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Sample records for performing complex tasks

  1. Performance in complex motor tasks deteriorates in hyperthermic humans

    DEFF Research Database (Denmark)

    Piil, Jacob Feder; Lundbye-Jensen, Jesper; Trangmar, Steven J

    2017-01-01

    -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 (bothP 1.3% (P math tasks...... 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...

  2. Task complexity and task, goal, and reward interdependence in group performance management : A prescriptive model

    NARCIS (Netherlands)

    van Vijfeijken, H.; Kleingeld, A.; van Tuijl, H.; Algera, J.A.; Thierry, Hk.

    2002-01-01

    A prescriptive model on how to design effective combinations of goal setting and contingent rewards for group performance management is presented. The model incorporates the constructs task complexity, task interdependence, goal interdependence, and reward interdependence and specifies optimal fit

  3. Task complexity and task, goal, and reward interdependence in group performance : a prescriptive model

    NARCIS (Netherlands)

    Vijfeijken, van H.T.G.A.; Kleingeld, P.A.M.; Tuijl, van H.F.J.M.; Algera, J.A.; Thierry, H.

    2002-01-01

    A prescriptive model on how to design effective combinations of goal setting and contingent rewards for group performance management is presented. The model incorporates the constructs task complexity, task interdependence, goal interdependence, and reward interdependence and specifies optimal fit

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

    Science.gov (United States)

    Kormos, Judit; Trebits, Anna

    2012-01-01

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

  5. Circadian Effects on Simple Components of Complex Task Performance

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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…

  7. Effects of Task Performance and Task Complexity on the Validity of Computational Models of Attention

    NARCIS (Netherlands)

    Koning, L. de; Maanen, P.P. van; Dongen, K. van

    2008-01-01

    Computational models of attention can be used as a component of decision support systems. For accurate support, a computational model of attention has to be valid and robust. The effects of task performance and task complexity on the validity of three different computational models of attention were

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

    Science.gov (United States)

    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 cognitive load (F(2.3,58.5)  = 57.7, p 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.

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

    Science.gov (United States)

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

    2013-03-01

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

  10. Estimating the operator's performance time of emergency procedural tasks based on a task complexity measure

    International Nuclear Information System (INIS)

    Jung, Won Dae; Park, Jink Yun

    2012-01-01

    It is important to understand the amount of time required to execute an emergency procedural task in a high-stress situation for managing human performance under emergencies in a nuclear power plant. However, the time to execute an emergency procedural task is highly dependent upon expert judgment due to the lack of actual data. This paper proposes an analytical method to estimate the operator's performance time (OPT) of a procedural task, which is based on a measure of the task complexity (TACOM). The proposed method for estimating an OPT is an equation that uses the TACOM as a variable, and the OPT of a procedural task can be calculated if its relevant TACOM score is available. The validity of the proposed equation is demonstrated by comparing the estimated OPTs with the observed OPTs for emergency procedural tasks in a steam generator tube rupture scenario.

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

    Science.gov (United States)

    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…

  12. Effects of task complexity on rhythmic reproduction performance in adults.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  15. The Effects of Differential Goal Weights on the Performance of a Complex Financial Task.

    Science.gov (United States)

    Edmister, Robert O.; Locke, Edwin A.

    1987-01-01

    Determined whether people could obtain outcomes on a complex task that would be in line with differential goal weights corresponding to different aspects of the task. Bank lending officers were run through lender-simulation exercises. Five performance goals were weighted. Demonstrated effectiveness of goal setting with complex tasks, using group…

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

    Science.gov (United States)

    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…

  17. Measuring working memory in aphasia: Comparing performance on complex span and N-back tasks

    Directory of Open Access Journals (Sweden)

    Maria Ivanova

    2014-04-01

    No significant correlations were observed between performance on complex span task and N-back tasks.Furthermore, performance on the modified listening span was related to performance on the comprehension subtest of the QASA, while no relationship was found for 2-back and 0-back tasks.Our results mirror studies in healthy controls that demonstrated no relationship between performance on the two tasks(Jaeggi et al., 2010; Kane et al., 2007. Thus although N-back tasks seem similar to traditional complex span measures and may also index abilities related to cognitive processing, the evidence to date does not warrant their direct association with the construct of WM. Implications for future investigation of cognitive deficits in aphasia will be discussed.

  18. The effects of physical threat on team processes during complex task performance

    NARCIS (Netherlands)

    Kamphuis, W.; Gaillard, A.W.K.; Vogelaar, A.L.W.

    2011-01-01

    Teams have become the norm for operating in dangerous and complex situations. To investigate how physical threat affects team performance, 27 threeperson teams engaged in a complex planning and problem-solving task, either under physical threat or under normal conditions. Threat consisted of the

  19. Does complexity matter? Meta-analysis of learner performance in artificial grammar tasks.

    Science.gov (United States)

    Schiff, Rachel; Katan, Pesia

    2014-01-01

    Complexity has been shown to affect performance on artificial grammar learning (AGL) tasks (categorization of test items as grammatical/ungrammatical according to the implicitly trained grammar rules). However, previously published AGL experiments did not utilize consistent measures to investigate the comprehensive effect of grammar complexity on task performance. The present study focused on computerizing Bollt and Jones's (2000) technique of calculating topological entropy (TE), a quantitative measure of AGL charts' complexity, with the aim of examining associations between grammar systems' TE and learners' AGL task performance. We surveyed the literature and identified 56 previous AGL experiments based on 10 different grammars that met the sampling criteria. Using the automated matrix-lift-action method, we assigned a TE value for each of these 10 previously used AGL systems and examined its correlation with learners' task performance. The meta-regression analysis showed a significant correlation, demonstrating that the complexity effect transcended the different settings and conditions in which the categorization task was performed. The results reinforced the importance of using this new automated tool to uniformly measure grammar systems' complexity when experimenting with and evaluating the findings of AGL studies.

  20. The Effect of Performance-Contingent Incentives when Task Complexity is Manipulated through Instruction

    Directory of Open Access Journals (Sweden)

    Monte Wynder

    2010-12-01

    Full Text Available When, and how, performance-contingent incentives improve performance is an important question fororganisations. Empirical results have been mixed – performance-contingent incentives sometimes increaseperformance, sometimes decrease performance, and sometimes have no effect. Theorists have called forfurther research to identify the effect of various moderating variables, including knowledge and taskcomplexity. This study responds by considering the role of instruction in providing the necessary knowledgeto reduce task complexity. The results suggest that a performance-contingent penalty can be a particularlyeffective means of directing effort for a simple task. For a complex task, performance can be improvedthrough instruction. The type of instruction is important – with rule-based instruction effectively directingeffort – however principle-based instruction is necessary to facilitate problem investigation and problemsolving.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  3. The effect of two complexity factors on the performance of emergency tasks-An experimental verification

    International Nuclear Information System (INIS)

    Park, Jinkyun; Jung, Wondea; Jung, Kwangtae

    2008-01-01

    It is well known that the use of procedures is very important in securing the safety of process systems, since good procedures effectively guide human operators by providing 'what should be done' and 'how to do it', especially under stressful conditions. At the same time, it has been emphasized that the use of complicated procedures could drastically impair operators' performance. This means that a systematic approach that can properly evaluate the complexity of procedures is indispensable for minimizing the side effects of complicated procedures. For this reason, Park et al. have developed a task complexity measure called TACOM that can be used to quantify the complexity of tasks stipulated in emergency operating procedures (EOPs) of nuclear power plants (NPPs). The TACOM measure consists of five sub-measures that can cover five important factors making the performance of emergency tasks complicated. However, a verification activity for two kinds of complexity factors-the level of abstraction hierarchy (AH) and engineering decision (ED)-seems to be insufficient. In this study, therefore, an experiment is conducted by using a low-fidelity simulator in order to clarify the appropriateness of these complexity factors. As a result, it seems that subjects' performance data are affected by the level of AH as well as ED. Therefore it is anticipate that both the level of AH and ED will play an important role in evaluating the complexity of EOPs

  4. Cognitive function predicts listening effort performance during complex tasks in normally aging adults

    Directory of Open Access Journals (Sweden)

    Jennine Harvey

    2017-01-01

    Full Text Available Purpose: This study examines whether cognitive function, as measured by the subtests of the Woodcock–Johnson III (WCJ-III assessment, predicts listening-effort performance during dual tasks across the adults of varying ages. Materials and Methods: Participants were divided into two groups. Group 1 consisted of 14 listeners (number of females = 11 who were 41–61 years old [mean = 53.18; standard deviation (SD = 5.97]. Group 2 consisted of 15 listeners (number of females = 9 who were 63–81 years old (mean = 72.07; SD = 5.11. Participants were administered the WCJ-III Memory for Words, Auditory Working Memory, Visual Matching, and Decision Speed subtests. All participants were tested in each of the following three dual-task experimental conditions, which were varying in complexity: (1 auditory word recognition + visual processing, (2 auditory working memory (word + visual processing, and (3 auditory working memory (sentence + visual processing in noise. Results: A repeated measures analysis of variance revealed that task complexity significantly affected the performance measures of auditory accuracy, visual accuracy, and processing speed. Linear regression revealed that the cognitive subtests of the WCJ-III test significantly predicted performance across dependent variable measures. Conclusion: Listening effort is significantly affected by task complexity, regardless of age. Performance on the WCJ-III test may predict listening effort in adults and may assist speech-language pathologist (SLPs to understand challenges faced by participants when subjected to noise.

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

    Science.gov (United States)

    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…

  6. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    , is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...

  7. High-performance execution of psychophysical tasks with complex visual stimuli in MATLAB

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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…

  9. The effects of overtime work and task complexity on the performance of nuclear plant operators: A proposed methodology

    International Nuclear Information System (INIS)

    Banks, W.W.; Potash, L.

    1985-01-01

    This document presents a very general methodology for determining the effect of overtime work and task complexity on operator performance in response to simulated out-of-limit nuclear plant conditions. The independent variables consist of three levels of overtime work and three levels of task complexity. Multiple dependent performance measures are proposed for use and discussion. Overtime work is operationally defined in terms of the number of hours worked by nuclear plant operators beyond the traditional 8 hours per shift. Task complexity is operationalized in terms of the number of operator tasks required to remedy a given plant anomalous condition and bring the plant back to a ''within limits'' or ''normal'' steady-state condition. The proposed methodology would employ a 2 factor repeated measures design along with the analysis of variance (linear) model

  10. Decision paths in complex tasks

    Science.gov (United States)

    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.

  11. The effect of task complexity and task conditions on foreign language development and performance: three empirical studies

    NARCIS (Netherlands)

    Sercu, L.; de Wachter, L.; Peters, E.; Kuiken, F.; Vedder, I.

    2006-01-01

    It has been argued that tasks constitute a valid alternative unit to sequence the language learning process, as opposed to linguistically defined syllabuses. Implementing this claim presupposes that it is possible to access the cognitive and linguistic demands of tasks, so that they can be sequenced

  12. Three propositions on why characteristics of performance management systems converge across policy areas with different levels of task complexity

    DEFF Research Database (Denmark)

    Bjørnholt, Bente; Lindholst, Andrej Christian; Agger Nielsen, Jeppe

    2014-01-01

    of task complexity amidst a lack of formal and overarching, government-wide policies. We advance our propositions from a case study comparing the characteristics of performance management systems across social services (eldercare) and technical services (park services) in Denmark. Contrary to expectations......This article investigates the differences and similarities between performance management systems across public services. We offer three propositions as to why the characteristics of performance management systems may still converge across policy areas in the public sector with different levels...... for divergence due to differences in task complexity, the characteristics of performance management systems in the two policy areas are observed to converge. On the basis of a case study, we propose that convergence has occurred due to 1) similarities in policy-specific reforms, 2) institutional pressures, and 3...

  13. The cognitive complexity of concurrent cognitive-motor tasks reveals age-related deficits in motor performance

    DEFF Research Database (Denmark)

    Oliveira, Anderson Souza; Reiche, Mikkel Staall; Vinescu, Cristina Ioana

    2018-01-01

    Aging reduces cognitive functions, and such impairments have implications in mental and motor performance. Cognitive function has been recently linked to the risk of falls in older adults. Physical activities have been used to attenuate the declines in cognitive functions and reduce fall incidence......, but little is known whether a physically active lifestyle can maintain physical performance under cognitively demanding conditions. The aim of this study was to verify whether physically active older adults present similar performance deficits during upper limb response time and precision stepping walking...... tasks when compared to younger adults. Both upper limb and walking tasks involved simple and complex cognitive demands through decision-making. For both tasks, decision-making was assessed by including a distracting factor to the execution. The results showed that older adults were substantially slower...

  14. Board Task Performance

    DEFF Research Database (Denmark)

    Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina

    2012-01-01

    identify three board processes as micro-level determinants of board effectiveness. Specifically, we focus on effort norms, cognitive conflicts and the use of knowledge and skills as determinants of board control and advisory task performance. Further, we consider how two different institutional settings....... The findings show that: (i) Board processes have a larger potential than demographic variables to explain board task performance; (ii) board task performance differs significantly between boards operating in different contexts; and (iii) national context moderates the relationships between board processes...... and board task performance....

  15. Predictive performance models and multiple task performance

    Science.gov (United States)

    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.

  16. Using information systems while performing complex tasks: An example from architectural design

    NARCIS (Netherlands)

    de Vries, Erica; de Jong, Anthonius J.M.

    1997-01-01

    Nowadays, information systems, such as hypertexts, allow a variety of ways in which to structure information. Information systems are also used for an increasing number of purposes. In our study we examined two different purposes for using information systems in the context of a real task:

  17. A neuroergonomic quasi-experiment: Predictors of situation awareness and display usability while performing complex tasks

    Science.gov (United States)

    Harbour, Steven D.; Christensen, James C.

    2015-05-01

    Situation awareness (SA) is the ability and capacity to perceive information and act on it acceptably. Head Up Display (HUD) versus Head Down Display (HDD) manipulation induced variation in task difficulty. HUD and HDD cockpit displays or display designs promoted or impaired SA. The quantitative research presented in this paper examines basic neurocognitive factors in order to identify their specific contributions to the formation of SA, while studying display usability and the effects on SA. Visual attentiveness (Va), perceptiveness (Vp), and spatial working memory (Vswm) were assessed as predictors of SA under varying task difficulty. The study participants were 19 tactical airlift pilots, selected from the Ohio Air National Guard. Neurocognitive tests were administered to the participants prior to flight. In-flight SA was objectively and subjectively assessed for 24 flights. At the completion of this field experiment, the data were analyzed and the tests were statistically significant for the three predictor visual abilities Vp, Va, and Vswm as task difficulty was varied, F(3,11) = 8.125, p = .008. In addition, multiple regression analyses revealed that the visual abilities together predicted a majority of the variance in SA, R2 = 0.753, p = .008. As validated and verified by ECG and EEG data, the HUD yielded a full ability and capacity to anticipate and accommodate trends were as the HDD yielded a saturated ability to anticipate and accommodate trends. Post-hoc tests revealed a Cohen's f2 = 3.05 yielding statistical power to be 0.98. This work results in a significant contribution to the field by providing an improved understanding of SA and path to safer travel for society worldwide. PA 88ABW-2015-1282.

  18. The Role of Awareness for Complex Planning Task Performance: A Microgaming Study

    Science.gov (United States)

    Lukosch, Heide; Groen, Daan; Kurapati, Shalini; Klemke, Roland; Verbraeck, Alexander

    2016-01-01

    This study introduces the concept of microgames to support situated learning in order to foster situational awareness (SA) of planners in seaport container terminals. In today's complex working environments, it is often difficult to develop the required level of understanding of a given situation, described as situational awareness. A container…

  19. Autonomous Task Primitives for Complex Manipulation Operations

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this research effort is to enable robots to autonomously perform the complex manipulation tasks that are necessary to maintain a spacecraft. Robots, like...

  20. Authentic Performance of Complex Problem-Solving Tasks with an EPSS.

    Science.gov (United States)

    Leighton, Chet; McCabe, Cynthia

    Just-In-Time Learning (JIT Learning) is a semester-long graduate course that teaches corporate trainers and instructional designers how to design performance improvement interventions. This course is part of a Master's program in Instructional Technology at San Francisco State University. The course has been offered three times and has been…

  1. Can motto-goals outperform learning and performance goals? Influence of goal setting on performance and affect in a complex problem solving task

    Directory of Open Access Journals (Sweden)

    Miriam S. Rohe

    2016-09-01

    Full Text Available In this paper, we bring together research on complex problem solving with that on motivational psychology about goal setting. Complex problems require motivational effort because of their inherent difficulties. Goal Setting Theory has shown with simple tasks that high, specific performance goals lead to better performance outcome than do-your-best goals. However, in complex tasks, learning goals have proven more effective than performance goals. Based on the Zurich Resource Model (Storch & Krause, 2014, so-called motto-goals (e.g., "I breathe happiness" should activate a person’s resources through positive affect. It was found that motto-goals are effective with unpleasant duties. Therefore, we tested the hypothesis that motto-goals outperform learning and performance goals in the case of complex problems. A total of N = 123 subjects participated in the experiment. In dependence of their goal condition, subjects developed a personal motto, learning, or performance goal. This goal was adapted for the computer-simulated complex scenario Tailorshop, where subjects worked as managers in a small fictional company. Other than expected, there was no main effect of goal condition for the management performance. As hypothesized, motto goals led to higher positive and lower negative affect than the other two goal types. Even though positive affect decreased and negative affect increased in all three groups during Tailorshop completion, participants with motto goals reported the lowest rates of negative affect over time. Exploratory analyses investigated the role of affect in complex problem solving via mediational analyses and the influence of goal type on perceived goal attainment.

  2. Acute social stress before the planning phase improves memory performance in a complex real life-related prospective memory task.

    Science.gov (United States)

    Glienke, Katharina; Piefke, Martina

    2016-09-01

    Successful execution of intentions, but also the failure to recall are common phenomena in everyday life. The planning, retention, and realization of intentions are often framed as the scientific concept of prospective memory. The current study aimed to examine the influence of acute stress on key dimensions of complex "real life" prospective memory. To this end, we applied a prospective memory task that involved the planning, retention, and performance of intentions during a fictional holiday week. Forty healthy males participated in the study. Half of the subjects were stressed with the Socially Evaluated Cold Pressor Test (SECPT) before the planning of intentions, and the other half of the participants underwent a control procedure at the same time. Salivary cortisol was used to measure the effectiveness of the SECPT stress induction. Stressed participants did not differ from controls in planning accuracy. However, when we compared stressed participants with controls during prospective memory retrieval, we found statistically significant differences in PM across the performance phase. Participants treated with the SECPT procedure before the planning phase showed improved prospective memory retrieval over time, while performance of controls declined. Particularly, there was a significant difference between the stress and control group for the last two days of the holiday week. Interestingly, control participants showed significantly better performance for early than later learned items, which could be an indicator of a primacy effect. This differential effect of stress on performance was also found in time- and event-dependent prospective memory. Our results demonstrate for the first time, that acute stress induced before the planning phase may improve prospective memory over the time course of the performance phase in time- and event-dependent prospective memory. Our data thus indicate that prospective memory can be enhanced by acute stress. Copyright © 2016

  3. The task complexity experiment 2003/2004

    International Nuclear Information System (INIS)

    Laumann, Karin; Braarud, Per Oeivind; Svengren, Haakan

    2005-08-01

    The purpose of this experiment was to explore how additional tasks added to base case scenarios affected the operators' performance of the main tasks. These additional tasks were in different scenario variants intended to cause high time pressure, high information load, and high masking. The experiment was run in Halden Man-Machine Laboratory's BWR simulator. Seven crews participated, each for one week. There were three operators in each crew. Five main types of scenarios and 20 scenario variants were run. The data from the experiment were analysed by completion time for important actions and by in-depth qualitative analyses of the crews' communications. The results showed that high time pressure decreased some of the crews' performance in the scenarios. When a crew had problems in solving a task for which the time pressure was high, they had even more problems in solving other important tasks. High information load did not affect the operators' performance much and in general the crews were very good at selecting the most important tasks in the scenarios. The scenarios that included both high time pressure and high information load resulted in more reduced performance for the crews compared to the scenarios that only included high time pressure. The total amount of tasks to do and information load to attend to seemed to affect the crews' performance. To solve the scenarios with high time pressure well, it was important to have good communication and good allocation of tasks within the crew. Furthermore, the results showed that scenarios with an added complex, masked task created problems for some crews when solving a relatively simple main task. Overall, the results confirmed that complicating, but secondary tasks, that are not normally taken into account when modelling the primary tasks in a PRA scenario can adversely affect the performance of the main tasks modelled in the PRA scenario. (Author)

  4. Subjective task complexity in the control room

    International Nuclear Information System (INIS)

    Braarud, Per Oeivind

    2000-05-01

    Understanding of what makes a control room situation difficult to handle is important when studying operator performance, both with respect to prediction as well as improvement of the human performance. Previous exploratory work on complexity showed a potential for prediction and explanation of operator performance. This report investigates in further detail the theoretical background and the structure of operator rated task complexity. The report complements the previous work on complexity to make a basis for development of operator performance analysis tools. The first part of the report outlines an approach for studying the complexity of the control room crew's work. The approach draws upon man-machine research as well as problem solving research. The approach identifies five complexity-shaping components: 'task work characteristics', 'teamwork characteristics', 'individual skill', 'teamwork skill', and 'interface and support systems'. The crew's work complexity is related to concepts of human performance quality and human error. The second part of the report is a post-hoc exploratory analysis of four empirical HRP studies, where operators' conception of the complexity of control room work is assessed by questionnaires. The analysis deals with the structure of complexity questionnaire ratings, and the relationship between complexity ratings and human performance measures. The main findings from the analysis of structure was the identification of three task work factors which were named Masking, Information load and Temporal demand, and in addition the identification of one interface factor which was named Navigation. Post-hoc analysis suggests that operator's subjective complexity, which was assessed by questionnaires, is related to workload, task and system performance, and operator's self-rated performance. (Author). 28 refs., 47 tabs

  5. Effects of long-term practice and task complexity on brain activities when performing abacus-based mental calculations: a PET study

    International Nuclear Information System (INIS)

    Wu, Tung-Hsin; Chen, Chia-Lin; Huang, Yung-Hui; Liu, Ren-Shyan; Hsieh, Jen-Chuen; Lee, Jason J.S.

    2009-01-01

    The aim of this study was to examine the neural bases for the exceptional mental calculation ability possessed by Chinese abacus experts through PET imaging. We compared the different regional cerebral blood flow (rCBF) patterns using 15 O-water PET in 10 abacus experts and 12 non-experts while they were performing each of the following three tasks: covert reading, simple addition, and complex contiguous addition. All data collected were analyzed using SPM2 and MNI templates. For non-experts during the tasks of simple addition, the observed activation of brain regions were associated with coordination of language (inferior frontal network) and visuospatial processing (left parietal/frontal network). Similar activation patterns but with a larger visuospatial processing involvement were observed during complex contiguous addition tasks, suggesting the recruitment of more visuospatial memory for solving the complex problems. For abacus experts, however, the brain activation patterns showed slight differences when they were performing simple and complex addition tasks, both of which involve visuospatial processing (bilateral parietal/frontal network). These findings supported the notion that the experts were completing all the calculation process on a virtual mental abacus and relying on this same computational strategy in both simple and complex tasks, which required almost no increasing brain workload for solving the latter. In conclusion, after intensive training and practice, the neural pathways in an abacus expert have been connected more effectively for performing the number encoding and retrieval that are required in abacus tasks, resulting in exceptional mental computational ability. (orig.)

  6. 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.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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…

  8. Is a "Complex" Task Really Complex? Validating the Assumption of Cognitive Task Complexity

    Science.gov (United States)

    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…

  9. Work-based identity and work engagement as potential antecedents of task performance and turnover intention: Unravelling a complex relationship

    Directory of Open Access Journals (Sweden)

    F. Chris Bothma

    2012-09-01

    Research purpose: The main purpose of the study was to investigate whether work-based identity and work engagement differed (in combination with personal alienation, helping behaviour and burnout as potential antecedents (amongst numerous others of task performance and turnover intention. Research design: A census-based sampling approach amongst 23 134 employees in the employment of an ICT company yielded a sample of 2429 usable questionnaires. Scales used in the study were the Maslach Burnout Inventory (MBI-HSS-20, Utrecht Work Engagement Scale (UWES, Work-based Identity, Personal Alienation, Helping Behaviour, Turnover Intention and Task Performance Scales. Main findings: The findings indicate that work-based identity and work engagement give similar appearing results as potential predictors of turnover intention and task performance. Practical/managerial implications: Reducing withdrawal behaviours and enhancing work performance are everyday challenges for organisations. Interventions focused on enhancing work-based identity and work engagement in the work environment should have a meaningful impact when these behaviours need to be addressed. Contribution/value-add: Work-based identity as a multidimensional construct has the potential, with further refinement, to become a valuable construct that can play a leading role in future work engagement research.

  10. Work-based identity and work engagement as potential antecedents of task performance and turnover intention: Unravelling a complex relationship

    Directory of Open Access Journals (Sweden)

    F. Chris Bothma

    2012-01-01

    Full Text Available Orientation: Work-based identity, used as a reference to the self, is the answer to the question ’Who am I at work?’ Work-related identities, derived from different social foci through identity formation processes, have as behavioural guides a significant influence on employee behaviour, which, in turn has an impact on work outcomes. Engagement, presented in different conceptualisations, is viewed by practitioners and academic researchers as an important antecedent of employee behaviour.Research purpose: The main purpose of the study was to investigate whether work-based identity and work engagement differed (in combination with personal alienation, helping behaviour and burnout as potential antecedents (amongst numerous others of task performance and turnover intention.Research design: A census-based sampling approach amongst 23 134 employees in the employment of an ICT company yielded a sample of 2429 usable questionnaires. Scales used in the study were the Maslach Burnout Inventory (MBI-HSS-20, Utrecht Work Engagement Scale (UWES, Work-based Identity, Personal Alienation, Helping Behaviour, Turnover Intention and Task Performance Scales.Main findings: The findings indicate that work-based identity and work engagement give similar appearing results as potential predictors of turnover intention and task performance. Practical/managerial implications: Reducing withdrawal behaviours and enhancing work performance are everyday challenges for organisations. Interventions focused on enhancing work-based identity and work engagement in the work environment should have a meaningful impact when these behaviours need to be addressed.Contribution/value-add: Work-based identity as a multidimensional construct has the potential, with further refinement, to become a valuable construct that can play a leading role in future work engagement research.

  11. Performing Task Integration

    DEFF Research Database (Denmark)

    Elkjaer, Bente; Nickelsen, Niels Christian Mossfeldt

    by shared goals and knowledge as well as mutual respect and frequent, timely, accurate and problem-solving ways of communication with the purpose of dealing with the tasks at hand in an integrated way. We introduce and discuss relational coordination theory through a case-study within public healthcare....... Here cross-professional coordination of work was done by scheduled communication twice a day. When we proposed a way for further integration of tasks through an all-inclusive team organization, we were met with resistance. We use the study to discuss whether relational coordination theory is able to do...... away with differences regarding task definitions and working conditions as well as professional knowledge hierarchies and responsibilities for parts and wholes....

  12. Phonological similarity effect in complex span task.

    Science.gov (United States)

    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.

  13. Second Workshop on Supporting Complex Search Tasks

    NARCIS (Netherlands)

    Belkin, Nicholas J.; Bogers, Toine; Kamps, Jaap; Kelly, Diane; Koolen, Marijn; Yilmaz, Emine

    2017-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks, is

  14. Computer-Related Task Performance

    DEFF Research Database (Denmark)

    Longstreet, Phil; Xiao, Xiao; Sarker, Saonee

    2016-01-01

    The existing information system (IS) literature has acknowledged computer self-efficacy (CSE) as an important factor contributing to enhancements in computer-related task performance. However, the empirical results of CSE on performance have not always been consistent, and increasing an individual......'s CSE is often a cumbersome process. Thus, we introduce the theoretical concept of self-prophecy (SP) and examine how this social influence strategy can be used to improve computer-related task performance. Two experiments are conducted to examine the influence of SP on task performance. Results show...... that SP and CSE interact to influence performance. Implications are then discussed in terms of organizations’ ability to increase performance....

  15. Toward a Learning Science for Complex Crowdsourcing Tasks

    Science.gov (United States)

    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…

  16. Mentalization of complex emotions in borderline personality disorder: The impact of parenting and exposure to trauma on the performance in a novel cartoon-based task.

    Science.gov (United States)

    Brüne, Martin; Walden, Sarah; Edel, Marc-Andreas; Dimaggio, Giancarlo

    2016-01-01

    Borderline personality disorder (BPD) is characterized by a range of interpersonal difficulties, which are, in part, related to adverse experiences during childhood. Unresponsive parenting and traumatization may cause functional impairment of mentalization, i.e. the ability to reflect upon own and others' mental states. However, the relationship of poor parenting, trauma and mentalization in BPD has not exhaustively been studied. Thirty patients diagnosed with BPD and 30 matched control subjects were asked to sequence a novel cartoon-based mentalization task involving complex emotions such as jealousy, shame, guilt etc. In addition, they were required to reason about cognitive and affective mental states of the cartoon characters. The quality of parental care was assessed using a self-report measure for recalled parental rearing style, and childhood trauma was measured in retrospect using the Childhood Trauma Questionnaire. Patients with BPD performed more poorly in all aspects of the cartoon task. Mentalizing skills, particularly relating to affective mental states, were uniquely associated with the quality of recalled parental care and childhood trauma. Together, the quality of parental care and the experience of childhood trauma negatively impact on mentalization in BPD, even in an experimental "offline" task. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Lessons Learned from Crowdsourcing Complex Engineering Tasks.

    Science.gov (United States)

    Staffelbach, Matthew; Sempolinski, Peter; Kijewski-Correa, Tracy; Thain, Douglas; Wei, Daniel; Kareem, Ahsan; Madey, Gregory

    2015-01-01

    Crowdsourcing is the practice of obtaining needed ideas, services, or content by requesting contributions from a large group of people. Amazon Mechanical Turk is a web marketplace for crowdsourcing microtasks, such as answering surveys and image tagging. We explored the limits of crowdsourcing by using Mechanical Turk for a more complicated task: analysis and creation of wind simulations. Our investigation examined the feasibility of using crowdsourcing for complex, highly technical tasks. This was done to determine if the benefits of crowdsourcing could be harnessed to accurately and effectively contribute to solving complex real world engineering problems. Of course, untrained crowds cannot be used as a mere substitute for trained expertise. Rather, we sought to understand how crowd workers can be used as a large pool of labor for a preliminary analysis of complex data. We compared the skill of the anonymous crowd workers from Amazon Mechanical Turk with that of civil engineering graduate students, making a first pass at analyzing wind simulation data. For the first phase, we posted analysis questions to Amazon crowd workers and to two groups of civil engineering graduate students. A second phase of our experiment instructed crowd workers and students to create simulations on our Virtual Wind Tunnel website to solve a more complex task. With a sufficiently comprehensive tutorial and compensation similar to typical crowd-sourcing wages, we were able to enlist crowd workers to effectively complete longer, more complex tasks with competence comparable to that of graduate students with more comprehensive, expert-level knowledge. Furthermore, more complex tasks require increased communication with the workers. As tasks become more complex, the employment relationship begins to become more akin to outsourcing than crowdsourcing. Through this investigation, we were able to stretch and explore the limits of crowdsourcing as a tool for solving complex problems.

  18. Error Sonification of a Complex Motor Task

    Directory of Open Access Journals (Sweden)

    Riener Robert

    2011-12-01

    Full Text Available Visual information is mainly used to master complex motor tasks. Thus, additional information providing augmented feedback should be displayed in other modalities than vision, e.g. hearing. The present work evaluated the potential of error sonification to enhance learning of a rowing-type motor task. In contrast to a control group receiving self-controlled terminal feedback, the experimental group could not significantly reduce spatial errors. Thus, motor learning was not enhanced by error sonification, although during the training the participant could benefit from it. It seems that the motor task was too slow, resulting in immediate corrections of the movement rather than in an internal representation of the general characteristics of the motor task. Therefore, further studies should elaborate the impact of error sonification when general characteristics of the motor tasks are already known.

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

    Science.gov (United States)

    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.

  20. Performance Enhancements Under Dual-task Conditions

    Science.gov (United States)

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

    1984-01-01

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

  1. Effects of Task Complexity, Task Conditions, and Task Difficulty on the Grammatical Accuracy of EFL Learners in Written Discourse

    Directory of Open Access Journals (Sweden)

    Saeideh Ahangari

    2012-11-01

    Full Text Available Different methods of language teaching have tried to help EFL learners to develop good language skills based on their various perspectives. Research findings have underscored the effect of using task types in promoting language skills in terms of accuracy in written discourse. Therefore, this study set out to investigate whether there is an evidence of correct use of simple past tense (Accuracy based on Task Complexity (Task type :Here-and now & There-and-then,Task Conditions (Gender: Male & Female, and Task Difficulty (Proficiency: Lower-intermediate & Intermediate. Sixty Iranian English learners in a language institute participated in the study and were assigned to four groups of lower-intermediate male, lower-intermediate female, intermediate male and intermediate female. Initial homogeneity of the groups was verified using two general proficiency tests; KET for lower-intermediate and PET for intermediate. All groups in here-and-now task type were asked to write a story using simple past based on a picture strip while for there-and-then task type the participants were supposed to write about their last birthday. The results from paired samples t-test, independent samples t-test and two-way ANOVA analysis of the written data revealed significant differences in performing task types, at different proficiency levels and interaction between them. The findings have significant pedagogical implications for EFL learners to understand the relationship among Task Complexity,Task Conditions, Task Difficulty and L2 written production leading to various degrees of Accuracy.

  2. Postural adjustments are modulated by manual task complexity

    Directory of Open Access Journals (Sweden)

    Luis Augusto Teixeira

    2009-09-01

    Full Text Available Daily life activities of humans are characterized by dual tasks, in which a manual task is performed concomitantly with a postural task. Based on the assumption that both manual and postural tasks require attentional resources, no consensus exists as to how the central nervous system modulates postural adjustments in dual tasks. The aim of the present study was to analyze the effect of a manual task requiring attentional resources on shoulder and ankle adjustments as a function of the direction and predictability of postural perturbation. The participants (n=6 were evaluated during the performance of a simple and a complex manual task, while the base of support was moved backward or forward. Latency of activation of the tibialis anterior and gastroc-nemius muscles and angular acceleration of the shoulder were analyzed. The results showed that execution of the complex manual task delayed postural adjustment. Moreover, this delay occurred differently depending on the direction of postural perturbation. The delay in postural adjustment occurred proximally in the case of anterior displacement of the platform, and distally in the case of posterior displacement. Postural adjustments were more affected by the attentional task than by the predictability of platform displacement. These results are consistent with the concept of an integrated control between manual actions and the maintenance of static posture.

  3. Self-Controlled Feedback for a Complex Motor Task

    Directory of Open Access Journals (Sweden)

    Wolf Peter

    2011-12-01

    Full Text Available Self-controlled augmented feedback enhances learning of simple motor tasks. Thereby, learners tend to request feedback after trials that were rated as good by themselves. Feedback after good trials promotes positive reinforcement, which enhances motor learning. The goal of this study was to investigate when naïve learners request terminal visual feedback in a complex motor task, as conclusions drawn on simple tasks can hardly be transferred to complex tasks. Indeed, seven of nine learners stated to have intended to request feedback predominantly after good trials, but in contrast to their intention, kinematic analysis showed that feedback was rather requested randomly (23% after good, 44% after intermediate, 33% after bad trials. Moreover, requesting feedback after good trials did not correlate with learning success. It seems that self-estimation of performance in complex tasks is challenging. As a consequence, learners might have focused on certain movement aspects rather than on the overall movement. Further studies should assess the current focus of the learner in detail to gain more insight in self-estimation capabilities during complex motor task learning.

  4. Pre-task music improves swimming performance.

    Science.gov (United States)

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

    2015-12-01

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

  5. Biobehavioral Insights into Adaptive Behavior in Complex and Dynamic Operational Settings: Lessons learned from the Soldier Performance and Effective, Adaptable Response Task

    Directory of Open Access Journals (Sweden)

    Amy J. Haufler

    2018-02-01

    Full Text Available The purpose of this study was to explore the biobehavioral correlates of adaptive behavior in the context of a standardized laboratory-based mission-relevant challenge [the Soldier Performance and Effective, Adaptable Response (SPEAR task]. Participants were 26 healthy male volunteers (M = 34.85 years, SD = 4.12 with active military duty and leadership experience within the last 5 years (i.e., multiple leadership positions, operational deployments in combat, interactions with civilians and partner nation forces on the battlefield, experience making decisions under fire. The SPEAR task simultaneously engages perception, cognition, and action aspects of human performance demands similar to those encountered in the operational setting. Participants must engage with military-relevant text, visual, and auditory stimuli, interpret new information, and retain the commander’s intent in working memory to create a new plan of action for mission success. Time-domain measures of heart period and respiratory sinus arrhythmia (RSA were quantified, and saliva was sampled [later assayed for cortisol and alpha-amylase (sAA] before-, during-, and post-SPEAR. Results revealed a predictable pattern of withdraw and recovery of the cardiac vagal tone during repeated presentation of battlefield challenges. Recovery of vagal inhibition following executive function challenge was strongly linked to better task-related performance. Rate of RSA recovery was also associated with better recall of the commander’s intent. Decreasing magnitude in the skin conductance response prior to the task was positively associated with better overall task-related performance. Lower levels of RSA were observed in participants who reported higher rates of combat deployments, and reduced RSA flexibility was associated with higher rates of casualty exposure. Greater RSA flexibility during SPEAR was associated with greater self-reported resilience. There was no consistent

  6. The Use of Conjunctions in Cognitively Simple versus Complex Oral L2 Tasks

    Science.gov (United States)

    Michel, Marije C.

    2013-01-01

    The present study explores the use of conjunctions in simple versus complex argumentative tasks performed by second language (L2) learners as a specific measure for the amount of reasoning involved in task performance. The Cognition Hypothesis (Robinson, 2005) states that an increase in cognitive task complexity promotes improvements in L2…

  7. The Curvilinear Relationship between State Neuroticism and Momentary Task Performance

    Science.gov (United States)

    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

  8. Examining the locus of age effects on complex span tasks.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

  11. Pleasantness of Creative Tasks and Creative Performance

    Science.gov (United States)

    Zenasni, Franck; Lubart, Todd

    2011-01-01

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

  12. Workshift and Antihistamine Effects on Task Performance

    National Research Council Canada - National Science Library

    Gilliland, Kirby

    1997-01-01

    Sixteen male subjects, well trained on a battery of cognitive performance assessment tasks, participated in a study to Investigate the effects on human operator performance of work shift (Day Shift vs. Mid shift...

  13. Complex performance in construction

    DEFF Research Database (Denmark)

    Bougrain, Frédéric; Forman, Marianne; Gottlieb, Stefan Christoffer

    To fulfil the expectations of demanding clients, new project-delivery mechanisms have been developed. Approaches focusing on performance-based building or new procurement processers such as new forms of private-public partnerships are considered as solutions improving the overall performance...... to the end users. This report summarises the results from work undertaken in the international collaborative project “Procuring and Operating Complex Products and Systems in Construction” (POCOPSC). POCOPSC was carried out in the period 2010-2014. The project was executed in collaboration between CSTB...

