam, Mythily; Kraus, Michael; Keefe, Richard S E; Collinson, Simon Lowes

2013-03-01

The complex interplay of education, age, and cognitive performance on various neuropsychological tests is examined in the current study. New education indices were formulated and further investigated to reveal how age and education variances work together to account for performance on neuropsychological tests. Participants were 830 English-speaking ethnic Chinese. Neuropsychological measures such as Verbal Memory, Digit Sequencing, Token Motor Task, Semantic Fluency, Symbol Coding, Tower of London, Judgment of Line Orientation, and Matrix Reasoning of the Wechsler Adult Intelligence Scale were administered. Education was measured by total years of education and adjusted years of education, as well as ratios of both measures with age. Age and education were associated with neuropsychological performance. Adjusted years of education was associated with fluency and higher cognitive processes, while the ratio between adjusted years of education and age was associated with tasks implicating working memory. Changes in education modalities implicated tasks requiring language abilities. Education and age represent key neurodevelopmental milestones. In light of our findings, special consideration should to be given when neuropsychological assessments are carried out in cross-cultural contexts and in societies where educational systems and pedagogy tend to be complex. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Performance impact of mutation operators of a subpopulation-based genetic algorithm for multi-robot task allocation problems.

PubMed

Liu, Chun; Kroll, Andreas

2016-01-01

Multi-robot task allocation determines the task sequence and distribution for a group of robots in multi-robot systems, which is one of constrained combinatorial optimization problems and more complex in case of cooperative tasks because they introduce additional spatial and temporal constraints. To solve multi-robot task allocation problems with cooperative tasks efficiently, a subpopulation-based genetic algorithm, a crossover-free genetic algorithm employing mutation operators and elitism selection in each subpopulation, is developed in this paper. Moreover, the impact of mutation operators (swap, insertion, inversion, displacement, and their various combinations) is analyzed when solving several industrial plant inspection problems. The experimental results show that: (1) the proposed genetic algorithm can obtain better solutions than the tested binary tournament genetic algorithm with partially mapped crossover; (2) inversion mutation performs better than other tested mutation operators when solving problems without cooperative tasks, and the swap-inversion combination performs better than other tested mutation operators/combinations when solving problems with cooperative tasks. As it is difficult to produce all desired effects with a single mutation operator, using multiple mutation operators (including both inversion and swap) is suggested when solving similar combinatorial optimization problems.

Emotional reactivity and cognitive performance in aversively motivated tasks: a comparison between four rat strains

PubMed Central

2009-01-01

Background Cognitive function might be affected by the subjects' emotional reactivity. We assessed whether behavior in different tests of emotional reactivity is correlated with performance in aversively motivated learning tasks, using four strains of rats generally considered to have a different emotional reactivity. Methods The performance of male Brown Norway, Lewis, Fischer 344, and Wistar Kyoto rats in open field (OF), elevated plus-maze (EPM), and circular light-dark preference box (cLDB) tasks, which are believed to provide measures of emotional reactivity, was evaluated. Spatial working and reference memory were assessed in two aversively motivated learning and memory tasks: the standard and the "repeated acquisition" versions of the Morris water maze escape task, respectively. All rats were also tested in a passive avoidance task. At the end of the study, levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid, and 5-HT turnover in the hippocampus and frontal cortex were determined. Results Strain differences showed a complex pattern across behavioral tests and serotonergic measures. Fischer 344 rats had the poorest performance in both versions of the Morris water escape task, whereas Brown Norway rats performed these tasks very well but the passive avoidance task poorly. Neither correlation analysis nor principal component analysis provided convincing support for the notion that OF, EPM, and cLDB tasks measure the same underlying trait. Conclusions Our findings do not support the hypothesis that the level of emotional reactivity modulates cognitive performance in aversively motivated tasks. Concepts such as "emotional reactivity" and "learning and memory" cannot adequately be tapped with only one behavioral test. Our results emphasize the need for multiple testing. PMID:20003525

Acquisition of dental skills in preclinical technique courses: influence of spatial and manual abilities.

