Ghinescu, Rodica; Ramsey, Ashley K.; Gratton, Gabriele; Fabiani, Monica
Two experiments investigated competition between cues that predicted the correct target response to a target stimulus in a response conflict procedure using a flanker task. Subjects received trials with five-character arrays with a central target character and distractor flanker characters that matched (compatible) or did not match (incompatible) the central target. Subjects’ expectancies for compatible and incompatible trials were manipulated by presenting pre-trial cues that signaled the occurrence of compatible or incompatible trials. On some trials, a single cue predicted the target stimulus and the required target response. On other trials, a second redundant, predictive cue was also present on such trials. The results showed an effect of competition between cues for control over strategic responding to the target stimuli, a finding that is predicted by associative learning theories. The finding of competition between pre-trial cues that predict incompatible trials, but not cues that predict compatible trials, suggests that different strategic processes may occur during adaptation to conflict when different kinds of trials are expected. PMID:27941977
Ghinescu, Rodica; Schachtman, Todd R; Stadler, Michael A; Fabiani, Monica; Gratton, Gabriele
This experiment investigated whether subjects' selection and use of strategies in detecting a target letter in a flanker task requires intention. Subjects' expectancies for compatible and incompatible trials (trials on which the response to the flanker stimulus was consistent or inconsistent with the target response) were manipulated by presenting cues that signaled the occurrence of these types of trials. Three groups of subjects received explicit, partially explicit, or implicit instructions about the meaning of the cues. By the end of the experiment, all the groups were able to select and use strategies based on the cues to improve their performance. However, this strategy selection developed slowly with practice in the latter two groups, whereas it was present from the outset in the first group. In addition, forced choice tests performed after the experiment showed that the subjects in the implicit condition could not intentionally indicate which stimuli were most likely to follow a given cue. Thus, the data suggest that the selection of strategies occurred outside the subjects' awareness, and without their intention.
McDermott, Timothy J; Wiesman, Alex I; Proskovec, Amy L; Heinrichs-Graham, Elizabeth; Wilson, Tony W
The flanker task is a test of visual selective attention that has been widely used to probe error monitoring, response conflict, and related constructs. However, to date, few studies have focused on the selective attention component of this task and imaged the underlying oscillatory dynamics serving task performance. In this study, 21 healthy adults successfully completed an arrow-based version of the Eriksen flanker task during magnetoencephalography (MEG). All MEG data were pre-processed and transformed into the time-frequency domain. Significant oscillatory brain responses were imaged using a beamforming approach, and voxel time series were extracted from the peak responses to identify the temporal dynamics. Across both congruent and incongruent flanker conditions, our results indicated robust decreases in alpha (9-12Hz) activity in medial and lateral occipital regions, bilateral parietal cortices, and cerebellar areas during task performance. In parallel, increases in theta (3-7Hz) oscillatory activity were detected in dorsal and ventral frontal regions, and the anterior cingulate. As per conditional effects, stronger alpha responses (i.e., greater desynchronization) were observed in parietal, occipital, and cerebellar cortices during incongruent relative to congruent trials, whereas the opposite pattern emerged for theta responses (i.e., synchronization) in the anterior cingulate, left dorsolateral prefrontal, and ventral prefrontal cortices. Interestingly, the peak latency of theta responses in these latter brain regions was significantly correlated with reaction time, and may partially explain the amplitude difference observed between congruent and incongruent trials. Lastly, whole-brain exploratory analyses implicated the frontal eye fields, right temporoparietal junction, and premotor cortices. These findings suggest that regions of both the dorsal and ventral attention networks contribute to visual selective attention processes during incongruent trials
Full Text Available Background: Tourette Syndrome (TS is a neurodevelopmental disorder with childhood-onset, with a typical decline in tic severity, as well as an increasing ability to suppress tics in late childhood and adolescence. These processes develop in parallel with general improvement of self-regulatory abilities, and performance monitoring during this age-span. Hence, changes in performance monitoring over time might provide insight into the regulation of tics in children and adolescents with TS.Method: We measured reaction time, reaction time variability, accuracy, and event-related potentials (ERP in 17 children with TS, including 10 children with comorbid Attention-Deficit/Hyperactivity Disorder (ADHD, 24 children with ADHD, and 29 typically developing children, using a modified Eriksen Flanker task in two testing sessions administered on average 4.5 years apart. We then compared task performance, as well as ERP components across groups, and over time using regression models.Results: Task performance improved in all groups with age, and behavioral differences between children with TS and controls diminished at second assessment, while differences between controls and children with ADHD largely persisted. In terms of ERP, the early P3 developed earlier in children with TS compared with controls at the first assessment, but trajectories converged with maturation. ERP component amplitudes correlated with worst-ever tic scores.Conclusions: Merging trajectories between children with TS and controls are consistent with the development of compensatory self-regulation mechanisms during early adolescence, probably facilitating tic suppression, in contrast to children with ADHD. Correlations between ERP amplitudes and tic scores also support this notion.
Eichele, Heike; Eichele, Tom; Marquardt, Lynn; Adolfsdottir, Steinunn; Hugdahl, Kenneth; Sørensen, Lin; Plessen, Kerstin J.