  14. Prefrontal Activity and Connectivity with the Basal Ganglia during Performance of Complex Cognitive Tasks Is Associated with Apathy in Healthy Subjects.

    Science.gov (United States)

    Fazio, Leonardo; Logroscino, Giancarlo; Taurisano, Paolo; Amico, Graziella; Quarto, Tiziana; Antonucci, Linda Antonella; Barulli, Maria Rosaria; Mancini, Marina; Gelao, Barbara; Ferranti, Laura; Popolizio, Teresa; Bertolino, Alessandro; Blasi, Giuseppe

    2016-01-01

    Convergent evidence indicates that apathy affects cognitive behavior in different neurological and psychiatric conditions. Studies of clinical populations have also suggested the primary involvement of the prefrontal cortex and the basal ganglia in apathy. These brain regions are interconnected at both the structural and functional levels and are deeply involved in cognitive processes, such as working memory and attention. However, it is unclear how apathy modulates brain processing during cognition and whether such a modulation occurs in healthy young subjects. To address this issue, we investigated the link between apathy and prefrontal and basal ganglia function in healthy young individuals. We hypothesized that apathy may be related to sub-optimal activity and connectivity in these brain regions. Three hundred eleven healthy subjects completed an apathy assessment using the Starkstein's Apathy Scale and underwent fMRI during working memory and attentional performance tasks. Using an ROI approach, we investigated the association of apathy with activity and connectivity in the DLPFC and the basal ganglia. Apathy scores correlated positively with prefrontal activity and negatively with prefrontal-basal ganglia connectivity during both working memory and attention tasks. Furthermore, prefrontal activity was inversely related to attentional behavior. These results suggest that in healthy young subjects, apathy is a trait associated with inefficient cognitive-related prefrontal activity, i.e., it increases the need for prefrontal resources to process cognitive stimuli. Furthermore, apathy may alter the functional relationship between the prefrontal cortex and the basal ganglia during cognition.

  15. Prefrontal Activity and Connectivity with the Basal Ganglia during Performance of Complex Cognitive Tasks Is Associated with Apathy in Healthy Subjects.

    Directory of Open Access Journals (Sweden)

    Leonardo Fazio

    Full Text Available Convergent evidence indicates that apathy affects cognitive behavior in different neurological and psychiatric conditions. Studies of clinical populations have also suggested the primary involvement of the prefrontal cortex and the basal ganglia in apathy. These brain regions are interconnected at both the structural and functional levels and are deeply involved in cognitive processes, such as working memory and attention. However, it is unclear how apathy modulates brain processing during cognition and whether such a modulation occurs in healthy young subjects. To address this issue, we investigated the link between apathy and prefrontal and basal ganglia function in healthy young individuals. We hypothesized that apathy may be related to sub-optimal activity and connectivity in these brain regions.Three hundred eleven healthy subjects completed an apathy assessment using the Starkstein's Apathy Scale and underwent fMRI during working memory and attentional performance tasks. Using an ROI approach, we investigated the association of apathy with activity and connectivity in the DLPFC and the basal ganglia.Apathy scores correlated positively with prefrontal activity and negatively with prefrontal-basal ganglia connectivity during both working memory and attention tasks. Furthermore, prefrontal activity was inversely related to attentional behavior.These results suggest that in healthy young subjects, apathy is a trait associated with inefficient cognitive-related prefrontal activity, i.e., it increases the need for prefrontal resources to process cognitive stimuli. Furthermore, apathy may alter the functional relationship between the prefrontal cortex and the basal ganglia during cognition.

  16. Procuring complex performance

    DEFF Research Database (Denmark)

    Hartmann, A.; Roehrich, J.; Frederiksen, Lars

    2014-01-01

    the transition process. Design/methodology/approach – A multiple, longitudinal case study method is used to examine the transition towards PCP. The study deploys rich qualitative data sets by combining semi-structured interviews, focus group meetings and organisational reports and documents. Findings...... and relational challenges they need to master when facing higher levels of performance and infrastructural complexity. Originality/value – The study adds to the limited empirical and conceptual understanding on the nature of long-term public-private interactions in PCP. It contributes through a rare focus...

  17. Workplace for analysis of task performance

    NARCIS (Netherlands)

    Bos, J; Mulder, LJM; van Ouwerkerk, RJ; Maarse, FJ; Akkerman, AE; Brand, AN; Mulder, LJM

    2003-01-01

    In current research on mental workload and task performance a large gap exists between laboratory based studies and research projects in real life working practice. Tasks conducted within a laboratory environment often lack a strong resemblance with real life working situations. This paper presents

  18. Training improves laparoscopic tasks performance and decreases operator workload.

    Science.gov (United States)

    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 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 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.

  19. Trait Mindfulness and Cognitive Task Performance

    Directory of Open Access Journals (Sweden)

    Emalee J. W. Quickel

    2014-11-01

    Full Text Available Mindfulness meditation (MM training has been shown to have positive effects on working memory and focused attention tasks. Clarifying the construct of mindfulness is important so that mindfulness can be studied effectively in individual differences and cognition research. The current study tested whether trait mindfulness alone explains any of the variability on task performance. Five commonly used mindfulness scales, as well as six standardized and experimental attention and working memory tasks were administered to 164 participants with no meditation experience. Confirmatory factor analysis found that the common variance denoted by measures of trait mindfulness is unrelated to the common variance among tasks requiring focused attention. These results indicate that mindfulness scales may not be capturing the attentional aspects of mindfulness. Individuals who score high on mindfulness scales do not perform better on focused attention tasks than those who score lower on mindfulness scales. These results have implications for defining and operationalizing mindfulness.

  20. Task performance in astronomical adaptive optics

    Science.gov (United States)

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

    2006-06-01

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

  1. Facilitation of responses by task-irrelevant complex deviant stimuli.

    Science.gov (United States)

    Schomaker, J; Meeter, M

    2014-05-01

    Novel stimuli reliably attract attention, suggesting that novelty may disrupt performance when it is task-irrelevant. However, under certain circumstances novel stimuli can also elicit a general alerting response having beneficial effects on performance. In a series of experiments we investigated whether different aspects of novelty--stimulus novelty, contextual novelty, surprise, deviance, and relative complexity--lead to distraction or facilitation. We used a version of the visual oddball paradigm in which participants responded to an occasional auditory target. Participants responded faster to this auditory target when it occurred during the presentation of novel visual stimuli than of standard stimuli, especially at SOAs of 0 and 200 ms (Experiment 1). Facilitation was absent for both infrequent simple deviants and frequent complex images (Experiment 2). However, repeated complex deviant images did facilitate responses to the auditory target at the 200 ms SOA (Experiment 3). These findings suggest that task-irrelevant deviant visual stimuli can facilitate responses to an unrelated auditory target in a short 0-200 millisecond time-window after presentation. This only occurs when the deviant stimuli are complex relative to standard stimuli. We link our findings to the novelty P3, which is generated under the same circumstances, and to the adaptive gain theory of the locus coeruleus-norepinephrine system (Aston-Jones and Cohen, 2005), which may explain the timing of the effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Estimating functional cognition in older adults using observational assessments of task performance in complex everyday activities: A systematic review and evaluation of measurement properties.

    Science.gov (United States)

    Wesson, Jacqueline; Clemson, Lindy; Brodaty, Henry; Reppermund, Simone

    2016-09-01

    Functional cognition is a relatively new concept in assessment of older adults with mild cognitive impairment or dementia. Instruments need to be reliable and valid, hence we conducted a systematic review of observational assessments of task performance used to estimate functional cognition in this population. Two separate database searches were conducted: firstly to identify instruments; and secondly to identify studies reporting on the psychometric properties of the instruments. Studies were analysed using a published checklist and their quality reviewed according to specific published criteria. Clinical utility was reviewed and the information formulated into a best evidence synthesis. We found 21 instruments and included 58 studies reporting on measurement properties. The majority of studies were rated as being of fair methodological quality and the range of properties investigated was restricted. Most instruments had studies reporting on construct validity (hypothesis testing), none on content validity and there were few studies reporting on reliability. Overall the evidence on psychometric properties is lacking and there is an urgent need for further evaluation of instruments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Performance samples on academic tasks : improving prediction of academic performance

    NARCIS (Netherlands)

    Tanilon, Jenny

    2011-01-01

    This thesis is about the development and validation of a performance-based test, labeled as Performance Samples on academic tasks in Education and Child Studies (PSEd). PSEd is designed to identify students who are most able to perform the academic tasks involved in an Education and Child Studies

  4. Performance assessment task team progress report

    International Nuclear Information System (INIS)

    Wood, D.E.; Curl, R.U.; Armstrong, D.R.; Cook, J.R.; Dolenc, M.R.; Kocher, D.C.; Owens, K.W.; Regnier, E.P.; Roles, G.W.; Seitz, R.R.

    1994-05-01

    The U.S. Department of Energy (DOE) Headquarters EM-35, established a Performance Assessment Task Team (referred to as the Team) to integrate the activities of the sites that are preparing performance assessments (PAs) for disposal of new low-level waste, as required by Chapter III of DOE Order 5820.2A, open-quotes Low-Level Waste Managementclose quotes. The intent of the Team is to achieve a degree of consistency among these PAs as the analyses proceed at the disposal sites. The Team's purpose is to recommend policy and guidance to the DOE on issues that impact the PAs, including release scenarios and parameters, so that the approaches are as consistent as possible across the DOE complex. The Team has identified issues requiring attention and developed discussion papers for those issues. Some issues have been completed, and the recommendations are provided in this document. Other issues are still being discussed, and the status summaries are provided in this document. A major initiative was to establish a subteam to develop a set of test scenarios and parameters for benchmarking codes in use at the various sites. The activities of the Team are reported here through December 1993

  5. Model-Based Approach to the Evaluation of Task Complexity in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Ham, Dong Han

    2007-02-01

    This study developed a model-based method for evaluating task complexity and examined the ways of evaluating the complexity of tasks designed for abnormal situations and daily task situations in NPPs. The main results of this study can be summarised as follows. First, this study developed a conceptual framework for studying complexity factors and a model of complexity factors that classifies complexity factors according to the types of knowledge that human operators use. Second, this study developed a more practical model of task complexity factors and identified twenty-one complexity factors based on the model. The model emphasizes that a task is a system to be designed and its complexity has several dimensions. Third, we developed a method of identifying task complexity factors and evaluating task complexity qualitatively based on the developed model of task complexity factors. This method can be widely used in various task situations. Fourth, this study examined the applicability of TACOM to abnormal situations and daily task situations, such as maintenance and confirmed that it can be reasonably used in those situations. Fifth, we developed application examples to demonstrate the use of the theoretical results of this study. Lastly, this study reinterpreted well-know principles for designing information displays in NPPs in terms of task complexity and suggested a way of evaluating the conceptual design of displays in an analytical way by using the concept of task complexity. All of the results of this study will be used as a basis when evaluating the complexity of tasks designed on procedures or information displays and designing ways of improving human performance in NPPs

  6. Model-based identification and use of task complexity factors of human integrated systems

    International Nuclear Information System (INIS)

    Ham, Dong-Han; Park, Jinkyun; Jung, Wondea

    2012-01-01

    Task complexity is one of the conceptual constructs that are critical to explain and predict human performance in human integrated systems. A basic approach to evaluating the complexity of tasks is to identify task complexity factors and measure them. Although a great deal of task complexity factors have been studied, there is still a lack of conceptual frameworks for identifying and organizing them analytically, which can be generally used irrespective of the types of domains and tasks. This study proposes a model-based approach to identifying and using task complexity factors, which has two facets—the design aspects of a task and complexity dimensions. Three levels of design abstraction, which are functional, behavioral, and structural aspects of a task, characterize the design aspect of a task. The behavioral aspect is further classified into five cognitive processing activity types. The complexity dimensions explain a task complexity from different perspectives, which are size, variety, and order/organization. Twenty-one task complexity factors are identified by the combination of the attributes of each facet. Identification and evaluation of task complexity factors based on this model is believed to give insights for improving the design quality of tasks. This model for complexity factors can also be used as a referential framework for allocating tasks and designing information aids. The proposed approach is applied to procedure-based tasks of nuclear power plants (NPPs) as a case study to demonstrate its use. Last, we compare the proposed approach with other studies and then suggest some future research directions.

  7. Report on the Second Workshop on Supporting Complex Search Tasks

    DEFF Research Database (Denmark)

    Koolen, Marijn; Kamps, Jaap; Bogers, Toine

    2017-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain-specific collections, and both in our professional and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks...

  8. Task complexity modulates pilot electroencephalographic activity during real flights.

    Science.gov (United States)

    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.

  9. Using Performance Task Data to Improve Instruction

    Science.gov (United States)

    Abbott, Amy L.; Wren, Douglas G.

    2016-01-01

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

  10. Strategic predictors of performance in a divided attention task

    Science.gov (United States)

    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

  11. Strategic predictors of performance in a divided attention task.

    Directory of Open Access Journals (Sweden)

    Róbert Adrian Rill

    Full Text Available 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.

  12. Strategic predictors of performance in a divided attention task.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. Basic considerations in predicting error probabilities in human task performance

    International Nuclear Information System (INIS)

    Fleishman, E.A.; Buffardi, L.C.; Allen, J.A.; Gaskins, R.C. III

    1990-04-01

    It is well established that human error plays a major role in the malfunctioning of complex systems. This report takes a broad look at the study of human error and addresses the conceptual, methodological, and measurement issues involved in defining and describing errors in complex systems. In addition, a review of existing sources of human reliability data and approaches to human performance data base development is presented. Alternative task taxonomies, which are promising for establishing the comparability on nuclear and non-nuclear tasks, are also identified. Based on such taxonomic schemes, various data base prototypes for generalizing human error rates across settings are proposed. 60 refs., 3 figs., 7 tabs

  15. Thrive or overload? The effect of task complexity on novices' simulation-based learning.

    Science.gov (United States)

    Haji, Faizal A; Cheung, Jeffrey J H; Woods, Nicole; Regehr, Glenn; de Ribaupierre, Sandrine; Dubrowski, Adam

    2016-09-01

    Fidelity is widely viewed as an important element of simulation instructional design based on its purported relationship with transfer of learning. However, higher levels of fidelity may increase task complexity to a point at which novices' cognitive resources become overloaded. In this experiment, we investigate the effects of variations in task complexity on novices' cognitive load and learning during simulation-based procedural skills training. Thirty-eight medical students were randomly assigned to simulation training on a simple or complex lumbar puncture (LP) task. Participants completed four practice trials on this task (skill acquisition). After 10 days of rest, all participants completed one additional trial on their assigned task (retention) and one trial on a 'very complex' simulation designed to be similar to the complex task (transfer). We assessed LP performance and cognitive load on each trial using multiple measures. In both groups, LP performance improved significantly during skill acquisition (p ≤ 0.047, f = 0.29-0.96) and was maintained at retention. The simple task group demonstrated superior performance compared with the complex task group throughout these phases (p ≤ 0.002, d = 1.13-2.31). Cognitive load declined significantly in the simple task group (p Education.

  16. The Importance of Team Sex Composition in Team-Training Research Employing Complex Psychomotor Tasks.

    Science.gov (United States)

    Jarrett, Steven M; Glaze, Ryan M; Schurig, Ira; Arthur, Winfred

    2017-08-01

    The relationship between team sex composition and team performance on a complex psychomotor task was examined because these types of tasks are commonly used in the lab-based teams literature. Despite well-documented sex-based differences on complex psychomotor tasks, the preponderance of studies-mainly lab based-that use these tasks makes no mention of the sex composition of teams across or within experimental conditions. A sample of 123 four-person teams with varying team sex composition learned and performed a complex psychomotor task, Steal Beasts Pro PE. Each team completed a 5-hr protocol whereby they conducted several performance missions. The results indicated significant large mean differences such that teams with larger proportions of males had higher performance scores. These findings demonstrate the potential effect of team sex composition on the validity of studies that use complex psychomotor tasks to explore and investigate team performance-related phenomena when (a) team sex composition is not a focal variable of interest and (b) it is not accounted for or controlled. Given the proclivity of complex psychomotor action-based tasks used in lab-based team studies, it is important to understand and control for the impact of team sex composition on team performance. When team sex composition is not controlled for, either methodologically or statistically, it may affect the validity of the results in teams studies using these types of tasks.

  17. Frontal subregions mediating Elevator Counting task performance.

    Science.gov (United States)

    MacPherson, Sarah E; Turner, Martha S; Bozzali, Marco; Cipolotti, Lisa; Shallice, Tim

    2010-10-01

    Deficits in sustained attention may lead to action slips in everyday life as irrelevant action sequences are inappropriately triggered internally or by the environment. While deficits in sustained attention have been associated with damage to the frontal lobes of the brain, little is known about the role of the frontal lobes in the Elevator Counting subtest of the Test of Everyday Attention. In the current study, 55 frontal patients subdivided into medial, orbital and lateral subgroups, 18 patients with posterior lesions and 82 healthy controls performed the Elevator Counting task. The results revealed that patients with medial and left lateral prefrontal lesions were significantly impaired on the task compared to healthy controls. Research suggests that patients with medial lesions are susceptible to competition from task irrelevant schema; whereas the left lateral group in the current study may fail to keep track of the tones already presented. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Pointing Device Performance in Steering Tasks.

    Science.gov (United States)

    Senanayake, Ransalu; Goonetilleke, Ravindra S

    2016-06-01

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

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

    Science.gov (United States)

    Macnamara, Brooke N; Frank, David J

    2018-05-01

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

  20. Complexity factors and prediction of performance

    International Nuclear Information System (INIS)

    Braarud, Per Oeyvind

    1998-03-01

    Understanding of what makes a control room situation difficult to handle is important when studying operator performance, both with respect to prediction as well as improvement of the human performance. A factor analytic approach identified eight factors from operators' answers to an 39 item questionnaire about complexity of the operator's task in the control room. A Complexity Profiling Questionnaire was developed, based on the factor analytic results from the operators' conception of complexity. The validity of the identified complexity factors was studied by prediction of crew performance and prediction of plant performance from ratings of the complexity of scenarios. The scenarios were rated by both process experts and the operators participating in the scenarios, using the Complexity Profiling Questionnaire. The process experts' complexity ratings predicted both crew performance and plant performance, while the operators' rating predicted plant performance only. The results reported are from initial studies of complexity, and imply a promising potential for further studies of the concept. The approach used in the study as well as the reported results are discussed. A chapter about the structure of the conception of complexity, and a chapter about further research conclude the report. (author)

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

    Science.gov (United States)

    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.

  2. Lexical Complexity of Decision-Making Writing Tasks: Form-focused Guided Strategic Planning

    OpenAIRE

    Mahdavirad, Fatemeh

    2016-01-01

    The present study is an attempt to investigate the effect of form-focused guided strategic planning on lexical complexity of learners’ performance in writing tasks. The twenty intermediate level participants of the study performed an unplanned and then a planned decision-making task. In the planned task condition, the participants were provided with form-focused guided strategic planning which contained detailed instructions about how to plan, by being instructed to focus on form. The guidanc...

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

    Science.gov (United States)

    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...

  4. Promising high monetary rewards for future task performance increases intermediate task performance.

    Directory of Open Access Journals (Sweden)

    Claire M Zedelius

    Full Text Available In everyday life contexts and work settings, monetary rewards are often contingent on future performance. Based on research showing that the anticipation of rewards causes improved task performance through enhanced task preparation, the present study tested the hypothesis that the promise of monetary rewards for future performance would not only increase future performance, but also performance on an unrewarded intermediate task. Participants performed an auditory Simon task in which they responded to two consecutive tones. While participants could earn high vs. low monetary rewards for fast responses to every second tone, their responses to the first tone were not rewarded. Moreover, we compared performance under conditions in which reward information could prompt strategic performance adjustments (i.e., when reward information was presented for a relatively long duration to conditions preventing strategic performance adjustments (i.e., when reward information was presented very briefly. Results showed that high (vs. low rewards sped up both rewarded and intermediate, unrewarded responses, and the effect was independent of the duration of reward presentation. Moreover, long presentation led to a speed-accuracy trade-off for both rewarded and unrewarded tones, whereas short presentation sped up responses to rewarded and unrewarded tones without this trade-off. These results suggest that high rewards for future performance boost intermediate performance due to enhanced task preparation, and they do so regardless whether people respond to rewards in a strategic or non-strategic manner.

  5. Promising high monetary rewards for future task performance increases intermediate task performance.

    Science.gov (United States)

    Zedelius, Claire M; Veling, Harm; Bijleveld, Erik; Aarts, Henk

    2012-01-01

    In everyday life contexts and work settings, monetary rewards are often contingent on future performance. Based on research showing that the anticipation of rewards causes improved task performance through enhanced task preparation, the present study tested the hypothesis that the promise of monetary rewards for future performance would not only increase future performance, but also performance on an unrewarded intermediate task. Participants performed an auditory Simon task in which they responded to two consecutive tones. While participants could earn high vs. low monetary rewards for fast responses to every second tone, their responses to the first tone were not rewarded. Moreover, we compared performance under conditions in which reward information could prompt strategic performance adjustments (i.e., when reward information was presented for a relatively long duration) to conditions preventing strategic performance adjustments (i.e., when reward information was presented very briefly). Results showed that high (vs. low) rewards sped up both rewarded and intermediate, unrewarded responses, and the effect was independent of the duration of reward presentation. Moreover, long presentation led to a speed-accuracy trade-off for both rewarded and unrewarded tones, whereas short presentation sped up responses to rewarded and unrewarded tones without this trade-off. These results suggest that high rewards for future performance boost intermediate performance due to enhanced task preparation, and they do so regardless whether people respond to rewards in a strategic or non-strategic manner.

  6. Manual lateralization in macaques: handedness, target laterality and task complexity.

    Science.gov (United States)

    Regaiolli, Barbara; Spiezio, Caterina; Vallortigara, Giorgio

    2016-01-01

    Non-human primates represent models to understand the evolution of handedness in humans. Despite several researches have been investigating non-human primates handedness, few studies examined the relationship between target position, hand preference and task complexity. This study aimed at investigating macaque handedness in relation to target laterality and tastiness, as well as task complexity. Seven pig-tailed macaques (Macaca nemestrina) were involved in three different "two alternative choice" tests: one low-level task and two high-level tasks (HLTs). During the first and the third tests macaques could select a preferred food and a non-preferred food, whereas by modifying the design of the second test, macaques were presented with no-difference alternative per trial. Furthermore, a simple-reaching test was administered to assess hand preference in a social context. Macaques showed hand preference at individual level both in simple and complex tasks, but not in the simple-reaching test. Moreover, target position seemed to affect hand preference in retrieving an object in the low-level task, but not in the HLT. Additionally, individual hand preference seemed to be affected from the tastiness of the item to be retrieved. The results suggest that both target laterality and individual motivation might influence hand preference of macaques, especially in simple tasks.

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

    Science.gov (United States)

    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…

  8. Task complexity and maximal isometric strength gains through motor learning

    Science.gov (United States)

    McGuire, Jessica; Green, Lara A.; Gabriel, David A.

    2014-01-01

    Abstract This study compared the effects of a simple versus complex contraction pattern on the acquisition, retention, and transfer of maximal isometric strength gains and reductions in force variability. A control group (N = 12) performed simple isometric contractions of the wrist flexors. An experimental group (N = 12) performed complex proprioceptive neuromuscular facilitation (PNF) contractions consisting of maximal isometric wrist extension immediately reversing force direction to wrist flexion within a single trial. Ten contractions were completed on three consecutive days with a retention and transfer test 2‐weeks later. For the retention test, the groups performed their assigned contraction pattern followed by a transfer test that consisted of the other contraction pattern for a cross‐over design. Both groups exhibited comparable increases in strength (20.2%, P < 0.01) and reductions in mean torque variability (26.2%, P < 0.01), which were retained and transferred. There was a decrease in the coactivation ratio (antagonist/agonist muscle activity) for both groups, which was retained and transferred (35.2%, P < 0.01). The experimental group exhibited a linear decrease in variability of the torque‐ and sEMG‐time curves, indicating transfer to the simple contraction pattern (P < 0.01). The control group underwent a decrease in variability of the torque‐ and sEMG‐time curves from the first day of training to retention, but participants returned to baseline levels during the transfer condition (P < 0.01). However, the difference between torque RMS error versus the variability in torque‐ and sEMG‐time curves suggests the demands of the complex task were transferred, but could not be achieved in a reproducible way. PMID:25428951

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

    Science.gov (United States)

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

    2013-01-01

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

  10. Models for Understanding Student Thinking using Data from Complex Computerized Science Tasks

    OpenAIRE

    LaMar, Michelle

    2014-01-01

    The Next Generation Science Standards (NGSS Lead States, 2013) define performance targets which will require assessment tasks that can integrate discipline knowledge and cross-cutting ideas with the practices of science. Complex computerized tasks will likely play a large role in assessing these standards, but many questions remain about how best to make use of such tasks within a psychometric framework (National Research Council, 2014). This dissertation explores the use of a more extensive...

  11. Effect of music tempo on task performance.

    Science.gov (United States)

    Mayfield, C; Moss, S

    1989-12-01

    Two studies were conducted to evaluate the effect of music tempo on task performance. In Study 1, 44 undergraduate business students were asked to be "workers" in a stock market project by collecting closing stock prices and calculating the percentage of change in the price from week to week. Subjects were randomly divided into groups such that they either listened to fast-paced music while they worked, to slow-paced music, or to no music. Analyses of variance and covariance were conducted on both the quantity and quality of the subjects' work, using music listening habits as a covariate. There were no differences in either the quantity or quality of the work produced by the groups. There were some methodological concerns regarding Study 1, so a second study was conducted. The 70 undergraduate business students in Study 2 completed the same task under the same music conditions as in Study 1. Analyses of variance indicated women performed significantly better than men, performance was significantly higher in the rock condition than in the heartbeat condition, and subjects in the rock condition had a significantly higher perceived level of distraction by the music.

  12. Lexical Complexity of Decision-Making Writing Tasks: Form-focused Guided Strategic Planning

    Directory of Open Access Journals (Sweden)

    Fatemeh Mahdavirad

    2016-06-01

    Full Text Available The present study is an attempt to investigate the effect of form-focused guided strategic planning on lexical complexity of learners’ performance in writing tasks. The twenty intermediate level participants of the study performed an unplanned and then a planned decision-making task. In the planned task condition, the participants were provided with form-focused guided strategic planning which contained detailed instructions about how to plan, by being instructed to focus on form. The guidance included an explanation of the necessary structural and lexical patterns employed to express the learners’ views while developing a comparison-and-contrast paragraph in each task. The results of the statistical analysis indicated that the participants produced a written product with a greater lexical complexity in their performance of the task in the form-focused strategic planning condition. The findings emphasize the importance of guided strategic planning as a task condition in syllabus design for task-based language teaching and the necessity of incorporating this task feature for accomplishing lexical complexity in decision-making writing tasks.

  13. A Study on Relationships between Functional Performance and Task Performance Measure through Experiments in NPP MCR

    International Nuclear Information System (INIS)

    Jang, In Seok; Seong, Poong Hyun; Park, Jin Kyun

    2011-01-01

    Further improvements in levels of organization, management, man-machine interfaces, education, training, etc. are required, if high operating reliability of operators in huge and complex plants such as chemical plants and electrical power generating plants is to be maintained. Improvement requires good understanding of operators' behavior, including defining what is good performance for operators, especially in emergency situations. Human performance measures, therefore, are important to enhance performance and to reduce the probability of incidents and accidents in Nuclear Power Plants (NPPs). Operators' performance measures are used for multi-objectives such as control room design, human system interface evaluation, training, procedure and so on. There are two kinds of representative methods to measure operators' performance. These methods are now known as the functional performance measure and task performance measure. Functional performance measures are basically based on the plant process parameters. Functional performance measures indicate how well the operators controlled selected critical parameters. The parameters selected in this paper are derived from the four Critical Safety Functions (CSFs) identified in the emergency operating procedures such as achievement of subcriticality, maintenance of core cooling, maintenance of heat sink and maintenance of containment integrity. Task performance measures are based on the task analysis. Task analysis is to determine the tasks required and how operators are performed. In this paper, task analysis is done with ideal path for an accident completed by experts and Emergency Operation Procedure (EOP). However, most literatures related to operators' performance have been using one of these measures and there is no research to find out the relationships between two measures. In this paper, the relationships between functional performance measure and task performance measure are investigated using experiments. Shortly

  14. Task Complexity Modulates Sleep-Related Offline Learning in Sequential Motor Skills

    Directory of Open Access Journals (Sweden)

    Klaus Blischke

    2017-07-01

    Full Text Available Recently, a number of authors have advocated the introduction of gross motor tasks into research on sleep-related motor offline learning. Such tasks are often designed to be more complex than traditional key-pressing tasks. However, until now, little effort has been undertaken to scrutinize the role of task complexity in any systematic way. Therefore, the effect of task complexity on the consolidation of gross motor sequence memory was examined by our group in a series of three experiments. Criterion tasks always required participants to produce unrestrained arm movement sequences by successively fitting a small peg into target holes on a pegboard. The sequences always followed a certain spatial pattern in the horizontal plane. The targets were visualized prior to each transport movement on a computer screen. The tasks differed with respect to sequence length and structural complexity. In each experiment, half of the participants initially learned the task in the morning and were retested 12 h later following a wake retention interval. The other half of the subjects underwent practice in the evening and was retested 12 h later following a night of sleep. The dependent variables were the error rate and total sequence execution time (inverse to the sequence execution speed. Performance generally improved during acquisition. The error rate was always low and remained stable during retention. The sequence execution time significantly decreased again following sleep but not after waking when the sequence length was long and structural complexity was high. However, sleep-related offline improvements were absent when the sequence length was short or when subjects performed a highly regular movement pattern. It is assumed that the occurrence of sleep-related offline performance improvements in sequential motor tasks is associated with a sufficient amount of motor task complexity.

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

    Science.gov (United States)

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

    2017-01-01

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

  16. Clinical Complexity in Medicine: A Measurement Model of Task and Patient Complexity.

    Science.gov (United States)

    Islam, R; Weir, C; Del Fiol, G

    2016-01-01

    Complexity in medicine needs to be reduced to simple components in a way that is comprehensible to researchers and clinicians. Few studies in the current literature propose a measurement model that addresses both task and patient complexity in medicine. The objective of this paper is to develop an integrated approach to understand and measure clinical complexity by incorporating both task and patient complexity components focusing on the infectious disease domain. The measurement model was adapted and modified for the healthcare domain. Three clinical infectious disease teams were observed, audio-recorded and transcribed. Each team included an infectious diseases expert, one infectious diseases fellow, one physician assistant and one pharmacy resident fellow. The transcripts were parsed and the authors independently coded complexity attributes. This baseline measurement model of clinical complexity was modified in an initial set of coding processes and further validated in a consensus-based iterative process that included several meetings and email discussions by three clinical experts from diverse backgrounds from the Department of Biomedical Informatics at the University of Utah. Inter-rater reliability was calculated using Cohen's kappa. The proposed clinical complexity model consists of two separate components. The first is a clinical task complexity model with 13 clinical complexity-contributing factors and 7 dimensions. The second is the patient complexity model with 11 complexity-contributing factors and 5 dimensions. The measurement model for complexity encompassing both task and patient complexity will be a valuable resource for future researchers and industry to measure and understand complexity in healthcare.

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

    Science.gov (United States)

    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

  18. Association Between Gross-Motor and Executive Function Depends on Age and Motor Task Complexity

    DEFF Research Database (Denmark)

    Spedden, Meaghan E; Malling, Anne Sofie B; Andersen, Ken K

    2017-01-01

    The objective was to examine associations between motor and executive function across the adult lifespan and to investigate the role of motor complexity in these associations. Young, middle-aged and older adults (n = 82; 19-83y) performed two gross-motor tasks with different levels of complexity...... and a Stroop-like computer task. Performance was decreased in older adults. The association between motor and cognitive performance was significant for older adults in the complex motor task (p = 0.03, rs = -0.41), whereas no significant associations were found for young or middle-aged groups, suggesting...... that the link between gross-motor and executive function emerges with age and depends on motor complexity....

  19. Expertise, Task Complexity, and Artificial Intelligence: A Conceptual Framework.

    Science.gov (United States)

    Buckland, Michael K.; Florian, Doris

    1991-01-01

    Examines the relationship between users' expertise, task complexity of information system use, and artificial intelligence to provide the basis for a conceptual framework for considering the role that artificial intelligence might play in information systems. Cognitive and conceptual models are discussed, and cost effectiveness is considered. (27…

  20. Is it health information technology? : Task complexity and work substitution

    NARCIS (Netherlands)

    Medina Palomino, Hector; Rutkowski, Anne; Verhulst, Matthijs

    2015-01-01

    New technology is making it possible to replace professions built on complex knowledge, e.g. medicine. In our exploratory research we examined how Information Technologies might be replacing some of the tasks formerly processed by physician anesthesiologists (MDAs). Data (N=1178) were collected at a

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

    Science.gov (United States)

    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 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.

  2. Dividing attention between tasks : Testing whether explicit payoff functions elicit optimal dual-task performance

    NARCIS (Netherlands)

    Farmer, George D.; Janssen, C.P.|info:eu-repo/dai/nl/412781654; Nguyen, Anh T; Brumby, Duncan P.

    2018-01-01

    We test people's ability to optimize performance across two concurrent tasks. Participants performed a number entry task while controlling a randomly moving cursor with a joystick. Participants received explicit feedback on their performance on these tasks in the form of a single combined score.

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

    Science.gov (United States)

    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.

  4. Shift Work and Cognitive Flexibility: Decomposing Task Performance.

    Science.gov (United States)

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

    2017-04-01

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

  5. Swimming Pool Hygiene: Self-Monitoring, Task Clarification, and Performance Feedback Increase Lifeguard Cleaning Behaviors

    Science.gov (United States)

    Rose, Henry M. S.; Ludwig, Timothy D.

    2009-01-01

    The effects of task clarification, self-monitoring, and performance feedback on cleaning behaviors of 9 lifeguards in 3 performance areas (vacuuming, lobby tidying, and pool deck maintenance) were investigated using an ABA reversal design at a county swim complex. A specific task in each performance area was used as a behavioral control. Following…

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 performance improvement only for the sub-group of participants with lower performance levels as compared to that with sham-tDCS (p 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.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

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

    2017-05-01

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

  10. Task Performance induced Work Load in Nursing

    Directory of Open Access Journals (Sweden)

    Shirazeh Arghami

    2015-12-01

    Full Text Available Background & objective: High workload may lead to increase human errors, compromise quality and safety of care, and reduce the nurses’ quality of working life. The aim of this study is to determine the task-induced workload in nursing. Methods: This is a descriptive analytical study. All of 214 nurses of one of the educational hospital took part in. After obtaining informed consent from participants, data were collected based on NASA-TLX questionnaire and the desired level assumed less than 50%. Analysis of data was performed by descriptive statistics and Anova in SPSS software (version 11. 0 at significant level of 0.05. Results: The results showed that perceived mental pressure for nurses is more than other NASA-TLX subscales (P< .001. Also, the mean perceived workload was more than 50%. However, mean workload score of NASA-TLX showed significant correlation with age (P< .001, work experience (P< .001, shift work (P< .02, and department (P< .001. Conclusion: The results show that effective programs will be required to reduce the work load, and to enhance nurses' performance

  11. Paw Preference Correlates to Task Performance in Dogs

    NARCIS (Netherlands)

    Alphen, A. van; Bosse, T.; Frank, I.; Jonker, C.M.; Koeman, F.; Bara, B.G.; Barsalou, L.; Bucciarelli, M.

    2005-01-01

    A study involving 36 domestic dogs (Canis familiaris) in a simple search task provides evidence of a correlation between paw use and performance. The study was carried out to determine whether or not paw use is related to task performance. Different aspects of task performance were taken into

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

    Science.gov (United States)

    Strobach, Tilo; Schütz, Anja; Schubert, Torsten

    2015-01-01

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

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

    Science.gov (United States)

    Strobach, Tilo; Schütz, Anja; Schubert, Torsten

    2015-01-01

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

  14. The Task Is Not Enough: Processing Approaches to Task-Based Performance

    Science.gov (United States)

    Skehan, Peter; Xiaoyue, Bei; Qian, Li; Wang, Zhan

    2012-01-01

    This article reports on three research studies, all of which concern second language task performance. The first focuses on planning, and compares on-line and strategic planning as well as task repetition. The second study examines the role of familiarity on task performance, and compares this with conventional strategic planning. The third study…

  15. Decentralization of Decision Authority in Complex Task Structures DRUID

    DEFF Research Database (Denmark)

    Dobrajska, Magdalena; Billinger, Stephan; Karim, Samina

    -relevant knowledge, the matching of required knowledge and manager?s expertise, and information processing intensity affect (a) the occurrence of delegation, and (b), if delegation occurs, how far down the organizational hierarchy authority is delegated. We discuss how these findings complement existing theories......We investigate tradeoffs associated with delegating authority over multiple interrelated decisions in a complex task structure. The empirical setting is a business process of a global Fortune 50 firm. The firm decentralized its organization and redefined decision authority across organizational...... hierarchies between 2008 and 2011. We employ regression analysis of micro-level data on the organization design of 761 decision tasks and we investigate the allocation of decision authority at the level of all observable individual decision tasks. Our findings show how the specialization of decision...

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

    Science.gov (United States)

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

    1986-01-01

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

  17. Limitations in dual-task performance

    NARCIS (Netherlands)

    Pannebakker, Merel Mathilde

    2009-01-01

    In this thesis, the effect of information-processing overload on working-memory dependent information processing was examined using dual-task paradigms. The experiments described strengthen the importance of a functional explanation for dual-task limitations. First, it showed evidence for a unified

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

    Directory of Open Access Journals (Sweden)

    Tilo eStrobach

    2015-04-01

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

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

    Science.gov (United States)

    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.

  20. Working memory capacity predicts conflict-task performance.

    Science.gov (United States)

    Gulbinaite, Rasa; Johnson, Addie

    2014-01-01

    The relationship between the ability to maintain task goals and working memory capacity (WMC) is firmly established, but evidence for WMC-related differences in conflict processing is mixed. We investigated whether WMC (measured using two complex-span tasks) mediates differences in adjustments of cognitive control in response to conflict. Participants performed a Simon task in which congruent and incongruent trials were equiprobable, but in which the proportion of congruency repetitions (congruent trials followed by congruent trials or incongruent trials followed by incongruent trials) and thus the need for trial-by-trial adjustments in cognitive control varied by block. The overall Simon effect did not depend on WMC capacity. However, for the low-WMC participants the Simon effect decreased as the proportion of congruency repetitions decreased, whereas for the high- and average-WMC participants it was relatively constant across conditions. Distribution analysis of the Simon effect showed more evidence for the inhibition of stimulus location in the low- than in the high-WMC participants, especially when the proportion of congruency repetitions was low. We hypothesize that low-WMC individuals exhibit more interference from task-irrelevant information due to weaker preparatory control prior to stimulus presentation and, thus, stronger reliance on reactive recruitment of cognitive control.

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

    Science.gov (United States)

    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.