PubMed

Schwibbe, Anja; Kothe, Christian; Hampe, Wolfgang; Konradt, Udo

2016-10-01

Sixty years of research have not added up to a concordant evaluation of the influence of spatial and manual abilities on dental skill acquisition. We used Ackerman's theory of ability determinants of skill acquisition to explain the influence of spatial visualization and manual dexterity on the task performance of dental students in two consecutive preclinical technique courses. We measured spatial and manual abilities of applicants to Hamburg Dental School by means of a multiple choice test on Technical Aptitude and a wire-bending test, respectively. Preclinical dental technique tasks were categorized as consistent-simple and inconsistent-complex based on their contents. For analysis, we used robust regression to circumvent typical limitations in dental studies like small sample size and non-normal residual distributions. We found that manual, but not spatial ability exhibited a moderate influence on the performance in consistent-simple tasks during dental skill acquisition in preclinical dentistry. Both abilities revealed a moderate relation with the performance in inconsistent-complex tasks. These findings support the hypotheses which we had postulated on the basis of Ackerman's work. Therefore, spatial as well as manual ability are required for the acquisition of dental skills in preclinical technique courses. These results support the view that both abilities should be addressed in dental admission procedures in addition to cognitive measures.

The paradoxical effect of long instructions on negative affect and performance: When, for whom and why do they backfire?

NASA Astrophysics Data System (ADS)

Goemaere, Sophie; Beyers, Wim; De Muynck, Gert-Jan; Vansteenkiste, Maarten

2018-06-01

For reasons of bureaucracy and safety, astronauts on the International Space Station are provided with excruciatingly detailed instructions and a lack of decision-making power, even for simple routine tasks. Besides being time-consuming, many astronauts report feelings of demotivation, irritation, and even defiance when confronted with this working method. Anecdotic evidence suggests that this method leads to situations where astronauts read instructions diagonally or avoid checking in with mission support, thereby ironically increasing the risk of error making. There is a need to consider under which circumstances, for whom, and why the provision of long instructions could be detrimental for well-being and performance. An experimental study with LEGO assembly tasks examined whether length of instructions (i.e. short versus long) and task complexity (simple vs. complex) impact negative affect, motivational experiences and performance of participants (N = 113, Mage = 18.75 ± 2.46 years). Long instructions for simple tasks provoked greater feelings of irritation, diminished the perceived value of instructions, and negatively influenced productivity and accuracy. The negative effect of long instructions on irritation was explained via decreased perceived value. Additionally, the effect of length of instructions on irritation differed for participants high versus those low in need for achievement.

The effects of dextroamphetamine on physiological responses and complex performance during sleep loss.

DOT National Transportation Integrated Search

1975-11-01

On two separate occasions, performance of 10 male subjects was measured on the Civil Aeromedical Institute Multiple Task Performance Battery at 4-hour intervals for a period of 24 hours without sleep. Each subject received a capsule at 4-hour interva...

Empirical validation of the triple-code model of numerical processing for complex math operations using functional MRI and group Independent Component Analysis of the mental addition and subtraction of fractions.

PubMed

Schmithorst, Vincent J; Brown, Rhonda Douglas

2004-07-01

The suitability of a previously hypothesized triple-code model of numerical processing, involving analog magnitude, auditory verbal, and visual Arabic codes of representation, was investigated for the complex mathematical task of the mental addition and subtraction of fractions. Functional magnetic resonance imaging (fMRI) data from 15 normal adult subjects were processed using exploratory group Independent Component Analysis (ICA). Separate task-related components were found with activation in bilateral inferior parietal, left perisylvian, and ventral occipitotemporal areas. These results support the hypothesized triple-code model corresponding to the activated regions found in the individual components and indicate that the triple-code model may be a suitable framework for analyzing the neuropsychological bases of the performance of complex mathematical tasks. Copyright 2004 Elsevier Inc.

Multiple paths in complex tasks

NASA Technical Reports Server (NTRS)

Galanter, Eugene; Wiegand, Thomas; Mark, Gloria

1987-01-01

The relationship between utility judgments of subtask paths and the utility of the task as a whole was examined. The convergent validation procedure is based on the assumption that measurements of the same quantity done with different methods should covary. The utility measures of the subtasks were obtained during the performance of an aircraft flight controller navigation task. Analyses helped decide among various models of subtask utility combination, whether the utility ratings of subtask paths predict the whole tasks utility rating, and indirectly, whether judgmental models need to include the equivalent of cognitive noise.