Background: Tourette Syndrome (TS) is a neurodevelopmental disorder with childhood-onset, with a typical decline in tic severity, as well as an increasing ability to suppress tics in late childhood and adolescence. These processes develop in parallel with general improvement of self-regulatory abilities, and performance monitoring during this age-span. Hence, changes in performance monitoring over time might provide insight into the regulation of tics in children and adolescents with TS. Method: We measured reaction time, reaction time variability, accuracy, and event-related potentials (ERP) in 17 children with TS, including 10 children with comorbid Attention-Deficit/Hyperactivity Disorder (ADHD), 24 children with ADHD, and 29 typically developing children, using a modified Eriksen Flanker task in two testing sessions administered on average 4.5 years apart. We then compared task performance, as well as ERP components across groups, and over time using regression models. Results: Task performance improved in all groups with age, and behavioral differences between children with TS and controls diminished at second assessment, while differences between controls and children with ADHD largely persisted. In terms of ERP, the early P3 developed earlier in children with TS compared with controls at the first assessment, but trajectories converged with maturation. ERP component amplitudes correlated with worst-ever tic scores. Conclusions: Merging trajectories between children with TS and controls are consistent with the development of compensatory self-regulation mechanisms during early adolescence, probably facilitating tic suppression, in contrast to children with ADHD. Correlations between ERP amplitudes and tic scores also support this notion. PMID:28659750
Eichele, Heike; Eichele, Tom; Marquardt, Lynn; Adolfsdottir, Steinunn; Hugdahl, Kenneth; Sørensen, Lin; Plessen, Kerstin J
Background: Tourette Syndrome (TS) is a neurodevelopmental disorder with childhood-onset, with a typical decline in tic severity, as well as an increasing ability to suppress tics in late childhood and adolescence. These processes develop in parallel with general improvement of self-regulatory abilities, and performance monitoring during this age-span. Hence, changes in performance monitoring over time might provide insight into the regulation of tics in children and adolescents with TS. Method: We measured reaction time, reaction time variability, accuracy, and event-related potentials (ERP) in 17 children with TS, including 10 children with comorbid Attention-Deficit/Hyperactivity Disorder (ADHD), 24 children with ADHD, and 29 typically developing children, using a modified Eriksen Flanker task in two testing sessions administered on average 4.5 years apart. We then compared task performance, as well as ERP components across groups, and over time using regression models. Results: Task performance improved in all groups with age, and behavioral differences between children with TS and controls diminished at second assessment, while differences between controls and children with ADHD largely persisted. In terms of ERP, the early P3 developed earlier in children with TS compared with controls at the first assessment, but trajectories converged with maturation. ERP component amplitudes correlated with worst-ever tic scores. Conclusions: Merging trajectories between children with TS and controls are consistent with the development of compensatory self-regulation mechanisms during early adolescence, probably facilitating tic suppression, in contrast to children with ADHD. Correlations between ERP amplitudes and tic scores also support this notion.
Nieuwenhuis, Sander; Stins, John F; Posthuma, Danielle; Polderman, Tinca J C; Boomsma, Dorret I; de Geus, Eco J
The conflict-control loop theory proposes that the detection of conflict in information processing triggers an increase in cognitive control, resulting in improved performance on the subsequent trial. This theory seems consistent with the robust finding that conflict susceptibility is reduced following correct trials associated with high conflict: the conflict adaptation effect. However, despite providing favorable conditions for eliciting and detecting conflict-triggered performance adjustments, none of the five experiments reported here provide unequivocal evidence of such adjustments. Instead, the results corroborate and extend earlier findings by demonstrating that the conflict adaptation effect, at least in the flanker task, is only present for a specific subset of trial sequences that is characterized by a response repetition. This pattern of results provides strong evidence that the conflict adaptation effect reflects associative stimulus-response priming instead of conflict-driven adaptations in cognitive control.
Runger, Dennis; Schwager, Sabine; Frensch, Peter A.
Fernandez-Duque and Knight (2008, Experiment 4) described an across-task effect of endogenously generated, anticipatory control: A cue that predicted conflict in an upcoming Eriksen flanker task modulated conflict regulation in a subsequent number Stroop task. In 3 experiments, 1 of which included an exact replication condition, we failed to…
Full Text Available An important question is whether attentional selectivity improves discretely or continuously during stimulus processing. In a recent study, Hübner, et al. (2010 found that the discrete DSTP model accounted better for flanker-task data than various continuous improvement models. However, in a subsequent study, White, et al. (2011 introduced the continuous SSP model and showed that it was superior to the DSTP model. From this result they concluded that attentional selectivity improves continuously rather than discretely. Because different stimuli and procedures were used in these two studies, though, we questioned that the superiority of the SSP model holds generally. Therefore, we fit the SSP model to Hübner et al.’s data and found that the DSTP model was again superior. A series of four experiments revealed that model superiority depends on the response-stimulus interval (RSI. Together, our results demonstrate that methodological details can be crucial for model selection, and that further comparisons between the models are needed before it can be decided whether attentional selectivity improves continuously or discretely.
Rusnáková, S.; Daniel, P.; Chládek, Jan; Jurák, Pavel; Rektor, I.
Roč. 28, č. 1 (2011), s. 30-35 ISSN 0736-0258 R&D Projects: GA ČR(CZ) GA102/05/0402 Institutional research plan: CEZ:AV0Z20650511 Keywords : generator of P3 * temporal neocortex * orbitofrontal cortex * flanker test * neurocognitive network Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.451, year: 2011
Lamers, M.J.M.; Roelofs, A.P.A.