  2. Limitations in dual-task performance

    OpenAIRE

    Pannebakker, Merel Mathilde

    2009-01-01

    In this thesis, the effect of information-processing overload on working-memory dependent information processing was examined using dual-task paradigms. The experiments described strengthen the importance of a functional explanation for dual-task limitations. First, it showed evidence for a unified coding medium (as put forward in the theory of event coding; Hommel, Müsseler, Aschersleben, & Prinz, 2001) in which features, operations and responses are available and can influence each other. A...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Operational testing of a figure of merit for overall task performance

    Science.gov (United States)

    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.

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

    NARCIS (Netherlands)

    Koolen, S.; Vissers, C.T.W.M.; Egger, J.I.M.; Verhoeven, L.T.W.

    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

  10. Successfully carrying out complex learning-tasks through guiding teams' qualitative and quantitative reasoning

    NARCIS (Netherlands)

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

    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

  11. Continuous Performance Tasks: Not Just about Sustaining Attention

    Science.gov (United States)

    Roebuck, Hettie; Freigang, Claudia; Barry, Johanna G.

    2016-01-01

    Purpose: Continuous performance tasks (CPTs) are used to measure individual differences in sustained attention. Many different stimuli have been used as response targets without consideration of their impact on task performance. Here, we compared CPT performance in typically developing adults and children to assess the role of stimulus processing…

  12. Rapid Authoring of Task Knowledge for Training and Performance Support

    National Research Council Canada - National Science Library

    Mohammed, John L; Sorensen, Barbara; Ong, James C; Li, Jian

    2005-01-01

    .... These systems use hierarchical, object-oriented task representations that enable rapid authoring by non-programmers while supporting sophisticated job aiding and student performance evaluation...

  13. Working memory capacity predicts conflict-task performance

    NARCIS (Netherlands)

    Gulbinaite, Rasa; Johnson, Addie

    The relationship between the ability to maintain task goals and working memory capacity (WMC) is firmly established, but evidence for WMC-related differences in conflict processing is mixed. We investigated whether WMC (measured using two complex-span tasks) mediates differences in adjustments of

  14. Appraisal, Coping, Task Performance, and Cardiovascular Responses during the Evaluated Speaking Task.

    Science.gov (United States)

    Baggett, H. Lane; And Others

    1996-01-01

    Appraisal, coping, task performance, and cardiovascular responses were examined among men high and low in speech anxiety who prepared and performed a speech under evaluative conditions. Speech-anxious men saw the task as more threatening. They were more stressed, anxious, distracted, and aware of their emotions, focused on the passage of time, and…

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

    Science.gov (United States)

    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.

  16. Computer task performance by subjects with Duchenne muscular dystrophy.

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  18. Administrative Task Performance by Heads of Senior High Schools ...

    African Journals Online (AJOL)

    This study aimed at examining the administrative task performance of heads of senior high schools (SHS) in Ghana from the organising perspective. The study hypothesized that there is no statistically significant difference in the compliance level of organising as an administrative task performance by heads in the rural and ...

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

    Directory of Open Access Journals (Sweden)

    Daniel eErlacher

    2014-01-01

    Full Text Available 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 (Erlacher & Schredl, 2004; LaBerge, 1985, 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.

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

    Science.gov (United States)

    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.

  1. Do absorption and realistic distraction influence performance of component task surgical procedure?

    OpenAIRE

    Pluyter, J.R.; Buzink, S.N.; Rutkowski, A.F.; Jakimowicz, J.J.

    2009-01-01

    Background. 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. Methods. Twelve medical interns performed a laparoscopic cholecystectomy task with the Xitact LC 3.0 virtual reality simulator under distracting con...

  2. When predictions take control: The effect of task predictions on task switching performance

    Directory of Open Access Journals (Sweden)

    Wout eDuthoo

    2012-08-01

    Full Text Available In this paper, we aimed to investigate the role of self-generated predictions in the flexible control of behaviour. Therefore, we ran a task switching experiment in which participants were asked to try to predict the upcoming task in three conditions varying in switch rate (30%, 50% and 70%. Irrespective of their predictions, the colour of the target indicated which task participants had to perform. In line with previous studies (Mayr, 2006; Monsell & Mizon, 2006, the switch cost was attenuated as the switch rate increased. Importantly, a clear task repetition bias was found in all conditions, yet the task repetition prediction rate dropped from 78% over 66% to 49% with increasing switch probability in the three conditions. Irrespective of condition, the switch cost was strongly reduced in expectation of a task alternation compared to the cost of an unexpected task alternation following repetition predictions. Hence, our data suggest that the reduction in the switch cost with increasing switch probability is caused by a diminished expectancy for the task to repeat. Taken together, this paper highlights the importance of predictions in the flexible control of behaviour, and suggests a crucial role for task repetition expectancy in the context-sensitive adjusting of task switching performance.

  3. [Interest of complex tasks on laparoscopic virtual reality simulator].

    Science.gov (United States)

    Valentin, L; Rabischong, B; Compan, C; Botchorichvili, R; Pereira, B; Avan, P

    2016-03-01

    The purpose of this study was to assess the contribution of complex tasks on virtual reality simulator (VRS) for novice surgeons in laparoscopy learning. Fifty-five medical students were prospectively randomized in two groups (A: basic skills, n=28 and B: basic and complex skills, n=27) and then trained during two sessions on VRS. Evaluations took place before and after each training. These evaluations consisted of the achievement of an intracorporeal suture, recorded on video, with the left then with the right hand. Two independent experts evaluated those gestures blindly. A significant progression in terms of times and technical scores was observed in both groups between the first and the last evaluations (P between 0.001 and 0.04). Students in group B improved slower and longer than those in group A. However, left and right hands results confused did not highlight significant differences between the two groups. At the third session, the first hand to train is significantly faster in group B than in group A (P=0.04). This study found only a late and minimal impact of complex skills to reduce the execution time of intracorporeal suture. It also showed an slower and longer overall progression for those who use them compared to subjects using basic skills only. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. Masticatory muscle activity during deliberately performed oral tasks

    International Nuclear Information System (INIS)

    Farella, M; Palla, S; Erni, S; Gallo, L M; Michelotti, A

    2008-01-01

    The aim of this study was to investigate masticatory muscle activity during deliberately performed functional and non-functional oral tasks. Electromyographic (EMG) surface activity was recorded unilaterally from the masseter, anterior temporalis and suprahyoid muscles in 11 subjects (5 men, 6 women; age = 34.6 ± 10.8 years), who were accurately instructed to perform 30 different oral tasks under computer guidance using task markers. Data were analyzed by descriptive statistics, repeated measurements analysis of variance (ANOVA) and hierarchical cluster analysis. The maximum EMG amplitude of the masseter and anterior temporalis muscles was more often found during hard chewing tasks than during maximum clenching tasks. The relative contribution of masseter and anterior temporalis changed across the tasks examined (F ≥ 5.2; p ≤ 0.001). The masseter muscle was significantly (p ≤ 0.05) more active than the anterior temporalis muscle during tasks involving incisal biting, jaw protrusion, laterotrusion and jaw cupping, the difference being statistically significant (p ≤ 0.05). The anterior temporalis muscle was significantly (p ≤ 0.01) more active than the masseter muscle during tasks performed in intercuspal position, during tooth grinding, and during hard chewing on the working side. Based upon the relative contribution of the masseter, anterior temporalis, and suprahyoid muscles, the investigated oral tasks could be grouped into six separate clusters. The findings provided further insight into muscle- and task-specific EMG patterns during functional and non-functional oral behaviors

  5. Short-term memory and dual task performance

    Science.gov (United States)

    Regan, J. E.

    1982-01-01

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

  6. A Dynamic Intelligent Decision Approach to Dependency Modeling of Project Tasks in Complex Engineering System Optimization

    Directory of Open Access Journals (Sweden)

    Tinggui Chen

    2013-01-01

    Full Text Available Complex engineering system optimization usually involves multiple projects or tasks. On the one hand, dependency modeling among projects or tasks highlights structures in systems and their environments which can help to understand the implications of connectivity on different aspects of system performance and also assist in designing, optimizing, and maintaining complex systems. On the other hand, multiple projects or tasks are either happening at the same time or scheduled into a sequence in order to use common resources. In this paper, we propose a dynamic intelligent decision approach to dependency modeling of project tasks in complex engineering system optimization. The approach takes this decision process as a two-stage decision-making problem. In the first stage, a task clustering approach based on modularization is proposed so as to find out a suitable decomposition scheme for a large-scale project. In the second stage, according to the decomposition result, a discrete artificial bee colony (ABC algorithm inspired by the intelligent foraging behavior of honeybees is developed for the resource constrained multiproject scheduling problem. Finally, a certain case from an engineering design of a chemical processing system is utilized to help to understand the proposed approach.

  7. Relationship between Usefulness Assessments and Perceptions of Work Task Complexity and Search Topic Specificity: An Exploratory Study

    DEFF Research Database (Denmark)

    Ingwersen, Peter; Wang, Peiling

    2012-01-01

    This research investigates the relations between the usefulness assessments of retrieved documents and the perceptions of task complexity and search topic specificity. Twenty-three academic researchers submitted 65 real task-based information search topics. These task topics were searched...... in an integrated document collection consisting of full text research articles in PDFs, abstracts, and bibliographic records (the iSearch Test Collection in Physics). The search results were provided to the researchers who, as task performers, made assessments of usefulness using a four-point sale (highly, fairly......, marginally, or not useful). In addition, they also assessed the perceived task complexity (highly, fairly, and routine/low) and the perceived specificity of the search topic (highly, fairly, and generic/low). It is found that highly specific topics associate with all degrees of task complexity, whereas...

  8. Game elements improve performance in a working memory training task

    OpenAIRE

    Manuel Ninaus; Gonçalo Pereira; René Stefitz; Rui Prada; Ana Paiva; Christa Neuper; Guilherme Wood

    2015-01-01

    The utilization of game elements in a non-game context is currently used in a vast range of different domains. However, research on game elements’ effects in cognitive tasks is still sparse. Thus, in this study we implemented three game elements, namely, progress bar, level indicator, and a thematic setting, in a working memory training task. We evaluated the impact of game elements on user performance and perceived state of flow when compared to a conventional version of the task. Participan...

  9. Teaching Software Developers to Perform UX Tasks

    DEFF Research Database (Denmark)

    Øvad, Tina; Bornoe, Nis; Larsen, Lars Bo

    2015-01-01

    . This is done via an action research study where the developers were provided with material concerning a modified AB usability test, by training them in performing this type of work, and by using their feedback to improve the method and the material. The overall result of the study is positive and it is found...... that by using the developers' feedback in the modification process, the method has truly become applicable within an agile, industrial setting. In combination with a guideline and template this has induced the developers to feel confident in independently performing this type of work....

  10. Training Attentional Control Improves Cognitive and Motor Task Performance.

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

    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…

  12. Software Performs Complex Design Analysis

    Science.gov (United States)

    2008-01-01

    Designers use computational fluid dynamics (CFD) to gain greater understanding of the fluid flow phenomena involved in components being designed. They also use finite element analysis (FEA) as a tool to help gain greater understanding of the structural response of components to loads, stresses and strains, and the prediction of failure modes. Automated CFD and FEA engineering design has centered on shape optimization, which has been hindered by two major problems: 1) inadequate shape parameterization algorithms, and 2) inadequate algorithms for CFD and FEA grid modification. Working with software engineers at Stennis Space Center, a NASA commercial partner, Optimal Solutions Software LLC, was able to utilize its revolutionary, one-of-a-kind arbitrary shape deformation (ASD) capability-a major advancement in solving these two aforementioned problems-to optimize the shapes of complex pipe components that transport highly sensitive fluids. The ASD technology solves the problem of inadequate shape parameterization algorithms by allowing the CFD designers to freely create their own shape parameters, therefore eliminating the restriction of only being able to use the computer-aided design (CAD) parameters. The problem of inadequate algorithms for CFD grid modification is solved by the fact that the new software performs a smooth volumetric deformation. This eliminates the extremely costly process of having to remesh the grid for every shape change desired. The program can perform a design change in a markedly reduced amount of time, a process that would traditionally involve the designer returning to the CAD model to reshape and then remesh the shapes, something that has been known to take hours, days-even weeks or months-depending upon the size of the model.

  13. The impact of task characteristics on the performance of nursing teams

    Directory of Open Access Journals (Sweden)

    Azlyn Ahmad Zawawi, PhD

    2017-07-01

    Conclusions: This study demonstrated that task significance is important to predict team task performance. Task significance reflects meaningfulness and nobility of tasks, thus elevate the desire to perform better in each assigned task.

  14. Performance management in healthcare : performance indicator development, task uncertainty, and types of performance indicators

    NARCIS (Netherlands)

    Geer-Rutten-Rijswijk, van der E.; Tuijl, van H.F.J.M.; Rutte, C.G.

    2009-01-01

    In healthcare, performance indicators are increasingly used to measure and control quality and efficiency of care-providing teams. This article demonstrates that when controllability is emphasized during indicator development, the level of task uncertainty influences the type of resulting

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

    Science.gov (United States)

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

    2016-12-01

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

  16. Effects of the Use of Social Network Sites on Task Performance: Toward a Sustainable Performance in a Distracting Work Environment

    Directory of Open Access Journals (Sweden)

    Jinyoung Min

    2017-12-01

    Full Text Available As the use of social network sites (SNS has become increasingly prevalent, its effect on sustainable performance has received much attention. The existing literature has taken either a positive or negative view of SNS, arguing that it either decreases performance by taking time and effort away from work, or increases performance by providing social benefits for enhancing performance. In contrast, this experimental study, investigates how SNS use can disturb or enhance the performance of different types of tasks differently, thus influencing the sustainability of task performance. Based on distraction-conflict theory, this study distinguishes between simple and complex tasks, examines the role of SNS, and analyzes data including electroencephalography data captured by a brain-computer interface. The results show that task performance can be sustainable such that SNS use positively influences performance when participants are engaged in a simple task and influences performance neither positively nor negatively when participants are engaged in a complex task. The study finds the former result is attributable to the positive effect of the psychological arousal induced by SNS use and the latter result to the negative effect of the psychological arousal offsetting the positive effect of reduced stress resulting from SNS use.

  17. The Effects of Distraction on Cognitive Task Performance during Toddlerhood

    Science.gov (United States)

    Wyss, Nancy M.; Kannass, Kathleen N.; Haden, Catherine A.

    2013-01-01

    We investigated the effects of distraction on attention and task performance during toddlerhood. Thirty toddlers (24- to 26-month-olds) completed different tasks (2 of each: categorization, problem solving, memory, free play) in one of two conditions: No Distraction or Distraction. The results revealed that the distractor had varying effects on…

  18. Early Numerical Competence and Number Line Task Performance in Kindergarteners

    Science.gov (United States)

    Fanari, Rachele; Meloni, Carla; Massidda, Davide

    2017-01-01

    This work aims to evaluate the relationship between early numerical competence in kindergarteners and their numerical representations as measured by the number line task (NLT). Thirty-four 5-year-old children participated in the study. Children's early performance on symbolic and non-symbolic numerical tasks was considered to determine which was a…

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

    Science.gov (United States)

    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 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.

  20. The predictive value of general movement tasks in assessing occupational task performance.

    Science.gov (United States)

    Frost, David M; Beach, Tyson A C; McGill, Stuart M; Callaghan, Jack P

    2015-01-01

    Within the context of evaluating individuals' movement behavior it is generally assumed that the tasks chosen will predict their competency to perform activities relevant to their occupation. This study sought to examine whether a battery of general tasks could be used to predict the movement patterns employed by firefighters to perform select job-specific skills. Fifty-two firefighters performed a battery of general and occupation-specific tasks that simulated the demands of firefighting. Participants' peak lumbar spine and frontal plane knee motion were compared across tasks. During 85% of all comparisons, the magnitude of spine and knee motion was greater during the general movement tasks than observed during the firefighting skills. Certain features of a worker's movement behavior may be exhibited across a range of tasks. Therefore, provided that a movement screen's tasks expose the motions of relevance for the population being tested, general evaluations could offer valuable insight into workers' movement competency or facilitate an opportunity to establish an evidence-informed intervention.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2017-06-01

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

  3. An Initial Investigation of Factors Affecting Multi-Task Performance

    National Research Council Canada - National Science Library

    Branscome, Tersa A; Swoboda, Jennifer C; Fatkin, Linda T

    2007-01-01

    This report presents the results of the first in a series of investigations designed to increase fundamental knowledge and understanding of the factors affecting multi-task performance in a military environment...

  4. How different types of participant payments alter task performance

    Directory of Open Access Journals (Sweden)

    Gary L. Brase

    2009-08-01

    Full Text Available Researchers typically use incentives (such as money or course credit in order to obtain participants who engage in the specific behaviors of interest to the researcher. There is, however, little understanding or agreement on the effects of different types and levels of incentives used. Some results in the domain of statistical reasoning suggest that performance differences --- previously deemed theoretically important --- may actually be due to differences in incentive types across studies. 704 participants completed one of five variants of a statistical reasoning task, for which they received either course credit, flat fee payment, or performance-based payment incentives. Successful task completion was more frequent with performance-based incentives than with either of the other incentive types. Performance on moderately difficult tasks (compared to very easy and very hard tasks was most sensitive to incentives. These results can help resolve existing debates about inconsistent findings, guide more accurate comparisons across studies, and be applied beyond research settings.

  5. Task Performance with List-Mode Data

    Science.gov (United States)

    Caucci, Luca

    This dissertation investigates the application of list-mode data to detection, estimation, and image reconstruction problems, with an emphasis on emission tomography in medical imaging. We begin by introducing a theoretical framework for list-mode data and we use it to define two observers that operate on list-mode data. These observers are applied to the problem of detecting a signal (known in shape and location) buried in a random lumpy background. We then consider maximum-likelihood methods for the estimation of numerical parameters from list-mode data, and we characterize the performance of these estimators via the so-called Fisher information matrix. Reconstruction from PET list-mode data is then considered. In a process we called "double maximum-likelihood" reconstruction, we consider a simple PET imaging system and we use maximum-likelihood methods to first estimate a parameter vector for each pair of gamma-ray photons that is detected by the hardware. The collection of these parameter vectors forms a list, which is then fed to another maximum-likelihood algorithm for volumetric reconstruction over a grid of voxels. Efficient parallel implementation of the algorithms discussed above is then presented. In this work, we take advantage of two low-cost, mass-produced computing platforms that have recently appeared on the market, and we provide some details on implementing our algorithms on these devices. We conclude this dissertation work by elaborating on a possible application of list-mode data to X-ray digital mammography. We argue that today's CMOS detectors and computing platforms have become fast enough to make X-ray digital mammography list-mode data acquisition and processing feasible.

  6. Effect of tDCS on task relevant and irrelevant perceptual learning of complex objects.

    Science.gov (United States)

    Van Meel, Chayenne; Daniels, Nicky; de Beeck, Hans Op; Baeck, Annelies

    2016-01-01

    During perceptual learning the visual representations in the brain are altered, but these changes' causal role has not yet been fully characterized. We used transcranial direct current stimulation (tDCS) to investigate the role of higher visual regions in lateral occipital cortex (LO) in perceptual learning with complex objects. We also investigated whether object learning is dependent on the relevance of the objects for the learning task. Participants were trained in two tasks: object recognition using a backward masking paradigm and an orientation judgment task. During both tasks, an object with a red line on top of it were presented in each trial. The crucial difference between both tasks was the relevance of the object: the object was relevant for the object recognition task, but not for the orientation judgment task. During training, half of the participants received anodal tDCS stimulation targeted at the lateral occipital cortex (LO). Afterwards, participants were tested on how well they recognized the trained objects, the irrelevant objects presented during the orientation judgment task and a set of completely new objects. Participants stimulated with tDCS during training showed larger improvements of performance compared to participants in the sham condition. No learning effect was found for the objects presented during the orientation judgment task. To conclude, this study suggests a causal role of LO in relevant object learning, but given the rather low spatial resolution of tDCS, more research on the specificity of this effect is needed. Further, mere exposure is not sufficient to train object recognition in our paradigm.

  7. Investigating long-range correlation properties in EEG during complex cognitive tasks

    International Nuclear Information System (INIS)

    Karkare, Siddharth; Saha, Goutam; Bhattacharya, Joydeep

    2009-01-01

    Previous work shows the presence of scale invariance and long-range correlations in ongoing and spontaneous activity of large scale brain responses (i.e. EEG), and such scaling behavior can also be modulated by simple sensory stimulus. However, little is known whether such alteration but not destruction in scaling properties also occurs during complex cognitive processing and if neuroplasticity plays any role in mediating such changes. In this study, we addressed these issues by investigating scaling properties of multivariate EEG signals obtained from two broad groups - artists and non-artists - while they performed complex tasks of perception and mental imagery of visual art objects. We found that brain regions showing increased correlation properties from rest were similar for both tasks, suggesting that brain networks responsible for visual perception are reactivated for mental imagery. Further, we observed that the two groups could be differentiated by scaling exponents and an artificial neural network based classifier achieved a classification efficiency of over 80%. These results altogether suggest that specific complex cognitive task demands and task-specific expertise can modify the temporal scale-free dynamics of brain responses.

  8. Investigating long-range correlation properties in EEG during complex cognitive tasks

    Energy Technology Data Exchange (ETDEWEB)

    Karkare, Siddharth [Department of Electrical Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Saha, Goutam [Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Bhattacharya, Joydeep [Department of Psychology, Goldsmiths College, University of London, New Cross, London SE14 6NW (United Kingdom); Commission for Scientific Visualization, Austrian Academy of Sciences, Vienna A1220 (Austria)], E-mail: j.bhattacharya@gold.ac.uk

    2009-11-30

    Previous work shows the presence of scale invariance and long-range correlations in ongoing and spontaneous activity of large scale brain responses (i.e. EEG), and such scaling behavior can also be modulated by simple sensory stimulus. However, little is known whether such alteration but not destruction in scaling properties also occurs during complex cognitive processing and if neuroplasticity plays any role in mediating such changes. In this study, we addressed these issues by investigating scaling properties of multivariate EEG signals obtained from two broad groups - artists and non-artists - while they performed complex tasks of perception and mental imagery of visual art objects. We found that brain regions showing increased correlation properties from rest were similar for both tasks, suggesting that brain networks responsible for visual perception are reactivated for mental imagery. Further, we observed that the two groups could be differentiated by scaling exponents and an artificial neural network based classifier achieved a classification efficiency of over 80%. These results altogether suggest that specific complex cognitive task demands and task-specific expertise can modify the temporal scale-free dynamics of brain responses.

  9. An ergonomics study of computerized emergency operating procedures: Presentation style, task complexity, and training level

    International Nuclear Information System (INIS)

    Xu Song; Song Fei; Li Zhizhong; Zhao Qianyi; Luo Wei; He Xuhong; Salvendy, Gavriel

    2008-01-01

    Emergency operating procedures (EOPs) are widely used in nuclear power plants (NPPs). With the development of information technology, computerized EOPs are taking the place of paper-based ones. Unlike paper-based EOPs, the industrial practice of computerized EOPs is still quite limited. Ergonomics issues of computerized EOPs have not been studied adequately. This study focuses on the effects of EOP presentation style, task complexity, and training level on the performance of the operators in the execution of computerized EOPs. One simulated computerized EOP system was developed to present two EOPs, each with different task complexity levels, by two presentation styles (Style A: one- and two-dimensional flowcharts combination; Style B: two-dimensional flowchart and success logic tree combination). Forty subjects participated in the experiment of EOP execution using the simulated system. Statistical analysis of the experimental results indicates that: (1) complexity, presentation style, and training level all can significantly influence the error rate. High-complexity tasks and lack of sufficient training may lead to a higher error rate. Style B caused a significantly higher error rate than style A did in the skilled phase. So the designers of computerized procedures should take the presentation styles of EOPs into account. (2) Task complexity and training level can significantly influence operation time. No significant difference was found in operation time between the two presentation styles. (3) Training level can also significantly influence the subjective workload of EOPs operations. This implies that adequate training is very important for the performance of computerized EOPs even if emergency responses with computerized EOPs are much more simple and easy than that with paper-based EOPs

  10. An ergonomics study of computerized emergency operating procedures: Presentation style, task complexity, and training level

    Energy Technology Data Exchange (ETDEWEB)

    Xu Song; Song Fei [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China); Li Zhizhong [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China)], E-mail: zzli@tsinghua.edu.cn; Zhao Qianyi; Luo Wei [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China); He Xuhong [Scanpower Risk Management China Inc., Towercrest International Plaza, No. 3 Maizidian West Road, Chaoyang District, Beijing 100016 (China); Salvendy, Gavriel [Department of Industrial Engineering, Tsinghua University, Beijing 100084 (China)

    2008-10-15

    Emergency operating procedures (EOPs) are widely used in nuclear power plants (NPPs). With the development of information technology, computerized EOPs are taking the place of paper-based ones. Unlike paper-based EOPs, the industrial practice of computerized EOPs is still quite limited. Ergonomics issues of computerized EOPs have not been studied adequately. This study focuses on the effects of EOP presentation style, task complexity, and training level on the performance of the operators in the execution of computerized EOPs. One simulated computerized EOP system was developed to present two EOPs, each with different task complexity levels, by two presentation styles (Style A: one- and two-dimensional flowcharts combination; Style B: two-dimensional flowchart and success logic tree combination). Forty subjects participated in the experiment of EOP execution using the simulated system. Statistical analysis of the experimental results indicates that: (1) complexity, presentation style, and training level all can significantly influence the error rate. High-complexity tasks and lack of sufficient training may lead to a higher error rate. Style B caused a significantly higher error rate than style A did in the skilled phase. So the designers of computerized procedures should take the presentation styles of EOPs into account. (2) Task complexity and training level can significantly influence operation time. No significant difference was found in operation time between the two presentation styles. (3) Training level can also significantly influence the subjective workload of EOPs operations. This implies that adequate training is very important for the performance of computerized EOPs even if emergency responses with computerized EOPs are much more simple and easy than that with paper-based EOPs.

  11. Tasks of the Shipboard Independent Duty Hospital Corpsman. Task Training Adequacy and Performance Frequency.

    Science.gov (United States)

    1987-11-01

    Frequency List E-1 Appendix F - Submarine Quick Reference Task Frequency List . F-1 0 Appendix G - Mean Performance...j~~~~~~, -,,-p.r.. ... .0 -. %... h. • - III APPENDIX E I SURFACE SHIP QUICK REFERENCE TASK FREQUENCY LIST A Q N E Dl It T T E A E H HI K I L L L1 L...34. - - - ----------------------------------------- ---.--- ---------------------- - - E-4 APPENDIX F " SUBMARINE QUICK REFERENCE TASK FREQUENCY LIST (N 1l0) "% R 0 W 4. A Q N E D R T T

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

    Science.gov (United States)

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

    2016-02-01

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

  13. The influence of principal managerial task performance on ...

    African Journals Online (AJOL)

    Poor performance of managerial tasks culminates declining staff productivity and thus deteriorating students academic performance. Secondary school students performance in most public examinations are not satisfactory in most states in Nigeria. Hence, this study investigate the extent to which secondary school principal ...

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

    Science.gov (United States)

    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.

  15. Analysis of Operators Comments on the PSF Questionnaire of the Task Complexity Experiment 2003/2004

    Energy Technology Data Exchange (ETDEWEB)

    Torralba, B.; Martinez-Arias, R.

    2007-07-01

    Human Reliability Analysis (HRA) methods usually take into account the effect of Performance Shaping Factors (PSF). Therefore, the adequate treatment of PSFs in HRA of Probabilistic Safety Assessment (PSA) models has a crucial importance. There is an important need for collecting PSF data based on simulator experiments. During the task complexity experiment 2003-2004, carried out in the BWR simulator of Halden Man-Machine Laboratory (HAMMLAB), there was a data collection on PSF by means of a PSF Questionnaire. Seven crews (composed of shift supervisor, reactor operator and turbine operator) from Swedish Nuclear Power Plants participated in the experiment. The PSF Questionnaire collected data on the factors: procedures, training and experience, indications, controls, team management, team communication, individual work practice, available time for the tasks, number of tasks or information load, masking and seriousness. The main statistical significant results are presented on Performance Shaping Factors data collection and analysis of the task complexity experiment 2003/2004 (HWR-810). The analysis of the comments about PSFs, which were provided by operators on the PSF Questionnaire, is described. It has been summarised the comments provided for each PSF on the scenarios, using a content analysis technique. (Author)

  16. Analysis of Operators Comments on the PSF Questionnaire of the Task Complexity Experiment 2003/2004

    International Nuclear Information System (INIS)

    Torralba, B.; Martinez-Arias, R.

    2007-01-01

    Human Reliability Analysis (HRA) methods usually take into account the effect of Performance Shaping Factors (PSF). Therefore, the adequate treatment of PSFs in HRA of Probabilistic Safety Assessment (PSA) models has a crucial importance. There is an important need for collecting PSF data based on simulator experiments. During the task complexity experiment 2003-2004, carried out in the BWR simulator of Halden Man-Machine Laboratory (HAMMLAB), there was a data collection on PSF by means of a PSF Questionnaire. Seven crews (composed of shift supervisor, reactor operator and turbine operator) from Swedish Nuclear Power Plants participated in the experiment. The PSF Questionnaire collected data on the factors: procedures, training and experience, indications, controls, team management, team communication, individual work practice, available time for the tasks, number of tasks or information load, masking and seriousness. The main statistical significant results are presented on Performance Shaping Factors data collection and analysis of the task complexity experiment 2003/2004 (HWR-810). The analysis of the comments about PSFs, which were provided by operators on the PSF Questionnaire, is described. It has been summarised the comments provided for each PSF on the scenarios, using a content analysis technique. (Author)

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

    Science.gov (United States)

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

    2011-01-01

    Space flight is known to cause alterations in multiple physiological systems including changes in sensorimotor, cardiovascular, and neuromuscular systems. These changes may affect a crewmember s ability to perform critical mission tasks immediately after landing on a planetary surface. The overall goal of this project is to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. This presentation will focus on the sensorimotor contributions to postflight functional performance.

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

    Directory of Open Access Journals (Sweden)

    Bettina eGathmann

    2015-02-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  20. Improving Physical Task Performance with Counterfactual and Prefactual Thinking.

    Science.gov (United States)

    Hammell, Cecilia; Chan, Amy Y C

    2016-01-01

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

  1. An opportunity cost model of subjective effort and task performance

    Science.gov (United States)

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

    2013-01-01

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

  2. Game elements improve performance in a working memory training task

    Directory of Open Access Journals (Sweden)

    Manuel Ninaus

    2015-02-01

    Full Text Available The utilization of game elements in a non-game context is currently used in a vast range of different domains. However, research on game elements’ effects in cognitive tasks is still sparse. Thus, in this study we implemented three game elements, namely, progress bar, level indicator, and a thematic setting, in a working memory training task. We evaluated the impact of game elements on user performance and perceived state of flow when compared to a conventional version of the task. Participants interacting with game elements showed higher scores in the working memory training task than participants from a control group who completed the working memory training task without the game elements. Moreover, game elements facilitated the individuals’ performance closer to their maximum working memory capacity. Finally, the perceived flow did not differ between the two groups, which indicates that game elements can induce better performance without changing the perception of being “in the zone”, that is without an increase in anxiety or boredom. This empirical study indicates that certain game elements can improve the performance and efficiency in a working memory task by increasing users’ ability and willingness to train at their optimal performance level. 

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

    Science.gov (United States)

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

    2015-03-01

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

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

    Science.gov (United States)

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

    2008-06-01

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

  5. High-definition television evaluation for remote handling task performance

    International Nuclear Information System (INIS)

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

    1986-01-01

    In a plant that employs remote handling techniques for equipment maintenance, operators perform maintenance tasks primarily by using the information from television systems. The efficiency of the television system has a significant impact on remote maintenance task performance. High-definition television (HDTV) transmits a video image with more than twice the number of horizontal scan lines as standard-resolution television (1125 for HDTV to 525 for standard-resolution NTSC television). The added scan lines dramatically improve the resolution of images on the HDTV monitors. This paper describes experiments designed to evaluate the impact of HDTV on the performance of typical remote tasks. The experiments described in this paper compared the performance of four operators using HDTV with their performance while using other television systems. The experiments included four television systems: (a) high-definition color television, (b) high-definition monochromatic television, (c) standard-resolution monochromatic television, and (d) standard-resolution stereoscopic monochromatic television

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

    Science.gov (United States)

    Moore, Alex M; Ashcraft, Mark H

    2015-07-01

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

  7. Manipulating perceptual parameters in a continuous performance task.

    Science.gov (United States)

    Shalev, Nir; Humphreys, Glyn; Demeyere, Nele

    2018-02-01

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

  8. Does Degree of Work Task Completion Influence Retrieval Performance?

    DEFF Research Database (Denmark)

    Ingwersen, Peter; Bogers, Toine; Lykke, Marianne

    2010-01-01

    their perception of task completion. Also, with the exception of full text records and across all document types, both measured at rank 10, no statistically significant correlation is observed with respect to retrieval performance influenced by degrees of perceived work task completion or individual types......In this contribution we investigate the potential influence between assessors’ perceived completion of their work task at hand and their actual assessment of usefulness of the retrieved information. The results indicate that the number of useful documents found by assessors does not influence...

  9. Manipulator Performance Evaluation Using Fitts' Taping Task

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-04-25

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2017-07-01

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

  12. Balancing Human-machine Interface (HMI) Design in Complex Supervisory Tasks

    International Nuclear Information System (INIS)

    Ha, Junsu; Kim, Arryum; Jang, Inseok; Seong, Poonghyun

    2013-01-01

    Human performance aspects such as plant performance, personnel task performance, situation awareness, cognitive workload, teamwork, and anthropomorphic/physiological factor are evaluated with the HUPESS. Even though the HUPESS provides evaluation results in each of the performance aspects for the integrated system validation (ISV), additional researches have been needed to develop methods on how to find out design deficiency leading to poor performance and give a solution for design improvement in HMI. The authors have developed a method of HMI design improvement for the monitoring and detection tasks which was named as 'DEMIS (Difficulty Evaluation Method in Information Searching)'. The DEMIS is a HMI evaluation method which bridge poor performance and design improvement. Lessons learned from the existing studies lead to a question about how to optimize the whole HMI design. Human factors principles provide the foundation for guidelines of various codes and standards in designing HMIs. Also in NPPs, a lot of guidelines directly from various codes and standard and derived from various research and development projects are available for designing MCR HMIs. In this study, a balancing principle and relevant two measures for HMI design optimization are proposed to be used in the HMI design of complex supervisory tasks in NPPs. The balancing principle is that a HMI element (e. g., an indicator or a push button) should be designed according to its importance

  13. Balancing Human-machine Interface (HMI) Design in Complex Supervisory Tasks

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Junsu [Khalifa Univ. of Science, Abu Dhabi (United Arab Emirates); Kim, Arryum; Jang, Inseok; Seong, Poonghyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    Human performance aspects such as plant performance, personnel task performance, situation awareness, cognitive workload, teamwork, and anthropomorphic/physiological factor are evaluated with the HUPESS. Even though the HUPESS provides evaluation results in each of the performance aspects for the integrated system validation (ISV), additional researches have been needed to develop methods on how to find out design deficiency leading to poor performance and give a solution for design improvement in HMI. The authors have developed a method of HMI design improvement for the monitoring and detection tasks which was named as 'DEMIS (Difficulty Evaluation Method in Information Searching)'. The DEMIS is a HMI evaluation method which bridge poor performance and design improvement. Lessons learned from the existing studies lead to a question about how to optimize the whole HMI design. Human factors principles provide the foundation for guidelines of various codes and standards in designing HMIs. Also in NPPs, a lot of guidelines directly from various codes and standard and derived from various research and development projects are available for designing MCR HMIs. In this study, a balancing principle and relevant two measures for HMI design optimization are proposed to be used in the HMI design of complex supervisory tasks in NPPs. The balancing principle is that a HMI element (e. g., an indicator or a push button) should be designed according to its importance.

  14. Sustained and transient attention in the Continuous Performance Task

    NARCIS (Netherlands)

    Smid, HGOM; de Witte, MR; Homminga, [No Value; van den Bosch, RJ

    One of the most frequently applied methods to study abnormal cognition is the Continuous Performance Task (CPT). It is unclear, however, which cognitive functions are engaged in normal CPT performance. The aims of the present study were to identify the neurocognitive functions engaged in the main

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

    Science.gov (United States)

    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.

  16. Automated Cognitive Health Assessment Using Smart Home Monitoring of Complex Tasks.

    Science.gov (United States)

    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.

  17. Deep Plant Phenomics: A Deep Learning Platform for Complex Plant Phenotyping Tasks

    Science.gov (United States)

    Ubbens, Jordan R.; Stavness, Ian

    2017-01-01

    Plant phenomics has received increasing interest in recent years in an attempt to bridge the genotype-to-phenotype knowledge gap. There is a need for expanded high-throughput phenotyping capabilities to keep up with an increasing amount of data from high-dimensional imaging sensors and the desire to measure more complex phenotypic traits (Knecht et al., 2016). In this paper, we introduce an open-source deep learning tool called Deep Plant Phenomics. This tool provides pre-trained neural networks for several common plant phenotyping tasks, as well as an easy platform that can be used by plant scientists to train models for their own phenotyping applications. We report performance results on three plant phenotyping benchmarks from the literature, including state of the art performance on leaf counting, as well as the first published results for the mutant classification and age regression tasks for Arabidopsis thaliana. PMID:28736569

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

    Science.gov (United States)

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

    2010-09-01

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

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

    Science.gov (United States)

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

    2012-10-01

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

  20. Effects of force reflection on servomanipulator task performance

    International Nuclear Information System (INIS)

    Draper, J.V.; Moore, W.E.; Herndon, J.N.; Weil, B.S.

    1986-01-01

    This paper reports results of a testing program that assessed the impact of force reflection on servomanipulator task performance. The testing program compared three force-reflection levels: 4 to 1 (four units of force on the slave produce one unit of force at the master controller), 1 to 1, and infinity to 1 (no force reflection). Time required to complete tasks, rate of occurrence of errors, the maximum force applied to task components, and variability in forces during completion of representative remote handling tasks were used as dependent variables. Operators exhibited lower error rates, lower peak forces, and more consistent application of forces using force reflection than they did without it. These data support the hypothesis that force reflection provides useful information for servomanipulator operators

  1. Experimental study of the effect of task priority and coordination strategy on crew performance

    International Nuclear Information System (INIS)

    Braarud, Per Oeivind; Ludvigsen, Jan Tore

    2002-08-01

    This report documents the background and the results from the Teamwork and Task Management experiment 2001 (TTM-2001) performed in the HAlden Man-Machine LABoratory (HAMMLAB). The experiment emphasises concepts that are suggested as an alternative to the application of general workload measures, namely (1) task management; how operators plan, prioritise and accomplish their tasks individually, and (2) teamwork; coordination of work within the team. The concepts were operationalised for the experimental study by crews operating in accordance with 4 work styles combined from 2 experimental factors: Task Priority and Coordination Strategy. The results indicate that Task Priority has no effect on the operator's ability to handle plant malfunction, but that it increases operator ability to prioritise between the importance of the process data, and increases subjective performance. The results demonstrate that Coordination Strategies significantly improve crew performance. However, contrary to the expectations, there is no clear evidence that coordination supports the operator's situation understanding. The stable characteristics of teamwork observed across different tasks may indicate that teamwork is performed in a procedural way, and as a strategy to cope with a complex and uncertain situation. The practical lessons learned from the experiment were that the crews managed to learn the work styles with the given training and were able to perform the work style of the experimental conditions. Thus, it is possible to carry out studies of important task management and teamwork issues in HAMMLAB. (Author)

  2. Working memory in children predicts performance on a gambling task.

    Science.gov (United States)

    Audusseau, Jean; Juhel, Jacques

    2015-01-01

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

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

    Science.gov (United States)

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

    2017-06-22

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

  4. Ranking Performance Measures in Multi-Task Agencies

    DEFF Research Database (Denmark)

    Christensen, Peter Ove; Sabac, Florin; Tian, Joyce

    2010-01-01

    We derive sufficient conditions for ranking performance evaluation systems in multi-task agency models (using both optimal and linear contracts) in terms of a second-order stochastic dominance (SSD) condition on the likelihood ratios. The SSD condition can be replaced by a variance-covariance mat......We derive sufficient conditions for ranking performance evaluation systems in multi-task agency models (using both optimal and linear contracts) in terms of a second-order stochastic dominance (SSD) condition on the likelihood ratios. The SSD condition can be replaced by a variance...