CoreTSAR: Core Task-Size Adapting Runtime

DOE PAGES

Scogland, Thomas R. W.; Feng, Wu-chun; Rountree, Barry; ...

2014-10-27

Heterogeneity continues to increase at all levels of computing, with the rise of accelerators such as GPUs, FPGAs, and other co-processors into everything from desktops to supercomputers. As a consequence, efficiently managing such disparate resources has become increasingly complex. CoreTSAR seeks to reduce this complexity by adaptively worksharing parallel-loop regions across compute resources without requiring any transformation of the code within the loop. Lastly, our results show performance improvements of up to three-fold over a current state-of-the-art heterogeneous task scheduler as well as linear performance scaling from a single GPU to four GPUs for many codes. In addition, CoreTSAR demonstratesmore » a robust ability to adapt to both a variety of workloads and underlying system configurations.« less

Dealing with task interruptions in complex dynamic environments: are two heads better than one?

PubMed

Tremblay, Sébastien; Vachon, François; Lafond, Daniel; Kramer, Chelsea

2012-02-01

This study examined whether teaming up mitigates individual vulnerability to task interruptions in complex dynamic situations. Omnipresent in everyday multitasking environments, task interruptions are usually detrimental to individual performance. This is particularly crucial in dynamic command and control (C2) safety-critical contexts because of the additional challenge imposed by the continually evolving situation during the interruption. We employed a firefighting microworld to simulate C2 in the context of supervisory control to examine the relative impact of interruptions on participants working in a functional dyad versus operators working alone. Although task interruption was detrimental to participants' efficacy of monitoring resources, the negative impact of interruption was reduced for those working in teams. Teaming up translated into faster resumption time, but only if both teammates were interrupted simultaneously. Interrupting only one team member was associated with increased postinterruption communications and slower resumption time. These findings suggest that in complex dynamic situations working in a small team confers more resistance to task interruption than working alone by virtue of the reduced individual workload typical of teamwork. The benefit of collaborative work seems nevertheless mediated by the coordination and communication overhead associated with teamwork. The present findings have practical implications for operators dealing with unexpected events such as task interruptions in C2 environments.

Parallel effects of memory set activation and search on timing and working memory capacity.

PubMed

Schweickert, Richard; Fortin, Claudette; Xi, Zhuangzhuang; Viau-Quesnel, Charles

2014-01-01

Accurately estimating a time interval is required in everyday activities such as driving or cooking. Estimating time is relatively easy, provided a person attends to it. But a brief shift of attention to another task usually interferes with timing. Most processes carried out concurrently with timing interfere with it. Curiously, some do not. Literature on a few processes suggests a general proposition, the Timing and Complex-Span Hypothesis: A process interferes with concurrent timing if and only if process performance is related to complex span. Complex-span is the number of items correctly recalled in order, when each item presented for study is followed by a brief activity. Literature on task switching, visual search, memory search, word generation and mental time travel supports the hypothesis. Previous work found that another process, activation of a memory set in long term memory, is not related to complex-span. If the Timing and Complex-Span Hypothesis is true, activation should not interfere with concurrent timing in dual-task conditions. We tested such activation in single-task memory search task conditions and in dual-task conditions where memory search was executed with concurrent timing. In Experiment 1, activating a memory set increased reaction time, with no significant effect on time production. In Experiment 2, set size and memory set activation were manipulated. Activation and set size had a puzzling interaction for time productions, perhaps due to difficult conditions, leading us to use a related but easier task in Experiment 3. In Experiment 3 increasing set size lengthened time production, but memory activation had no significant effect. Results here and in previous literature on the whole support the Timing and Complex-Span Hypotheses. Results also support a sequential organization of activation and search of memory. This organization predicts activation and set size have additive effects on reaction time and multiplicative effects on percent correct, which was found.

Delayed match-to-sample early performance decrement in monkeys after $sup 60$Co irradiation

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

Bruner, A.; Bogo, V.; Jones, R.K.