Evidence from go/no-go performance on the Eriksen flanker task with manual responding suggests that individuals gaze at stimuli just as long as needed to identify them (e.g.. Sanders, 1998). In contrast, evidence from dual-task performance with vocal responding suggests that gaze shifts occur after
Liu, T.; Xiao, T; Shi, Jiannong
it was flanked by happy distractors comparing with sad distractors. Taken together, the current findings of temporal dynamic of brain activity during cognitive control on affective conflicts shed light on the essential relationship between cognitive control and affective information processing.......Conflict control is an important cognitive control ability and it is also crucial for human beings to execute conflict control on affective information. To address the neural correlates of cognitive control on affective conflicts, the present study recorded event-related potentials (ERPs) during...... a revised Eriksen Flanker Task. Participants were required to indicate the valence of the central target expression while ignoring the flanker expressions in the affective congruent condition, affective incongruent condition and neutral condition (target expressions flanked by scramble blocks). Behavioral...
Nicholls, Clare; Bruno, Raimondo; Matthews, Allison
The aim of the study was to investigate the relationship between chronic cannabis use and visual selective attention by examining event-related potentials (ERPs) during the performance of a flanker go/nogo task. Male participants were 15 chronic cannabis users (minimum two years use, at least once per week) and 15 drug naive controls. Cannabis users showed longer reaction times compared to controls with equivalent accuracy. Cannabis users also showed a reduction in the N2 'nogo effect' at frontal sites, particularly for incongruent stimuli, and particularly in the right hemisphere. This suggests differences between chronic cannabis users and controls in terms of inhibitory processing within the executive control network, and may implicate the right inferior frontal cortex. There was also preliminary evidence for differences in early selective attention, with controls but not cannabis users showing modulation of N1 amplitude by flanker congruency. Further investigation is required to examine the potential reversibility of these residual effects after long-term abstinence and to examine the role of early selective attention mechanisms in more detail. Copyright © 2015 Elsevier B.V. All rights reserved.
Polderman Tinca JC
Full Text Available Abstract Background There is great interest in appropriate phenotypes that serve as indicator of genetically transmitted frontal (dysfunction, such as ADHD. Here we investigate the ability to deal with response conflict, and we ask to what extent performance variation on response interference tasks is caused by genetic variation. We tested a large sample of 12-year old monozygotic and dizygotic twins on two well-known and closely related response interference tasks; the color Stroop task and the Eriksen flanker task. Using structural equation modelling we assessed the heritability of several performance indices derived from those tasks. Results In the Stroop task we found high heritabilities of overall reaction time and – more important – Stroop interference (h2 = nearly 50 %. In contrast, we found little evidence of heritability on flanker performance. For both tasks no effects of sex on performance variation were found. Conclusions These results suggest that normal variation in Stroop performance is influenced by underlying genetic variation. Given that Stroop performance is often hampered not only in people suffering from frontal dysfunction, but also in their unaffected relatives, we conclude that this variable may constitute a suitable endophenotype for future genetic studies. We discuss several reasons for the absence of genetic effects on the flanker task.
Brion, Mélanie; Dormal, Valérie; Lannoy, Séverine; Mertens, Serge; de Timary, Philippe; Maurage, Pierre
Alcohol-dependent individuals (ALC) simultaneously present decreased inhibitory control and increased attention towards alcohol-related cues. The dual-process models have proposed that these symptoms reflect an imbalance between prefrontal/reflective and limbic/automatic systems, respectively leading to cognitive dysfunctions in executive processes and to alcohol-related bias. However, most previous research has focused on a separate exploration of these systems among ALC, and the direct measure of their interactions remains to be conducted. Moreover, no study has explored the evolution of this imbalance across the successive stages of alcohol-related disorders, and particularly in Korsakoff syndrome (KS), the most frequent neurological complication of alcohol-dependence. Ten KS, 14 ALC, and 14 matched control participants performed a modified Flanker task, the "Alcohol Flanker Task," based on congruent, incongruent, and neutral conditions with alcohol-related stimuli. This task required inhibitory processing on alcohol-related stimuli and evaluated, through a behavioral approach, the interaction between reflective and automatic systems, as well as its evolution between ALC and KS. ALC and KS both presented high reactivity towards alcohol-related stimuli, confirming the presence of alcohol-related bias. KS showed increased omission rates (related to distractor interference) while ALC showed higher false-alarm rates (related to prepotent response inhibition). These results suggest that different inhibitory subcomponents might be altered at the successive stages of the pathology, and experimentally confirms the crucial role of the interaction between reflective and automatic processes in alcohol-use disorders. The present results reinforce the proposal that alcohol-related cues significantly impact inhibitory control in alcohol-related disorders. However, ALC and KS present different patterns of deficits depending on task complexity (i.e., executive load), thus
Bradley, Kailyn A L; Case, Julia A C; Freed, Rachel D; Stern, Emily R; Gabbay, Vilma
There has been growing interest under the Research Domain Criteria initiative to investigate behavioral constructs and their underlying neural circuitry. Abnormalities in reward processes are salient across psychiatric conditions and may precede future psychopathology in youth. However, the neural circuitry underlying such deficits has not been well defined. Therefore, in this pilot, we studied youth with diverse psychiatric symptoms and examined the neural underpinnings of reward anticipation, attainment, and positive prediction error (PPE, unexpected reward gain). Clinically, we focused on anhedonia, known to reflect deficits in reward function. Twenty-two psychotropic medication-free youth, 16 with psychiatric symptoms, exhibiting a full range of anhedonia, were scanned during the Reward Flanker Task. Anhedonia severity was quantified using the Snaith-Hamilton Pleasure Scale. Functional magnetic resonance imaging analyses were false discovery rate corrected for multiple comparisons. Anticipation activated a broad network, including the medial frontal cortex and ventral striatum, while attainment activated memory and emotion-related regions such as the hippocampus and parahippocampal gyrus, but not the ventral striatum. PPE activated a right-dominant fronto-temporo-parietal network. Anhedonia was only correlated with activation of the right angular gyrus during anticipation and the left precuneus during PPE at an uncorrected threshold. Findings are preliminary due to the small sample size. This pilot characterized the neural circuitry underlying different aspects of reward processing in youth with diverse psychiatric symptoms. These results highlight the complexity of the neural circuitry underlying reward anticipation, attainment, and PPE. Furthermore, this study underscores the importance of RDoC research in youth. Copyright © 2016 Elsevier B.V. All rights reserved.