  5. Effects of orientation on Rey complex figure performance.

    Science.gov (United States)

    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 orientation was not significant, nor did orientation interact with task (Fs .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).

  6. Do absorption and realistic distraction influence performance of component task surgical procedure?

    NARCIS (Netherlands)

    Pluyter, J.R.; Buzink, S.N.; Rutkowski, A.F.; Jakimowicz, J.J.

    2009-01-01

    Background. 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

  7. Computer-mediated communication: task performance and satisfaction.

    Science.gov (United States)

    Simon, Andrew F

    2006-06-01

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

  8. An Exploratory Study into Perceived Task Complexity, Topic Specificity and Usefulness for Integrated Search

    DEFF Research Database (Denmark)

    Ingwersen, Peter; Lioma, Christina; Larsen, Birger

    2012-01-01

    We investigate the relations between user perceptions of work task complexity, topic specificity, and usefulness of retrieved results. 23 academic researchers submitted detailed descriptions of 65 real-life work tasks in the physics domain, and assessed documents retrieved from an integrated...... collection consisting of full text research articles in PDF, abstracts, and bibliographic records [6]. Bibliographic records were found to be more precise than full text PDFs, regardless of task complexity and topic specificity. PDFs were found to be more useful. Overall, for higher task complexity and topic...

  9. Report on the Second Workshop on Supporting Complex Search Tasks : CHIIR 2017 Workshop Report

    NARCIS (Netherlands)

    Koolen, M.; Kamps, J.; Bogers, T.; Belkin, N.; Kelly, D.; Yilmaz, E.

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain-specific collections, and both in our professional and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks, is

  10. The Differential Effects of Task Complexity on Domain-Specific and Peer Assessment Skills

    Science.gov (United States)

    van Zundert, Marjo J.; Sluijsmans, Dominique M. A.; Konings, Karen D.; van Merrienboer, Jeroen J. G.

    2012-01-01

    In this study the relationship between domain-specific skills and peer assessment skills as a function of task complexity is investigated. We hypothesised that peer assessment skills were superposed on domain-specific skills and will therefore suffer more when higher cognitive load is induced by increased task complexity. In a mixed factorial…

  11. The Role of Self-Regulated Learning Capacities in Iranian EFL Undergraduates’ Argumentative Writing Task Performance

    Directory of Open Access Journals (Sweden)

    Ali Akbar Khomeijani Farahani

    2017-09-01

    Full Text Available The current study was an attempt to explore the relationship between Iranian EFL learners’ self-regulatory capacities and their argumentative writing task performance in order to analyze measures of complexity, accuracy, and fluency (CAF. To this end, 44 Iranian EFL undergraduates majoring in English literature at the University of Tehran were recruited based on convenience sampling to participate in this study. Employing a correlational design, the participants were required to perform an argumentative writing task and complete the Motivated Strategies for Learning Questionnaire designed by Pintrich, Smith, Garcia, and McKeachie (1991. Pearson product moment correlation indicated a significant relationship between self-regulated learning and writing task performance in relation to CAF measures. In addition, the results of multiple regression showed that resource management strategies and value component predicted 56.9% of grammatical accuracy of writing task. It was also shown that resource management strategies, value, and expectancy components predicted 56.5% of lexical complexity of writing task. Lastly, cognitive and metacognitive strategies, expectancy, and value components predicted 55.2% of the fluency of writing task. The findings of this study informs EFL writing pedagogy and English language teachers and syllabus designers  with regard to the benefits of applying self-regulatory strategies in teaching and assessing writing.

  12. Preparatory neural activity predicts performance on a conflict task.

    Science.gov (United States)

    Stern, Emily R; Wager, Tor D; Egner, Tobias; Hirsch, Joy; Mangels, Jennifer A

    2007-10-24

    Advance preparation has been shown to improve the efficiency of conflict resolution. Yet, with little empirical work directly linking preparatory neural activity to the performance benefits of advance cueing, it is not clear whether this relationship results from preparatory activation of task-specific networks, or from activity associated with general alerting processes. Here, fMRI data were acquired during a spatial Stroop task in which advance cues either informed subjects of the upcoming relevant feature of conflict stimuli (spatial or semantic) or were neutral. Informative cues decreased reaction time (RT) relative to neutral cues, and cues indicating that spatial information would be task-relevant elicited greater activity than neutral cues in multiple areas, including right anterior prefrontal and bilateral parietal cortex. Additionally, preparatory activation in bilateral parietal cortex and right dorsolateral prefrontal cortex predicted faster RT when subjects responded to spatial location. No regions were found to be specific to semantic cues at conventional thresholds, and lowering the threshold further revealed little overlap between activity associated with spatial and semantic cueing effects, thereby demonstrating a single dissociation between activations related to preparing a spatial versus semantic task-set. This relationship between preparatory activation of spatial processing networks and efficient conflict resolution suggests that advance information can benefit performance by leading to domain-specific biasing of task-relevant information.

  13. Task conflict asymmetries : Effects on expectations and performance

    NARCIS (Netherlands)

    Jehn, Karen A.; De Wit, Frank R C; Barreto, Manuela; Rink, Floor

    2015-01-01

    Purpose-The purpose of this paper is to examine the effects of asymmetric perceptions of task conflict (i.e. one person experiencing more conflict than the other) on the anticipated relationship with the partner, as well as subjective and objective performance. Design/methodology/approach–In a 2= 2

  14. Effects of Refresher Training on Job-Task Typewriting Performance.

    Science.gov (United States)

    Hagman, Joseph D.; Schendel, Joel D.

    Two groups of 15 Administrative Specialists, 7lL Military Occupational Speciality (MOS), participated in four job-task refresher training sessions designed to enhance the typewriting of military correspondence. One group performed under a study training method which allowed use of a Correspondence Manual while arranging materials into the correct…

  15. Effects of Social Incentives on Task Performance in the Elderly

    Science.gov (United States)

    Levendusky, Philip G.

    1978-01-01

    The performance of 60 elderly volunteers on two cancellation tasks was examined under one of three experimental conditions: social praise, social reproof, or no comment. The clear implications from these data are that social incentives may well facilitate behavioral change in the aged. (Author)

  16. Task Monotony and Performance Efficacy of Mentally Retarded Young Adults.

    Science.gov (United States)

    Locke, Bill J.; And Others

    1982-01-01

    Thirty-six mildly mentally retarded young adults were exposed to one of three training arrangements for vigilance performance, a monitoring task that some professionals consider uniquely appropriate for such persons because they are assumed to be less susceptible to boredom. (Author)

  17. Ergonomic evaluation of tasks performed by female workers in the ...

    African Journals Online (AJOL)

    Two main types of task are performed by the female workers in the brick fields in the unorganized sectors viz, brick moulding and brick carrying. Modified Nordic Questionnaire and Body Part Discomfort (BPD) scale was applied on these workers to identify the MSDs and the zones of discomfort in different body parts.

  18. Ranking Performance Measures in Multi-Task Agencies

    DEFF Research Database (Denmark)

    Christensen, Peter Ove; Sabac, Florin; Tian, Joyce

    We derive sufficient conditions for ranking performance evaluation systems in multi-task agency models using both optimal and linear contracts in terms of a second-order stochastic dominance (SSD) condition on the likelihood ratios. The SSD condition can be replaced by a variance-covariance matrix...

  19. Monitoring User-System Performance in Interactive Retrieval Tasks

    NARCIS (Netherlands)

    Boldareva, L.; de Vries, A.P.; Hiemstra, Djoerd

    Monitoring user-system performance in interactive search is a challenging task. Traditional measures of retrieval evaluation, based on recall and precision, are not of any use in real time, for they require a priori knowledge of relevant documents. This paper shows how a Shannon entropy-based

  20. Career Development, Collective Efficacy, and Individual Task Performance

    Science.gov (United States)

    Kellett, Janet B.; Humphrey, Ronald H.; Sleeth, Randall G.

    2009-01-01

    Purpose: The purpose of this paper is to test the hypothesis that perceived collective efficacy would mediate the effects of self-efficacy on individual task performance. Design/methodology/approach: An assessment center design with 147 participants in 49 three-person groups was used. Findings: It is found that for individuals working on an…

  1. Disentangling task and contextual performance : a multitrait-multimethod approach

    NARCIS (Netherlands)

    Demerouti, E.; Xanthopoulou, D.; Tsaousis, I.; Bakker, A.B.

    2014-01-01

    This study among 244 employees and their colleagues working in various sectors investigated the dimensionality of self-ratings and peer-ratings of task and contextual performance, using the scales of Goodman and Svyantek (1999). By applying the multitrait-multimethod approach, we examined the degree

  2. Engineering tools for complex task of reducing energy consumption

    NARCIS (Netherlands)

    Hensen, J.L.M.

    1994-01-01

    Reduction of energy consumption in buildings while ensuring a good indoor environment is a very challenging and difficult engineering task. For this we need tools which are based on an integral approach of the building, control systems, occupants and outdoor environment. A building energy simulation

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

    Science.gov (United States)

    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.

  4. An account of cognitive flexibility and inflexibility for a complex dynamic task

    OpenAIRE

    De Obeso Orendain, Alberto; Wood, Sharon

    2012-01-01

    Problem solving involves adapting known problem solving methods and strategies to the task at hand (Schunn & Reder, 2001) and cognitive flexibility is considered to be “the human ability to adapt the cognitive processing strategies to face new and unexpected conditions of the environment” (Cañas et al., 2005, p. 95). This work presents an ACT-R 6.0 model of complex problem solving behavior for the dynamic microworld game FireChief (Omodei & Wearing, 1995) that models the performance of partic...

  5. Videogame training strategy-induced change in brain function during a complex visuomotor task.

    Science.gov (United States)

    Lee, Hyunkyu; Voss, Michelle W; Prakash, Ruchika Shaurya; Boot, Walter R; Vo, Loan T K; Basak, Chandramallika; Vanpatter, Matt; Gratton, Gabriele; Fabiani, Monica; Kramer, Arthur F

    2012-07-01

    Although changes in brain function induced by cognitive training have been examined, functional plasticity associated with specific training strategies is still relatively unexplored. In this study, we examined changes in brain function during a complex visuomotor task following training using the Space Fortress video game. To assess brain function, participants completed functional magnetic resonance imaging (fMRI) before and after 30 h of training with one of two training regimens: Hybrid Variable-Priority Training (HVT), with a focus on improving specific skills and managing task priority, or Full Emphasis Training (FET), in which participants simply practiced the game to obtain the highest overall score. Control participants received only 6 h of FET. Compared to FET, HVT learners reached higher performance on the game and showed less brain activation in areas related to visuo-spatial attention and goal-directed movement after training. Compared to the control group, HVT exhibited less brain activation in right dorsolateral prefrontal cortex (DLPFC), coupled with greater performance improvement. Region-of-interest analysis revealed that the reduction in brain activation was correlated with improved performance on the task. This study sheds light on the neurobiological mechanisms of improved learning from directed training (HVT) over non-directed training (FET), which is related to visuo-spatial attention and goal-directed motor planning, while separating the practice-based benefit, which is related to executive control and rule management. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Task-irrelevant auditory feedback facilitates motor performance in musicians

    Directory of Open Access Journals (Sweden)

    Virginia eConde

    2012-05-01

    Full Text Available An efficient and fast auditory–motor network is a basic resource for trained musicians due to the importance of motor anticipation of sound production in musical performance. When playing an instrument, motor performance always goes along with the production of sounds and the integration between both modalities plays an essential role in the course of musical training. The aim of the present study was to investigate the role of task-irrelevant auditory feedback during motor performance in musicians using a serial reaction time task (SRTT. Our hypothesis was that musicians, due to their extensive auditory–motor practice routine during musical training, have a superior performance and learning capabilities when receiving auditory feedback during SRTT relative to musicians performing the SRTT without any auditory feedback. Here we provide novel evidence that task-irrelevant auditory feedback is capable to reinforce SRTT performance but not learning, a finding that might provide further insight into auditory-motor integration in musicians on a behavioral level.

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

    Science.gov (United States)

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

    2009-01-01

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

  8. Evaluation of high-definition television for remote task performance

    International Nuclear Information System (INIS)

    Draper, J.V.; Fujita, Y.; Herndon, J.N.

    1987-04-01

    High-definition television (HDTV) transmits a video image with more than twice the number (1125 for HDTV to 525 for standard-resolution TV) of horizontal scan lines that standard-resolution TV provides. The improvement in picture quality (compared to standard-resolution TV) that the extra scan lines provide is impressive. Objects in the HDTV picture have more sharply defined edges, better contrast, and more accurate reproduction of shading and color patterns than do those in the standard-resolution TV picture. Because the TV viewing system is a key component for teleoperator performance, an improvement in TV picture quality could mean an improvement in the speed and accuracy with which teleoperators perform tasks. This report describes three experiments designed to evaluate the impact of HDTV on the performance of typical remote tasks. The performance of HDTV was compared to that of standard-resolution, monochromatic TV and standard-resolution, stereoscopic, monochromatic TV in the context of judgment of depth in a televised scene, visual inspection of an object, and performance of a typical remote handling task. The results of the three experiments show that in some areas HDTV can lead to improvement in teleoperator performance. Observers inspecting a small object for a flaw were more accurate with HDTV than with either of the standard-resolution systems. High resolution is critical for detection of small-scale flaws of the type in the experiment (a scratch on a glass bottle). These experiments provided an evaluation of HDTV television for use in tasks that must be routinely performed to remotely maintain a nuclear fuel reprocessing facility. 5 refs., 7 figs., 9 tabs

  9. Structural Correlates of Skilled Performance on a Motor Sequence Task

    Directory of Open Access Journals (Sweden)

    Christopher J Steele

    2012-10-01

    Full Text Available The brain regions functionally engaged in motor sequence performance are well established, but the structural characteristics of these regions and the fibre pathways involved have been less well studied. In addition, relatively few studies have combined multiple magnetic resonance imaging (MRI and behavioural performance measures in the same sample. Therefore, the current study used diffusion tensor imaging, probabilistic tractography, and voxel-based morphometry to determine the structural correlates of skilled motor performance. Further, we compared these findings with fMRI results in the same sample. We correlated final performance and rate of improvement measures on a temporal motor sequence task with skeletonised fractional anisotropy (FA and whole brain grey matter (GM volume. Final synchronisation performance was negatively correlated with FA in white matter underlying bilateral sensorimotor cortex – an effect that was mediated by a positive correlation with radial diffusivity. Multi-fibre tractography indicated that this region contained crossing fibres from the corticospinal tract and superior longitudinal fasciculus (SLF. The identified SLF pathway linked parietal and auditory cortical regions that have been shown to be functionally engaged in this task. Thus, we hypothesise that enhanced synchronisation performance on this task may be related to greater fibre integrity of the SLF. Rate of improvement on synchronisation was positively correlated with GM volume in cerebellar lobules HVI and V – regions that showed training-related decreases in activity in the same sample. Taken together, our results link individual differences in brain structure and function to motor sequence performance on the same task. Further, our study illustrates the utility of using multiple MR measures and analysis techniques to specify the interpretation of structural findings.

  10. The disruptive effects of pain on complex cognitive performance and executive control.

    Directory of Open Access Journals (Sweden)

    Edmund Keogh

    Full Text Available Pain interferes and disrupts attention. What is less clear is how pain affects performance on complex tasks, and the strategies used to ensure optimal outcomes. The aim of the current study was to examine the effect of pain on higher-order executive control processes involved in managing complex tasks. Sixty-two adult volunteers (40 female completed two computer-based tasks: a breakfast making task and a word generation puzzle. Both were complex, involving executive control functions, including goal-directed planning and switching. Half of those recruited performed the tasks under conditions of thermal heat pain, and half with no accompanying pain. Whilst pain did not affect central performance on either task, it did have indirect effects. For the breakfast task, pain resulted in a decreased ability to multitask, with performance decrements found on the secondary task. However, no effects of pain were found on the processes thought to underpin this task. For the word generation puzzle, pain did not affect task performance, but did alter subjective accounts of the processes used to complete the task; pain affected the perceived allocation of time to the task, as well as switching perceptions. Sex differences were also found. When studying higher-order cognitive processes, pain-related interference effects are varied, and may result in subtle or indirect changes in cognition.

  11. The disruptive effects of pain on complex cognitive performance and executive control.

    Science.gov (United States)

    Keogh, Edmund; Moore, David J; Duggan, Geoffrey B; Payne, Stephen J; Eccleston, Christopher

    2013-01-01

    Pain interferes and disrupts attention. What is less clear is how pain affects performance on complex tasks, and the strategies used to ensure optimal outcomes. The aim of the current study was to examine the effect of pain on higher-order executive control processes involved in managing complex tasks. Sixty-two adult volunteers (40 female) completed two computer-based tasks: a breakfast making task and a word generation puzzle. Both were complex, involving executive control functions, including goal-directed planning and switching. Half of those recruited performed the tasks under conditions of thermal heat pain, and half with no accompanying pain. Whilst pain did not affect central performance on either task, it did have indirect effects. For the breakfast task, pain resulted in a decreased ability to multitask, with performance decrements found on the secondary task. However, no effects of pain were found on the processes thought to underpin this task. For the word generation puzzle, pain did not affect task performance, but did alter subjective accounts of the processes used to complete the task; pain affected the perceived allocation of time to the task, as well as switching perceptions. Sex differences were also found. When studying higher-order cognitive processes, pain-related interference effects are varied, and may result in subtle or indirect changes in cognition.

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

    Science.gov (United States)

    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.

  13. RAFCON: A Graphical Tool for Engineering Complex, Robotic Tasks

    Science.gov (United States)

    2016-10-09

    manipulation , vision, navigation, etc.). All these components need to be coordi- nated both in terms of communication and task flow. ROS [1] is a common...editing, is an important supportive feature of a programming tool for robots. How- ever, this is not an easy feature to achieve, as bigger state... children of a HierarchyState can be considered as a flat state machine on its own with a single entry state. ConcurrencyStates are also ContainerStates

  14. The potential impact of 3D telepresence technology on task performance in emergency trauma care

    DEFF Research Database (Denmark)

    Söderholm, Hanna M.; Sonnenwald, Diane H.; Cairns, Bruce

    2007-01-01

    a simulated emergency situation 60 paramedics diagnosed and treated a trauma victim while working alone or in collaboration with a physician via 2D video or a 3D proxy. Analysis of paramedics' task performance shows that the fewest harmful procedures occurred in the 3D proxy condition. Paramedics in the 3D...... proxy condition also reported higher levels of self-efficacy. These results indicate 3D telepresence technology has potential to improve paramedics' performance of complex emergency medical tasks and improve emergency trauma health care when designed appropriately....

  15. Predicting Subsequent Task Performance From Goal Motivation and Goal Failure

    Directory of Open Access Journals (Sweden)

    Laura Catherine Healy

    2015-07-01

    Full Text Available Recent research has demonstrated that the cognitive processes associated with goal pursuit can continue to interfere with unrelated tasks when a goal is unfulfilled. Drawing from the self-regulation and goal-striving literatures, the present study explored the impact of goal failure on subsequent cognitive and physical task performance. Furthermore, we examined if the autonomous or controlled motivation underpinning goal striving moderates the responses to goal failure. Athletes (75 male, 59 female, Mage = 19.90 years, SDage = 3.50 completed a cycling trial with the goal of covering a given distance in 8 minutes. Prior to the trial, their motivation was primed using a video. During the trial they were provided with manipulated performance feedback, thus creating conditions of goal success or failure. No differences emerged in the responses to goal failure between the primed motivation or performance feedback conditions. We make recommendations for future research into how individuals can deal with failure in goal striving.

  16. Exploration of task performance tests in a physics laboratory

    Science.gov (United States)

    Liu, Dan; El Turkey, Houssein

    2017-11-01

    In this article, we investigate the implementation of task performance tests in an undergraduate physics laboratory. Two performance tests were carried out over two semesters using the task of building a DC circuit. The first implementation in Spring 2014 had certain concerns such as the privacy of students’ testing and their ‘trial and error’ attempts. These concerns were addressed in Fall 2015 through implementing a second performance test. The second implementation was administered differently but the content of the two tests was the same. We discuss the validity of both implementations and present the correlation (or lack of) between the time that students needed to complete the tests and their grades from a paper-based laboratory assessment method.

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

    Science.gov (United States)

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

    2018-01-01

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

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

    Science.gov (United States)

    Langeslag, Sandra J E; van Strien, Jan W

    2017-09-18

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

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

    Science.gov (United States)

    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.

  20. Managing teams performing complex innovation projects

    NARCIS (Netherlands)

    Oeij, P.R.A.; Vroome, E.M.M. de; Dhondt, S.; Gaspersz, J.B.R.

    2012-01-01

    Complexity of projects is hotly debated and a factor which affects innovativeness of team performance. Much attention in the past is paid to technical complexity and many issues are related to natural and physical sciences. A growing awareness of the importance of socio-organisational issues is

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

    Science.gov (United States)

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

    2018-01-01

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

  2. Group performance and group learning at dynamic system control tasks

    International Nuclear Information System (INIS)

    Drewes, Sylvana

    2013-01-01

    Proper management of dynamic systems (e.g. cooling systems of nuclear power plants or production and warehousing) is important to ensure public safety and economic success. So far, research has provided broad evidence for systematic shortcomings in individuals' control performance of dynamic systems. This research aims to investigate whether groups manifest synergy (Larson, 2010) and outperform individuals and if so, what processes lead to these performance advantages. In three experiments - including simulations of a nuclear power plant and a business setting - I compare the control performance of three-person-groups to the average individual performance and to nominal groups (N = 105 groups per experiment). The nominal group condition captures the statistical advantage of aggregated group judgements not due to social interaction. First, results show a superior performance of groups compared to individuals. Second, a meta-analysis across all three experiments shows interaction-based process gains in dynamic control tasks: Interacting groups outperform the average individual performance as well as the nominal group performance. Third, group interaction leads to stable individual improvements of group members that exceed practice effects. In sum, these results provide the first unequivocal evidence for interaction-based performance gains of groups in dynamic control tasks and imply that employers should rely on groups to provide opportunities for individual learning and to foster dynamic system control at its best.

  3. Effect of task complexity on intelligence and neural efficiency in children: an event-related potential study.

    Science.gov (United States)

    Zhang, Qiong; Shi, Jiannong; Luo, Yuejia; Liu, Sainan; Yang, Jie; Shen, Mowei

    2007-10-08

    The present study investigates the effects of task complexity, intelligence and neural efficiency on children's performance on an Elementary Cognitive Task. Twenty-three children were divided into two groups on the basis of their Raven Progressive Matrix scores and were then asked to complete a choice reaction task with two test conditions. We recorded the electroencephalogram and calculated the peak latencies and amplitudes for anteriorly distributed P225, N380 and late positive component. Our results suggested shorter late positive component latencies in brighter children, possibly reflecting a higher processing speed in these individuals. Increased P225 amplitude and increased N380 amplitudes for brighter children may indicate a more efficient allocation of attention for brighter children. No moderating effect of task complexity on brain-intelligence relationship was found.

  4. Identifying the neural substrates of intrinsic motivation during task performance.

    Science.gov (United States)

    Lee, Woogul; Reeve, Johnmarshall

    2017-10-01

    Intrinsic motivation is the inherent tendency to seek out novelty and challenge, to explore and investigate, and to stretch and extend one's capacities. When people imagine performing intrinsically motivating tasks, they show heightened anterior insular cortex (AIC) activity. To fully explain the neural system of intrinsic motivation, however, requires assessing neural activity while people actually perform intrinsically motivating tasks (i.e., while answering curiosity-inducing questions or solving competence-enabling anagrams). Using event-related functional magnetic resonance imaging, we found that the neural system of intrinsic motivation involves not only AIC activity, but also striatum activity and, further, AIC-striatum functional interactions. These findings suggest that subjective feelings of intrinsic satisfaction (associated with AIC activations), reward processing (associated with striatum activations), and their interactions underlie the actual experience of intrinsic motivation. These neural findings are consistent with the conceptualization of intrinsic motivation as the pursuit and satisfaction of subjective feelings (interest and enjoyment) as intrinsic rewards.

  5. Trajectory generation for two robots cooperating to perform a task

    International Nuclear Information System (INIS)

    Lewis, C.L.

    1995-01-01

    This paper formulates an algorithm for trajectory generation for two robots cooperating to perform an assembly task. Treating the two robots as a single redundant system, this paper derives two Jacobian matrices which relate the joint rates of the entire system to the relative motion of the grippers with respect to one another. The advantage of this formulation over existing methods is that a variety of secondary criteria can be conveniently satisfied using motion in the null-space of the relative Jacobian. This paper presents methods for generating dual-arm joint trajectories which perform assembly tasks while at the same time avoiding obstacles and joint limits, and also maintaining constraints on the absolute position and orientation of the end-effectors

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

    Science.gov (United States)

    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.

  7. Fostering Self-Regulation in Training Complex Cognitive Tasks

    Science.gov (United States)

    van Meeuwen, Ludo W.; Brand-Gruwel, Saskia; Kirschner, Paul A.; de Bock, Jeano J. P. R.; van Merriënboer, Jeroen J. G.

    2018-01-01

    In complex cognitive domains such as air traffic control, professionals must be able to adapt to and act upon continuing changes in a highly advanced technological work environment. To function optimally in such an environment, the controllers must be able to regulate their learning. Although these regulation skills should be part of their…

  8. Representational scripting for carrying out complex learning tasks

    NARCIS (Netherlands)

    Slof, B.

    2011-01-01

    Learning to solve complex problems is important because in our rapidly changing modern society and work environments knowing the answer is often not possible. Although educators and instructional designers acknowledge the benefits of problem solving, they also realize that learners need good

  9. Influence of visual feedback on human task performance in ITER remote handling

    Energy Technology Data Exchange (ETDEWEB)

    Schropp, Gwendolijn Y.R., E-mail: g.schropp@heemskerk-innovative.nl [Utrecht University, Utrecht (Netherlands); Heemskerk Innovative Technology, Noordwijk (Netherlands); Heemskerk, Cock J.M. [Heemskerk Innovative Technology, Noordwijk (Netherlands); Kappers, Astrid M.L.; Tiest, Wouter M. Bergmann [Helmholtz Institute-Utrecht University, Utrecht (Netherlands); Elzendoorn, Ben S.Q. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM/FOM, Partner in the Trilateral Euregio Clusterand ITER-NL, PO box 1207, 3430 BE Nieuwegein (Netherlands); Bult, David [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM/FOM, Partner in the Trilateral Euregio Clusterand ITER-NL, PO box 1207, 3430 BE Nieuwegein (Netherlands)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer The performance of human operators in an ITER-like test facility for remote handling. Black-Right-Pointing-Pointer Different sources of visual feedback influence how fast one can complete a maintenance task. Black-Right-Pointing-Pointer Insights learned could be used in design of operator work environment or training procedures. - Abstract: In ITER, maintenance operations will be largely performed by remote handling (RH). Before ITER can be put into operation, safety regulations and licensing authorities require proof of maintainability for critical components. Part of the proof will come from using standard components and procedures. Additional verification and validation is based on simulation and hardware tests in 1:1 scale mockups. The Master Slave manipulator system (MS2) Benchmark Product was designed to implement a reference set of maintenance tasks representative for ITER remote handling. Experiments were performed with two versions of the Benchmark Product. In both experiments, the quality of visual feedback varied by exchanging direct view with indirect view (using video cameras) in order to measure and analyze its impact on human task performance. The first experiment showed that both experienced and novice RH operators perform a simple task significantly better with direct visual feedback than with camera feedback. A more complex task showed a large variation in results and could not be completed by many novice operators. Experienced operators commented on both the mechanical design and visual feedback. In a second experiment, a more elaborate task was tested on an improved Benchmark product. Again, the task was performed significantly faster with direct visual feedback than with camera feedback. In post-test interviews, operators indicated that they regarded the lack of 3D perception as the primary factor hindering their performance.

  10. Influence of visual feedback on human task performance in ITER remote handling

    International Nuclear Information System (INIS)

    Schropp, Gwendolijn Y.R.; Heemskerk, Cock J.M.; Kappers, Astrid M.L.; Tiest, Wouter M. Bergmann; Elzendoorn, Ben S.Q.; Bult, David

    2012-01-01

    Highlights: ► The performance of human operators in an ITER-like test facility for remote handling. ► Different sources of visual feedback influence how fast one can complete a maintenance task. ► Insights learned could be used in design of operator work environment or training procedures. - Abstract: In ITER, maintenance operations will be largely performed by remote handling (RH). Before ITER can be put into operation, safety regulations and licensing authorities require proof of maintainability for critical components. Part of the proof will come from using standard components and procedures. Additional verification and validation is based on simulation and hardware tests in 1:1 scale mockups. The Master Slave manipulator system (MS2) Benchmark Product was designed to implement a reference set of maintenance tasks representative for ITER remote handling. Experiments were performed with two versions of the Benchmark Product. In both experiments, the quality of visual feedback varied by exchanging direct view with indirect view (using video cameras) in order to measure and analyze its impact on human task performance. The first experiment showed that both experienced and novice RH operators perform a simple task significantly better with direct visual feedback than with camera feedback. A more complex task showed a large variation in results and could not be completed by many novice operators. Experienced operators commented on both the mechanical design and visual feedback. In a second experiment, a more elaborate task was tested on an improved Benchmark product. Again, the task was performed significantly faster with direct visual feedback than with camera feedback. In post-test interviews, operators indicated that they regarded the lack of 3D perception as the primary factor hindering their performance.

  11. The Effect of Task Type and Pre-task Planning Condition on the Accuracy of Intermediate EFL Learners' Writing Performance

    Directory of Open Access Journals (Sweden)

    Seyeed Mohammad Alavi

    2012-05-01

    Full Text Available Task-based language teaching, which requires learners to transact tasks resembling their real life language needs, demands language learners to perform planning at different stages of their learning. Since various types of tasks can be used in task-based instruction, the present study examined the effect of task types and various participatory structures during pre-task planning on the quality of learners' writing performance, (i.e., accuracy. Towards this end, 120 intermediate EFL students were randomly assigned to 3 experimental groups and one control group. While the experimental groups were subjected to different pre-task planning conditions, (i.e., individual, pair, and group, the control group performed tasks without any planning. During the treatment, they experienced task modeling, presentation and completion. A factorial design was followed in the present study, and the collected data were analyzed through ANOVAs that revealed task type and pre-task planning condition influenced the writing accuracy of the participants in a way that resulted in greater accuracy in the decision-making task in the experimental groups, thereby ensuring the effectiveness of the treatment in mitigating the long-standing problem of EFL learners in achieving higher levels of accuracy when a specific task type is concerned.

  12. Task dynamics in self-organising task groups : expertise, motivational, and performance differences of specialists and generalists

    NARCIS (Netherlands)

    Zoethout, Kees; Jager, Wander; Molleman, Eric

    Multi-agent simulation is applied to explore how different types of task variety cause workgroups to change their task allocation accordingly. We studied two groups, generalists and specialists. We hypothesised that the performance of the specialists would decrease when task variety increases. The

  13. Reduced Electromyographic Fatigue Threshold after Performing a Cognitive Fatiguing Task.

    Science.gov (United States)

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

    2018-02-22

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

  14. Walking while performing working memory tasks changes the prefrontal cortex hemodynamic activations and gait kinematics

    Directory of Open Access Journals (Sweden)

    Ming-I Brandon Lin

    2016-05-01

    Full Text Available BackgroundIncreasing evidence suggests that walking while performing a concurrent task negatively influences gait performance. However, it remains unclear how higher-level cognitive processes and coordination of limb movements are altered in challenging walking environments. This study investigated the influence of cognitive task complexity and walking road condition on the neutral correlates of executive function and postural control in dual-task walking. MethodsTwenty-four healthy young adults completed a series of overground walks with three walking road conditions (wide, narrow, with obstacles with and without the concurrent n-back working memory tasks of two complexity levels (1-back and 3-back. Prefrontal brain activation was assessed by functional near-infrared spectroscopy. A three-dimensional motion analysis system was used simultaneously to measure gait performance and lower-extremity kinematics. Repeated measures analysis of variance were performed to examine the differences between the conditions. ResultsIn comparison with standing still, participants showed lower n-back task accuracy while walking, with the worst performance from the road with obstacles. Spatiotemporal gait parameters, lower-extremity joint movements, and the relative changes in oxygenated hemoglobin (HbO concentration levels were all significantly different across the task complexity and walking path conditions. While dual-tasking participants were found to flex their hips and knees less, leading to a slower gait speed, longer stride time, shorter step length, and greater gait variability than during normal walking. For narrow-road walking, smaller ankle dorsiflexion and larger hip flexion were observed, along with a reduced gait speed. Obstacle negotiation was mainly characterized by increased gait variability than other conditions. HbO levels appeared to be lower during dual-task walking than normal walking. Compared to wide and obstacle conditions, walking on

  15. SOCIAL COMPLEXITY AND LEARNING FORAGING TASKS IN BEES

    Directory of Open Access Journals (Sweden)

    AMAYA-MÁRQUEZ MARISOL

    2008-12-01

    Full Text Available Social complexity and models concerning central place foraging were tested with respect to learning predictions using the social honey bee (Apis mellifera and solitary blue orchard bee (Osmia lignaria when given foraging problems. Both species were presented the same foraging problems, where 1 only reward molarity varied between flower morphs, and 2 only reward volume varied between flower morphs. Experiments utilized blue vs. white flower patches to standardize rewards in each experimental situation. Although honey bees learned faster than blue orchard bees when given a molarity difference reward problem, there was no significant difference in learning rate when presented a volume difference reward problem. Further, the rate at which blue orchard bees learned the volume difference problem was not significantly different from that with which honey bees learned about reward molarity differences. The results do not support the predictions of the social complexity theory, but do support those of the central place model

  16. Grammatical production deficits in PPA: Relating narrative and structured task performance

    Directory of Open Access Journals (Sweden)

    Elena Barbieri

    2015-05-01

    Full Text Available Introduction Grammatical production impairments in primary progressive aphasia (PPA have been investigated using structured language tasks and analysis of narrative language samples (for review see Thompson & Mack, 2014; Wilson et al., 2012. However, little research has examined the relationship between them in PPA. Whereas structured tasks often assess production accuracy at different levels of syntactic complexity (e.g., Thompson et al., 2013, narrative measures typically assess overall lexical and grammatical usage (e.g., % grammatical sentences; noun-to-verb ratio, with lesser emphasis on complexity. The present study investigated the relationship between narrative measures of grammatical production and performance on structured language tests in the domains of syntax, verb morphology, and verb-argument structure (VAS. Materials and methods Data from 101 individuals with PPA were included. Participants completed a test battery including the Northwestern Assessment of Verbs and Sentences (NAVS, Thompson, 2011, the Northwestern Assessment of Verb Inflection (NAVI, Lee & Thompson, experimental version and the Northwestern Anagram Test (NAT, Thompson, Weintraub, & Mesulam, 2012. Grammatical production deficits were quantified as follows: for syntax, accuracy of non-canonical sentence production on the NAVS Sentence Production Priming Test (SPPT and the NAT; for morphology, the accuracy on finite verbs on the NAVI; for VAS, the accuracy of sentences produced with 2- and 3-argument verbs on the NAVS Argument Structure Production Test (ASPT. Cinderella narrative samples were analyzed using the Northwestern Narrative Language Analysis system (e.g., Thompson et al., 2012. For syntax, complexity was measured by the ratio of syntactically complex to simple sentences produced, whereas accuracy was indexed by computing the proportion of words with a locally grammatical lexical category. Morphological complexity was measured by mean number of verb

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

    Directory of Open Access Journals (Sweden)

    Grace Vincent

    Full Text Available 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.

  18. PENGARUH SISTEM INFORMASI TEKNOLOGI ELEKTRONIK ATAS TASK PERFORMANCE AUDITOR KANTOR AKUNTAN PUBLIK BIG 4

    Directory of Open Access Journals (Sweden)

    Antonius Herusetya

    2010-06-01

    Full Text Available Auditors of public accounting firms frequently deal with the tasks oriented to the audit judgment decision makings. And due to the nature of these tasks are frequently complex and unstructured, they need electronic technology based information system to achieve higher audit quality and to minimize audit risks. The purpose of this study is to examine whether the information system used by the auditors of public accounting firms in the form of Group Support Systems (GSS, Group Decision Support Systems (GDSS or other electronic information technology software could increase auditors’ performance in their audit tasks. With the respondent of practicing auditors from the Big 4 public accounting firms in Indonesia, and by using structural equation model (SEM analysis, we found evidence that the usage of Electronic Information System Technology (EIST has significantly positive impact on audit task performance. We found evidence that the perceived ease of use from the Big 4 auditors has positive significant impact on the perceive usefulness of electronic information system technology adopted by public accounting firms. We have also found evidence that the nature of critical, judgmental, and non-routine audit task complexities in the audit fields has significant impact on the system usage. On the other hands the perceived of ease of use, and the perceived usefulness of electronic information system technology have weak significant impact on the system utilization of the Big 4 auditors.

  19. Visual Motor and Perceptual Task Performance in Astigmatic Students

    Directory of Open Access Journals (Sweden)

    Erin M. Harvey

    2017-01-01

    Full Text Available Purpose. To determine if spectacle corrected and uncorrected astigmats show reduced performance on visual motor and perceptual tasks. Methods. Third through 8th grade students were assigned to the low refractive error control group (astigmatism < 1.00 D, myopia < 0.75 D, hyperopia < 2.50 D, and anisometropia < 1.50 D or bilateral astigmatism group (right and left eye ≥ 1.00 D based on cycloplegic refraction. Students completed the Beery-Buktenica Developmental Test of Visual Motor Integration (VMI and Visual Perception (VMIp. Astigmats were randomly assigned to testing with/without correction and control group was tested uncorrected. Analyses compared VMI and VMIp scores for corrected and uncorrected astigmats to the control group. Results. The sample included 333 students (control group 170, astigmats tested with correction 75, and astigmats tested uncorrected 88. Mean VMI score in corrected astigmats did not differ from the control group (p=0.829. Uncorrected astigmats had lower VMI scores than the control group (p=0.038 and corrected astigmats (p=0.007. Mean VMIp scores for uncorrected (p=0.209 and corrected astigmats (p=0.124 did not differ from the control group. Uncorrected astigmats had lower mean scores than the corrected astigmats (p=0.003. Conclusions. Uncorrected astigmatism influences visual motor and perceptual task performance. Previously spectacle treated astigmats do not show developmental deficits on visual motor or perceptual tasks when tested with correction.