1975-07-01

Sixteen monkeys were trained on a delayed match-to-sample task (DMTS) based on shock avoidance and irradiated with single, whole-body exposures of from 396 to 2000 rad $sup 60$Co (midbody dose) at between 163 and 233 rad/min. Pre- to post-irradiation performance changes were assessed using a penalty-scaling measure which differentially weighted incorrect responses, response omissions, and error-omission sequences. Thirteen of the animals displayed early performance decrement, including five incapacitations, at lower doses (less than 1000 rad) than heretofore found effective. This was considered a function of task complexity, measurement sensitivity, and gamma effectiveness. The minimum effective midbody dose for inducing decrementmore » using the DMTS task was estimated to be on the order of 500 rad. The nature of early, transient performance decrement seems to reflect more of an inability to perform than an inability to perform correctly. (auth)« less

Enhancing cognition with video games: a multiple game training study.

PubMed

Oei, Adam C; Patterson, Michael D

2013-01-01

Previous evidence points to a causal link between playing action video games and enhanced cognition and perception. However, benefits of playing other video games are under-investigated. We examined whether playing non-action games also improves cognition. Hence, we compared transfer effects of an action and other non-action types that required different cognitive demands. We instructed 5 groups of non-gamer participants to play one game each on a mobile device (iPhone/iPod Touch) for one hour a day/five days a week over four weeks (20 hours). Games included action, spatial memory, match-3, hidden- object, and an agent-based life simulation. Participants performed four behavioral tasks before and after video game training to assess for transfer effects. Tasks included an attentional blink task, a spatial memory and visual search dual task, a visual filter memory task to assess for multiple object tracking and cognitive control, as well as a complex verbal span task. Action game playing eliminated attentional blink and improved cognitive control and multiple-object tracking. Match-3, spatial memory and hidden object games improved visual search performance while the latter two also improved spatial working memory. Complex verbal span improved after match-3 and action game training. Cognitive improvements were not limited to action game training alone and different games enhanced different aspects of cognition. We conclude that training specific cognitive abilities frequently in a video game improves performance in tasks that share common underlying demands. Overall, these results suggest that many video game-related cognitive improvements may not be due to training of general broad cognitive systems such as executive attentional control, but instead due to frequent utilization of specific cognitive processes during game play. Thus, many video game training related improvements to cognition may be attributed to near-transfer effects.

Is a "Complex" Task Really Complex? Validating the Assumption of Cognitive Task Complexity

ERIC Educational Resources Information Center

Sasayama, Shoko

2016-01-01

In research on task-based learning and teaching, it has traditionally been assumed that differing degrees of cognitive task complexity can be inferred through task design and/or observations of differing qualities in linguistic production elicited by second language (L2) communication tasks. Without validating this assumption, however, it is…

On the complexity of classical guitar playing: functional adaptations to task constraints.

PubMed

Heijink, Hank; Meulenbroek, Ruud G J

2002-12-01

The authors performed a behavioral study of the complexity of left-hand finger movements in classical guitar playing. Six professional guitarists played movement sequences in a fixed tempo. Left-hand finger movements were recorded in 3 dimensions, and the guitar sound was recorded synchronously. Assuming that performers prefer to avoid extreme joint angles when moving, the authors hypothesized 3 complexity factors. The results showed differential effects of the complexity factors on the performance measures and on participants' judgments of complexity. The results demonstrated that keeping the joints in the middle of their range is an important principle in guitar playing, and players exploit the available tolerance in timing and placement of the left-hand fingers to control the acoustic output variability.

Automation bias and verification complexity: a systematic review.