Liu, Tongran; Xiao, Tong; Shi, Jian-Nong
Conflict control is an important cognitive control ability and it is also crucial for human beings to execute conflict control on affective information. To address the neural correlates of cognitive control on affective conflicts, the present study recorded event-related potentials (ERPs) during a revised Eriksen Flanker Task. Participants were required to indicate the valence of the central target expression while ignoring the flanker expressions in the affective congruent condition, affective incongruent condition and neutral condition (target expressions flanked by scramble blocks). Behavioral results manifested that participants exhibited faster response speed in identifying neutral target face when it was flanked by neutral distractors than by happy distractors. Electrophysiological results showed that happy target expression induced larger N2 amplitude when flanked by sad distractors than by happy distractors and scramble blocks during the conflict monitoring processing. During the attentional control processing, happy target expression induced faster P3 response when it was flanked by happy distractors than by sad distractors, and sad target expression evoked larger P3 amplitude when it was flanked by happy distractors comparing with sad distractors. Taken together, the current findings of temporal dynamic of brain activity during cognitive control on affective conflicts shed light on the essential relationship between cognitive control and affective information processing.
Full Text Available Conflict control is an important cognitive control ability and it is also crucial for human beings to execute conflict control on affective information. To address the neural correlates of cognitive control on affective conflicts, the present study recorded event-related potentials (ERPs during a revised Eriksen Flanker Task. Participants were required to indicate the valence of the central target expression while ignoring the flanker expressions in the affective congruent condition, affective incongruent condition and neutral condition (target expressions flanked by scramble blocks. Behavioral results manifested that participants exhibited faster response speed in identifying neutral target face when it was flanked by neutral distractors than by happy distractors. Electrophysiological results showed that happy target expression induced larger N2 amplitude when flanked by sad distractors than by happy distractors and scramble blocks during the conflict monitoring processing. During the attentional control processing, happy target expression induced faster P3 response when it was flanked by happy distractors than by sad distractors, and sad target expression evoked larger P3 amplitude when it was flanked by happy distractors comparing with sad distractors. Taken together, the current findings of temporal dynamic of brain activity during cognitive control on affective conflicts shed light on the essential relationship between cognitive control and affective information processing.
Dash, Tanya; Kar, Bhoomika R.
Background. Bilingualism results in an added advantage with respect to cognitive control. The interaction between bilingual language control and general purpose cognitive control systems can also be understood by studying executive control among individuals with bilingual aphasia. Objectives. The current study examined the subcomponents of cognitive control in bilingual aphasia. A case study approach was used to investigate whether cognitive control and language control are two separate systems and how factors related to bilingualism interact with control processes. Methods. Four individuals with bilingual aphasia performed a language background questionnaire, picture description task, and two experimental tasks (nonlinguistic negative priming task and linguistic and nonlinguistic versions of flanker task). Results. A descriptive approach was used to analyse the data using reaction time and accuracy measures. The cumulative distribution function plots were used to visualize the variations in performance across conditions. The results highlight the distinction between general purpose cognitive control and bilingual language control mechanisms. Conclusion. All participants showed predominant use of the reactive control mechanism to compensate for the limited resources system. Independent yet interactive systems for bilingual language control and general purpose cognitive control were postulated based on the experimental data derived from individuals with bilingual aphasia. PMID:24982591
Dash, Tanya; Kar, Bhoomika R
Bilingualism results in an added advantage with respect to cognitive control. The interaction between bilingual language control and general purpose cognitive control systems can also be understood by studying executive control among individuals with bilingual aphasia. objectives: The current study examined the subcomponents of cognitive control in bilingual aphasia. A case study approach was used to investigate whether cognitive control and language control are two separate systems and how factors related to bilingualism interact with control processes. Four individuals with bilingual aphasia performed a language background questionnaire, picture description task, and two experimental tasks (nonlinguistic negative priming task and linguistic and nonlinguistic versions of flanker task). A descriptive approach was used to analyse the data using reaction time and accuracy measures. The cumulative distribution function plots were used to visualize the variations in performance across conditions. The results highlight the distinction between general purpose cognitive control and bilingual language control mechanisms. All participants showed predominant use of the reactive control mechanism to compensate for the limited resources system. Independent yet interactive systems for bilingual language control and general purpose cognitive control were postulated based on the experimental data derived from individuals with bilingual aphasia.