  20. Self-Associations Influence Task-Performance through Bayesian Inference.

    Science.gov (United States)

    Bengtsson, Sara L; Penny, Will D

    2013-01-01

    The way we think about ourselves impacts greatly on our behavior. This paper describes a behavioral study and a computational model that shed new light on this important area. Participants were primed "clever" and "stupid" using a scrambled sentence task, and we measured the effect on response time and error-rate on a rule-association task. First, we observed a confirmation bias effect in that associations to being "stupid" led to a gradual decrease in performance, whereas associations to being "clever" did not. Second, we observed that the activated self-concepts selectively modified attention toward one's performance. There was an early to late double dissociation in RTs in that primed "clever" resulted in RT increase following error responses, whereas primed "stupid" resulted in RT increase following correct responses. We propose a computational model of subjects' behavior based on the logic of the experimental task that involves two processes; memory for rules and the integration of rules with subsequent visual cues. The model incorporates an adaptive decision threshold based on Bayes rule, whereby decision thresholds are increased if integration was inferred to be faulty. Fitting the computational model to experimental data confirmed our hypothesis that priming affects the memory process. This model explains both the confirmation bias and double dissociation effects and demonstrates that Bayesian inferential principles can be used to study the effect of self-concepts on behavior.

  1. Self-associations influence task-performance through Bayesian inference

    Directory of Open Access Journals (Sweden)

    Sara L Bengtsson

    2013-08-01

    Full Text Available The way we think about ourselves impacts greatly on our behaviour. This paper describes a behavioural study and a computational model that sheds new light on this important area. Participants were primed 'clever' and 'stupid' using a scrambled sentence task, and we measured the effect on response time and error-rate on a rule-association task. First, we observed a confirmation bias effect in that associations to being 'stupid' led to a gradual decrease in performance, whereas associations to being 'clever' did not. Second, we observed that the activated self-concepts selectively modified attention towards one's performance. There was an early to late double dissociation in RTs in that primed 'clever' resulted in RT increase following error responses, whereas primed 'stupid' resulted in RT increase following correct responses. We propose a computational model of subjects' behaviour based on the logic of the experimental task that involves two processes; memory for rules and the integration of rules with subsequent visual cues. The model also incorporates an adaptive decision threshold based on Bayes rule, whereby decision thresholds are increased if integration was inferred to be faulty. Fitting the computational model to experimental data confirmed our hypothesis that priming affects the memory process. This model explains both the confirmation bias and double dissociation effects and demonstrates that Bayesian inferential principles can be used to study the effect of self-concepts on behaviour.

  2. Effect of Passive Hyperthermia on Working Memory Resources during Simple and Complex Cognitive Tasks.

    Science.gov (United States)

    Gaoua, Nadia; Herrera, Christopher P; Périard, Julien D; El Massioui, Farid; Racinais, Sebastien

    2017-01-01

    The aim of this study was to verify the hypothesis that hyperthermia represents a cognitive load limiting available resources for executing concurrent cognitive tasks. Electroencephalographic activity (EEG: alpha and theta power) was obtained in 10 hyperthermic participants in HOT (50°C, 50% RH) conditions and in a normothermic state in CON (25°C, 50% RH) conditions in counterbalanced order. In each trial, EEG was measured over the frontal lobe prior to task engagement (PRE) in each condition and during simple (One Touch Stockings of Cambridge, OTS-4) and complex (OTS-6) cognitive tasks. Core (39.5 ± 0.5 vs. 36.9 ± 0.2°C) and mean skin (39.06 ± 0.3 vs. 31.6 ± 0.6°C) temperatures were significantly higher in HOT than CON ( p cognitive load. However, this load disappeared during OTS-6 together with an impaired performance, suggesting a potential saturation of the available resources.

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

    Science.gov (United States)

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

    2015-01-01

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

  4. Task complexity as a driver for collaborative learning efficiency: The collective working-memory effect

    NARCIS (Netherlands)

    Kirschner, Femke; Paas, Fred; Kirschner, Paul A.

    2010-01-01

    Kirschner, F., Paas, F., & Kirschner, P. A. (2011). Task complexity as a driver for collaborative learning efficiency: The collective working-memory effect. Applied Cognitive Psychology, 25, 615–624. doi: 10.1002/acp.1730.

  5. Complex Span versus Updating Tasks of Working Memory: The Gap Is Not that Deep

    Science.gov (United States)

    Schmiedek, Florian; Hildebrandt, Andrea; Lovden, Martin; Wilhelm, Oliver; Lindenberger, Ulman

    2009-01-01

    How to best measure working memory capacity is an issue of ongoing debate. Besides established complex span tasks, which combine short-term memory demands with generally unrelated secondary tasks, there exists a set of paradigms characterized by continuous and simultaneous updating of several items in working memory, such as the n-back, memory…

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

    NARCIS (Netherlands)

    Nadolski, Rob; Kirschner, Paul A.; Van Merriënboer, Jeroen

    2007-01-01

    Background. 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 optimised for efficient and effective learning. Aim. The aim of the study is

  7. Memory Indexing: A Novel Method for Tracing Memory Processes in Complex Cognitive Tasks

    Science.gov (United States)

    Renkewitz, Frank; Jahn, Georg

    2012-01-01

    We validate an eye-tracking method applicable for studying memory processes in complex cognitive tasks. The method is tested with a task on probabilistic inferences from memory. It provides valuable data on the time course of processing, thus clarifying previous results on heuristic probabilistic inference. Participants learned cue values of…

  8. Error affect inoculation for a complex decision-making task.

    Science.gov (United States)

    Tabernero, Carmen; Wood, Robert E

    2009-05-01

    Individuals bring knowledge, implicit theories, and goal orientations to group meetings. Group decisions arise out of the exchange of these orientations. This research explores how a trainee's exploratory and deliberate process (an incremental theory and learning goal orientation) impacts the effectiveness of individual and group decision-making processes. The effectiveness of this training program is compared with another program that included error affect inoculation (EAI). Subjects were 40 Spanish Policemen in a training course. They were distributed in two training conditions for an individual and group decision-making task. In one condition, individuals received the Self-Guided Exploration plus Deliberation Process instructions, which emphasised exploring the options and testing hypotheses. In the other condition, individuals also received instructions based on Error Affect Inoculation (EAI), which emphasised positive affective reactions to errors and mistakes when making decisions. Results show that the quality of decisions increases when the groups share their reasoning. The AIE intervention promotes sharing information, flexible initial viewpoints, and improving the quality of group decisions. Implications and future directions are discussed.

  9. Task demands moderate stereotype threat effects on memory performance.

    Science.gov (United States)

    Hess, Thomas M; Emery, Lisa; Queen, Tara L

    2009-06-01

    Previous research has demonstrated that older adults' memory performance is adversely affected by the explicit activation of negative stereotypes about aging. In this study, we examined the impact of stereotype threat on recognition memory, with specific interest in (a) the generalizability of previously observed effects, (b) the subjective experience of memory, and (c) the moderating effects of task demands. Older participants subjected to threat performed worse than did those in a nonthreat condition but only when performance constraints were high (i.e., memory decisions had to be made within a limited time frame). This effect was reflected in the subjective experience of memory, with participants in this condition having a lower ratio of "remember" to "know" responses. The absence of threat effects when constraints were minimal provides important boundary information regarding stereotype influences on memory performance.

  10. Do absorption and realistic distraction influence performance of component task surgical procedure?

    Science.gov (United States)

    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.

  11. 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

    Science.gov (United States)

    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…

  12. Is Performance in Task-Cuing Experiments Mediated by Task Set Selection or Associative Compound Retrieval?

    Science.gov (United States)

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

    2014-01-01

    Task-cuing experiments are usually intended to explore control of task set. But when small stimulus sets are used, they plausibly afford learning of the response associated with a combination of cue and stimulus, without reference to tasks. In 3 experiments we presented the typical trials of a task-cuing experiment: a cue (colored shape) followed,…

  13. The Effect of a Workload-Preview on Task-Prioritization and Task-Performance

    Science.gov (United States)

    Minotra, Dev

    2012-01-01

    With increased volume and sophistication of cyber attacks in recent years, maintaining situation awareness and effective task-prioritization strategy is critical to the task of cybersecurity analysts. However, high levels of mental-workload associated with the task of cybersecurity analyst's limits their ability to prioritize tasks.…

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

    Science.gov (United States)

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

    2008-01-01

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

  15. Relation between task complexity and variability of procedure progression during an emergency operation

    International Nuclear Information System (INIS)

    Kim, Yochan; Park, Jinkyun; Jung, Wondea

    2013-01-01

    Highlights: • The relation between task complexity and the variability of procedure progression was investigated. • The two quantitative measures, TACOM and VPP, were applied to this study. • The task complexity was positively related with the operator’s procedural variability. • The VPP measure can be useful for explaining the operator’s behaviors. - Abstract: In this study, the relation between task complexity and variability of procedure progression during an emergency operation was investigated by comparing the two quantitative measures. To this end, the TACOM measure and VPP measure were applied to evaluate the complexity of tasks and variability of procedure progression, respectively. The TACOM scores and VPP scores were obtained for 60 tasks in the OPERA database, and a correlation analysis between two measures and a multiple regression analysis between the sub-measures of the TACOM measure and VPP measure were conducted. The results showed that the TACOM measure is positively associated with the VPP measure, and the abstraction hierarchy complexity mainly affected the variability among the sub-measures of TACOM. From these findings, it was discussed that the task complexity is related to an operator’s procedural variability and VPP measure can be useful for explaining the operator’s behaviors

  16. The appropriateness of TACOM for a task complexity measure for emergency operating procedures of nuclear power plants - A comparison with OPAS scores

    International Nuclear Information System (INIS)

    Park, Jinkyun; Jung, Wondea

    2007-01-01

    It is well known that complicated procedures frequently cause human performance related problems that can result in a serious consequence. Unfortunately a systematic framework to evaluate the complexity of procedures is very rare. For this reason Park et al. suggested a measure called TACOM (Task Complexity) which is able to quantify the complexity of tasks stipulated in procedures. In addition, it was observed that there is a significant correlation between averaged task performance time data and estimated TACOM scores. In this study, for an additional verification activity, TACOM scores are compared with operators' performance data that are measured by Operator Performance Assessment System (OPAS). As a result, it is believed that TACOM scores seem to be meaningfully correlated with OPAS scores. Thus, it is reasonable to expect that the result of this study can be regarded as a supplementary evidence for supporting the fact that TACOM measure is applicable for quantifying the complexity of tasks to be done by operators

  17. A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance.

    Science.gov (United States)

    Astrand, Elaine

    2018-06-01

    Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, [Formula: see text]. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-by-trial working memory task performance is demonstrated (r  =  0.47, p  performance before action (r  =  0.49, p  <  0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain-machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or using the continuous measure as neurofeedback opens up new possibilities to develop novel rehabilitation techniques for

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

    Science.gov (United States)

    Morrell, R W; Park, D C

    1993-09-01

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

  19. Performance Potential at one Complex, Specific Site

    DEFF Research Database (Denmark)

    Laursen, Bjørn

    2015-01-01

    disciplines: performance, drama, dance and music. Complex rules of “borders” between audience and actors/performers appeared to be present and active during this long happening. Different narrative genres were active simultaneously during the experimental session. A lot of complex and surprising phenomena...... and combinations of spatial, dramaturgical, narrative and interactive challenges, which appear to be of special interest for the kind of experiences an audience might gather in a site like this, originally created with totally different intentions. Or was it?...

  20. Evaluation of Cognitive Complexity of Tasks for the Topic Hydrogen Exponent in the Solutions of Acids and Bases

    Directory of Open Access Journals (Sweden)

    Saša Horvat

    2018-02-01

    Full Text Available The aim of this study was evaluation of cognitive complexity of tasks for the topic hydrogen exponent in the solutions of acids and bases and its validation. The created procedure included an assessment of the difficulty of concepts and an assessment of their interactivity. There were 48 freshmen students enrolled in the study program Basic academic studies in chemistry. As a research instrument for assessing performance, test of knowledge was specifically constructed for this research. Each task in the test was followed by a seven-point Likert scale for the evaluation of invested mental effort. The evaluation of cognitive complexity was confirmed by a series of linear regression analysis where high values of correlation coefficients are obtained among the examined variables: student’s performance and invested mental effort (dependent variables and cognitive complexity (independent variable.

  1. Effect of Error Augmentation on Brain Activation and Motor Learning of a Complex Locomotor Task

    Directory of Open Access Journals (Sweden)

    Laura Marchal-Crespo

    2017-09-01

    Full Text Available Up to date, the functional gains obtained after robot-aided gait rehabilitation training are limited. Error augmenting strategies have a great potential to enhance motor learning of simple motor tasks. However, little is known about the effect of these error modulating strategies on complex tasks, such as relearning to walk after a neurologic accident. Additionally, neuroimaging evaluation of brain regions involved in learning processes could provide valuable information on behavioral outcomes. We investigated the effect of robotic training strategies that augment errors—error amplification and random force disturbance—and training without perturbations on brain activation and motor learning of a complex locomotor task. Thirty-four healthy subjects performed the experiment with a robotic stepper (MARCOS in a 1.5 T MR scanner. The task consisted in tracking a Lissajous figure presented on a display by coordinating the legs in a gait-like movement pattern. Behavioral results showed that training without perturbations enhanced motor learning in initially less skilled subjects, while error amplification benefited better-skilled subjects. Training with error amplification, however, hampered transfer of learning. Randomly disturbing forces induced learning and promoted transfer in all subjects, probably because the unexpected forces increased subjects' attention. Functional MRI revealed main effects of training strategy and skill level during training. A main effect of training strategy was seen in brain regions typically associated with motor control and learning, such as, the basal ganglia, cerebellum, intraparietal sulcus, and angular gyrus. Especially, random disturbance and no perturbation lead to stronger brain activation in similar brain regions than error amplification. Skill-level related effects were observed in the IPS, in parts of the superior parietal lobe (SPL, i.e., precuneus, and temporal cortex. These neuroimaging findings

  2. The concentric model of human working memory: A validation study using complex span and updating tasks

    Directory of Open Access Journals (Sweden)

    Velichkovsky B. B.

    2017-09-01

    Full Text Available Background. Working memory (WM seems to be central to most forms of high-level cognition. This fact is fueling the growing interest in studying its structure and functional organization. The influential “concentric model” (Oberauer, 2002 suggests that WM contains a processing component and two storage components with different capacity limitations and sensitivity to interference. There is, to date, only limited support for the concentric model in the research literature, and it is limited to a number of specially designed tasks. Objective. In the present paper, we attempted to validate the concentric model by testing its major predictions using complex span and updating tasks in a number of experimental paradigms. Method. The model predictions were tested with the help of review of data obtained primarily in our own experiments in several research domains, including Sternberg’s additive factors method; factor structure of WM; serial position effects in WM; and WM performance in a sample with episodic long-term memory deficits. Results. Predictions generated by the concentric model were shown to hold in all these domains. In addition, several new properties of WM were identified. In particular, we recently found that WM indeed contains a processing component which functions independent of storage components. In turn, the latter were found to form a storage hierarchy which balances fast access to selected items, with the storing of large amounts of potentially relevant information. Processing and storage in WM were found to be dependent on shared cognitive resources which are dynamically allocated between WM components according to actual task requirements. e implications of these findings for the theory of WM are discussed. Conclusion. The concentric model was shown to be valid with respect to standard WM tasks. The concentric model others promising research perspectives for the study of higher- order cognition, including underlying

  3. Effect of Passive Hyperthermia on Working Memory Resources during Simple and Complex Cognitive Tasks

    Directory of Open Access Journals (Sweden)

    Nadia Gaoua

    2018-01-01

    Full Text Available The aim of this study was to verify the hypothesis that hyperthermia represents a cognitive load limiting available resources for executing concurrent cognitive tasks. Electroencephalographic activity (EEG: alpha and theta power was obtained in 10 hyperthermic participants in HOT (50°C, 50% RH conditions and in a normothermic state in CON (25°C, 50% RH conditions in counterbalanced order. In each trial, EEG was measured over the frontal lobe prior to task engagement (PRE in each condition and during simple (One Touch Stockings of Cambridge, OTS-4 and complex (OTS-6 cognitive tasks. Core (39.5 ± 0.5 vs. 36.9 ± 0.2°C and mean skin (39.06 ± 0.3 vs. 31.6 ± 0.6°C temperatures were significantly higher in HOT than CON (p < 0.005. Theta power significantly increased with task demand (p = 0.017, η2 = 0.36 and was significantly higher in HOT than CON (p = 0.041, η2 = 0.39. The difference between HOT and CON was large (η2 = 0.40 and significant (p = 0.036 PRE, large (η2 = 0.20 but not significant (p = 0.17 during OTS-4, and disappeared during OTS-6 (p = 0.87, η2 = 0.00. Those changes in theta power suggest that hyperthermia may act as an additional cognitive load. However, this load disappeared during OTS-6 together with an impaired performance, suggesting a potential saturation of the available resources.

  4. High-definition television evaluation for remote handling task performance

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  5. Helicopter Pilot Performance for Discrete-maneuver Flight Tasks

    Science.gov (United States)

    Heffley, R. K.; Bourne, S. M.; Hindson, W. S.

    1984-01-01

    This paper describes a current study of several basic helicopter flight maneuvers. The data base consists of in-flight measurements from instrumented helicopters using experienced pilots. The analysis technique is simple enough to apply without automatic data processing, and the results can be used to build quantitative matah models of the flight task and some aspects of the pilot control strategy. In addition to describing the performance measurement technqiue, some results are presented which define the aggressiveness and amplitude of maneuvering for several lateral maneuvers including turns and sidesteps.

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

    Science.gov (United States)

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

    2018-06-01

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

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

    Science.gov (United States)

    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.

  8. Joining Distributed Complex Objects: Definition and Performance

    NARCIS (Netherlands)

    Teeuw, W.B.; Teeuw, Wouter B.; Blanken, Henk

    1992-01-01

    The performance of a non-standard distributed database system is strongly ifluenced by complex objects. The effective exploitation of parallelism in querying them and a suitable structure to store them are required in order to obtain acceptable response times in these database environments where

  9. Heuristics in Managing Complex Clinical Decision Tasks in Experts' Decision Making.

    Science.gov (United States)

    Islam, Roosan; Weir, Charlene; Del Fiol, Guilherme

    2014-09-01

    Clinical decision support is a tool to help experts make optimal and efficient decisions. However, little is known about the high level of abstractions in the thinking process for the experts. The objective of the study is to understand how clinicians manage complexity while dealing with complex clinical decision tasks. After approval from the Institutional Review Board (IRB), three clinical experts were interviewed the transcripts from these interviews were analyzed. We found five broad categories of strategies by experts for managing complex clinical decision tasks: decision conflict, mental projection, decision trade-offs, managing uncertainty and generating rule of thumb. Complexity is created by decision conflicts, mental projection, limited options and treatment uncertainty. Experts cope with complexity in a variety of ways, including using efficient and fast decision strategies to simplify complex decision tasks, mentally simulating outcomes and focusing on only the most relevant information. Understanding complex decision making processes can help design allocation based on the complexity of task for clinical decision support design.

  10. The Regulation of Task Performance: A Trans-disciplinary Review

    Directory of Open Access Journals (Sweden)

    Ian eClark

    2016-01-01

    Full Text Available Definitions of meta-cognition typically have two components: (1 knowledge about one’s own cognitive functioning; and, (2 control over one’s own cognitive activities. Since Flavell and his colleagues provided the empirical foundation on which to build studies of metacognition and the autonoetic (self knowledge required for effective learning, the intervening years have seen the extensive dissemination of theoretical and empirical research on metacognition, which now encompasses a variety of issues and domains including educational psychology and neuroscience. Nevertheless, the psychological and neural underpinnings of metacognitive predictions and reflections that determine subsequent regulation of task performance remain ill understood. This article provides an outline of metacognition in the science of education with evidence drawn from neuroimaging, psycho-physiological, and psychological literature. We will rigorously explore research that addresses the pivotal role of the prefrontal cortex (PFC in controlling the metacognitive processes that underpin the self-regulated learning (SRL strategies learners employ to regulate task performance. The article delineates what those strategies are, and how the learning environment can facilitate or frustrate strategy use by influencing learners’ self-efficacy.

  11. EFFECTIVE INDICES FOR MONITORING MENTAL WORKLOAD WHILE PERFORMING MULTIPLE TASKS.

    Science.gov (United States)

    Hsu, Bin-Wei; Wang, Mao-Jiun J; Chen, Chi-Yuan; Chen, Fang

    2015-08-01

    This study identified several physiological indices that can accurately monitor mental workload while participants performed multiple tasks with the strategy of maintaining stable performance and maximizing accuracy. Thirty male participants completed three 10-min. simulated multitasks: MATB (Multi-Attribute Task Battery) with three workload levels. Twenty-five commonly used mental workload measures were collected, including heart rate, 12 HRV (heart rate variability), 10 EEG (electroencephalography) indices (α, β, θ, α/θ, θ/β from O1-O2 and F4-C4), and two subjective measures. Analyses of index sensitivity showed that two EEG indices, θ and α/θ (F4-C4), one time-domain HRV-SDNN (standard deviation of inter-beat intervals), and four frequency-domain HRV: VLF (very low frequency), LF (low frequency), %HF (percentage of high frequency), and LF/HF were sensitive to differentiate high workload. EEG α/θ (F4-C4) and LF/HF were most effective for monitoring high mental workload. LF/HF showed the highest correlations with other physiological indices. EEG α/θ (F4-C4) showed strong correlations with subjective measures across different mental workload levels. Operation strategy would affect the sensitivity of EEG α (F4-C4) and HF.

  12. The Regulation of Task Performance: A Trans-Disciplinary Review

    Science.gov (United States)

    Clark, Ian; Dumas, Guillaume

    2016-01-01

    Definitions of meta-cognition typically have two components: (1) knowledge about one's own cognitive functioning; and, (2) control over one's own cognitive activities. Since Flavell and his colleagues provided the empirical foundation on which to build studies of meta-cognition and the autonoetic (self) knowledge required for effective learning, the intervening years have seen the extensive dissemination of theoretical and empirical research on meta-cognition, which now encompasses a variety of issues and domains including educational psychology and neuroscience. Nevertheless, the psychological and neural underpinnings of meta-cognitive predictions and reflections that determine subsequent regulation of task performance remain ill understood. This article provides an outline of meta-cognition in the science of education with evidence drawn from neuroimaging, psycho-physiological, and psychological literature. We will rigorously explore research that addresses the pivotal role of the prefrontal cortex (PFC) in controlling the meta-cognitive processes that underpin the self-regulated learning (SRL) strategies learners employ to regulate task performance. The article delineates what those strategies are, and how the learning environment can facilitate or frustrate strategy use by influencing learners' self-efficacy. PMID:26779050

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

    Science.gov (United States)

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

    2017-01-01

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

  14. Motor planning flexibly optimizes performance under uncertainty about task goals.

    Science.gov (United States)

    Wong, Aaron L; Haith, Adrian M

    2017-03-03

    In an environment full of potential goals, how does the brain determine which movement to execute? Existing theories posit that the motor system prepares for all potential goals by generating several motor plans in parallel. One major line of evidence for such theories is that presenting two competing goals often results in a movement intermediate between them. These intermediate movements are thought to reflect an unintentional averaging of the competing plans. However, normative theories suggest instead that intermediate movements might actually be deliberate, generated because they improve task performance over a random guessing strategy. To test this hypothesis, we vary the benefit of making an intermediate movement by changing movement speed. We find that participants generate intermediate movements only at (slower) speeds where they measurably improve performance. Our findings support the normative view that the motor system selects only a single, flexible motor plan, optimized for uncertain goals.

  15. Sleep-related offline improvements in gross motor task performance occur under free recall requirements

    Directory of Open Access Journals (Sweden)

    Andreas eMalangre

    2016-03-01

    Full Text Available Nocturnal sleep effects on memory consolidation following gross motor sequence learning were examined using a complex arm movement task. This task required participants to produce non-regular spatial patterns in the horizontal plane by successively fitting a small peg into different target-holes on an electronic pegboard. The respective reaching movements typically differed in amplitude and direction. Targets were visualized prior to each transport movement on a computer screen. With this task we tested 18 subjects (22.6 +/- 1.9 years; 8 female using a between-subjects design. Participants initially learned a 10-element arm movement sequence either in the morning or in the evening. Performance was retested under free recall requirements 15 minutes post training, as well as 12 hrs and 24 hrs later. Thus each group was provided with one sleep-filled and one wake retention interval. Dependent variables were error rate (number of erroneous sequences and average sequence execution time (correct sequences only. Performance improved during acquisition. Error rate remained stable across retention. Sequence execution time (inverse to execution speed significantly decreased again during the sleep-filled retention intervals, but remained stable during the respective wake intervals. These results corroborate recent findings on sleep-related enhancement consolidation in ecological valid, complex gross motor tasks. At the same time they suggest this effect to be truly memory-based and independent from repeated access to extrinsic sequence information during retests.

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Cloud Computing for Complex Performance Codes.

    Energy Technology Data Exchange (ETDEWEB)

    Appel, Gordon John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Klein, Brandon Thorin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miner, John Gifford [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    This report describes the use of cloud computing services for running complex public domain performance assessment problems. The work consisted of two phases: Phase 1 was to demonstrate complex codes, on several differently configured servers, could run and compute trivial small scale problems in a commercial cloud infrastructure. Phase 2 focused on proving non-trivial large scale problems could be computed in the commercial cloud environment. The cloud computing effort was successfully applied using codes of interest to the geohydrology and nuclear waste disposal modeling community.

  18. Sleep restriction and cognitive load affect performance on a simulated marksmanship task.

    Science.gov (United States)

    Smith, Carl D; Cooper, Adam D; Merullo, Donna J; Cohen, Bruce S; Heaton, Kristin J; Claro, Pedro J; Smith, Tracey

    2017-11-24

    Sleep restriction degrades cognitive and motor performance, which can adversely impact job performance and increase the risk of accidents. Military personnel are prone to operating under sleep restriction, and previous work suggests that military marksmanship may be negatively affected under such conditions. Results of these studies, however, are mixed and have often incorporated additional stressors (e.g. energy restriction) beyond sleep restriction. Moreover, few studies have investigated how the degree of difficulty of a marksmanship task impacts performance following sleep restriction. The purpose of the current experiment was to study the effects of sleep restriction on marksmanship while minimizing the potential influence of other forms of stress. A friend-foe discrimination challenge with greater or lesser degrees of complexity (high versus low load) was used as the primary marksmanship task. Active duty Soldiers were recruited, and allowed 2 h of sleep every 24 h over a 72-h testing period. Marksmanship tasks, cognitive assessment metrics and the NASA-Task Load Index were administered daily. Results indicated that reaction times to shoot foe targets and signal friendly targets slowed over time. In addition, the ability to correctly discriminate between friend and foe targets significantly decreased in the high-cognitive-load condition over time despite shot accuracy remaining stable. The NASA-Task Load Index revealed that, although marksmanship performance degraded, participants believed their performance did not change over time. These results further characterize the consequences of sleep restriction on marksmanship performance and the perception of performance, and reinforce the importance of adequate sleep among service members when feasible. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

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

    Science.gov (United States)

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

    2017-07-05

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

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

    Science.gov (United States)

    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.

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

    OpenAIRE

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

    2017-01-01

    Dual tasking, or the simultaneous execution of two continuous tasks, is frequently associated with a performance decline that can be explained within a capacity sharing framework. In this study, we assessed the effects of a concurrent motor task on the efficiency of visual information uptake based on the ‘theory of visual attention’ (TVA). TVA provides parameter estimates reflecting distinct components of visual processing capacity: perceptual threshold, visual processing speed, and visual sh...

  2. The development of a quantitative measure for the complexity of emergency tasks stipulated in emergency operating procedures of nuclear power plants

    International Nuclear Information System (INIS)

    Park, Jin Kyun; Jung, Won Dea

    2006-11-01

    Previous studies have continuously pointed out that human performance is a decisive factor affecting the safety of complicated process systems. Subsequently, as the result of extensive efforts, it has been revealed that the provision of procedures is one of the most effective countermeasures, especially if human operators have to carry out their tasks under a very stressful environment. That is, since good procedures are helpful to not only enhance the performance of human operators but also the reduction of the possibility of a human error through stipulating detailed tasks to be done by human operators. Ironically, it has been emphasized that the performance of human operators could be impaired due to complicated procedures, because procedures directly govern the physical as well as cognitive behavior of human operators by institutionalizing detailed actions. Therefore, it is a prerequisite to develop a systematic framework that properly evaluate the complexity of tasks described in procedures. For this reason, a measure called TACOM (Task Complexity) that can quantify the complexity of emergency tasks described in the emergency operating procedures (EOPs) of NPPs has been developed. In this report, a technical background as well as practical steps to quantify the complexity of tasks were presented with a series of studies that were conducted to ensure the validity of the TACOM measure. As a result of validation studies, since it is shown that the TACOM measure seem to properly quantify the complexity of emergency tasks, it is desirable that the TACOM measure plays an important role in improving the performance of human operators

  3. The development of a quantitative measure for the complexity of emergency tasks stipulated in emergency operating procedures of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Kyun; Jung, Won Dea

    2006-11-15

    Previous studies have continuously pointed out that human performance is a decisive factor affecting the safety of complicated process systems. Subsequently, as the result of extensive efforts, it has been revealed that the provision of procedures is one of the most effective countermeasures, especially if human operators have to carry out their tasks under a very stressful environment. That is, since good procedures are helpful to not only enhance the performance of human operators but also the reduction of the possibility of a human error through stipulating detailed tasks to be done by human operators. Ironically, it has been emphasized that the performance of human operators could be impaired due to complicated procedures, because procedures directly govern the physical as well as cognitive behavior of human operators by institutionalizing detailed actions. Therefore, it is a prerequisite to develop a systematic framework that properly evaluate the complexity of tasks described in procedures. For this reason, a measure called TACOM (Task Complexity) that can quantify the complexity of emergency tasks described in the emergency operating procedures (EOPs) of NPPs has been developed. In this report, a technical background as well as practical steps to quantify the complexity of tasks were presented with a series of studies that were conducted to ensure the validity of the TACOM measure. As a result of validation studies, since it is shown that the TACOM measure seem to properly quantify the complexity of emergency tasks, it is desirable that the TACOM measure plays an important role in improving the performance of human operators.

  4. 78 FR 15112 - Rulemaking Advisory Committee; Transport Airplane Performance and Handling Characteristics-New Task

    Science.gov (United States)

    2013-03-08

    ... Committee; Transport Airplane Performance and Handling Characteristics--New Task AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of new task assignment for the Aviation Rulemaking Advisory Committee... findings. The Task The FAA tasked ARAC to consider several areas within the airplane performance and...

  5. Boon and Bane of Being Sure: The Effect of Performance Certainty and Expectancy on Task Performance

    Science.gov (United States)

    Schindler, Simon; Reinhard, Marc-André; Dickhäuser, Oliver

    2016-01-01

    Previous research has suggested certainty to be an important factor when investigating effects of level of expectancies on future behavior. With the present study, we addressed the interplay of expectancy certainty and level of expectancies regarding task performance. We assumed that certain performance expectancies provide a better basis for the…

  6. The impact of diurnal sleep on the consolidation of a complex gross motor adaptation task

    Science.gov (United States)

    Hoedlmoser, Kerstin; Birklbauer, Juergen; Schabus, Manuel; Eibenberger, Patrick; Rigler, Sandra; Mueller, Erich

    2015-01-01

    Diurnal sleep effects on consolidation of a complex, ecological valid gross motor adaptation task were examined using a bicycle with an inverse steering device. We tested 24 male subjects aged between 20 and 29 years using a between-subjects design. Participants were trained to adapt to the inverse steering bicycle during 45 min. Performance was tested before (TEST1) and after (TEST2) training, as well as after a 2 h retention interval (TEST3). During retention, participants either slept or remained awake. To assess gross motor performance, subjects had to ride the inverse steering bicycle 3 × 30 m straight-line and 3 × 30 m through a slalom. Beyond riding time, we sophisticatedly measured performance accuracy (standard deviation of steering angle) in both conditions using a rotatory potentiometer. A significant decrease of accuracy during straight-line riding after nap and wakefulness was shown. Accuracy during slalom riding remained stable after wakefulness but was reduced after sleep. We found that the duration of rapid eye movement sleep as well as sleep spindle activity are negatively related with gross motor performance changes over sleep. Together these findings suggest that the consolidation of adaptation to a new steering device does not benefit from a 2 h midday nap. We speculate that in case of strongly overlearned motor patterns such as normal cycling, diurnal sleep spindles and rapid eye movement sleep might even help to protect everyday needed skills, and to rapidly forget newly acquired, interfering and irrelevant material. PMID:25256866

  7. The effect of haptic guidance and visual feedback on learning a complex tennis task.

    Science.gov (United States)

    Marchal-Crespo, Laura; van Raai, Mark; Rauter, Georg; Wolf, Peter; Riener, Robert

    2013-11-01

    While haptic guidance can improve ongoing performance of a motor task, several studies have found that it ultimately impairs motor learning. However, some recent studies suggest that the haptic demonstration of optimal timing, rather than movement magnitude, enhances learning in subjects trained with haptic guidance. Timing of an action plays a crucial role in the proper accomplishment of many motor skills, such as hitting a moving object (discrete timing task) or learning a velocity profile (time-critical tracking task). The aim of the present study is to evaluate which feedback conditions-visual or haptic guidance-optimize learning of the discrete and continuous elements of a timing task. The experiment consisted in performing a fast tennis forehand stroke in a virtual environment. A tendon-based parallel robot connected to the end of a racket was used to apply haptic guidance during training. In two different experiments, we evaluated which feedback condition was more adequate for learning: (1) a time-dependent discrete task-learning to start a tennis stroke and (2) a tracking task-learning to follow a velocity profile. The effect that the task difficulty and subject's initial skill level have on the selection of the optimal training condition was further evaluated. Results showed that the training condition that maximizes learning of the discrete time-dependent motor task depends on the subjects' initial skill level. Haptic guidance was especially suitable for less-skilled subjects and in especially difficult discrete tasks, while visual feedback seems to benefit more skilled subjects. Additionally, haptic guidance seemed to promote learning in a time-critical tracking task, while visual feedback tended to deteriorate the performance independently of the task difficulty and subjects' initial skill level. Haptic guidance outperformed visual feedback, although additional studies are needed to further analyze the effect of other types of feedback visualization on

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

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-01-01

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

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

    Science.gov (United States)

    Lee, Scott Weng Fai

    2013-01-01

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

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

    Science.gov (United States)

    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.

  11. Information Distribution in Complex Systems to Improve Team Performance

    National Research Council Canada - National Science Library

    Sperling, Brian K; Pritchett, Amy; Estrada, Arthur; Adam, Gina E

    2006-01-01

    .... Specifically, this study hypothesizes that providing task specific information to individual team members will improve coordination and decision-making, and therefore team performance, at time-critical tasks...

  12. Affect Response to Simulated Information Attack during Complex Task Performance

    Science.gov (United States)

    2014-12-02

    Positive), and 11 discrete emotions, Fear, Hostility, Guilt , Sadness, Joviality, Self- Assurance, Attentiveness, Shyness, Fatigue, Serenity, and...Force his parents to move into a home. (1.4/0) * 16. Max prides himself on his work being of the highest quality. On a joint project, other

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

    Science.gov (United States)

    Botzer, Assaf; Meyer, Joachim; Parmet, Yisrael

    2016-09-01

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

  14. A continuous time-resolved measure decoded from EEG oscillatory activity predicts working memory task performance

    Science.gov (United States)

    Astrand, Elaine

    2018-06-01

    Objective. Working memory (WM), crucial for successful behavioral performance in most of our everyday activities, holds a central role in goal-directed behavior. As task demands increase, inducing higher WM load, maintaining successful behavioral performance requires the brain to work at the higher end of its capacity. Because it is depending on both external and internal factors, individual WM load likely varies in a continuous fashion. The feasibility to extract such a continuous measure in time that correlates to behavioral performance during a working memory task remains unsolved. Approach. Multivariate pattern decoding was used to test whether a decoder constructed from two discrete levels of WM load can generalize to produce a continuous measure that predicts task performance. Specifically, a linear regression with L2-regularization was chosen with input features from EEG oscillatory activity recorded from healthy participants while performing the n-back task, n\\in [1,2] . Main results. The feasibility to extract a continuous time-resolved measure that correlates positively to trial-by-trial working memory task performance is demonstrated (r  =  0.47, p  <  0.05). It is furthermore shown that this measure allows to predict task performance before action (r  =  0.49, p  <  0.05). We show that the extracted continuous measure enables to study the temporal dynamics of the complex activation pattern of WM encoding during the n-back task. Specifically, temporally precise contributions of different spectral features are observed which extends previous findings of traditional univariate approaches. Significance. These results constitute an important contribution towards a wide range of applications in the field of cognitive brain–machine interfaces. Monitoring mental processes related to attention and WM load to reduce the risk of committing errors in high-risk environments could potentially prevent many devastating consequences or

  15. High-performers use the phonological loop less to process mental arithmetic during working memory tasks.

    Science.gov (United States)

    Otsuka, Yuki; Osaka, Naoyuki

    2015-01-01

    This study investigated the effects of three working memory components-the central executive, phonological loop, and visuospatial sketchpad-on performance differences in complex mental arithmetic between individuals. Using the dual-task method, we examined how performance during two-digit addition was affected by load on the central executive (random tapping condition), phonological loop (articulatory suppression condition), and visuospatial sketchpad (spatial tapping condition) compared to that under no load (control condition) in high- and low-performers of complex mental arithmetic in Experiment 1. Low-performers showed an increase in errors under the random tapping and articulatory suppression conditions, whereas high-performers showed an increase of errors only under the random tapping condition. In Experiment 2, we conducted similar experiments on only the high-performers but used a shorter presentation time of each number. We found the same pattern for performing complex mental arithmetic as seen in Experiment 1. These results indicate that high-performers might reduce their dependence on the phonological loop, because the central executive enables them to choose a strategy in which they use less working memory capacity.

  16. Radioactive Waste Management Complex performance assessment: Draft

    Energy Technology Data Exchange (ETDEWEB)

    Case, M.J.; Maheras, S.J.; McKenzie-Carter, M.A.; Sussman, M.E.; Voilleque, P.

    1990-06-01

    A radiological performance assessment of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory was conducted to demonstrate compliance with appropriate radiological criteria of the US Department of Energy and the US Environmental Protection Agency for protection of the general public. The calculations involved modeling the transport of radionuclides from buried waste, to surface soil and subsurface media, and eventually to members of the general public via air, ground water, and food chain pathways. Projections of doses were made for both offsite receptors and individuals intruding onto the site after closure. In addition, uncertainty analyses were performed. Results of calculations made using nominal data indicate that the radiological doses will be below appropriate radiological criteria throughout operations and after closure of the facility. Recommendations were made for future performance assessment calculations.