PubMed

Lyell, David; Coiera, Enrico

2017-03-01

While potentially reducing decision errors, decision support systems can introduce new types of errors. Automation bias (AB) happens when users become overreliant on decision support, which reduces vigilance in information seeking and processing. Most research originates from the human factors literature, where the prevailing view is that AB occurs only in multitasking environments. This review seeks to compare the human factors and health care literature, focusing on the apparent association of AB with multitasking and task complexity. EMBASE, Medline, Compendex, Inspec, IEEE Xplore, Scopus, Web of Science, PsycINFO, and Business Source Premiere from 1983 to 2015. Evaluation studies where task execution was assisted by automation and resulted in errors were included. Participants needed to be able to verify automation correctness and perform the task manually. Tasks were identified and grouped. Task and automation type and presence of multitasking were noted. Each task was rated for its verification complexity. Of 890 papers identified, 40 met the inclusion criteria; 6 were in health care. Contrary to the prevailing human factors view, AB was found in single tasks, typically involving diagnosis rather than monitoring, and with high verification complexity. The literature is fragmented, with large discrepancies in how AB is reported. Few studies reported the statistical significance of AB compared to a control condition. AB appears to be associated with the degree of cognitive load experienced in decision tasks, and appears to not be uniquely associated with multitasking. Strategies to minimize AB might focus on cognitive load reduction. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Abrupt strategy change underlies gradual performance change: Bayesian hierarchical models of component and aggregate strategy use.

PubMed

Wynton, Sarah K A; Anglim, Jeromy

2017-10-01

While researchers have often sought to understand the learning curve in terms of multiple component processes, few studies have measured and mathematically modeled these processes on a complex task. In particular, there remains a need to reconcile how abrupt changes in strategy use can co-occur with gradual changes in task completion time. Thus, the current study aimed to assess the degree to which strategy change was abrupt or gradual, and whether strategy aggregation could partially explain gradual performance change. It also aimed to show how Bayesian methods could be used to model the effect of practice on strategy use. To achieve these aims, 162 participants completed 15 blocks of practice on a complex computer-based task-the Wynton-Anglim booking (WAB) task. The task allowed for multiple component strategies (i.e., memory retrieval, information reduction, and insight) that could also be aggregated to a global measure of strategy use. Bayesian hierarchical models were used to compare abrupt and gradual functions of component and aggregate strategy use. Task completion time was well-modeled by a power function, and global strategy use explained substantial variance in performance. Change in component strategy use tended to be abrupt, whereas change in global strategy use was gradual and well-modeled by a power function. Thus, differential timing of component strategy shifts leads to gradual changes in overall strategy efficiency, and this provides one reason for why smooth learning curves can co-occur with abrupt changes in strategy use. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Survey of Intelligent Computer-Aided Training

NASA Technical Reports Server (NTRS)

Loftin, R. B.; Savely, Robert T.

1992-01-01

Intelligent Computer-Aided Training (ICAT) systems integrate artificial intelligence and simulation technologies to deliver training for complex, procedural tasks in a distributed, workstation-based environment. Such systems embody both the knowledge of how to perform a task and how to train someone to perform that task. This paper briefly reviews the antecedents of ICAT systems and describes the approach to their creation developed at the NASA Lyndon B. Johnson Space Center. In addition to the general ICAT architecture, specific ICAT applications that have been or are currently under development are discussed. ICAT systems can offer effective solutions to a number of training problems of interest to the aerospace community.

Attending to the Execution of a Complex Sensorimotor Skill: Expertise Differences, Choking, and Slumps

ERIC Educational Resources Information Center

Gray, Rob

2004-01-01

A simulated baseball batting task was used to compare the relative effects of attending to extraneous information (tone frequency) and attending to skill execution (direction of bat movement) on performance and swing kinematics and to evaluate how these effects differ as a function of expertise. The extraneous dual task degraded batting…

Similar Neural Correlates for Language and Sequential Learning: Evidence from Event-Related Brain Potentials

ERIC Educational Resources Information Center

Christiansen, Morten H.; Conway, Christopher M.; Onnis, Luca

2012-01-01

We used event-related potentials (ERPs) to investigate the time course and distribution of brain activity while adults performed (1) a sequential learning task involving complex structured sequences and (2) a language processing task. The same positive ERP deflection, the P600 effect, typically linked to difficult or ungrammatical syntactic…

A new modified listening span task to enhance validity of working memory assessment for people with and without aphasia.