Beaton, Lauren E; Azma, Sheeva; Marinkovic, Ksenija
Despite the subjective experience of being in full and deliberate control of our actions, our daily routines rely on a continuous and interactive engagement of sensory evaluation and response preparation streams. They unfold automatically and unconsciously and are seamlessly integrated with cognitive control which is mobilized by stimuli that evoke ambiguity or response conflict. Methods with high spatio-temporal sensitivity are needed to provide insight into the interplay between automatic and controlled processing. This study used anatomically-constrained MEG to examine the underlying neural dynamics in a flanker task that manipulated S-R incongruity at the stimulus (SI) and response levels (RI). Though irrelevant, flankers evoked automatic preparation of motor plans which had to be suppressed and reversed following the target presentation on RI trials. Event-related source power estimates in beta (15-25 Hz) frequency band in the sensorimotor cortex tracked motor preparation and response in real time and revealed switching from the incorrectly-primed to the correctly-responding hemisphere. In contrast, theta oscillations (4-7 Hz) were sensitive to the levels of incongruity as the medial and ventrolateral frontal cortices were especially activated by response conflict. These two areas are key to cognitive control and their integrated contributions to response inhibition and switching were revealed by phase-locked co-oscillations. These processes were pharmacologically manipulated with a moderate alcohol beverage or a placebo administered to healthy social drinkers. Alcohol selectively decreased accuracy to response conflict. It strongly attenuated theta oscillations during decision making and partly re-sculpted relative contributions of the frontal network without affecting the motor switching process subserved by beta band. Our results indicate that motor preparation is initiated automatically even when counterproductive but that it is monitored and regulated by
Lauren E Beaton
Full Text Available Despite the subjective experience of being in full and deliberate control of our actions, our daily routines rely on a continuous and interactive engagement of sensory evaluation and response preparation streams. They unfold automatically and unconsciously and are seamlessly integrated with cognitive control which is mobilized by stimuli that evoke ambiguity or response conflict. Methods with high spatio-temporal sensitivity are needed to provide insight into the interplay between automatic and controlled processing. This study used anatomically-constrained MEG to examine the underlying neural dynamics in a flanker task that manipulated S-R incongruity at the stimulus (SI and response levels (RI. Though irrelevant, flankers evoked automatic preparation of motor plans which had to be suppressed and reversed following the target presentation on RI trials. Event-related source power estimates in beta (15-25 Hz frequency band in the sensorimotor cortex tracked motor preparation and response in real time and revealed switching from the incorrectly-primed to the correctly-responding hemisphere. In contrast, theta oscillations (4-7 Hz were sensitive to the levels of incongruity as the medial and ventrolateral frontal cortices were especially activated by response conflict. These two areas are key to cognitive control and their integrated contributions to response inhibition and switching were revealed by phase-locked co-oscillations. These processes were pharmacologically manipulated with a moderate alcohol beverage or a placebo administered to healthy social drinkers. Alcohol selectively decreased accuracy to response conflict. It strongly attenuated theta oscillations during decision making and partly re-sculpted relative contributions of the frontal network without affecting the motor switching process subserved by beta band. Our results indicate that motor preparation is initiated automatically even when counterproductive but that it is monitored
Verleger, Rolf; Kuniecki, Michal; Möller, Friderike
in the contralateral first dorsal interosseus muscle was taken as an index of corticospinal excitability. Guided by the previous LRP measurement, magnetic stimuli were applied 0-90 ms after the individual LRP peak, to cover the epoch of conflict resolution. When flankers were incompatible with the target, excitability......An important aspect of human motor control is the ability to resolve conflicting response tendencies. Here we used single-pulse transcranial magnetic stimulation (TMS) to track the time course of excitability changes in the primary motor hand areas (M1(HAND)) while the motor system resolved...... response conflicts. Healthy volunteers had to respond fast with their right and left index fingers to right- and left-pointing arrows. These central target stimuli were preceded by flanking arrows, inducing premature response tendencies which competed with correct response activation. The time point...
Cosman, Joshua D; Mordkoff, J Toby; Vecera, Shaun P
A dominant account of selective attention, perceptual load theory, proposes that when attentional resources are exhausted, task-irrelevant information receives little attention and goes unrecognized. However, the flanker effect-typically used to assay stimulus identification-requires an arbitrary mapping between a stimulus and a response. We looked for failures of flanker identification by using a more-sensitive measure that does not require arbitrary stimulus-response mappings: the correlated flankers effect. We found that flanking items that were task-irrelevant but that correlated with target identity produced a correlated flanker effect. Participants were faster on trials in which the irrelevant flanker had previously correlated with the target than when it did not. Of importance, this correlated flanker effect appeared regardless of perceptual load, occurring even in high-load displays that should have abolished flanker identification. Findings from a standard flanker task replicated the basic perceptual load effect, with flankers not affecting response times under high perceptual load. Our results indicate that task-irrelevant information can be processed to a high level (identification), even under high perceptual load. This challenges a strong account of high perceptual load effects that hypothesizes complete failures of stimulus identification under high perceptual load. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
The study of sex differences in cognition has often focused on differences in spatial processing. Recently, sex differences in selective attention have been observed by Bayliss, di Pellegrino, and Tipper (2005), showing that women are more influenced than men by irrelevant spatial cues. The current study elaborates on this finding and tests whether sex differences in the processing of irrelevant information also occur in a simpler task, in which there is no need to redirect visual attention and no need to remember multiple spatial stimulus-response associations. Here, attention is studied using a novel combination of a go/no-go task and a flanker task. A total of 80 neurotypical participants were studied, and it was found that responses in women were more strongly affected by flanker information than were responses in men. This suggests that these sex differences were not due to difficulties with spatial reorientation, or remembering spatial stimulus-response relationships. The findings are discussed in the context of the hunter-gatherer theory of sex differences.