  17. Radioactive Waste Management Complex performance assessment: Draft

    International Nuclear Information System (INIS)

    Case, M.J.; Maheras, S.J.; McKenzie-Carter, M.A.; Sussman, M.E.; Voilleque, P.

    1990-06-01

    A radiological performance assessment of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory was conducted to demonstrate compliance with appropriate radiological criteria of the US Department of Energy and the US Environmental Protection Agency for protection of the general public. The calculations involved modeling the transport of radionuclides from buried waste, to surface soil and subsurface media, and eventually to members of the general public via air, ground water, and food chain pathways. Projections of doses were made for both offsite receptors and individuals intruding onto the site after closure. In addition, uncertainty analyses were performed. Results of calculations made using nominal data indicate that the radiological doses will be below appropriate radiological criteria throughout operations and after closure of the facility. Recommendations were made for future performance assessment calculations

  18. Using cognitive architectures to study issues in team cognition in a complex task environment

    Science.gov (United States)

    Smart, Paul R.; Sycara, Katia; Tang, Yuqing

    2014-05-01

    Cognitive social simulation is a computer simulation technique that aims to improve our understanding of the dynamics of socially-situated and socially-distributed cognition. This makes cognitive social simulation techniques particularly appealing as a means to undertake experiments into team cognition. The current paper reports on the results of an ongoing effort to develop a cognitive social simulation capability that can be used to undertake studies into team cognition using the ACT-R cognitive architecture. This capability is intended to support simulation experiments using a team-based problem solving task, which has been used to explore the effect of different organizational environments on collective problem solving performance. The functionality of the ACT-R-based cognitive social simulation capability is presented and a number of areas of future development work are outlined. The paper also describes the motivation for adopting cognitive architectures in the context of social simulation experiments and presents a number of research areas where cognitive social simulation may be useful in developing a better understanding of the dynamics of team cognition. These include the use of cognitive social simulation to study the role of cognitive processes in determining aspects of communicative behavior, as well as the impact of communicative behavior on the shaping of task-relevant cognitive processes (e.g., the social shaping of individual and collective memory as a result of communicative exchanges). We suggest that the ability to perform cognitive social simulation experiments in these areas will help to elucidate some of the complex interactions that exist between cognitive, social, technological and informational factors in the context of team-based problem-solving activities.

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

    Science.gov (United States)

    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.

  20. Trajectories of Resilience during Dyadic Task Performance among Children Six to Seven Years of Age

    Science.gov (United States)

    Mykkänen, Arttu; Kronqvist, Eeva-Liisa; Järvelä, Sanna

    2013-01-01

    The aim of this study is to analyse resilience displayed by young children in dyadic task performance situations. Data were collected by videotaping children (aged six to seven years; N?=?40) during a geometrical task performance. Results describe ways in which children confronted the challenges during task performance, and the order in which the…

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

    Science.gov (United States)

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

    2017-01-02

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

  2. Thermal effects on human performance in office environment measured by integrating task speed and accuracy

    DEFF Research Database (Denmark)

    Lan, Li; Wargocki, Pawel; Lian, Zhiwei

    2014-01-01

    We have proposed a method in which the speed and accuracy can be integrated into one metric of human performance. This was achieved by designing a performance task in which the subjects receive feedback on their performance by informing them whether they have committed errors, and if did, they can......, 12 subjects performed tasks under two thermal conditions (neutral & warm) repeatedly. The tasks were presented with and without feedback on errors committed, as outlined above. The results indicate that there was a greater decrease in task performance due to thermal discomfort when feedback was given......, compared to the performance of tasks presented without feedback....

  3. Context-Sensitive Adjustment of Cognitive Control in Dual-Task Performance

    Science.gov (United States)

    Fischer, Rico; Gottschalk, Caroline; Dreisbach, Gesine

    2014-01-01

    Performing 2 highly similar tasks at the same time requires an adaptive regulation of cognitive control to shield prioritized primary task processing from between-task (cross-talk) interference caused by secondary task processing. In the present study, the authors investigated how implicitly and explicitly delivered information promotes the…

  4. Potential Performance Theory (PPT): A General Theory of Task Performance Applied to Morality

    Science.gov (United States)

    Trafimow, David; Rice, Stephen

    2008-01-01

    People can use a variety of different strategies to perform tasks and these strategies all have two characteristics in common. First, they can be evaluated in comparison with either an absolute or a relative standard. Second, they can be used at varying levels of consistency. In the present article, the authors develop a general theory of task…

  5. Better decision making in complex, dynamic tasks training with human-facilitated interactive learning environments

    CERN Document Server

    Qudrat-Ullah, Hassan

    2015-01-01

    This book describes interactive learning environments (ILEs) and their underlying concepts. It explains how ILEs can be used to improve the decision-making process and how these improvements can be empirically verified. The objective of this book is to enhance our understanding of and to gain insights into the process by which human facilitated ILEs are effectively designed and used in improving users’ decision making in complex, dynamic tasks. This book is divided into four major parts. Part I serves as an introduction to the importance and complexity of decision making in dynamic tasks. Part II provides background material, drawing upon relevant literature, for the development of an integrated process model on the effectiveness of human facilitated ILEs in improving decision making in dynamic tasks. Part III focuses on the design, development, and application of FishBankILE in laboratory experiments to gather empirical evidence for the validity of the process model. Finally, part IV presents a comprehensi...

  6. Transfer of skill engendered by complex task training under conditions of variable priority.

    Science.gov (United States)

    Boot, Walter R; Basak, Chandramallika; Erickson, Kirk I; Neider, Mark; Simons, Daniel J; Fabiani, Monica; Gratton, Gabriele; Voss, Michelle W; Prakash, Ruchika; Lee, HyunKyu; Low, Kathy A; Kramer, Arthur F

    2010-11-01

    We explored the theoretical underpinnings of a commonly used training strategy by examining issues of training and transfer of skill in the context of a complex video game (Space Fortress, Donchin, 1989). Participants trained using one of two training regimens: Full Emphasis Training (FET) or Variable Priority Training (VPT). Transfer of training was assessed with a large battery of cognitive and psychomotor tasks ranging from basic laboratory paradigms measuring reasoning, memory, and attention to complex real-world simulations. Consistent with previous studies, VPT accelerated learning and maximized task mastery. However, the hypothesis that VPT would result in broader transfer of training received limited support. Rather, transfer was most evident in tasks that were most similar to the Space Fortress game itself. Results are discussed in terms of potential limitations of the VPT approach. Copyright © 2010 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-07-01

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

  8. The effect of a priori probability and complexity on decision making in a supervisory control task

    NARCIS (Netherlands)

    Kerstholt, J.H.; Passenier, P.O.; Houttuin, K.; Schuffel, H.

    1996-01-01

    In the present study we investigated how monitoring and fault management in a ship control task are affected by complexity and a priori probability of disturbances. Partici-pants were required to supervise four independent shipping subsystems and to adjust the subsystems whenever deviations

  9. Core Self-Evaluations as Causes of Satisfaction: The Mediating Role of Seeking Task Complexity

    Science.gov (United States)

    Srivastava, Abhishek; Locke, Edwin A.; Judge, Timothy A.; Adams, John W.

    2010-01-01

    This study examined the mediating role of task complexity in the relationship between core self-evaluations (CSE) and satisfaction. In Study 1, eighty three undergraduate business students worked on a strategic decision-making simulation. The simulated environment enabled us to verify the temporal sequence of variables, use an objective measure of…

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

    Science.gov (United States)

    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.

  11. Group cohesion, task performance, and the experimenter expectancy effect.

    NARCIS (Netherlands)

    Hoogstraten, J.; Vorst, H.C.M.

    1978-01-01

    Studied the effects of cohesion on task fulfillment and explored the influence of task fulfillment on the initial level of cohesion. Within 4-person groups of undergraduates, cohesion was manipulated successfully by a triple procedure. The level of cohesion was ascertained directly after the

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-08-19

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

  14. Gaze training enhances laparoscopic technical skill acquisition and multi-tasking performance: a randomized, controlled study.

    Science.gov (United States)

    Wilson, Mark R; Vine, Samuel J; Bright, Elizabeth; Masters, Rich S W; Defriend, David; McGrath, John S

    2011-12-01

    The operating room environment is replete with stressors and distractions that increase the attention demands of what are already complex psychomotor procedures. Contemporary research in other fields (e.g., sport) has revealed that gaze training interventions may support the development of robust movement skills. This current study was designed to examine the utility of gaze training for technical laparoscopic skills and to test performance under multitasking conditions. Thirty medical trainees with no laparoscopic experience were divided randomly into one of three treatment groups: gaze trained (GAZE), movement trained (MOVE), and discovery learning/control (DISCOVERY). Participants were fitted with a Mobile Eye gaze registration system, which measures eye-line of gaze at 25 Hz. Training consisted of ten repetitions of the "eye-hand coordination" task from the LAP Mentor VR laparoscopic surgical simulator while receiving instruction and video feedback (specific to each treatment condition). After training, all participants completed a control test (designed to assess learning) and a multitasking transfer test, in which they completed the procedure while performing a concurrent tone counting task. Not only did the GAZE group learn more quickly than the MOVE and DISCOVERY groups (faster completion times in the control test), but the performance difference was even more pronounced when multitasking. Differences in gaze control (target locking fixations), rather than tool movement measures (tool path length), underpinned this performance advantage for GAZE training. These results suggest that although the GAZE intervention focused on training gaze behavior only, there were indirect benefits for movement behaviors and performance efficiency. Additionally, focusing on a single external target when learning, rather than on complex movement patterns, may have freed-up attentional resources that could be applied to concurrent cognitive tasks.

  15. Differential effects of emotionally versus neutrally cued autobiographical memories on performance of a subsequent cognitive task: Effects of task difficulty

    Directory of Open Access Journals (Sweden)

    Kymberly eYoung

    2012-08-01

    Full Text Available Attention is a limited resource, and in order to improve processing of the attended information, competing processes must be suppressed. Although it is well established that an experimentally induced change in mood state comprises one type of competing process that can impair performance on a subsequent task, no study has investigated whether an emotionally valenced autobiographical memory (AM also can alter performance on a subsequent task. We therefore examined the effects of AM recall on cognitive performance. Healthy participants (n=20 per experiment recalled AMs in response to positive, negative, and neutral cue words. Following each AM participants completed a simple perceptual task (Experiment 1 or solved moderately difficult subtraction problems (Experiment 2. In Experiment 1 participants performed less accurately following exposure to positive or negative versus neutral cue words (ps<0.001, and also were less accurate following negative versus positive cue words (p<0.001. In Experiment 2, in contrast, no difference in accuracy or response times reached statistical significance. Performance accuracy even trended towards being higher following exposure to negative versus neutral cue words (p=0.08. The results of Experiment 1 suggested that recalling emotionally salient AMs reduces the attention directed toward a simple continuous performance task administered immediately following the AM task, conceivably due to persistent contemplation of the AM. The negative results of Experiment 2 suggested that the effect of AMs on attention was attenuated, however, by increasing the difficulty of the subsequent task. Our results have implications for patients with MDD, as performing cognitively demanding tasks may allow them to attenuate the impairing effects of negative rumination on cognition.

  16. Experimental evaluation of user performance in a pursuit tracking task with multimodal feedback

    Directory of Open Access Journals (Sweden)

    Obrenović Željko

    2004-01-01

    Full Text Available In this paper we describe the results of experimental evaluation of user performance in a pursuit-tracking task with multimodal feedback. Our experimental results indicate that audio can significantly improve the accuracy of pursuit tracking. Experiments with 19 participants have shown that addition of acoustic modalities reduces the error during pursuit tracking for up to 19%. Moreover, experiments indicated the existence of perceptual boundaries of multimodal HCI for different scene complexity and target speeds. We have also shown that the most appealing paradigms are not the most effective ones, which necessitates a careful quantitative analysis of proposed multimodal HCI paradigms.

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

    Science.gov (United States)

    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

  18. Task-based incidental vocabulary learning in L2 Arabic: The role of proficiency and task performance

    Directory of Open Access Journals (Sweden)

    Ayman A. Mohamed

    2016-03-01

    Full Text Available This study tests the claim that word learning in a second language are contingent upon a task’s involvement load (i.e. the amount of need, search, and evaluation it imposes, as proposed by Laufer and Hulstijn (2001. Fifty-three English-speaking learners of Arabic were assigned to one of three vocabulary learning tasks that varied in the degree of involvement: reading comprehension with glosses (low, fill-in-the-gap task (medium, and sentence writing (high. Ten words, selected based on a pretest, were targeted in the tasks. Results showed a main effect of task, with the sentence writing task yielding the highest rates of vocabulary learning, followed by the gap-fill task, and finally the reading comprehension task. A significant correlation was found between accuracy of performance across participants and their subsequent vocabulary acquisition in the immediate posttest. Within groups, only the performance of the writing group correlated significantly with their posttest scores. Results of the present study validate the hypothesis and point to multiple factors at play in incidental vocabulary acquisition. The study provides further arguments to refine the hypothesis and implement pedagogical practices that accommodate incidental learning in foreign language settings.

  19. The trickle-down effect of predictability: Secondary task performance benefits from predictability in the primary task.

    Directory of Open Access Journals (Sweden)

    Magdalena Ewa Król

    Full Text Available Predictions optimize processing by reducing attentional resources allocation to expected or predictable sensory data. Our study demonstrates that these saved processing resources can be then used on concurrent stimuli, and in consequence improve their processing and encoding. We illustrate this "trickle-down" effect with a dual task, where the primary task varied in terms of predictability. The primary task involved detection of a pre-specified symbol that appeared at some point of a short video of a dot moving along a random, semi-predictable or predictable trajectory. The concurrent secondary task involved memorization of photographs representing either emotionally neutral or non-neutral (social or threatening content. Performance in the secondary task was measured by a memory test. We found that participants allocated more attention to unpredictable (random and semi-predictable stimuli than to predictable stimuli. Additionally, when the stimuli in the primary task were more predictable, participants performed better in the secondary task, as evidenced by higher sensitivity in the memory test. Finally, social or threatening stimuli were allocated more "looking time" and a larger number of saccades than neutral stimuli. This effect was stronger for the threatening stimuli than social stimuli. Thus, predictability of environmental input is used in optimizing the allocation of attentional resources, which trickles-down and benefits the processing of concurrent stimuli.

  20. The trickle-down effect of predictability: Secondary task performance benefits from predictability in the primary task.

    Science.gov (United States)

    Król, Magdalena Ewa; Król, Michał

    2017-01-01

    Predictions optimize processing by reducing attentional resources allocation to expected or predictable sensory data. Our study demonstrates that these saved processing resources can be then used on concurrent stimuli, and in consequence improve their processing and encoding. We illustrate this "trickle-down" effect with a dual task, where the primary task varied in terms of predictability. The primary task involved detection of a pre-specified symbol that appeared at some point of a short video of a dot moving along a random, semi-predictable or predictable trajectory. The concurrent secondary task involved memorization of photographs representing either emotionally neutral or non-neutral (social or threatening) content. Performance in the secondary task was measured by a memory test. We found that participants allocated more attention to unpredictable (random and semi-predictable) stimuli than to predictable stimuli. Additionally, when the stimuli in the primary task were more predictable, participants performed better in the secondary task, as evidenced by higher sensitivity in the memory test. Finally, social or threatening stimuli were allocated more "looking time" and a larger number of saccades than neutral stimuli. This effect was stronger for the threatening stimuli than social stimuli. Thus, predictability of environmental input is used in optimizing the allocation of attentional resources, which trickles-down and benefits the processing of concurrent stimuli.

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

    Science.gov (United States)

    Swallow, Khena M; Jiang, Yuhong V

    2010-04-01

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

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

    Science.gov (United States)

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

    2006-06-01

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

  3. Internalizing versus Externalizing Control: Different Ways to Perform a Time-Based Prospective Memory Task

    Science.gov (United States)

    Huang, Tracy; Loft, Shayne; Humphreys, Michael S.

    2014-01-01

    "Time-based prospective memory" (PM) refers to performing intended actions at a future time. Participants with time-based PM tasks can be slower to perform ongoing tasks (costs) than participants without PM tasks because internal control is required to maintain the PM intention or to make prospective-timing estimates. However, external…

  4. Routing Cooperating Vehicles to Perform Precedence-Linked Tasks

    National Research Council Canada - National Science Library

    Vakhutinsky, Andrew; Wu, Cynara

    2005-01-01

    The problem of scheduling cooperating vehicles is a generalization of the classical vehicle routing problem where certain tasks are linked by precedence constraints and vehicles have varying constrained resources...

  5. Influence of Force and Torque Feedback on Operator Performance in a VR-Based Suturing Task

    Directory of Open Access Journals (Sweden)

    L. Santos-Carreras

    2010-01-01

    Full Text Available The introduction of Minimally Invasive Surgery (MIS has revolutionised surgical care, considerably improving the quality of many surgical procedures. Technological advances, particularly in robotic surgery systems, have reduced the complexity of such an approach, paving the way for even less invasive surgical trends. However, the fact that haptic feedback has been progressively lost through this transition is an issue that to date has not been solved. Whereas traditional open surgery provides full haptic feedback, the introduction of MIS has eliminated the possibility of direct palpation and tactile exploration. Nevertheless, these procedures still provide a certain amount of force feedback through the rigid laparoscopic tool. Many of the current telemanipulated robotic surgical systems in return do not provide full haptic feedback, which to a certain extent can be explained by the requirement of force sensors integrated into the tools of the slave robot and actuators in the surgeon’s master console. In view of the increased complexity and cost, the benefit of haptic feedback is open to dispute. Nevertheless, studies have shown the importance of haptic feedback, especially when visual feedback is unreliable or absent. In order to explore the importance of haptic feedback for the surgeon’s master console of a novel teleoperated robotic surgical system, we have identified a typical surgical task where performance could potentially be improved by haptic feedback, and investigate performance with and without this feedback. Two rounds of experiments are performed with 10 subjects, six of them with a medical background. Results show that feedback conditions, including force feedback, significantly improve task performance independently of the operator’s suturing experience. There is, however, no further significant improvement when torque feedback is added. Consequently, it is deduced that force feedback in translations improves subject

  6. The Intersection of Task-Based Interaction, Task Complexity, and Working Memory: L2 Question Development through Recasts in a Laboratory Setting

    Science.gov (United States)

    Kim, YouJin; Payant, Caroline; Pearson, Pamela

    2015-01-01

    The extent to which individual differences in cognitive abilities affect the relationship among task complexity, attention to form, and second language development has been addressed only minimally in the cognition hypothesis literature. The present study explores how reasoning demands in tasks and working memory (WM) capacity predict learners'…

  7. Analysis of Skeletal Muscle Metrics as Predictors of Functional Task Performance

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

    Wandtner, Bernhard; Schömig, Nadja; Schmidt, Gerald

    2018-04-01

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

  10. Combined factors effect of menstrual cycle and background noise on visual inspection task performance: a simulation-based task.

    Science.gov (United States)

    Wijayanto, Titis; Tochihara, Yutaka; Wijaya, Andi R; Hermawati, Setia

    2009-11-01

    It is well known that women are physiologically and psychologically influenced by the menstrual cycle. In addition, the presence of background noise may affect task performance. So far, it has proven difficult to describe how the menstrual cycle and background noise affect task performance; some researchers have found an increment of performance during menstruation or during the presence of noise, others found performance deterioration, while other still have reported no dominant effect either of the menstrual cycle in performance or of the presence of noise. However, no study to date has investigated the combinational effect between the menstrual cycle and the presence of background noise in task performance. Therefore, the purpose of this study was to examine the combined factor effect of menstrual cycle and background noise on visual inspection task performance indices by Signal Detection Theory (SDT) metrics: sensitivity index (d') and response criteria index (beta). For this purpose, ten healthy female students (21.5+/-1.08 years) with a regular menstrual cycle participated in this study. A VDT-based visual inspection task was used for the experiment in 3x2 factorial designs. Two factors, menstrual phase, pre-menstruation (PMS), menstruation (M), and post-menstruation (PM) and background noise, with 80 dB(A) background noise and without noise, were analyzed as the main factors in this study. The results concluded that the sensitivity index (d') of SDT was affected in all the menstrual cycle conditions (pbackground noise (pbackground noise was found in this study. On the other hand, no significant effect was observed in the subject's tendency in visual inspection, shown by beta along the menstrual cycle and the presence of background noise. According to the response criteria for each individual subject, the presence of noise affected the tendency of some subjects in detecting the object and making decision during the visual inspection task.

  11. Using task performance to inform treatment planning for youth with ADHD: A systematic review.

    Science.gov (United States)

    Molitor, Stephen J; Langberg, Joshua M

    2017-12-01

    The role that neuropsychological task performance plays in the assessment of Attention-Deficit/Hyperactivity Disorder (ADHD) is currently ambiguous, and findings are mixed regarding whether tasks have validity for diagnosing the disorder. Irrespective of their validity for diagnosing ADHD, neuropsychological tasks could provide valuable information to mental health professionals if they can inform recommendations for treatment targets and modalities. Therefore, this review sought to synthesize the available evidence related to the use of neuropsychological task performance as a tool for informing treatment planning for youth with ADHD. Reviewed studies focused on examinations of associations between task performance and academic, social, and health outcomes, as well as response to treatment. Twenty-five relevant studies using samples of youth diagnosed with ADHD in clinical, community, and school settings were identified. Review of the evidence suggests that task performance may be useful in identifying individuals with ADHD at risk for academic impairment. However, the evidence is less compelling for identifying youth at risk for impaired social functioning or poor health outcomes. The review also found that task performance is likely useful for predicting response to treatment with methylphenidate. Across studies, evidence indicated that interpreting task performance in an integrated manner, such as a factor score or mean score, was more consistently useful for predicting outcomes of interest than interpreting performance from a single task. Implications for the use of tasks in ADHD assessments are discussed, and future directions are outlined for further examining the clinical utility of task performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2016-11-01

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

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

    Science.gov (United States)

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

    2017-02-01

    Simultaneous performances of motor and attention-demanding tasks are common in activities of everyday life. The present cross-sectional study examined the changes and age-related differences on mobility performance with an additional cognitive or motor task, and evaluated the relative dual-task cost (DTC) on the motor performance in young, middle-aged and older women. A total of 30 young (mean age 25.12 ± 3.00 years), 30 middle-aged (mean age 47.82 ± 5.06 years) and 30 older women (mean age 72.74 ± 5.95 years) were recruited. Participants carried out: (i) single task: Timed Up & Go Test; (ii) cognitive dual-task: Timed Up & Go Test while counting backwards by three; (iii) manual dual-task: Timed Up & Go Test while carrying a glass of water. A repeated measures anova with between-factor as age groups and within-factor as tasks was carried out to assess the effect of aging on the performance of mobility tasks. DTC was calculated as ([performance in single-task - performance in dual-task] / performance in single task) × 100%. One-way ancova were carried out to compare the DTC among the three age groups. A significant interaction between age groups and task (F 4,172  = 6.716, P performance under dual-task condition compared with young and middle-aged groups. Furthermore, DTC differences in cognitive task were observed in older women compared with younger and middle-aged women (F 2,86  = 7.649, P task. Dual-task conditions might affect mobility performance differently across the lifespan, and could be particularly challenging in older women. Geriatr Gerontol Int 2017; 17: 315-321. © 2015 Japan Geriatrics Society.

  14. Performance on the Hamilton search task, and the influence of lateralization, in captive orange-winged Amazon parrots (Amazona amazonica).

    Science.gov (United States)

    Cussen, Victoria A; Mench, Joy A

    2014-07-01

    Psittacines are generally considered to possess cognitive abilities comparable to those of primates. Most psittacine research has evaluated performance on standardized complex cognition tasks, but studies of basic cognitive processes are limited. We tested orange-winged Amazon parrots (Amazona amazonica) on a spatial foraging assessment, the Hamilton search task. This task is a standardized test used in human and non-human primate studies. It has multiple phases, which require trial and error learning, learning set breaking, and spatial memory. We investigated search strategies used to complete the task, cognitive flexibility, and long-term memory for the task. We also assessed the effects of individual strength of motor lateralization (foot preference) and sex on task performance. Almost all (92%) of the parrots acquired the task. All had significant foot preferences, with 69% preferring their left foot, and showed side preferences contralateral to their preferred limb during location selection. The parrots were able to alter their search strategies when reward contingencies changed, demonstrating cognitive flexibility. They were also able to remember the task over a 6-month period. Lateralization had a significant influence on learning set acquisition but no effect on cognitive flexibility. There were no sex differences. To our knowledge, this is the first cognitive study using this particular species and one of the few studies of cognitive abilities in any Neotropical parrot species.

  15. Selecting Tasks for Evaluating Human Performance as a Function of Gravity

    Science.gov (United States)

    Norcross, Jason R.; Gernhardt, Michael L.

    2011-01-01

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

  16. Social motivation in prospective memory: higher importance ratings and reported performance rates for social tasks.

    Science.gov (United States)

    Penningroth, Suzanna L; Scott, Walter D; Freuen, Margaret

    2011-03-01

    Few studies have addressed social motivation in prospective memory (PM). In a pilot study and two main studies, we examined whether social PM tasks possess a motivational advantage over nonsocial PM tasks. In the pilot study and Study 1, participants listed their real-life important and less important PM tasks. Independent raters categorized the PM tasks as social or nonsocial. Results from both studies showed a higher proportion of tasks rated as social when important tasks were requested than when less important tasks were requested. In Study 1, participants also reported whether they had remembered to perform each PM task. Reported performance rates were higher for tasks rated as social than for those rated as nonsocial. Finally, in Study 2, participants rated the importance of two hypothetical PM tasks, one social and one nonsocial. The social PM task was rated higher in importance. Overall, these findings suggest that social PM tasks are viewed as more important than nonsocial PM tasks and they are more likely to be performed. We propose that consideration of the social relevance of PM will lead to a more complete and ecologically valid theoretical description of PM performance. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

  17. Very low birth weight piglets show improved cognitive performance in the spatial cognitive holeboard task

    Directory of Open Access Journals (Sweden)

    Alexandra eAntonides

    2015-02-01

    Full Text Available Low birth weight (LBW is common in humans and has been found to cause lasting cognitive and developmental deficits later in life. It is thought that the primary cause is intra-uterine growth restriction due to a shortage of oxygen and nutrients supply to the fetus. Pigs appear to be a good model animal to investigate long-term cognitive effects of LBW, as LBW is common in commercially farmed breeds of pigs. Moreover, pigs are developmentally similar to humans and can be trained to perform complex tasks. In this study, we trained ten very low birth weight (vLBW piglets and their ten normal birth weight (NBW siblings in a spatial cognitive holeboard task in order to investigate long-term cognitive effects of LBW. In this task, four out of sixteen holes contain a hidden food reward, which allows measuring working memory (short-term and reference memory (long-term in parallel. Piglets were trained for 46-54 trials during the acquisition phase, followed by a 20-trial reversal phase in which a different set of four holes was baited. Both groups acquired the task and improved their performance over time. A mixed model repeated measures ANOVA revealed that vLBW piglets showed a better reference memory performance than NBW piglets in both the acquisition and reversal phase. Additionally, the vLBW piglets fell back less in working memory scores than the NBW animals when switched to the reversal phase. These findings are contrary to findings in humans. Moreover, vLBW pigs had lower hair cortisol concentrations than NBW pigs in flank hair at 12 weeks of age. These results could indicate that restricted intra-uterine growth causes compensatory mechanisms to arise in early development that result in beneficial effects for vLBW piglets, increasing their low survival chances in early-life competition.

  18. Very low birth weight piglets show improved cognitive performance in the spatial cognitive holeboard task.

    Science.gov (United States)

    Antonides, Alexandra; Schoonderwoerd, Anne C; Nordquist, Rebecca E; van der Staay, Franz Josef

    2015-01-01

    Low birth weight (LBW) is common in humans and has been found to cause lasting cognitive and developmental deficits later in life. It is thought that the primary cause is intra-uterine growth restriction (IUGR) due to a shortage of oxygen and supply of nutrients to the fetus. Pigs appear to be a good model animal to investigate long-term cognitive effects of LBW, as LBW is common in commercially farmed breeds of pigs. Moreover, pigs are developmentally similar to humans and can be trained to perform complex tasks. In this study, we trained ten very low birth weight (vLBW) piglets and their ten normal birth weight (NBW) siblings in a spatial cognitive holeboard task in order to investigate long-term cognitive effects of LBW. In this task, four out of sixteen holes contain a hidden food reward, which allows measuring working memory (WM) (short-term memory) and reference memory (RM) (long-term memory) in parallel. Piglets were trained for 46-54 trials during the acquisition phase, followed by a 20-trial reversal phase in which a different set of four holes was baited. Both groups acquired the task and improved their performance over time. A mixed model repeated measures ANOVA revealed that vLBW piglets showed better RM performance than NBW piglets in both the acquisition and reversal phase. Additionally, WM scores in the vLBW were less disrupted than in the NBW animals when switched to the reversal phase. These findings are contrary to findings in humans. Moreover, vLBW pigs had lower hair cortisol concentrations (HCCs) than NBW pigs in flank hair at 12 weeks of age. These results could indicate that restricted intra-uterine growth causes compensatory mechanisms to arise in early development that result in beneficial effects for vLBW piglets, increasing their low survival chances in early-life competition.

  19. Conservatism and liberalism predict performance in two nonideological cognitive tasks.

    Science.gov (United States)

    Bernabel, Rodolpho Talaisys; Oliveira, Amâncio

    2017-01-01

    Intuitive thinking would argue that political or ideological orientation does not correlate with nonpolitical decisions, and certainly not with nonideological cognitive tasks. However, that is what happens in some cases. Previous neuropolitics studies have found that liberals are more adept at dealing with novel information than conservatives. This finding suggests that conservatives and liberals possess different cognitive skills. For the purposes of this article, two studies were executed to test whether this difference remained in alternative environmental settings. To this end, two novel cognitive tasks were designed in which one type of ideology or another was privileged according to the cognitive environment created by the tasks. Experimental findings indicate that liberals committed fewer errors than conservatives in one kind of cognitive environment, while conservatives scored higher in another.

  20. Who does the public think should perform health care tasks?

    Science.gov (United States)

    Koteski, D R; McKinney, S

    1988-10-01

    The dietitian was identified as the most appropriate provider of such key nutrition services as nutrition assessment, determination of caloric requirements, provision of diet counseling, and prescription of diets. Several tasks fundamental to nutrition services were not viewed as highly suitable tasks for the dietitian, e.g., plan for care at home, monitor client progress, and check laboratory values. Activities that constitute key nutrition services need to be accentuated to clarify the numerous skills and extensive knowledge that dietitians possess. In the health care system of today, the dietetic profession must be associated with a wider range of health-related tasks than the traditional triad of diet, food, and hospital. Public relations and marketing strategies should focus on activities that provide the public with a clearer understanding of how the dietetic profession contributes to patient/client care.

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

    Science.gov (United States)

    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.

  2. A study of the performance of patients with frontal lobe lesions in a financial planning task.

    Science.gov (United States)

    Goel, V; Grafman, J; Tajik, J; Gana, S; Danto, D

    1997-10-01

    It has long been argued that patients with lesions in the prefrontal cortex have difficulties in decision making and problem solving in real-world, ill-structured situations, particularly problem types involving planning and look-ahead components. Recently, several researchers have questioned our ability to capture and characterize these deficits adequately using just the standard neuropsychological test batteries, and have called for tests that reflect real-world task requirements more accurately. We present data from 10 patients with focal lesions to the prefrontal cortex and 10 normal control subjects engaged in a real-world financial planning task. We also introduce a theoretical framework and methodology developed in the cognitive science literature for quantifying and analysing the complex data generated by problem-solving tasks. Our findings indicate that patient performance is impoverished at a global level but not at the local level. Patients have difficulty in organizing and structuring their problem space. Once they begin problem solving, they have difficulty in allocating adequate effort to each problem-solving phase. Patients also have difficulty dealing with the fact that there are no right or wrong answers nor official termination points in real-world planning problems. They also find it problematic to generate their own feedback. They invariably terminate the session before the details are fleshed out and all the goals satisfied. Finally, patients do not take full advantage of the fact that constraints on real-world problems are negotiable. However, it is not necessary to postulate a 'planning' deficit. It is possible to understand the patients' difficulties in real world planning tasks in terms of the following four accepted deficits: inadequate access to 'structured event complexes', difficulty in generalizing from particulars, failure to shift between 'mental sets', and poor judgment regarding adequacy and completeness of a plan.

  3. Sonification and haptic feedback in addition to visual feedback enhances complex motor task learning.

    Science.gov (United States)

    Sigrist, Roland; Rauter, Georg; Marchal-Crespo, Laura; Riener, Robert; Wolf, Peter

    2015-03-01

    Concurrent augmented feedback has been shown to be less effective for learning simple motor tasks than for complex tasks. However, as mostly artificial tasks have been investigated, transfer of results to tasks in sports and rehabilitation remains unknown. Therefore, in this study, the effect of different concurrent feedback was evaluated in trunk-arm rowing. It was then investigated whether multimodal audiovisual and visuohaptic feedback are more effective for learning than visual feedback only. Naïve subjects (N = 24) trained in three groups on a highly realistic virtual reality-based rowing simulator. In the visual feedback group, the subject's oar was superimposed to the target oar, which continuously became more transparent when the deviation between the oars decreased. Moreover, a trace of the subject's trajectory emerged if deviations exceeded a threshold. The audiovisual feedback group trained with oar movement sonification in addition to visual feedback to facilitate learning of the velocity profile. In the visuohaptic group, the oar movement was inhibited by path deviation-dependent braking forces to enhance learning of spatial aspects. All groups significantly decreased the spatial error (tendency in visual group) and velocity error from baseline to the retention tests. Audiovisual feedback fostered learning of the velocity profile significantly more than visuohaptic feedback. The study revealed that well-designed concurrent feedback fosters complex task learning, especially if the advantages of different modalities are exploited. Further studies should analyze the impact of within-feedback design parameters and the transferability of the results to other tasks in sports and rehabilitation.

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

    Science.gov (United States)

    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.

  5. Exploring the Relationship of Task Performance and Physical and Cognitive Fatigue During a Daylong Light Precision Task.

    Science.gov (United States)

    Yung, Marcus; Manji, Rahim; Wells, Richard P

    2017-11-01

    Our aim was to explore the relationship between fatigue and operation system performance during a simulated light precision task over an 8-hr period using a battery of physical (central and peripheral) and cognitive measures. Fatigue may play an important role in the relationship between poor ergonomics and deficits in quality and productivity. However, well-controlled laboratory studies in this area have several limitations, including the lack of work relevance of fatigue exposures and lack of both physical and cognitive measures. There remains a need to understand the relationship between physical and cognitive fatigue and task performance at exposure levels relevant to realistic production or light precision work. Errors and fatigue measures were tracked over the course of a micropipetting task. Fatigue responses from 10 measures and errors in pipetting technique, precision, and targeting were submitted to principal component analysis to descriptively analyze features and patterns. Fatigue responses and error rates contributed to three principal components (PCs), accounting for 50.9% of total variance. Fatigue responses grouped within the three PCs reflected central and peripheral upper extremity fatigue, postural sway, and changes in oculomotor behavior. In an 8-hr light precision task, error rates shared similar patterns to both physical and cognitive fatigue responses, and/or increases in arousal level. The findings provide insight toward the relationship between fatigue and operation system performance (e.g., errors). This study contributes to a body of literature documenting task errors and fatigue, reflecting physical (both central and peripheral) and cognitive processes.

  6. Computerization and skill bifurcation: the role of of task complexity in creating skill gains and losses

    OpenAIRE

    Ben-Ner, Avner; Urtasun Alonso, Ainhoa

    2013-01-01

    Does computerization increase or reduce the extent of skills that workers are required to have? Autor, Levy and Murnane (2003) show empirically that adoption of computer-based technologies (CBT) was greater in industries historically intensive in routine tasks, and that computerization increased complex problem-solving and communication activities and reduced routine cognitive and manual activities. We extend this argument and argue that the effects of CBT are neither universal nor uniform, b...

  7. Impact of the motion and visual complexity of the background on players' performance in video game-like displays.

    Science.gov (United States)

    Caroux, Loïc; Le Bigot, Ludovic; Vibert, Nicolas

    2013-01-01

    The visual interfaces of virtual environments such as video games often show scenes where objects are superimposed on a moving background. Three experiments were designed to better understand the impact of the complexity and/or overall motion of two types of visual backgrounds often used in video games on the detection and use of superimposed, stationary items. The impact of background complexity and motion was assessed during two typical video game tasks: a relatively complex visual search task and a classic, less demanding shooting task. Background motion impaired participants' performance only when they performed the shooting game task, and only when the simplest of the two backgrounds was used. In contrast, and independently of background motion, performance on both tasks was impaired when the complexity of the background increased. Eye movement recordings demonstrated that most of the findings reflected the impact of low-level features of the two backgrounds on gaze control.

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

    Science.gov (United States)

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

    2016-01-01

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

  9. Short-term Music Training Enhances Complex, Distributed Neural Communication during Music and Linguistic Tasks.

    Science.gov (United States)

    Carpentier, Sarah M; Moreno, Sylvain; McIntosh, Anthony R

    2016-10-01

    Musical training is frequently associated with benefits to linguistic abilities, and recent focus has been placed on possible benefits of bilingualism to lifelong executive functions; however, the neural mechanisms for such effects are unclear. The aim of this study was to gain better understanding of the whole-brain functional effects of music and second-language training that could support such previously observed cognitive transfer effects. We conducted a 28-day longitudinal study of monolingual English-speaking 4- to 6-year-old children randomly selected to receive daily music or French language training, excluding weekends. Children completed passive EEG music note and French vowel auditory oddball detection tasks before and after training. Brain signal complexity was measured on source waveforms at multiple temporal scales as an index of neural information processing and network communication load. Comparing pretraining with posttraining, musical training was associated with increased EEG complexity at coarse temporal scales during the music and French vowel tasks in widely distributed cortical regions. Conversely, very minimal decreases in complexity at fine scales and trends toward coarse-scale increases were displayed after French training during the tasks. Spectral analysis failed to distinguish between training types and found overall theta (3.5-7.5 Hz) power increases after all training forms, with spatially fewer decreases in power at higher frequencies (>10 Hz). These findings demonstrate that musical training increased diversity of brain network states to support domain-specific music skill acquisition and music-to-language transfer effects.

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

    Science.gov (United States)

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

    2012-01-01

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

  11. Ready to rumble: how team personality composition and task conflict interact to improve performance.

    Science.gov (United States)

    Bradley, Bret H; Klotz, Anthony C; Postlethwaite, Bennett E; Brown, Kenneth G

    2013-03-01

    Although prior work has proposed a number of conditions under which task conflict in teams may improve performance, composition variables have been left unexplored. Given the effects of personality traits on team processes and outcomes demonstrated in prior work, investigating whether specific personality compositions influence the effect of task conflict on team performance is critical to researchers' understanding of conflict in teams. Our results indicate that team-level averages of both openness to experience and emotional stability function as moderators of the relationship between task conflict and team performance. Specifically, task conflict had a positive impact on performance in teams with high levels of openness or emotional stability; in contrast, task conflict had a negative impact on performance in teams with low levels of openness or emotional stability. Thus, when task conflict emerges, teams composed of members who are open minded or emotionally stable are best able to leverage conflict to improve performance. Implications for theory and practice are discussed.