PubMed

Ivanova, Maria V; Hallowell, Brooke

2014-01-01

Deficits in working memory (WM) are an important subset of cognitive processing deficits associated with aphasia. However, there are serious limitations to research on WM in aphasia largely due to the lack of an established valid measure of WM impairment for this population. The aim of the current study was to address shortcomings of previous measures by developing and empirically evaluating a novel WM task with a sentence-picture matching processing component designed to circumvent confounds inherent in existing measures of WM in aphasia. The novel WM task was presented to persons with (n=27) and without (n=33) aphasia. Results demonstrated high concurrent validity of a novel WM task. Individuals with aphasia performed significantly worse on all conditions of the WM task compared to individuals without aphasia. Different patterns of performance across conditions were observed for the two groups. Additionally, WM capacity was significantly related to auditory comprehension abilities in individuals with mild aphasia but not those with moderate aphasia. Strengths of the novel WM task are that it allows for differential control for length versus complexity of verbal stimuli and indexing of the relative influence of each, minimizes metalinguistic requirements, enables control for complexity of processing components, allows participants to respond with simple gestures or verbally, and eliminates reading requirements. Results support the feasibility and validity of using a novel task to assess WM in individuals with and without aphasia. Readers will be able to (1) discuss the limitations of current working memory measures for individuals with aphasia; (2) describe how task design features of a new working memory task for people with aphasia address shortcomings of existing measures; (3) summarize the evidence supporting the validity of the novel working memory task. Copyright © 2014 Elsevier Inc. All rights reserved.

Benefits of interhemispheric integration on the Japanese Kana script-matching tasks.

PubMed

Yoshizaki, K; Tsuji, Y

2000-02-01

We tested Banich's hypothesis that the benefits of bihemispheric processing were enhanced as task complexity increased, when some procedural shortcomings in the previous studies were overcome by using Japanese Kana script-matching tasks. In Exp. 1, the 20 right-handed subjects were given the Physical-Identity task (Katakana-Katakana scripts matching) and the Name-Identity task (Katakana-Hiragana scripts matching). On both tasks, a pair of Kana scripts was tachistoscopically presented in the left, right, and bilateral visual fields. Distractor stimuli were also presented with target Kana scripts on both tasks to equate the processing load between the hemispheres. Analysis showed that, while a bilateral visual-field advantage was found on the name-identity task, a unilateral visual-field advantage was found on the physical-identity task, suggesting that, as the computational complexity of the encoding stage was enhanced, the benefits of bilateral hemispheric processing increased. In Exp. 2, the 16 right-handed subjects were given the same physical-identity task as in Exp. 1, except Hiragana scripts were used as distractors instead of digits to enhance task difficulty. Analysis showed no differences in performance between the unilateral and bilateral visual fields. Taking into account these results of physical-identity tasks for both Exps. 1 and 2, enhancing task demand in the stage of ignoring distractors made the unilateral visual-field advantage obtained in Exp. 1 disappear in Exp. 2. These results supported Banich's hypothesis.

An Intelligent Man-Machine Interface—Multi-Robot Control Adapted for Task Engagement Based on Single-Trial Detectability of P300

PubMed Central

Kirchner, Elsa A.; Kim, Su K.; Tabie, Marc; Wöhrle, Hendrik; Maurus, Michael; Kirchner, Frank

2016-01-01

Advanced man-machine interfaces (MMIs) are being developed for teleoperating robots at remote and hardly accessible places. Such MMIs make use of a virtual environment and can therefore make the operator immerse him-/herself into the environment of the robot. In this paper, we present our developed MMI for multi-robot control. Our MMI can adapt to changes in task load and task engagement online. Applying our approach of embedded Brain Reading we improve user support and efficiency of interaction. The level of task engagement was inferred from the single-trial detectability of P300-related brain activity that was naturally evoked during interaction. With our approach no secondary task is needed to measure task load. It is based on research results on the single-stimulus paradigm, distribution of brain resources and its effect on the P300 event-related component. It further considers effects of the modulation caused by a delayed reaction time on the P300 component evoked by complex responses to task-relevant messages. We prove our concept using single-trial based machine learning analysis, analysis of averaged event-related potentials and behavioral analysis. As main results we show (1) a significant improvement of runtime needed to perform the interaction tasks compared to a setting in which all subjects could easily perform the tasks. We show that (2) the single-trial detectability of the event-related potential P300 can be used to measure the changes in task load and task engagement during complex interaction while also being sensitive to the level of experience of the operator and (3) can be used to adapt the MMI individually to the different needs of users without increasing total workload. Our online adaptation of the proposed MMI is based on a continuous supervision of the operator's cognitive resources by means of embedded Brain Reading. Operators with different qualifications or capabilities receive only as many tasks as they can perform to avoid mental overload as well as mental underload. PMID:27445742

Never forget a name: white matter connectivity predicts person memory

PubMed Central

Metoki, Athanasia; Alm, Kylie H.; Wang, Yin; Ngo, Chi T.; Olson, Ingrid R.