Hefer, Carmen; Cohen, Anna-Lisa; Jaudas, Alexander; Dreisbach, Gesine
Prospective memory (PM) refers to the ability to remember to perform a delayed intention. Here, we aimed to investigate the ability to suspend such an intention and thus to confirm previous findings (Cohen, Gordon, Jaudas, Hefer, & Dreisbach, 2016) demonstrating the ability to flexibly engage in monitoring processes. In the current study, we presented a perceptually salient PM cue (bold and red) to rule out that previous findings were limited to non-salient and, thus, easy to ignore PM cues. Moreover, we used both a non-focal (Experiment 1) and a focal PM (Experiment 2) cue. In both Experiments, three groups of participants performed an Eriksen flanker task as an ongoing task with an embedded PM task (they had to remember to press the F1 key if a pre-specified cue appeared). Participants were assigned to either a control condition (performed solely the flanker task), a standard PM condition (performed the flanker task along with the PM task), or a PM delayed condition (performed the flanker task but were instructed to postpone their PM task intention). The results of Experiment 1 with the non-focal PM cue closely replicated those of Cohen et al. (2016) and confirmed that participants were able to successfully postpone the PM cue intention without additional costs even when the PM cue was a perceptually salient one. However, when the PM cue was focal (Experiment 2), it was much more difficult for participants to ignore it as evidenced by commission errors and slower latencies on PM cue trials. In sum, results showed that the focality of the PM cue plays a more crucial role in the flexibility of the monitoring process whereas the saliency of the PM cue does not. Copyright © 2017 Elsevier B.V. All rights reserved.
Dittrich, Kerstin; Bossert, Marie-Luise; Rothe-Wulf, Annelie; Klauer, Karl Christoph
Previous studies observed compatibility effects in different interference paradigms such as the Simon and flanker task even when the task was distributed across two co-actors. In both Simon and flanker tasks, performance is improved in compatible trials relative to incompatible trials if one actor works on the task alone as well as if two co-actors share the task. These findings have been taken to indicate that actors automatically co-represent their co-actor's task. However, recent research on the joint Simon and joint flanker effect suggests alternative non-social interpretations. To which degree both joint effects are driven by the same underlying processes is the question of the present study, and it was scrutinized by manipulating the visibility of the co-actor. While the joint Simon effect was not affected by the visibility of the co-actor, the joint flanker effect was reduced when participants did not see their co-actors but knew where the co-actors were seated. These findings provide further evidence for a spatial interpretation of the joint Simon effect. In contrast to recent claims, however, we propose a new explanation of the joint flanker effect that attributes the effect to an impairment in the focusing of spatial attention contingent on the visibility of the co-actor.
Servant, Mathieu; White, Corey; Montagnini, Anna; Burle, Borís
A current challenge for decision-making research is in extending models of simple decisions to more complex and ecological choice situations. Conflict tasks (e.g., Simon, Stroop, Eriksen flanker) have been the focus of much interest, because they provide a decision-making context representative of everyday life experiences. Modeling efforts have led to an elaborated drift diffusion model for conflict tasks (DMC), which implements a superimposition of automatic and controlled decision activations. The DMC has proven to capture the diversity of behavioral conflict effects across various task contexts. This study combined DMC predictions with EEG and EMG measurements to test a set of linking propositions that specify the relationship between theoretical decision-making mechanisms involved in the Simon task and brain activity. Our results are consistent with a representation of the superimposed decision variable in the primary motor cortices. The decision variable was also observed in the EMG activity of response agonist muscles. These findings provide new insight into the neurophysiology of human decision-making. In return, they provide support for the DMC model framework.
Full Text Available This article reviews some of Tore Linné Eriksen’s works within development studies/development research. In a recent introduction to development studies from 2013, he presented development research as a cross-disciplinary social science approach that addresses the grand problems of mankind. Eriksen’s own research into these grand problems has concentrated on the causes of national and international inequality and poverty. In 1974 he supported the view of the “underdevelopment school”: “Underdevelopment” in Africa and Latin America was the outcome of the inclusion of those continents in a capitalist world economy dominated by Europe. Recent works by Eriksen on the origins of the “great divergence” between Western Europe and economically advanced non-European countries (2010 and on inequality and poverty in the current world (2012 are far more complex and empirically nuanced. Still, in a recent discussion of globalization and global capitalism (2013 he reverts to some of the earlier ”underdevelopment arguments” from 1974. The article concludes that there is a tension within Eriksen’s works on the role of capitalism in development and underdevelopment. In his programmatic writings, global capitalism is seen as the main cause of inequality and poverty. In his more empirically grounded works, global capitalism is viewed rather as an important part of the bigger picture of inequality and poverty.
Matthews, Allison Jane; Martin, Frances Heritage
To investigate facilitatory and inhibitory processes during selective attention among adults with good (n=17) and poor (n=14) phonological decoding skills, a go/nogo flanker task was completed while EEG was recorded. Participants responded to a middle target letter flanked by compatible or incompatible flankers. The target was surrounded by a small or large circular cue which was presented simultaneously or 500ms prior. Poor decoders showed a greater RT cost for incompatible stimuli preceded by large cues and less RT benefit for compatible stimuli. Poor decoders also showed reduced modulation of ERPs by cue-size at left hemisphere posterior sites (N1) and by flanker compatibility at right hemisphere posterior sites (N1) and frontal sites (N2), consistent with processing differences in fronto-parietal attention networks. These findings have potential implications for understanding the relationship between spatial attention and phonological decoding in dyslexia. Copyright © 2015 Elsevier Inc. All rights reserved.