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

    Science.gov (United States)

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

    2018-01-01

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

  13. Framing of task performance strategies: effects on performance in a multiattribute dynamic decision making environment.

    Science.gov (United States)

    Nygren, T E

    1997-09-01

    It is well documented that the way a static choice task is "framed" can dramatically alter choice behavior, often leading to observable preference reversals. This framing effect appears to result from perceived changes in the nature or location of a person's initial reference point, but it is not clear how framing effects might generalize to performance on dynamic decision making tasks that are characterized by high workload, time constraints, risk, or stress. A study was conducted to examine the hypothesis that framing can introduce affective components to the decision making process and can influence, either favorably (positive frame) or adversely (negative frame), the implementation and use of decision making strategies in dynamic high-workload environments. Results indicated that negative frame participants were significantly impaired in developing and employing a simple optimal decision strategy relative to a positive frame group. Discussion focuses on implications of these results for models of dynamic decision making.

  14. Bilateral contributions of the cerebellum to the complex motor tasks on EPI fMRI

    International Nuclear Information System (INIS)

    Chung, Eun Chul; Youn, Eun Kyung; Lee, Young Rae; Kim, Yoo Kyung; Park, Kee Duk

    1999-01-01

    To demonstrate activation signals within the cerebellar cortex and to determine the side of the cerebellar cortex eliciting activation signals in response to complex motor tasks, as seen on EPI fMRI. Seven right-handed subjects (M : F=3 : 4; mean age, 30.3 years) underwent repetitive finger apposition with the dominant right hand. Using a 1.5 T MRI scanner, EPI fMR images were obtained. MR parameters used for EPI fMRI were TR/TE/Flip angle : 0.96 msec/64msec/90 deg FOV 22cm, 128 X 128 matrix, 10 slices, 10mm thickness while those for SE T1 weighted localized images were TR/TE : 450/16, FOV 23cm, 256 X 256 matrix. The paradigm was three sets of alternate resting and moving fingers for six cycles, resulting in times of 360 seconds (10 slices X 15 EPI X 6 cycles = 900 images). Image processing involved the use of a 200mHz Dual Pentium PC with homemade software. T-testing (p < 0.005 approx.= p < 0.0005) and time series analysis were performed, and to verify the locations of activated regions, resulting images were analyzed in a color-coded overlay to reference T1-weighted spin echo coronal images. Percentage change in signal intensity (PCSI) was calculated from the processed data. All normal subjects showed significant activation signals in both the contralateral (left) primary motor cortex (PCSI = 3.12% 0.96) and ipsilateral (right) cerebellar cortex (PCSI = 3.09% ±1.14). Signal activation was detected in the contralateral supplemental motor area (2.91% ±0.82), and motor activation in the anterior upper half of the contralateral cerebellum (PCSI 2.50% ±0.69). The difference in activation signals between both sides of the cerebellar cortex was not statistically significant. All data were matched with time-series analysis. Bilateral cerebellar activation is associated with unilateral complex finger movements, as seen on fMRI. This result may support the recent neurological observation that the cerebellum may exert bilateral effects on motor performance

  15. Effects of task performance, helping, voice, and organizational loyalty on performance appraisal ratings.

    Science.gov (United States)

    Whiting, Steven W; Podsakoff, Philip M; Pierce, Jason R

    2008-01-01

    Despite the fact that several studies have investigated the relationship between organizational citizenship behavior and performance appraisal ratings, the vast majority of these studies have been cross-sectional, correlational investigations conducted in organizational settings that do not allow researchers to establish the causal nature of this relationship. To address this lack of knowledge regarding causality, the authors conducted 2 studies designed to investigate the effects of task performance, helping behavior, voice, and organizational loyalty on performance appraisal evaluations. Findings demonstrated that each of these forms of behavior has significant effects on performance evaluation decisions and suggest that additional attention should be directed at both voice and organizational loyalty as important forms of citizenship behavior aimed at the organization. 2008 APA

  16. Absorbed in the task : Personality measures predict engagement during task performance as tracked by error negativity and asymmetrical frontal activity

    NARCIS (Netherlands)

    Tops, Mattie; Boksem, Maarten A. S.

    2010-01-01

    We hypothesized that interactions between traits and context predict task engagement, as measured by the amplitude of the error-related negativity (ERN), performance, and relative frontal activity asymmetry (RFA). In Study 1, we found that drive for reward, absorption, and constraint independently

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

    NARCIS (Netherlands)

    Crone, E.A.; Bunge, S.A.; Latenstein, H.; van der Molen, M.W.

    2005-01-01

    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

  18. Children's Sleep, Sleepiness, and Performance on Cognitive Tasks.

    Science.gov (United States)

    Buckhalt, Joseph A

    2011-01-01

    While causal connections between sleep deprivation and attention, learning, and memory have been well established in adults, much less research has been done with children. Relations between the amount and quality of sleep and daytime sleepiness have been found for a number of cognitive and academic tasks in several groups of children. These relations have been found for children who have sleep disorders, for children with disorders involving cognitive impairment, and for typically developing children with no known disorders. The research is reviewed here with a focus on the types of cognitive and academic tasks that have been related to insufficient sleep. A series of studies is described that relates sleep parameters to the Woodcock-Johnson® III Tests of Cognitive Abilities and other, similar measures. Implications for educators and psychologists who work with children are discussed.

  19. Processing Resources in Attention, Dual Task Performance, and Workload Assessment.

    Science.gov (United States)

    1981-07-01

    levels of processing in encoding and memory ( Craik & Lockhart , 1972) employs the capacity metaphore when describing the amount of processing ...depending upon the nature of a paired task. Second, encoding or rehearsal of verbal material may differ in the "depth of processing " ( Craik & Lockhart ...F.I.M., & Lockhart , F.S. Levels of processing : A framework for mem- ory research. Journal of Verbal Learning & Verbal Behavior, 1972, 11, 671-684.

  20. Children's Sleep, Sleepiness, and Performance on Cognitive Tasks

    OpenAIRE

    Buckhalt, Joseph A.

    2011-01-01

    While causal connections between sleep deprivation and attention, learning, and memory have been well established in adults, much less research has been done with children. Relations between the amount and quality of sleep and daytime sleepiness have been found for a number of cognitive and academic tasks in several groups of children. These relations have been found for children who have sleep disorders, for children with disorders involving cognitive impairment, and for typically developing...

  1. Effect of a Body Model on Performance in a Virtual Environment Search Task

    National Research Council Canada - National Science Library

    Singer, Michael

    1998-01-01

    ...) in training dismounted soldiers. This experiment investigated full body representation (generic) versus a hand linked pointer on movement performance in an office building interior during a search task...

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

    Science.gov (United States)

    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…

  3. Experimental evaluation of the influence of various rests on task performance

    International Nuclear Information System (INIS)

    Nagasaka, Akihiko; Hirose, Ayako

    2000-01-01

    This report deals with the result of the experiment that 8 subjects had executed adding task and search task. They executed each task in 80 minutes under 5 conditions: (1) with no rest, and with 4 kinds of 20 minutes rests, in which they (2) opened eyes, (3) closed eyes, (4) closed eyes with listening classic music and (5) closed eyes with feet massage, in the middle of the task. The results of analysis of variance with the task performance in the latter half, there were significant differences between each condition with every subject in adding task, and with 6 subjects in search task. However, the orders of the task performance with each condition were not the same by each subject. It was suggested that transition of the arousal levels under the rest was related to the effects of the rest rather than the subjects' taste in rests. In the rest, the percentage of α wave of electroencephalogram and the coefficient of variation of R-R interval (time interval of heart beats) were increased than in executing task. The mean Kendall's rank correlation of coefficient with the order of increase rate of α/β wave and the task performance in the latter half was slightly negative in adding task, but was about 0.4 in search task. From these results, about six requirements for 'an effective rest' were able to be mentioned, for example, 'the devices that raises the arousal levels is carried out just before a rest end'. (author)

  4. Performance impact of mutation operators of a subpopulation-based genetic algorithm for multi-robot task allocation problems.

    Science.gov (United States)

    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.

  5. Staff Performance Analysis: A Method for Identifying Brigade Staff Tasks

    National Research Council Canada - National Science Library

    Ford, Laura

    1997-01-01

    ... members of conventional mounted brigade staff. Initial analysis of performance requirements in existing documentation revealed that the performance specifications were not sufficiently detailed for brigade battle staffs...

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

    Science.gov (United States)

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

    2013-01-01

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

  7. Can tutoring improve performance on a reasoning task under deadline conditions?

    Science.gov (United States)

    Osman, Magda

    2007-03-01

    The present study examined the effectiveness of a tutoring technique that has been used to identify and address participants' misunderstandings in Wason's selection task. In particular, the study investigated whether the technique would lead to improvements in performance when the task was presented in a deadline format (a condition in which time restrictions are imposed). In Experiment 1, the effects of tutoring on performance were compared in free time (conditions in which no time restrictions are imposed) and deadline task formats. In Experiment 2, improvements in performance were studied in deadline task formats, in which the tutoring and test phases were separated by an interval of 1 day. The results suggested that tutoring improved performance on the selection task under deadline and in free time conditions. Additionally, the study showed that participants made errors because they had misinterpreted the task. With tutoring, they were able to modify their initial misunderstandings.

  8. Identification of tasks performed by stroke patients using a mobility assistive device

    DEFF Research Database (Denmark)

    Hester, Todd; Sherrill, Delsey M; Hamel, Mathieu

    2006-01-01

    of these devices. In this study, we propose the use of wearable sensors to identify tasks performed by stroke patients with a mobility assistive device. Subjects performed ten tasks with a three-axis accelerometer attached to their ankle and a neural network was trained to identify the task being performed...... tasks associated with the use of a cane. Therefore, we envision that the methodology presented in this paper could be used to evaluate the use of a cane in the context of the task being performed........ Results from 15 stroke patients indicated that these motor tasks can be reliably identified with a median sensitivity of 90 % at a median specificity of 95%. These results indicate that it is possible to use a single module with a three-axis accelerometer attached to the ankle to reliably identify motor...

  9. Exploring the Performance Differences on the Flicker Task and the Conners' Continuous Performance Test in Adults with ADHD

    Science.gov (United States)

    Cohen, Andrew L.; Shapiro, Steven K.

    2007-01-01

    Objective: To examine the ability of the flicker task to demonstrate greater utility in discriminating performance in young adults with and without ADHD compared to the Conners' CPT (CCPT). Method: Flicker task and CCPT performance were compared between an ADHD (n = 28) and control (n = 30) group of college students. Results: This study replicated…

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

    Science.gov (United States)

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

    2018-05-01

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

  11. Current status of the tasks performed by the Nuclear Fuel Department for the CAREM project

    International Nuclear Information System (INIS)

    Kaufmann, Federico; Perez, Lidia E.; Perez, Aaldo; Marchi, Daniel E.

    2009-01-01

    CAREM Project required to the Nuclear Fuels Department to perform the necessary tasks to define the powder characteristics and natural UO 2 -Gd 2 O 3 , UO 2 -1.8 and 3.1 % enrichment fuel pellets manufacturing and control parameters. To start with these tasks it was necessary to hire and train staff, begin the licensing process of the facilities, update infrastructure works and equipment of existing facilities. A brief description of the tasks performed is shown. (author)

  12. EEG Analysis during complex diagnostic tasks in Nuclear Power Plants - Simulator-based Experimental Study

    International Nuclear Information System (INIS)

    Ha, Jun Su; Seong, Poong Hyun

    2005-01-01

    In literature, there are a lot of studies based on EEG signals during cognitive activities of human-beings but most of them dealt with simple cognitive activities such as transforming letters into Morse code, subtraction, reading, semantic memory search, visual search, memorizing a set of words and so on. In this work, EEG signals were analyzed during complex diagnostic tasks in NPP simulator-based environment. Investigated are the theta, alpha, beta, and gamma band EEG powers during the diagnostic tasks. The experimental design and procedure are represented in section 2 and the results are shown in section 3. Finally some considerations are discussed and the direction for the further work is proposed in section 4

  13. Stress influences decisions to break a safety rule in a complex simulation task in females.

    Science.gov (United States)

    Starcke, Katrin; Brand, Matthias; Kluge, Annette

    2016-07-01

    The current study examines the effects of acutely induced laboratory stress on a complex decision-making task, the Waste Water Treatment Simulation. Participants are instructed to follow a certain decision rule according to safety guidelines. Violations of this rule are associated with potential high rewards (working faster and earning more money) but also with the risk of a catastrophe (an explosion). Stress was induced with the Trier Social Stress Test while control participants underwent a non-stress condition. In the simulation task, stressed females broke the safety rule more often than unstressed females: χ(2) (1, N=24)=10.36, pbreak the safety rule because stressed female participants focused on the potential high gains while they neglected the risk of potential negative consequences. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. EEG Analysis during complex diagnostic tasks in Nuclear Power Plants - Simulator-based Experimental Study

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jun Su; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2005-07-01

    In literature, there are a lot of studies based on EEG signals during cognitive activities of human-beings but most of them dealt with simple cognitive activities such as transforming letters into Morse code, subtraction, reading, semantic memory search, visual search, memorizing a set of words and so on. In this work, EEG signals were analyzed during complex diagnostic tasks in NPP simulator-based environment. Investigated are the theta, alpha, beta, and gamma band EEG powers during the diagnostic tasks. The experimental design and procedure are represented in section 2 and the results are shown in section 3. Finally some considerations are discussed and the direction for the further work is proposed in section 4.

  15. Task Phase Recognition for Highly Mobile Workers in Large Building Complexes

    DEFF Research Database (Denmark)

    Stisen, Allan; Mathisen, Andreas; Krogh, Søren

    2016-01-01

    requirements on the accuracy of the indoor positioning, and thus come with low deployment and maintenance effort in real-world settings. We evaluated the proposed methods in a large hospital complex, where the highly mobile workers were recruited among the non-clinical workforce. The evaluation is based......-scale indoor work environments, namely from a WiFi infrastructure providing coarse grained indoor positioning, from inertial sensors in the workers’ mobile phones, and from a task management system yielding information about the scheduled tasks’ start and end locations. The methods presented have low...... on manually labelled real-world data collected over 4 days of regular work life of the mobile workforce. The collected data yields 83 tasks in total involving 8 different orderlies from a major university hospital with a building area of 160, 000 m2. The results show that the proposed methods can distinguish...

  16. Main tasks of studying strong regulation of excitation of complex electrical system generators

    Energy Technology Data Exchange (ETDEWEB)

    Gruzdev, I.A.; Yekimova, M.M.

    1982-01-01

    A survey is made of the current state of studies of the damping properties of complex electricity systems. The calculation programs of stability are based on frequency methods using the method of D-division. Now, when ARV of strong effect dominates at the SG, the task of coordinating their adjustments develops. Consequently, the following questions are discussed: study of the properties of quality functional with several points of regulation in the circuits of different structure; development of the efficient procedures for coordinating the ARV adjustment of the related energy systems; and creation of resources for solving these tasks. Results are presented of coordinating the ARV adjustments of the generators of the 3-machine electricity system. As an example, nonlinear relationships are shown between the obtained degree of stability and the coefficient of stabilization.

  17. Effect of aging on performance, muscle activation and perceived stress during mentally demanding computer tasks

    DEFF Research Database (Denmark)

    Alkjaer, Tine; Pilegaard, Marianne; Bakke, Merete

    2005-01-01

    OBJECTIVES: This study examined the effects of age on performance, muscle activation, and perceived stress during computer tasks with different levels of mental demand. METHODS: Fifteen young and thirteen elderly women performed two computer tasks [color word test and reference task] with different...... levels of mental demand but similar physical demands. The performance (clicking frequency, percentage of correct answers, and response time for correct answers) and electromyography from the forearm, shoulder, and neck muscles were recorded. Visual analogue scales were used to measure the participants......' perception of the stress and difficulty related to the tasks. RESULTS: Performance decreased significantly in both groups during the color word test in comparison with performance on the reference task. However, the performance reduction was more pronounced in the elderly group than in the young group...

  18. Chew on this: No support for facilitating effects of gum on spatial task performance.

    Science.gov (United States)

    Nader, Ingo W; Gittler, Georg; Waldherr, Karin; Pietschnig, Jakob

    2010-09-01

    To determine whether chewing of gum facilitates spatial task performance in healthy participants, two behavioral experiments were performed. In the first experiment, spatial task performance of 349 men and women preceding and after treatment administration (saccharated chewing gum, sugar-free chewing gum, no chewing gum) was assessed using effect modeling by means of Item Response Theory. In the second experiment, another 100 participants were either administered sugar-free chewing gum or no chewing gum during spatial task performance. Effects of gum in the second study were assessed by standard means of data analysis. Results indicated no significant effects of either chewing gum or sugar on spatial task performance in either experiment. Our findings are consistent with recent studies investigating the influences of chewing gum on various memory functions, extending them by another measure of cognitive ability. Thus, further doubt is cast on enhancing effects of chewing gum on cognitive task performance. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Effects on Task Performance and Psychophysiological Measures of Performance During Normobaric Hypoxia Exposure

    Science.gov (United States)

    Stephens, Chad; Kennedy, Kellie; Napoli, Nicholas; Demas, Matthew; Barnes, Laura; Crook, Brenda; Williams, Ralph; Last, Mary Carolyn; Schutte, Paul

    2017-01-01

    Human-autonomous systems have the potential to mitigate pilot cognitive impairment and improve aviation safety. A research team at NASA Langley conducted an experiment to study the impact of mild normobaric hypoxia induction on aircraft pilot performance and psychophysiological state. A within-subjects design involved non-hypoxic and hypoxic exposures while performing three 10-minute tasks. Results indicated the effect of 15,000 feet simulated altitude did not induce significant performance decrement but did produce increase in perceived workload. Analyses of psychophysiological responses evince the potential of biomarkers for hypoxia onset. This study represents on-going work at NASA intending to add to the current knowledge of psychophysiologically-based input to automation to increase aviation safety. Analyses involving coupling across physiological systems and wavelet transforms of cortical activity revealed patterns that can discern between the simulated altitude conditions. Specifically, multivariate entropy of ECG/Respiration components were found to be significant predictors (pTask performance was not appreciably impacted by the effect of 15,000 feet simulated altitude. Analyses of psychophysiological responses evince the potential of biomarkers for mild hypoxia onset.The potential for identifying shifts in underlying cortical and physiological systems could serve as a means to identify the onset of deteriorated cognitive state. Enabling such assessment in future flightdecks could permit increasingly autonomous systems-supported operations. Augmenting human operator through assessment of cognitive impairment has the potential to further improve operator performance and mitigate human error in safety critical contexts. This study represents ongoing work at NASA intending to add to the current knowledge of psychophysiologically-based input to automation to increase aviation safety.

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

    Science.gov (United States)

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

    1986-01-01

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

  1. Concurrent performance of two memory tasks: evidence for domain-specific working memory systems.

    Science.gov (United States)

    Cocchini, Gianna; Logie, Robert H; Della Sala, Sergio; MacPherson, Sarah E; Baddeley, Alan D

    2002-10-01

    Previous studies of dual-task coordination in working memory have shown a lack of dual-task interference when a verbal memory task is combined with concurrent perceptuomotor tracking. Two experiments are reported in which participants were required to perform pairwise combinations of (1) a verbal memory task, a visual memory task, and perceptuomotor tracking (Experiment 1), and (2) pairwise combinations of the two memory tasks and articulatory suppression (Experiment 2). Tracking resulted in no disruption of the verbal memory preload over and above the impact of a delay in recall and showed only minimal disruption of the retention of the visual memory load. Performing an ongoing verbal memory task had virtually no impact on retention of a visual memory preload or vice versa, indicating that performing two demanding memory tasks results in little mutual interference. Experiment 2 also showed minimal disruption when the two memory tasks were combined, although verbal memory (but not visual memory) was clearly disrupted by articulatory suppression interpolated between presentation and recall. These data suggest that a multiple-component working memory model provides a better account for performance in concurrent immediate memory tasks than do theories that assume a single processing and storage system or a limited-capacity attentional system coupled with activated memory traces.

  2. Attention Deficit ِDuring Dual-Task Performance in Alzheimer’s Disease Patients

    Directory of Open Access Journals (Sweden)

    Hamid Salehi

    2014-07-01

    Full Text Available Objectives: The aims of the present investigation was the evaluation of divided attention deficits in Alzheimer's disease (AD patients by using dual-task paradigm in order to ascertain whether this method can be useful in the early diagnosis of AD or not.  Methods & Materials: A total of 23 elderly individuals (11 females and 12 males voluntarily participated in the investigation: 13 patients with Alzheimer's disease (AD and 10 healthy elderly individuals. The experimental setup consisted of (a single -task and (b dual-task trials at two levels of difficulty. In singletask condition, the participants were asked to recite the months of the year continuously with normal order (easy and backward (difficult. They also performed a computerized visuospatial/motor tracking task. The participants then performed the tracking task in conjunction with each of the months reciting tasks as dual-task condition. Results: The results showed a significant interaction (disease×level of difficulty effect. So that, the performance impairment on combine performance in two simultaneous tasks was related to task difficulty, but the elderly control group did not differ in the easy and difficult conditions. Conclusion: These findings not only increase our understanding of the attention deficits in AD patients, but also have implications for the mediating effect of cognitive load in using dual-task paradigm for studying attention mechanisms of cognitively suffered individuals.

  3. Performance deficits in a voluntary saccade task in Chinese "express saccade makers".

    Directory of Open Access Journals (Sweden)

    Paul C Knox

    Full Text Available Differences in behaviour and cognition have been observed in different human populations. It has been reported that in various types of complex visual task, eye movement patterns differ systematically between Chinese and non-Chinese participants, an observation that has been related to differences in culture between groups. However, we confirm here that, in healthy, naïve adult Chinese participants, a far higher proportion (22% than expected (1-5% exhibit a pattern of reflexive eye movement behaviour (high numbers of low latency express saccades in circumstances designed to inhibit such responses (prosaccade overlap tasks. These participants are defined as "express saccade makers" (ESMs. We then show using the antisaccade paradigm, which requires the inhibition of reflexive responses and the programming and execution of voluntary saccades, that the performance of ESMs is compromised; they have higher antisaccade directional error rates, and the latency distributions of their error saccades again exhibit a higher proportion of low latency express saccade errors consistent with a reduced ability to inhibit reflexive responses. These results are difficult to reconcile with a cultural explanation as they relate to important and specific performance differences within a particular population. They suggest a potential unexpected confound relevant to those studies of Chinese versus other groups which have investigated group differences using oculomotor measures, and explained them in terms of culture. The confirmation of higher numbers of ESMs among Chinese participants provides new opportunities for examining oculomotor control.

  4. The effects of bedrest on crew performance during simulated shuttle reentry. Volume 2: Control task performance

    Science.gov (United States)

    Jex, H. R.; Peters, R. A.; Dimarco, R. J.; Allen, R. W.

    1974-01-01

    A simplified space shuttle reentry simulation performed on the NASA Ames Research Center Centrifuge is described. Anticipating potentially deleterious effects of physiological deconditioning from orbital living (simulated here by 10 days of enforced bedrest) upon a shuttle pilot's ability to manually control his aircraft (should that be necessary in an emergency) a comprehensive battery of measurements was made roughly every 1/2 minute on eight military pilot subjects, over two 20-minute reentry Gz vs. time profiles, one peaking at 2 Gz and the other at 3 Gz. Alternate runs were made without and with g-suits to test the help or interference offered by such protective devices to manual control performance. A very demanding two-axis control task was employed, with a subcritical instability in the pitch axis to force a high attentional demand and a severe loss-of-control penalty. The results show that pilots experienced in high Gz flying can easily handle the shuttle manual control task during 2 Gz or 3 Gz reentry profiles, provided the degree of physiological deconditioning is no more than induced by these 10 days of enforced bedrest.

  5. The Effects of Background Music on Primary School Pupils' Task Performance.

    Science.gov (United States)

    Hallam, Susan; Price, John; Katsarou, Georgia

    2002-01-01

    Presents two studies that explored the effects of music perceived as calming and relaxing on arithmetic and memory performance tasks of 10- to 12-year-old children. Reports that the calming music led to better performance on both tasks when compared with the non-music condition. Includes references. (CMK)

  6. Cognitive Load Theory: An Empirical Study of Anxiety and Task Performance in Language Learning

    Science.gov (United States)

    Chen, I-Jung; Chang, Chi-Cheng

    2009-01-01

    Introduction: This study explores the relationship among three variables--cognitive load, foreign language anxiety, and task performance. Cognitive load refers to the load imposed on working memory while performing a particular task. The authors hypothesized that anxiety consumes the resources of working memory, leaving less capacity for cognitive…

  7. Effects of Mindfulness-Based Intervention to Improve Task Performance for Children with Intellectual Disabilities

    Science.gov (United States)

    Kim, Jeongil; Kwon, Miyoung

    2018-01-01

    Background: Task performance is a critical factor for learning in individuals with intellectual disabilities. This study aimed to examine mindfulness-based intervention (MBI) to improve task performance for children with intellectual disability (ID). Methods: Three elementary school children with ID participated in the study. A multiple baseline…

  8. The effect of caffeine on cognitive task performance and motor fatigue

    NARCIS (Netherlands)

    van Duinen, Hiske; Lorist, Monicque M.; Zijdewind, Inge

    Rationale: In everyday life, people are usually capable of performing two tasks simultaneously. However, in a previous study we showed that during a fatiguing motor task, cognitive performance declined progressively. There is extensive literature on the ( positive) effects of caffeine on cognitive

  9. Decision criterion dynamics in animals performing an auditory detection task.

    Directory of Open Access Journals (Sweden)

    Robert W Mill

    Full Text Available Classical signal detection theory attributes bias in perceptual decisions to a threshold criterion, against which sensory excitation is compared. The optimal criterion setting depends on the signal level, which may vary over time, and about which the subject is naïve. Consequently, the subject must optimise its threshold by responding appropriately to feedback. Here a series of experiments was conducted, and a computational model applied, to determine how the decision bias of the ferret in an auditory signal detection task tracks changes in the stimulus level. The time scales of criterion dynamics were investigated by means of a yes-no signal-in-noise detection task, in which trials were grouped into blocks that alternately contained easy- and hard-to-detect signals. The responses of the ferrets implied both long- and short-term criterion dynamics. The animals exhibited a bias in favour of responding "yes" during blocks of harder trials, and vice versa. Moreover, the outcome of each single trial had a strong influence on the decision at the next trial. We demonstrate that the single-trial and block-level changes in bias are a manifestation of the same criterion update policy by fitting a model, in which the criterion is shifted by fixed amounts according to the outcome of the previous trial and decays strongly towards a resting value. The apparent block-level stabilisation of bias arises as the probabilities of outcomes and shifts on single trials mutually interact to establish equilibrium. To gain an intuition into how stable criterion distributions arise from specific parameter sets we develop a Markov model which accounts for the dynamic effects of criterion shifts. Our approach provides a framework for investigating the dynamics of decisions at different timescales in other species (e.g., humans and in other psychological domains (e.g., vision, memory.

  10. Factors Associated With Community Health Worker Performance Differ by Task in a Multi-Tasked Setting in Rural Zimbabwe.

    Science.gov (United States)

    Kambarami, Rukundo A; Mbuya, Mduduzi Nn; Pelletier, David; Fundira, Dadirai; Tavengwa, Naume V; Stoltzfus, Rebecca J

    2016-06-20

    Zimbabwe, like most low-income countries, faces health worker shortages. Community health workers (CHWs) bridge this gap by delivering essential health services and nutrition interventions to communities. However, as workloads increase, CHWs' ability to provide quality services may be compromised. We studied influences upon CHWs' performance related to pregnancy surveillance and nutrition and hygiene education in rural Zimbabwe. In the context of a cluster-randomized trial conducted in 2 rural districts between November 2012 and March 2015, 342 government-employed CHWs identified and referred pregnant women for early antenatal care and delivered household-level behavior change lessons about infant feeding and hygiene to more than 5,000 women. In 2013, we conducted a survey among 322 of the CHWs to assess the association between demographic and work characteristics and task performance. Exploratory factor analyses of the Likert-type survey questions produced 8 distinct and reliable constructs of job satisfaction and motivation, supervision, peer support, and feedback (Cronbach α range, 0.68 to 0.92). Pregnancy surveillance performance was assessed from pregnancy referrals, and nutrition and hygiene education performance was assessed by taking the average summative score (range, 5 to 30) of lesson delivery observations completed by a nurse supervisor using a 6-item Likert-type checklist. Poisson and multiple linear regressions were used to test associations between CHW demographic and work characteristics and performance. CHWs who referred more pregnant women were female, unmarried, under 40 years old, from larger households, and of longer tenure. They also perceived work resources to be adequate and received positive feedback from supervisors and the community, but they were less satisfied with remuneration. CHWs with high scores on behavior change lesson delivery were from smaller households, and they received more supportive supervision but less operational

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

    Science.gov (United States)

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

    1991-01-01

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

  12. Organizational Adaptative Behavior: The Complex Perspective of Individuals-Tasks Interaction

    Science.gov (United States)

    Wu, Jiang; Sun, Duoyong; Hu, Bin; Zhang, Yu

    Organizations with different organizational structures have different organizational behaviors when responding environmental changes. In this paper, we use a computational model to examine organizational adaptation on four dimensions: Agility, Robustness, Resilience, and Survivability. We analyze the dynamics of organizational adaptation by a simulation study from a complex perspective of the interaction between tasks and individuals in a sales enterprise. The simulation studies in different scenarios show that more flexible communication between employees and less hierarchy level with the suitable centralization can improve organizational adaptation.

  13. Merging assistance function with task distribution model to enhance user performance in collaborative virtual environment

    International Nuclear Information System (INIS)

    Khalid, S.; Alam, A.

    2016-01-01

    Collaborative Virtual Environments (CVEs) falls under Virtual Reality (VR) where two or more users manipulate objects collaboratively. In this paper we have made some experiments to make assembly from constituents parts scattered in Virtual Environment (VE) based on task distribution model using assistance functions for checking and enhancing user performance. The CVEs subjects setting on distinct connected machines via local area network. In this perspective, we consider the effects of assistance function with oral communication on collaboration, co-presence and users performance. Twenty subjects performed collaboratively an assembly task on static and dynamic based task distribution. We examine the degree of influence of assistance function with oral communications on user's performance based on task distribution model. The results show that assistance functions with oral communication based on task distribution model not only increase user performance but also enhance the sense of copresence and awareness. (author)

  14. Effect of temperature on task performance in officeenvironment

    Energy Technology Data Exchange (ETDEWEB)

    Seppanen, Olli; Fisk, William J.; Lei, Q.H.

    2006-07-01

    Indoor temperature is one of the fundamental characteristics of the indoor environment. It can be controlled with a degree of accuracy dependent on the building and its HVAC system. The indoor temperature affects several human responses, including thermal comfort, perceived air quality, sick building syndrome symptoms and performance at work. In this study, we focused on the effects of temperature on performance at office work. We included those studies that had used objective indicators of performance that are likely to be relevant in office type work, such as text processing, simple calculations (addition, multiplication), length of telephone customer service time, and total handling time per customer for call-center workers. We excluded data from studies of industrial work performance. We calculated from all studies the percentage of performance change per degree increase in temperature, and statistically analyzed measured work performance with temperature. The results show that performance increases with temperature up to 21-22 C, and decreases with temperature above 23-24 C. The highest productivity is at temperature of around 22 C. For example, at the temperature of 30 C, the performance is only 91.1% of the maximum i.e. the reduction in performance is 8.9%

  15. Age-related neural correlates of cognitive task performance under increased postural load

    NARCIS (Netherlands)

    Van Impe, A; Bruijn, S M; Coxon, J P; Wenderoth, N; Sunaert, S; Duysens, J; Swinnen, S P

    2013-01-01

    Behavioral studies suggest that postural control requires increased cognitive control and visuospatial processing with aging. Consequently, performance can decline when concurrently performing a postural and a demanding cognitive task. We aimed to identify the neural substrate underlying this

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

    NARCIS (Netherlands)

    de Dreu, C.K.W.; Weingart, L.R.

    2003-01-01

    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, resultsrevealed strong and negative correlations between relationship conflict, team performance, and

  17. Detection of auditory signals in quiet and noisy backgrounds while performing a visuo-spatial task

    Directory of Open Access Journals (Sweden)

    Vishakha W Rawool

    2016-01-01

    Full Text Available Context: The ability to detect important auditory signals while performing visual tasks may be further compounded by background chatter. Thus, it is important to know how task performance may interact with background chatter to hinder signal detection. Aim: To examine any interactive effects of speech spectrum noise and task performance on the ability to detect signals. Settings and Design: The setting was a sound-treated booth. A repeated measures design was used. Materials and Methods: Auditory thresholds of 20 normal adults were determined at 0.5, 1, 2 and 4 kHz in the following conditions presented in a random order: (1 quiet with attention; (2 quiet with a visuo-spatial task or puzzle (distraction; (3 noise with attention and (4 noise with task. Statistical Analysis: Multivariate analyses of variance (MANOVA with three repeated factors (quiet versus noise, visuo-spatial task versus no task, signal frequency. Results: MANOVA revealed significant main effects for noise and signal frequency and significant noise–frequency and task–frequency interactions. Distraction caused by performing the task worsened the thresholds for tones presented at the beginning of the experiment and had no effect on tones presented in the middle. At the end of the experiment, thresholds (4 kHz were better while performing the task than those obtained without performing the task. These effects were similar across the quiet and noise conditions. Conclusion: Detection of auditory signals is difficult at the beginning of a distracting visuo-spatial task but over time, task learning and auditory training effects can nullify the effect of distraction and may improve detection of high frequency sounds.

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

    Directory of Open Access Journals (Sweden)

    Prudence ePlummer

    2015-04-01

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

  19. Goal Setting and Task Performance: 1969-1980

    Science.gov (United States)

    1980-06-01

    self - esteem showed greater performance improvement than individuals with low self - esteem ...There was no self - esteem effect when instrumentality was high. When self - esteem was low , typists who perceived high goal instrumentality showed greater...performance improvement than M. 49 those with low goal instrumentality; when self - esteem was high, there was no instrumentality effect.

  20. Ramifications of single-port laparoscopic surgery: measuring differences in task performance using simulation.

    Science.gov (United States)

    Conway, Nathan E; Romanelli, John R; Bush, Ron W; Seymour, Neal E

    2014-02-01

    Single-port laparoscopic surgery imposes unique psychomotor challenges. We used surgical simulation to define performance differences between surgeons with and without single-port clinical experience and examined whether a short course of training resulted in improved performance. Study participants were assigned to 3 groups: resident group (RES), experienced laparoscopic surgeons with (SP) and without (LAP) prior single-port laparoscopic experience. Participants performed the Fundamentals of Laparoscopic Surgery precision cutting task on a ProMIS trainer through conventional ports or with articulating instruments via a SILS Port (Covidien, Inc). Two iterations of each method were performed. Then, 6 residents performed 10 successive single-port iterations to assess the effect of practice on task performance. The SP group had faster task times for both laparoscopic (P = .0486) and single-port (P = .0238) methods. The LAP group had longer path lengths for the single-port task than for the laparoscopic task (P = .03). The RES group was slower (P = .0019), with longer path length (P = .0010) but with greater smoothness (P = .0186) on the single-port task than the conventional laparoscopic task. Resident performance task time (P = .005) and smoothness (P = .045) improved with successive iterations. Our data show that surgeons with clinical single-port surgery experience perform a simulated single-port surgical task better than inexperienced single-port surgeons. Furthermore, this performance is comparable to that achieved with conventional laparoscopic techniques. Performance of residents declined dramatically when confronted with the challenges of the single-port task but improved with practice. These results suggest a role for lab-based single-port training.

  1. Human footprint variation while performing load bearing tasks.

    Directory of Open Access Journals (Sweden)

    Cara M Wall-Scheffler

    Full Text Available Human footprint fossils have provided essential evidence about the evolution of human bipedalism as well as the social dynamics of the footprint makers, including estimates of speed, sex and group composition. Generally such estimates are made by comparing footprint evidence with modern controls; however, previous studies have not accounted for the variation in footprint dimensions coming from load bearing activities. It is likely that a portion of the hominins who created these fossil footprints were carrying a significant load, such as offspring or foraging loads, which caused variation in the footprint which could extend to variation in any estimations concerning the footprint's maker. To identify significant variation in footprints due to load-bearing tasks, we had participants (N = 30, 15 males and 15 females walk at a series of speeds carrying a 20kg pack on their back, side and front. Paint was applied to the bare feet of each participant to create footprints that were compared in terms of foot length, foot width and foot area. Female foot length and width increased during multiple loaded conditions. An appreciation of footprint variability associated with carrying loads adds an additional layer to our understanding of the behavior and morphology of extinct hominin populations.

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

    Science.gov (United States)

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

    2013-01-01

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

  3. Uncovering the relationship between transformational leaders and followers' task performance.

    NARCIS (Netherlands)

    Breevaart, K.; Bakker, A. B.; Demerouti, E.; Sleebos, D. M.; Maduro, V.

    2015-01-01

    The purpose of the present study was to unravel the mechanisms underlying the relationship between transformational leadership, follower work engagement, and follower job performance and to investigate a possible boundary condition of transformational leadership. We used structural equation modeling

  4. Computational Modeling of Human Multiple-Task Performance

    National Research Council Canada - National Science Library

    Kieras, David E; Meyer, David

    2005-01-01

    This is the final report for a project that was a continuation of an earlier, long-term project on the development and validation of the EPIC cognitive architecture for modeling human cognition and performance...

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

    Science.gov (United States)

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

    2014-05-01

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

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

    Science.gov (United States)

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

    1990-01-01

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

  7. Modeling Operator Performance in Low Task Load Supervisory Domains

    Science.gov (United States)

    2011-06-01

    important to model the best and 65 worst performers separately. It is easy to see that the best performers were better multitaskers and more directed...the expected population this research will influence is expected to contain men and women between the ages of 18 and 50 with an interest in using...for your patience and great sense of humor. I could not ask for a better thesis reader. Thank you, Amy D’Agostino, for taking the time to read my

  8. Task-focused behavior mediates the associations between supportive interpersonal environments and students' academic performance.

    Science.gov (United States)

    Kiuru, Noona; Pakarinen, Eija; Vasalampi, Kati; Silinskas, Gintautas; Aunola, Kaisa; Poikkeus, Anna-Maija; Metsäpelto, Riitta-Leena; Lerkkanen, Marja-Kristiina; Nurmi, Jari-Erik

    2014-04-01

    In the longitudinal study presented here, we tested the theoretical assumption that children's task-focused behavior in learning situations mediates the associations between supportive interpersonal environments and academic performance. The sample consisted of 2,137 Finnish-speaking children. Data on supportive interpersonal environments (characterized by authoritative parenting, positive teacher affect toward the child, and peer acceptance) were gathered in Grade 1. The children's task-focused behavior was measured in Grades 2 and 3, and academic performance was measured in Grades 1 and 4. The results supported our assumption by showing that all three supportive environments were positively associated with children's subsequent academic performance via increased task-focused behavior in learning situations. These findings suggest that students' academic performance can be promoted by increasing the support they receive from peers, parents, and teachers because such increased support leads to better task focus in learning tasks.