2018-01-01

Through learning and practice, we can acquire numerous skills, ranging from the simple (whistling) to the complex (memorizing operettas in a foreign language). It has been proposed that complex learning requires a network of brain regions that interact with one another via white matter pathways. One candidate white matter pathway, the uncinate fasciculus (UF), has exhibited mixed results for this hypothesis: some studies have shown UF involvement across a range of memory tasks, while other studies report null results. Here, we tested the hypothesis that the UF supports associative memory processes and that this tract can be parcellated into subtracts that support specific types of memory. Healthy young adults performed behavioral tasks (two face-name learning tasks, one word pair memory task) and underwent a diffusion-weighted imaging scan. Our results revealed that variation in UF microstructure was significantly associated with individual differences in performance on both face-name tasks, as well as the word association memory task. A UF sub-tract, functionally defined by its connectivity between face-selective regions in the anterior temporal lobe and orbitofrontal cortex, selectively predicted face-name learning. In contrast, connectivity between the fusiform face patch and both anterior face patches had no predictive validity. These findings suggest that there is a robust and replicable relationship between the UF and associative learning and memory. Moreover, this large white matter pathway can be subdivided to reveal discrete functional profiles. PMID:28646241

The paradox of intragroup conflict: a meta-analysis.

PubMed

de Wit, Frank R C; Greer, Lindred L; Jehn, Karen A

2012-03-01

Since the meta-analysis by De Dreu and Weingart (2003b) on the effects of intragroup conflict on group outcomes, more than 80 new empirical studies of conflict have been conducted, often investigating more complex, moderated relationships between conflict and group outcomes, as well as new types of intragroup conflict, such as process conflict. To explore the trends in this new body of literature, we conducted a meta-analysis of 116 empirical studies of intragroup conflict (n = 8,880 groups) and its relationship with group outcomes. To address the heterogeneity across the studies included in the meta-analysis, we also investigated a number of moderating variables. Stable negative relationships were found between relationship and process conflict and group outcomes. In contrast to the results of De Dreu and Weingart, we did not find a strong and negative association between task conflict and group performance. Analyses of main effects as well as moderator analyses revealed a more complex picture. Task conflict and group performance were more positively related among studies where the association between task and relationship conflict was relatively weak, in studies conducted among top management teams rather than non-top management teams, and in studies where performance was measured in terms of financial performance or decision quality rather than overall performance.

Single- and dual-task performance during on-the-road driving at a low and moderate dose of alcohol: A comparison between young novice and more experienced drivers.

PubMed

Jongen, Stefan; van der Sluiszen, Nick N J J M; Brown, Dennis; Vuurman, Eric F P M

2018-05-01

Driving experience and alcohol are two factors associated with a higher risk of crash involvement in young novice drivers. Driving a car is a complex task involving multiple tasks leading to dividing attention. The aim of this study was to compare the single and combined effects of a low and moderate dose of alcohol on single- and dual-task performance between young novice and more experienced young drivers during actual driving. Nine healthy novice drivers were compared with 9 more experienced drivers in a three-way, placebo-controlled, cross-over study design. Driving performance was measured in actual traffic, with standard deviation of lateral position as the primary outcome variable. Secondary task performance was measured with an auditory word learning test during driving. Results showed that standard deviation of lateral position increased dose-dependently at a blood alcohol concentration (BAC) of 0.2 and 0.5 g/L in both novice and experienced drivers. Secondary task performance was impaired in both groups at a BAC of 0.5 g/L. Furthermore, it was found that driving performance in novice drivers was already impaired at a BAC of 0.2 g/L during dual-task performance. The findings suggest that young inexperienced drivers are especially vulnerable to increased mental load while under the influence of alcohol. © 2018 The Authors Human Psychopharmacology: Clinical and Experimental Published by John Wiley & Sons Ltd.