When subjects must respond to a relevant center letter and ignore irrelevant flanking letters, the identities of the flankers produce a response compatibility effect, indicating that they are processed semantically at least to some extent. Because this effect decreases as the separation between target and flankers increases, the effect appears to result from imperfect early selection (attenuation). In the present experiments, several features of the focused attention paradigm were examined, in order to determine whether they might produce the flanker compatibility effect by interfering with the operation of an early selective mechanism. Specifically, the effect might be produced because the paradigm requires subjects to (1) attend exclusively to stimuli within a very small visual angle, (2) maintain a long-term attentional focus on a constant display location, (3) focus attention on an empty display location, (4) exclude onset-transient flankers from semantic processing, or (5) ignore some of the few stimuli in an impoverished visual field. The results indicate that none of these task features is required for semantic processing of unattended stimuli to occur. In fact, visual angle is the only one of the task features that clearly has a strong influence on the size of the flanker compatibility effect. The invariance of the flanker compatibility effect across these conditions suggests that the mechanism for early selection rarely, if ever, completely excludes unattended stimuli from semantic analysis. In addition, it shows that selective mechanisms are relatively insensitive to several factors that might be expected to influence them, thereby supporting the view that spatial separation has a special status for visual selective attention.
Gaspelin, Nicholas; Ruthruff, Eric; Jung, Kyunghun
In the flanker paradigm, participants identify a target letter while attempting to ignore an irrelevant flanker. When the identity of this flanker mismatches the target, target identification is slowed (called the flanker compatibility effect). Interestingly, reducing the array set size greatly increases flanker compatibility effects. This finding inspired 2 prominent explanations: perceptual load (mandatory capacity spillover) and dilution (visual interference). However, an alternative explanation, based on early selection theory and attention capture research, can also explain the data pattern. According to this "slippage" account, observers sometimes accidentally allocate spatial attention to the flanker (see Lachter, Forster, & Ruthruff, 2004), especially when the flanker has the property used to find the target (cf. contingent capture). In Experiments 1 through 4, deterring slippage to the flanker nearly eliminated flanker compatibility effects, even at the low set size. In Experiment 5, promoting slippage to the flanker dramatically enhanced compatibility effects, even at the high set size. Thus, slippage strongly modulates flanker effects and can, by itself, readily explain the impact of set size. The perceptual load and dilution accounts are, at best, incomplete, and, at worst, not needed. PsycINFO Database Record (c) 2014 APA, all rights reserved.
Liu, Zan-Zan; Qu, Hui-Jie; Tian, Zhuo-Ling; Han, Meng-Jian; Fan, Yi; Ge, Lie-Zhong; Zang, Yu-Feng; Zhang, Hang
Increased levels of reaction time variability (RTV) are characteristics of sustained attention deficits. The clinical significance of RTV has been widely recognized. However, the reliability of RTV measurements has not been widely studied. The present study aimed to assess the test-retest reliability of RTV conventional measurements, e.g., the standard deviation (SD), the coefficient of variation (CV), and a new measurement called the amplitude of low frequency fluctuation (ALFF) of RT. In addition, we aimed to assess differences and similarities of these measurements between different tasks. Thirty-seven healthy college students participated in 2 tasks, i.e., an Eriksen flanker task (EFT) and a simple reaction task (SRT), twice over a mean interval of 56 days. Conventional measurements of RTV including RT-SD and RT-CV were assessed first. Then the RT time series were converted into frequency domains, and RT-ALFF was further calculated for the whole frequency band (0.0023-0.167 Hz) and for a few sub-frequency bands including Slow-6 (frequency bands (Slow-3), but SRT RT-ALFF values showed slightly higher ICC values than EFT values in lower frequency bands (Slow-5 and Slow-4). 2) RT-ALFF magnitudes in each sub-frequency band were greater for the SRT than those for the EFT. 3) The RT-ALFF in the Slow-4 of the EFT was found to be correlated with the RT-ALFF in the Slow-5 of the SRT for both two visits, but no consistently significant correlation was found between the same frequency bands. These findings reveal good test-retest reliability for conventional measurements and for the RT-ALFF of RTV. The RT-ALFF presented frequency-dependent similarities across tasks. All of our results reveal the presence of different frequency structures between the two tasks, and thus the frequency-dependent characteristics of different tasks deserve more attention in future studies.
Hedge, Craig; Powell, Georgina; Sumner, Petroc
Individual differences in cognitive paradigms are increasingly employed to relate cognition to brain structure, chemistry, and function. However, such efforts are often unfruitful, even with the most well established tasks. Here we offer an explanation for failures in the application of robust cognitive paradigms to the study of individual differences. Experimental effects become well established - and thus those tasks become popular - when between-subject variability is low. However, low between-subject variability causes low reliability for individual differences, destroying replicable correlations with other factors and potentially undermining published conclusions drawn from correlational relationships. Though these statistical issues have a long history in psychology, they are widely overlooked in cognitive psychology and neuroscience today. In three studies, we assessed test-retest reliability of seven classic tasks: Eriksen Flanker, Stroop, stop-signal, go/no-go, Posner cueing, Navon, and Spatial-Numerical Association of Response Code (SNARC). Reliabilities ranged from 0 to .82, being surprisingly low for most tasks given their common use. As we predicted, this emerged from low variance between individuals rather than high measurement variance. In other words, the very reason such tasks produce robust and easily replicable experimental effects - low between-participant variability - makes their use as correlational tools problematic. We demonstrate that taking such reliability estimates into account has the potential to qualitatively change theoretical conclusions. The implications of our findings are that well-established approaches in experimental psychology and neuropsychology may not directly translate to the study of individual differences in brain structure, chemistry, and function, and alternative metrics may be required.