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

    Science.gov (United States)

    Smirmaul, Bruno P

    2017-01-01

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

  10. Impulsivity modulates performance under response uncertainty in a reaching task.

    Science.gov (United States)

    Tzagarakis, C; Pellizzer, G; Rogers, R D

    2013-03-01

    We sought to explore the interaction of the impulsivity trait with response uncertainty. To this end, we used a reaching task (Pellizzer and Hedges in Exp Brain Res 150:276-289, 2003) where a motor response direction was cued at different levels of uncertainty (1 cue, i.e., no uncertainty, 2 cues or 3 cues). Data from 95 healthy adults (54 F, 41 M) were analysed. Impulsivity was measured using the Barratt Impulsiveness Scale version 11 (BIS-11). Behavioral variables recorded were reaction time (RT), errors of commission (referred to as 'early errors') and errors of precision. Data analysis employed generalised linear mixed models and generalised additive mixed models. For the early errors, there was an interaction of impulsivity with uncertainty and gender, with increased errors for high impulsivity in the one-cue condition for women and the three-cue condition for men. There was no effect of impulsivity on precision errors or RT. However, the analysis of the effect of RT and impulsivity on precision errors showed a different pattern for high versus low impulsives in the high uncertainty (3 cue) condition. In addition, there was a significant early error speed-accuracy trade-off for women, primarily in low uncertainty and a 'reverse' speed-accuracy trade-off for men in high uncertainty. These results extend those of past studies of impulsivity which help define it as a behavioural trait that modulates speed versus accuracy response styles depending on environmental constraints and highlight once more the importance of gender in the interplay of personality and behaviour.

  11. Thinking processes used by high-performing students in a computer programming task

    Directory of Open Access Journals (Sweden)

    Marietjie Havenga

    2011-07-01

    Full Text Available Computer programmers must be able to understand programming source code and write programs that execute complex tasks to solve real-world problems. This article is a trans- disciplinary study at the intersection of computer programming, education and psychology. It outlines the role of mental processes in the process of programming and indicates how successful thinking processes can support computer science students in writing correct and well-defined programs. A mixed methods approach was used to better understand the thinking activities and programming processes of participating students. Data collection involved both computer programs and students’ reflective thinking processes recorded in their journals. This enabled analysis of psychological dimensions of participants’ thinking processes and their problem-solving activities as they considered a programming problem. Findings indicate that the cognitive, reflective and psychological processes used by high-performing programmers contributed to their success in solving a complex programming problem. Based on the thinking processes of high performers, we propose a model of integrated thinking processes, which can support computer programming students. Keywords: Computer programming, education, mixed methods research, thinking processes.  Disciplines: Computer programming, education, psychology

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    Cardis, Marco; Casadio, Maura; Ranganathan, Rajiv

    2018-01-01

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

  14. The developmental dynamics of task-avoidant behavior and math performance in kindergarten and elementary school

    OpenAIRE

    Hirvonen, Riikka; Tolvanen, Asko; Aunola, Kaisa; Nurmi, Jari-Erik

    2012-01-01

    Besides cognitive factors, children's learning at school may be influenced by more dynamic phenomena, such as motivation and achievement-related task-avoidant behavior. The present study examined the developmental dynamics of task-avoidant behavior and math performance from kindergarten to Grade 4. A total of 225 children were tested for their arithmetic skills in kindergarten and in Grades 1, 2, and 4 of elementary school. Children's task-avoidant behavior in learning situations was rated by...

  15. Preempting Performance Challenges: The Effects of Inoculation Messaging on Attacks to Task Self-Efficacy

    Science.gov (United States)

    Jackson, Ben; Compton, Josh; Whiddett, Ryan; Anthony, David R.; Dimmock, James A.

    2015-01-01

    Although inoculation messages have been shown to be effective for inducing resistance to counter-attitudinal attacks, researchers have devoted relatively little attention toward studying the way in which inoculation theory principles might support challenges to psychological phenomena other than attitudes (e.g., self-efficacy). Prior to completing a physical (i.e., balance) task, undergraduates (N = 127, Mage = 19.20, SD = 2.16) were randomly assigned to receive either a control or inoculation message, and reported their confidence in their ability regarding the upcoming task. During the task, a confederate provided standardized negative feedback to all participants regarding their performance, and following the completion of the task, participants again reported their self-efficacy along with measures assessing in-task processes. Findings supported the viability of efficacy inoculation; controlling for pre-task self-efficacy, task performance, and relevant psycho-social variables (e.g., resilience, self-confidence robustness), participants in the inoculation condition reported greater confidence in their ability (i.e., task self-efficacy) than those in the control condition at post-task. Relative to those in the inoculation condition, participants in the control condition also experienced greater concentration disruption and self-presentation concerns during the task. PMID:25898287

  16. Complex Heat Exchangers for Improved Performance

    Science.gov (United States)

    Bran, Gabriela Alejandra

    After a detailed literature review, it was determined that there was a need for a more comprehensive study on the transient behavior of heat exchangers. Computational power was not readily available when most of the work on transient heat exchangers was done (1956 - 1986), so most of these solutions have restrictions, or very specific assumptions. More recently, authors have obtained numerical solutions for more general problems (2003 - 2013), but they have investigated very specific conditions, and cases. For a more complex heat exchanger (i.e. with heat generation), the transient solutions from literature are no longer valid. There was a need to develop a numerical model that relaxes the restrictions of current solutions to explore conditions that have not been explored. A one dimensional transient heat exchanger model was developed. There are no restrictions on the fluids and wall conditions. The model is able to obtain a numerical solution for a wide range of fluid properties and mass flow rates. Another innovative characteristic of the numerical model is that the boundary and initial conditions are not limited to constant values. The boundary conditions can be a function of time (i.e. sinusoidal signal), and the initial conditions can be a function of position. Four different cases were explored in this work. In the first case, the start-up of a system was investigated where the whole system is assumed to be at the same temperature. In the second case, the new steady state in case one gets disrupted by a smaller inlet temperature step change. In the third case, the new steady state in case one gets disrupted by a step change in one of the mass flow rates. The response of these three cases show that there are different transient behaviors, and they depend on the conditions imposed on the system. The fourth case is a system that has a sinusoidal time varying inlet temperature for one of the flows. The results show that the sinusoidal behavior at the inlet

  17. Disparity in Frontal Lobe Connectivity on a Complex Bimanual Motor Task Aids in Classification of Operator Skill Level.

    Science.gov (United States)

    Andreu-Perez, Javier; Leff, Daniel Richard; Shetty, Kunal; Darzi, Ara; Yang, Guang-Zhong

    2016-06-01

    Objective metrics of technical performance (e.g., dexterity, time, and path length) are insufficient to fully characterize operator skill level, which may be encoded deep within neural function. Unlike reports that capture plasticity across days or weeks, this articles studies long-term plasticity in functional connectivity that occurs over years of professional task practice. Optical neuroimaging data are acquired from professional surgeons of varying experience on a complex bimanual coordination task with the aim of investigating learning-related disparity in frontal lobe functional connectivity that arises as a consequence of motor skill level. The results suggest that prefrontal and premotor seed connectivity is more critical during naïve versus expert performance. Given learning-related differences in connectivity, a least-squares support vector machine with a radial basis function kernel is employed to evaluate skill level using connectivity data. The results demonstrate discrimination of operator skill level with accuracy ≥0.82 and Multiclass Matthew's Correlation Coefficient ≥0.70. Furthermore, these indices are improved when local (i.e., within-region) rather than inter-regional (i.e., between-region) frontal connectivity is considered (p = 0.002). The results suggest that it is possible to classify operator skill level with good accuracy from functional connectivity data, upon which objective assessment and neurofeedback may be used to improve operator performance during technical skill training.

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

    Science.gov (United States)

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

    2016-01-01

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

  19. Dependence of behavioral performance on material category in an object grasping task with monkeys.

    Science.gov (United States)

    Yokoi, Isao; Tachibana, Atsumichi; Minamimoto, Takafumi; Goda, Naokazu; Komatsu, Hidehiko

    2018-05-02

    Material perception is an essential part of our cognitive function that enables us to properly interact with our complex daily environment. One important aspect of material perception is its multimodal nature. When we see an object, we generally recognize its haptic properties as well as its visual properties. Consequently, one must examine behavior using real objects that are perceived both visually and haptically to fully understand the characteristics of material perception. As a first step, we examined whether there is any difference in the behavioral responses to different materials in monkeys trained to perform an object grasping task in which they saw and grasped rod-shaped real objects made of various materials. We found that the monkeys' behavior in the grasping task, measured based on the success rate and the pulling force, differed depending on the material category. Monkeys easily and correctly grasped objects of some materials, such as metal and glass, but failed to grasp objects of other materials. In particular, monkeys avoided grasping fur-covered objects. The differences in the behavioral responses to the material categories cannot be explained solely based on the degree of familiarity with the different materials. These results shed light on the organization of multimodal representation of materials, where their biological significance is an important factor. In addition, a monkey that avoided touching real fur-covered objects readily touched images of the same objects presented on a CRT display. This suggests employing real objects is important when studying behaviors related to material perception.

  20. The curvilinear relationship between work pressure and momentary task performance: the role of state and trait core self-evaluations.

    Science.gov (United States)

    Hofmans, Joeri; Debusscher, Jonas; Dóci, Edina; Spanouli, Andromachi; De Fruyt, Filip

    2015-01-01

    Whereas several studies have demonstrated that core self-evaluations (CSE)-or one's appraisals about one's own self-worth, capabilities, and competences-relate to job outcomes, less is known about the mechanisms underlying these relationships. In the present study, we address this issue by examining the role of within- and between-person variation in CSE in the relationship between work pressure and task performance. We hypothesized that (a) work pressure relates to task performance in a curvilinear way, (b) state CSE mediates the curvilinear relationship between work pressure and task performance, and (c) the relationship between work pressure and state CSE is moderated by trait CSE. Our hypotheses were tested via a 10-day daily diary study with 55 employees in which trait CSE was measured at baseline, while work pressure, task performance, and state CSE were assessed on a daily basis. Bayesian multilevel path analysis showed that work pressure affects task performance via state CSE, with state CSE increasing as long as the employee feels that (s)he is able to handle the work pressure, while it decreases when the level of work pressure exceeds the employees' coping abilities. Moreover, we found that for people low on trait CSE, the depleting effect of work pressure via state CSE happens for low levels of work pressure, while for people high in trait CSE the depleting effect is located at high levels of work pressure. Together, our findings suggest that the impact of work pressure on task performance is driven by a complex interplay of between- and within-person differences in CSE.

  1. Pupillary response to complex interdependent tasks: A cognitive-load theory perspective.

    Science.gov (United States)

    Mitra, Ritayan; McNeal, Karen S; Bondell, Howard D

    2017-10-01

    Pupil dilation is known to indicate cognitive load. In this study, we looked at the average pupillary responses of a cohort of 29 undergraduate students during graphical problem solving. Three questions were asked, based on the same graphical input. The questions were interdependent and comprised multiple steps. We propose a novel way of analyzing pupillometry data for such tasks on the basis of eye fixations, a commonly used eyetracking parameter. We found that pupil diameter increased during the solution process. However, pupil diameter did not always reflect the expected cognitive load. This result was studied within a cognitive-load theory model. Higher-performing students showed evidence of germane load and schema creation, indicating use of the interdependent nature of the tasks to inform their problem-solving process. However, lower-performing students did not recognize the interdependent nature of the tasks and solved each problem independently, which was expressed in a markedly different pupillary response pattern. We discuss the import of our findings for instructional design.

  2. Structural Design of HRA Database using generic task for Quantitative Analysis of Human Performance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hwan; Kim, Yo Chan; Choi, Sun Yeong; Park, Jin Kyun; Jung Won Dea [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    This paper describes a design of generic task based HRA database for quantitative analysis of human performance in order to estimate the number of task conductions. The estimation method to get the total task conduction number using direct counting is not easy to realize and maintain its data collection framework. To resolve this problem, this paper suggests an indirect method and a database structure using generic task that enables to estimate the total number of conduction based on instructions of operating procedures of nuclear power plants. In order to reduce human errors, therefore, all information on the human errors taken by operators in the power plant should be systematically collected and examined in its management. Korea Atomic Energy Research Institute (KAERI) is carrying out a research to develop a data collection framework to establish a Human Reliability Analysis (HRA) database that could be employed as technical bases to generate human error probabilities (HEPs) and performance shaping factors (PSFs)]. As a result of the study, the essential table schema was designed to the generic task database which stores generic tasks, procedure lists and task tree structures, and other supporting tables. The number of task conduction based on the operating procedures for HEP estimation was enabled through the generic task database and framework. To verify the framework applicability, case study for the simulated experiments was performed and analyzed using graphic user interfaces developed in this study.

  3. The Influence of Feedback on Task-Switching Performance: A Drift Diffusion Modeling Account

    Directory of Open Access Journals (Sweden)

    Russell Cohen Hoffing

    2018-02-01

    Full Text Available Task-switching is an important cognitive skill that facilitates our ability to choose appropriate behavior in a varied and changing environment. Task-switching training studies have sought to improve this ability by practicing switching between multiple tasks. However, an efficacious training paradigm has been difficult to develop in part due to findings that small differences in task parameters influence switching behavior in a non-trivial manner. Here, for the first time we employ the Drift Diffusion Model (DDM to understand the influence of feedback on task-switching and investigate how drift diffusion parameters change over the course of task switch training. We trained 316 participants on a simple task where they alternated sorting stimuli by color or by shape. Feedback differed in six different ways between subjects groups, ranging from No Feedback (NFB to a variety of manipulations addressing trial-wise vs. Block Feedback (BFB, rewards vs. punishments, payment bonuses and different payouts depending upon the trial type (switch/non-switch. While overall performance was found to be affected by feedback, no effect of feedback was found on task-switching learning. Drift Diffusion Modeling revealed that the reductions in reaction time (RT switch cost over the course of training were driven by a continually decreasing decision boundary. Furthermore, feedback effects on RT switch cost were also driven by differences in decision boundary, but not in drift rate. These results reveal that participants systematically modified their task-switching performance without yielding an overall gain in performance.

  4. Structural Design of HRA Database using generic task for Quantitative Analysis of Human Performance

    International Nuclear Information System (INIS)

    Kim, Seung Hwan; Kim, Yo Chan; Choi, Sun Yeong; Park, Jin Kyun; Jung Won Dea

    2016-01-01

    This paper describes a design of generic task based HRA database for quantitative analysis of human performance in order to estimate the number of task conductions. The estimation method to get the total task conduction number using direct counting is not easy to realize and maintain its data collection framework. To resolve this problem, this paper suggests an indirect method and a database structure using generic task that enables to estimate the total number of conduction based on instructions of operating procedures of nuclear power plants. In order to reduce human errors, therefore, all information on the human errors taken by operators in the power plant should be systematically collected and examined in its management. Korea Atomic Energy Research Institute (KAERI) is carrying out a research to develop a data collection framework to establish a Human Reliability Analysis (HRA) database that could be employed as technical bases to generate human error probabilities (HEPs) and performance shaping factors (PSFs)]. As a result of the study, the essential table schema was designed to the generic task database which stores generic tasks, procedure lists and task tree structures, and other supporting tables. The number of task conduction based on the operating procedures for HEP estimation was enabled through the generic task database and framework. To verify the framework applicability, case study for the simulated experiments was performed and analyzed using graphic user interfaces developed in this study.

  5. The Influence of Feedback on Task-Switching Performance: A Drift Diffusion Modeling Account.

    Science.gov (United States)

    Cohen Hoffing, Russell; Karvelis, Povilas; Rupprechter, Samuel; Seriès, Peggy; Seitz, Aaron R

    2018-01-01

    Task-switching is an important cognitive skill that facilitates our ability to choose appropriate behavior in a varied and changing environment. Task-switching training studies have sought to improve this ability by practicing switching between multiple tasks. However, an efficacious training paradigm has been difficult to develop in part due to findings that small differences in task parameters influence switching behavior in a non-trivial manner. Here, for the first time we employ the Drift Diffusion Model (DDM) to understand the influence of feedback on task-switching and investigate how drift diffusion parameters change over the course of task switch training. We trained 316 participants on a simple task where they alternated sorting stimuli by color or by shape. Feedback differed in six different ways between subjects groups, ranging from No Feedback (NFB) to a variety of manipulations addressing trial-wise vs. Block Feedback (BFB), rewards vs. punishments, payment bonuses and different payouts depending upon the trial type (switch/non-switch). While overall performance was found to be affected by feedback, no effect of feedback was found on task-switching learning. Drift Diffusion Modeling revealed that the reductions in reaction time (RT) switch cost over the course of training were driven by a continually decreasing decision boundary. Furthermore, feedback effects on RT switch cost were also driven by differences in decision boundary, but not in drift rate. These results reveal that participants systematically modified their task-switching performance without yielding an overall gain in performance.

  6. Complexity rating of abnormal events and operator performance

    International Nuclear Information System (INIS)

    Oeivind Braarud, Per

    1998-01-01

    The complexity of the work situation during abnormal situations is a major topic in a discussion of safety aspects of Nuclear Power plants. An understanding of complexity and its impact on operator performance in abnormal situations is important. One way to enhance understanding is to look at the dimensions that constitute complexity for NPP operators, and how those dimensions can be measured. A further step is to study how dimensions of complexity of the event are related to performance of operators. One aspect of complexity is the operator 's subjective experience of given difficulties of the event. Another related aspect of complexity is subject matter experts ratings of the complexity of the event. A definition and a measure of this part of complexity are being investigated at the OECD Halden Reactor Project in Norway. This paper focus on the results from a study of simulated scenarios carried out in the Halden Man-Machine Laboratory, which is a full scope PWR simulator. Six crews of two licensed operators each performed in 16 scenarios (simulated events). Before the experiment subject matter experts rated the complexity of the scenarios, using a Complexity Profiling Questionnaire. The Complexity Profiling Questionnaire contains eight previously identified dimensions associated with complexity. After completing the scenarios the operators received a questionnaire containing 39 questions about perceived complexity. This questionnaire was used for development of a measure of subjective complexity. The results from the study indicated that Process experts' rating of scenario complexity, using the Complexity Profiling Questionnaire, were able to predict crew performance quite well. The results further indicated that a measure of subjective complexity could be developed that was related to crew performance. Subjective complexity was found to be related to subjective work load. (author)

  7. Complex Situational Tasks in Assessment of Educational Outcomes in “Psychological Assessment of Students” Module of the Master’s Programme in School Psychology

    Directory of Open Access Journals (Sweden)

    Andruschenko T.Y.,

    2016-12-01

    Full Text Available The paper discusses the content of midterm performance evaluation of graduate students within the “Psychological Assessment” module of the master’s programme in School Psychology and focuses on the logic of the module’s design in relation to the professional standard in Educational Psychology. Complex situational tasks are considered in the modular program as the main means of assessing educational outcomes. The content of these tasks is determined by a range of diagnostic situations and closely corresponds with the real-life practice of educational psychologists. Setting complex situational tasks is related to a number of components of the educational psychologist’s professional activity in the field of psychological assessment, such as: planning the sequence of professional actions; ensuring the methodological background for assessment; taking into account deontological aspects of communication with assessed individuals; carrying out professional actions; reflecting on the process and outcomes of assessment. The paper analyses the place and role of graduate students’ self-assessment in finding solutions to complex situational tasks and offers a description of one such task that can be used in midterm performance evaluation of graduate students.

  8. Performance Measurement of Complex Event Platforms

    Directory of Open Access Journals (Sweden)

    Eva Zámečníková

    2016-12-01

    Full Text Available The aim of this paper is to find and compare existing solutions of complex event processing platforms (CEP. CEP platforms generally serve for processing and/or predicting of high frequency data. We intend to use CEP platform for processing of complex time series and integrate a solution for newly proposed method of decision making. The decision making process will be described by formal grammar. As there are lots of CEP solutions we will take the following characteristics under consideration - the processing in real time, possibility of processing of high volume data from multiple sources, platform independence, platform allowing integration with user solution and open license. At first we will talk about existing CEP tools and their specific way of use in praxis. Then we will mention the design of method for formalization of business rules used for decision making. Afterwards, we focus on two platforms which seem to be the best fit for integration of our solution and we will list the main pros and cons of each approach. Next part is devoted to benchmark platforms for CEP. Final part is devoted to experimental measurements of platform with integrated method for decision support.

  9. Sensorimotor Adaptability Training Improves Motor and Dual-Task Performance

    Science.gov (United States)

    Bloomberg, J.J.; Peters, B.T.; Mulavara, A.P.; Brady, R.; Batson, C.; Cohen, H.S.

    2009-01-01

    The overall objective of our project is to develop a sensorimotor adaptability (SA) training program designed to facilitate recovery of functional capabilities when astronauts transition to different gravitational environments. The goal of our current study was to determine if SA training using variation in visual flow and support surface motion produces improved performance in a novel sensory environment and demonstrate the retention characteristics of SA training.

  10. Relationships among gender, cognitive style, academic major, and performance on the Piaget water-level task.

    Science.gov (United States)

    Hammer, R E; Hoffer, N; King, W L

    1995-06-01

    Many researchers have found that more college-age adults than would be expected fail Piaget's water-level task, with women failing more frequently than men. It has been hypothesized that differences in cognitive style may account for performance differences on the water-level task. In the present study, 27 male and 27 female architectural students and 27 male and 27 female liberal-arts students were assessed for their performance on both Piaget's Water-level Task and Witkin's Group Embedded Figures Test. No difference was found in performance of male and female architectural students on either task, but male liberal-arts students scored significantly higher than female liberal-arts students on both measures. A disembedding cognitive style predicted success on the water-level task for the architectural students but not for the liberal arts students.

  11. Children exhibit different performance patterns in explicit and implicit theory of mind tasks.

    Science.gov (United States)

    Oktay-Gür, Nese; Schulz, Alexandra; Rakoczy, Hannes

    2018-04-01

    Three studies tested scope and limits of children's implicit and explicit theory of mind. In Studies 1 and 2, three- to six-year-olds (N = 84) were presented with closely matched explicit false belief tasks that differed in whether or not they required an understanding of aspectuality. Results revealed that children performed equally well in the different tasks, and performance was strongly correlated. Study 3 tested two-year-olds (N = 81) in implicit interactive versions of these tasks and found evidence for dis-unity: children performed competently only in those tasks that did not require an understanding of aspectuality. Taken together, the present findings suggest that early implicit and later explicit theory of mind tasks may tap different forms of cognitive capacities. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Methadone disrupts performance on the working memory version of the Morris water task.

    Science.gov (United States)

    Hepner, Ilana J; Homewood, Judi; Taylor, Alan J

    2002-05-01

    The aim of the study was to examine if administration of the mu-opiate agonist methadone hydrochloride resulted in deficits in performance on the Morris water tank task, a widely used test of spatial cognition. To this end, after initial training on the task, Long-Evans rats were administered saline or methadone at either 1.25, 2.5 or 5 mg/kg ip 15 min prior to testing. The performance of the highest-dose methadone group was inferior to that of the controls on the working memory version of the Morris task. There were also differences between the groups on the reference memory version of the task, but this result cannot be considered reliable. These data show that methadone has its most profound effect on cognition in rats when efficient performance on the task requires attention to and retention of new information, in this case, the relationship between platform location and the extramaze cues.

  13. Experimental evaluation of the influence of various rests on task performance

    Energy Technology Data Exchange (ETDEWEB)

    Nagasaka, Akihiko; Hirose, Ayako [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    2000-01-01

    This report deals with the result of the experiment that 8 subjects had executed adding task and search task. They executed each task in 80 minutes under 5 conditions: (1) with no rest, and with 4 kinds of 20 minutes rests, in which they (2) opened eyes, (3) closed eyes, (4) closed eyes with listening classic music and (5) closed eyes with feet massage, in the middle of the task. The results of analysis of variance with the task performance in the latter half, there were significant differences between each condition with every subject in adding task, and with 6 subjects in search task. However, the orders of the task performance with each condition were not the same by each subject. It was suggested that transition of the arousal levels under the rest was related to the effects of the rest rather than the subjects' taste in rests. In the rest, the percentage of {alpha} wave of electroencephalogram and the coefficient of variation of R-R interval (time interval of heart beats) were increased than in executing task. The mean Kendall's rank correlation of coefficient with the order of increase rate of {alpha}/{beta} wave and the task performance in the latter half was slightly negative in adding task, but was about 0.4 in search task. From these results, about six requirements for 'an effective rest' were able to be mentioned, for example, 'the devices that raises the arousal levels is carried out just before a rest end'. (author)

  14. The performance of cleaner wrasse, Labroides dimidiatus, in a reversal learning task varies across experimental paradigms

    Directory of Open Access Journals (Sweden)

    Simon Gingins

    2018-05-01

    Full Text Available Testing performance in controlled laboratory experiments is a powerful tool for understanding the extent and evolution of cognitive abilities in non-human animals. However, cognitive testing is prone to a number of potential biases, which, if unnoticed or unaccounted for, may affect the conclusions drawn. We examined whether slight modifications to the experimental procedure and apparatus used in a spatial task and reversal learning task affected performance outcomes in the bluestreak cleaner wrasse, Labroides dimidiatus (hereafter “cleaners”. Using two-alternative forced-choice tests, fish had to learn to associate a food reward with a side (left or right in their holding aquarium. Individuals were tested in one of four experimental treatments that differed slightly in procedure and/or physical set-up. Cleaners from all four treatment groups were equally able to solve the initial spatial task. However, groups differed in their ability to solve the reversal learning task: no individuals solved the reversal task when tested in small tanks with a transparent partition separating the two options, whereas over 50% of individuals solved the task when performed in a larger tank, or with an opaque partition. These results clearly show that seemingly insignificant details to the experimental set-up matter when testing performance in a spatial task and might significantly influence the outcome of experiments. These results echo previous calls for researchers to exercise caution when designing methodologies for cognition tasks to avoid misinterpretations.

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

    Science.gov (United States)

    And Others; Rader, Nancy

    1979-01-01

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

  16. An exploratory study of long-haul truck drivers' secondary tasks and reasons for performing them.

    Science.gov (United States)

    Iseland, Tobias; Johansson, Emma; Skoog, Siri; Dåderman, Anna M

    2018-08-01

    Research on drivers has shown how certain visual-manual secondary tasks, unrelated to driving, increase the risk of being involved in crashes. The purpose of the study was to investigate (1) if long-haul truck drivers in Sweden engage in secondary tasks while driving, what tasks are performed and how frequently, (2) the drivers' self-perceived reason/s for performing them, and (3) if psychological factors might reveal reasons for their engaging in secondary tasks. The study comprised 13 long-haul truck drivers and was conducted through observations, interviews, and questionnaires. The drivers performed secondary tasks, such as work environment related "necessities" (e.g., getting food and/or beverages from the refrigerator/bag, eating, drinking, removing a jacket, face rubbing, and adjusting the seat), interacting with a mobile phone/in-truck technology, and doing administrative tasks. The long-haul truck drivers feel bored and use secondary tasks as a coping strategy to alleviate boredom/drowsiness, and for social interaction. The higher number of performed secondary tasks could be explained by lower age, shorter driver experience, less openness to experience, lower honesty-humility, lower perceived stress, lower workload, and by higher health-related quality of life. These explanatory results may serve as a starting point for further studies on large samples to develop a safer and healthier environment for long-haul truck drivers. Copyright © 2018. Published by Elsevier Ltd.

  17. Does Listening to Slow Tempo Classical Music During Independent Writing Affect Children's On-Task Performance?

    Science.gov (United States)

    McKnight, Rosemary

    This project explored the effects of slow tempo classical music on children's on-task performance during independent writing. The project sample consisted of 24 students from a first grade classroom in the New York City Public School System. The students' on-task behavior was observed with and without use of slow tempo classical music playing, and…

  18. Human Error Probabilites (HEPs) for generic tasks and Performance Shaping Factors (PSFs) selected for railway operations

    DEFF Research Database (Denmark)

    Thommesen, Jacob; Andersen, Henning Boje

    This report describes an HRA (Human Reliability Assessment) of six generic tasks and four Perfor-mance Shaping Factors (PSFs) targeted at railway operations commissioned by Banedanmark. The selection and characterization of generic tasks and PSFs are elaborated by DTU Management in close...

  19. Inflectional Morphology and Dyslexia: Italian Children's Performance in a Nonword Pluralization Task

    Science.gov (United States)

    Vender, Maria; Mantione, Federica; Savazzi, Silvia; Delfitto, Denis; Melloni, Chiara

    2017-01-01

    In this study, we present the results of an original experimental protocol designed to assess the performance in a pluralization task of 52 Italian children divided into two groups: 24 children with developmental dyslexia (mean age 10.0 years old) and 28 typically developing children (mean age 9.11 years old). Our task, inspired by Berko's Wug…

  20. Effects of Mother-Infant Social Interactions on Infants' Subsequent Contingency Task Performance.

    Science.gov (United States)

    Dunham, Philip; Dunham, Frances

    1990-01-01

    Infants participated in a nonsocial contingency task immediately after a social interaction with their mothers. The amount of time mothers and infants spent in a state of vocal turn-taking predicted individual differences in infants' subsequent performance on the contingency task. (PCB)

  1. The performance of cleaner wrasse, Labroides dimidiatus, in a reversal learning task varies across experimental paradigms.

    Science.gov (United States)

    Gingins, Simon; Marcadier, Fanny; Wismer, Sharon; Krattinger, Océane; Quattrini, Fausto; Bshary, Redouan; Binning, Sandra A

    2018-01-01

    Testing performance in controlled laboratory experiments is a powerful tool for understanding the extent and evolution of cognitive abilities in non-human animals. However, cognitive testing is prone to a number of potential biases, which, if unnoticed or unaccounted for, may affect the conclusions drawn. We examined whether slight modifications to the experimental procedure and apparatus used in a spatial task and reversal learning task affected performance outcomes in the bluestreak cleaner wrasse, Labroides dimidiatus (hereafter "cleaners"). Using two-alternative forced-choice tests, fish had to learn to associate a food reward with a side (left or right) in their holding aquarium. Individuals were tested in one of four experimental treatments that differed slightly in procedure and/or physical set-up. Cleaners from all four treatment groups were equally able to solve the initial spatial task. However, groups differed in their ability to solve the reversal learning task: no individuals solved the reversal task when tested in small tanks with a transparent partition separating the two options, whereas over 50% of individuals solved the task when performed in a larger tank, or with an opaque partition. These results clearly show that seemingly insignificant details to the experimental set-up matter when testing performance in a spatial task and might significantly influence the outcome of experiments. These results echo previous calls for researchers to exercise caution when designing methodologies for cognition tasks to avoid misinterpretations.

  2. Self-Reported Stickiness of Mind-Wandering Affects Task Performance

    NARCIS (Netherlands)

    van Vugt, Marieke K; Broers, Nico

    2016-01-01

    When asked to perform a certain task, we typically spend a decent amount of time thinking thoughts unrelated to that task-a phenomenon referred to as "mind-wandering." It is thought that this mind-wandering is driven at least in part by our unfinished goals and concerns. Previous studies have shown

  3. Effects of four types of non-obtrusive feedback on computer behaviour, task performance and comfort

    NARCIS (Netherlands)

    Korte, E.M.; Huijsmans, M.A.; de Jong, A.M.; van de Ven, J.G.M.; Ruijsendaal, M.

    2012-01-01

    This study investigated the effects of non-obtrusive feedback on continuous lifted hand/finger behaviour, task performance and comfort. In an experiment with 24 participants the effects of two visual and two tactile feedback signals were compared to a no-feedback condition in a computer task.

  4. The Effect of Background Music and Background Noise on the Task Performance of Introverts and Extraverts

    Science.gov (United States)

    Cassidy, Gianna; MacDonald, Raymond A. R.

    2007-01-01

    The study investigated the effects of music with high arousal potential and negative affect (HA), music with low arousal potential and positive affect (LA), and everyday noise, on the cognitive task performance of introverts and extraverts. Forty participants completed five cognitive tasks: immediate recall, free recall, numerical and delayed…

  5. Research study on the effects of illumination on performance of control room tasks

    International Nuclear Information System (INIS)

    Silverman, E.B.; Horst, R.L.; Parris, H.L.; O'Brien, J.

    1990-01-01

    The illumination in the control rooms of many operating nuclear plants falls below the levels specified in the NUREG-0700 guidelines. However, these guidelines are based on human perception and performance data which were acquired under laboratory conditions and with tasks very different from those typically found in control rooms. The objective of the present studies was to gather empirical data regarding the levels of illumination sufficient for performing tasks analogous to those performed in control rooms. Several tasks were designed to engage the perceptual and cognitive processes that are representative of actual control room performance. In a computerized laboratory test-bed, subjects scanned edgewise meters, examined hard-copy X-Y plots to discern the value of the displayed function at specific coordinates, and proofread hard-copy plant procedures. In a power plant control room simulator, data were likewise collected in a meter reading task and similar tasks representing elements of specific job-performance measures. For each task, response time and accuracy were measured under a range of illumination levels. Subjective comfort ratings were also obtained for each illumination level. The results from both settings indicated that with decreasing illumination, increased errors and/or longer response times occurred only for levels below ten footcandles, if at all. These data suggest that adequate performance in control room tasks can be achieved at illumination levels below those recommended in NUREG-0700

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

    Science.gov (United States)

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

    2016-10-01

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

  7. Blue or red? Exploring the effect of color on cognitive task performances.

    Science.gov (United States)

    Mehta, Ravi; Zhu, Rui Juliet

    2009-02-27

    Existing research reports inconsistent findings with regard to the effect of color on cognitive task performances. Some research suggests that blue or green leads to better performances than red; other studies record the opposite. Current work reconciles this discrepancy. We demonstrate that red (versus blue) color induces primarily an avoidance (versus approach) motivation (study 1, n = 69) and that red enhances performance on a detail-oriented task, whereas blue enhances performance on a creative task (studies 2 and 3, n = 208 and 118). Further, we replicate these results in the domains of product design (study 4, n = 42) and persuasive message evaluation (study 5, n = 161) and show that these effects occur outside of individuals' consciousness (study 6, n = 68). We also provide process evidence suggesting that the activation of alternative motivations mediates the effect of color on cognitive task performances.

  8. Self-reported quality of ADL task performance among patients with COPD exacerbations

    DEFF Research Database (Denmark)

    Bendixen, Hans Jørgen; Wæhrens, Eva Elisabet Ejlersen; Wilcke, Jon Torgny

    2014-01-01

    OBJECTIVE: Patients suffering from chronic obstructive pulmonary disease (COPD) experience problems in the performance of activities of daily living (ADL) tasks. The objective was to examine the self-reported quality of ADL task performance among COPD patients, and to investigate whether age...... concerning age, gender, and routine COPD characteristics were drawn from the patients' medical records. RESULTS: The patients reported being inefficient to markedly inefficient when performing ADL tasks within the personal hygiene, toileting, dressing, household, mobility, and transportation domains. While...... more than 90% of the participants reported increased effort and/or fatigue when performing the ADL tasks, up to 88% of the participants relied on help from others in the performance of general household chores like cooking and shopping. Self-reported ADL ability did not correlate with age, gender...

  9. Impact of time on task on ADHD patient's performances in a virtual classroom.

    Science.gov (United States)

    Bioulac, Stéphanie; Lallemand, Stéphanie; Rizzo, Albert; Philip, Pierre; Fabrigoule, Colette; Bouvard, Manuel Pierre

    2012-09-01

    Use of virtual reality tool is interesting for the evaluation of Attention Deficit/Hyperactivity Disorder (ADHD) patients. The virtual environment offers the opportunity to administer controlled task like the typical neuropsychological tools, but in an environment much more like standard classroom. Previous studies showed that a virtual classroom was able to distinguish performances of children with and without ADHD, but the evolution of performances over time has not been explored. The aim of this work was to study time on task effects on performances of ADHD children compared to controls in a virtual classroom (VC). 36 boys aged from 7 to 10 years completed the virtual classroom task. We compared the performance of the children diagnosed with ADHD with those of the control children. We also compared attentional performances recorded in the virtual classroom with measures of the Continuous Performance Test (CPT II). Our results showed that patients differ from control subjects in term of time effect on performances. If controls sustained performances over time in the virtual reality task, ADHD patients showed a significant performance decrement over time. Performances at the VC correlated with CPT II measures. ADHD children are vulnerable to a time on task effect on performances which could explain part of their difficulties. Virtual reality is a reliable method to test ADHD children ability to sustain performances over time. Copyright © 2012 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  10. Effect of alcohol and divided attention task on simulated driving performance of young drivers

    OpenAIRE

    FREYDIER , Chloé; BERTHELON , Catherine; Bastien-Toniazzo , Mireille; GINEYT , Guy

    2013-01-01

    The aim of this study is to evaluate driving impairment linked to divided attention task and alcohol and determinate if it is higher for novice drivers compared to more experienced drivers. Sixteen novice drivers and sixteen experienced drivers participated in three experimental sessions corresponding to blood alcohol concentration [BAC] of 0.0 g/L, 0.2 g/L and 0.5 g/L. They performed a divided attention task [car-following task combined with a number parity identification task], and their re...

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

    Science.gov (United States)

    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.

  12. EEG and autonomic responses during performance of matching and non-matching to sample working memory tasks with emotional content.

    Directory of Open Access Journals (Sweden)

    Ana eGarcia

    2011-12-01

    Full Text Available Working memory (WM is a neural system responsible for the temporary storage of information and its utilization in problem solving. The central executive is theorized as the controller of storage functions that support WM. Neurophysiological data suggest that EEG theta and alpha oscillations in frontal and midline regions are involved in neural communication between the central executive and storage functions during WM performance. Emotion is known to modulate several memory systems, including WM, through central and peripheral pathways. However, the physiological correlations (electroencephalographic – EEG; autonomic nervous activity of the effect of emotion over WM are not well described. In this study we aimed to identify physiological responses related to emotional WM performance. EEG (21 channels, heart rate (HR and galvanic skin response (GSR recordings were obtained from 54 volunteers while performing delayed matching and non-matching to sample tasks (DMTS/DNMTS. Emotional and neutral pictures from the International Affective Picture System and geometric figures were used as stimuli. As expected, WM performance was accompanied by presence of theta (frontal and midline electrodes and Alpha power (parietal electrodes. Beta and gamma oscillations were concentrated in frontopolar and left temporal regions. DNMTS task was accompanied by increases in Beta power, HR and GSR compared to DMTS task. Correlation analysis showed a positive tendency for gamma in Fp2 site, ratio of LF/HF (HR low and high frequency and skin conductance in both tasks. The HR results indicate an inverse reaction related to parasympathetic and sympathetic nervous system during the performance of the tasks. Taken together, our results contribute to elucidate the complex interactions between central and autonomic nervous systems in the modulation of emotional WM tasks.

  13. The Effects of Training on Anxiety and Task Performance in Simulated Suborbital Spaceflight.

    Science.gov (United States)

    Blue, Rebecca