Intrinsic noise and deviations from criticality in Boolean gene-regulatory networks

NASA Astrophysics Data System (ADS)

Villegas, Pablo; Ruiz-Franco, José; Hidalgo, Jorge; Muñoz, Miguel A.

2016-10-01

Gene regulatory networks can be successfully modeled as Boolean networks. A much discussed hypothesis says that such model networks reproduce empirical findings the best if they are tuned to operate at criticality, i.e. at the borderline between their ordered and disordered phases. Critical networks have been argued to lead to a number of functional advantages such as maximal dynamical range, maximal sensitivity to environmental changes, as well as to an excellent tradeoff between stability and flexibility. Here, we study the effect of noise within the context of Boolean networks trained to learn complex tasks under supervision. We verify that quasi-critical networks are the ones learning in the fastest possible way -even for asynchronous updating rules- and that the larger the task complexity the smaller the distance to criticality. On the other hand, when additional sources of intrinsic noise in the network states and/or in its wiring pattern are introduced, the optimally performing networks become clearly subcritical. These results suggest that in order to compensate for inherent stochasticity, regulatory and other type of biological networks might become subcritical rather than being critical, all the most if the task to be performed has limited complexity.

Differential recall of derived and inflected word forms in working memory: examining the role of morphological information in simple and complex working memory tasks

PubMed Central

Service, Elisabet; Maury, Sini

2015-01-01

Working memory (WM) has been described as an interface between cognition and action, or a system for access to a limited amount of information needed in complex cognition. Access to morphological information is needed for comprehending and producing sentences. The present study probed WM for morphologically complex word forms in Finnish, a morphologically rich language. We studied monomorphemic (boy), inflected (boy+’s), and derived (boy+hood) words in three tasks. Simple span, immediate serial recall of words, in Experiment 1, is assumed to mainly rely on information in the focus of attention. Sentence span, a dual task combining sentence reading with recall of the last word (Experiment 2) or of a word not included in the sentence (Experiment 3) is assumed to involve establishment of a search set in long-term memory for fast activation into the focus of attention. Recall was best for monomorphemic and worst for inflected word forms with performance on derived words in between. However, there was an interaction between word type and experiment, suggesting that complex span is more sensitive to morphological complexity in derivations than simple span. This was explored in a within-subjects Experiment 4 combining all three tasks. An interaction between morphological complexity and task was replicated. Both inflected and derived forms increased load in WM. In simple span, recall of inflectional forms resulted in form errors. Complex span tasks were more sensitive to morphological load in derived words, possibly resulting from interference from morphological neighbors in the mental lexicon. The results are best understood as involving competition among inflectional forms when binding words from input into an output structure, and competition from morphological neighbors in secondary memory during cumulative retrieval-encoding cycles. Models of verbal recall need to be able to represent morphological as well as phonological and semantic information. PMID:25642181

Conceptualizing and Assessing Higher-Order Thinking in Reading

ERIC Educational Resources Information Center

Afflerbach, Peter; Cho, Byeong-Young; Kim, Jong-Yun

2015-01-01

Students engage in higher-order thinking as they read complex texts and perform complex reading-related tasks. However, the most consequential assessments, high-stakes tests, are currently limited in providing information about students' higher-order thinking. In this article, we describe higher-order thinking in relation to reading. We provide a…

Sentence Complexity and Working Memory Effects in Ambiguity Resolution

ERIC Educational Resources Information Center

Kim, Ji Hyon; Christianson, Kiel

2013-01-01

Two self-paced reading experiments using a paraphrase decision task paradigm were performed to investigate how sentence complexity contributed to the relative clause (RC) attachment preferences of speakers of different working memory capacities (WMCs). Experiment 1 (English) showed working memory effects on relative clause processing in both…

A Nonword Repetition Task to Assess Bilingual Children's Phonology

ERIC Educational Resources Information Center

dos Santos, Christophe; Ferré, Sandrine

2018-01-01

Children with specific language impairment (SLI) are particularly sensitive to phonological complexity in their language. Their performance drops when there are specific phonological structures or when complexity increases. A nonword repetition (NWR) test, which aims to assess the phonology of bilingual speakers with and without SLI, should…