Siemann, Julia; Herrmann, Manfred; Galashan, Daniela
The present study examined whether feature-based cueing affects early or late stages of flanker conflict processing using EEG and fMRI. Feature cues either directed participants' attention to the upcoming colour of the target or were neutral. Validity-specific modulations during interference processing were investigated using the N200 event-related potential (ERP) component and BOLD signal differences. Additionally, both data sets were integrated using an fMRI-constrained source analysis. Finally, the results were compared with a previous study in which spatial instead of feature-based cueing was applied to an otherwise identical flanker task. Feature-based and spatial attention recruited a common fronto-parietal network during conflict processing. Irrespective of attention type (feature-based; spatial), this network responded to focussed attention (valid cueing) as well as context updating (invalid cueing), hinting at domain-general mechanisms. However, spatially and non-spatially directed attention also demonstrated domain-specific activation patterns for conflict processing that were observable in distinct EEG and fMRI data patterns as well as in the respective source analyses. Conflict-specific activity in visual brain regions was comparable between both attention types. We assume that the distinction between spatially and non-spatially directed attention types primarily applies to temporal differences (domain-specific dynamics) between signals originating in the same brain regions (domain-general localization).
Dickter, Cheryl L; Bartholow, Bruce D
Three largely independent lines of research have investigated experimental manipulations that influence the amplitude of the N2 component of the event-related brain potential (ERP), one linking heightened N2 amplitude to response conflict, another showing that N2 is sensitive to stimulus infrequency, and the third showing larger N2 amplitude during categorization of racial ingroup relative to racial outgroup targets. The purpose of this research was to investigate potential interactions between these three features on the amplitude of the N2. ERPs were recorded while participants completed a modified flanker task using pictures of ingroup and outgroup faces. Results showed a 3-way interaction, indicating that the N2 was largest for ingroup targets on high-conflict trials but only when such trials were relatively infrequent. Implications of these findings for theories of both conflict monitoring and person perception are discussed.
Wylie, S.A.; van den Wildenberg, W.P.M.; Ridderinkhof, K.R.; Bashore, T.R.; Powell, V.D.; Manning, C.A.; Wooten, G.F.
Studies that used conflict paradigms such as the Eriksen Flanker task show that many individuals with Parkinson's disease (PD) have pronounced difficulty resolving the conflict that arises from the simultaneous activation of mutually exclusive responses. This finding fits well with contemporary
Hein, Elisabeth; Moore, Cathleen M
A central bar repeatedly presented in alternation with two flanking bars can lead to the disappearance of the central bar. Recently it has been suggested that this masking effect could be explained by object-mediated updating: the information from the central bar is integrated into the representation of the flankers, leading not only to the disappearance of the central bar as a separate object, but also to the perception of the flankers in apparent motion between their real position and the position of the central bar. This account suggests that the visibility of the central bar should depend on the same factors as those that influence the construction and maintenance of object representations. Therefore separation between central bar and flankers should not influence visibility as long as the time interval between them is adequate to make an interpretation of the scene in terms of one object moving from one location to the other possible location. We found that if the time interval between the central bar and the flankers is neither too short nor too long, the central bar becomes invisible even at large separations. These findings are inconsistent with traditional accounts of the cycling lateral masking displays in terms of local inhibitory mechanisms.
胡凤培; 王倩; 徐莲; 葛列众
In order to improve the performance of the conflict tasks, the human brain detects and resolves conflicts through the cognitive control system. However, we do not know the multiple conflict-driven control mechanisms. In order to investigate this issue, this study fully integrates the Flanker, Stroop, and Simon conflict. This study included two experiments： Experiment 1 integrated the Flanker and Simon conflict, Experiment 2 integrates the Flanker and Stroop conflict. This study combined behavioral responses and event-related potential （ERP） technology to investigate the mechanisms of the cognitive control. On the one hand, the behavioral response data showed that firstly, all the types of the conflicts in all the experiments show the Congruency Effect and the Conflict Adaptation Effects ; secondly, each type of conflict of a previous trial in all the experiments only interacted with a current trial of its own kind, but did not interact with other kinds of current trial. On the other hand, ERP data of the two experiments showed that with the exception of Flanker conflict in Experiment 2, all the conflict types in all the experiments showed that the P300 latency, the N450, and the SP component were in line with the congruency effect. The data above show that firstly, in a variety of types of conflict conditions, the conflict monitoring theory is still applicable ; sec- ondly, in face of a variety of types of conflict conditions, the human brain can monitor and then solve the conflict at the same time and also achieve successful task performance; thirdly, the human brain uses local control mechanism to resolve the conflict, that is to say, each type of conflict facilitates the resolution of its own kind, but does not affect the resolution of the other kind. To sum up, multiple conflict-driven control mechanisms are based on the conflict-specific manner, different types of conflicts have different types conflict monitor units which trigger the corresponding
Hillman, Charles H.; Buck, Sarah M.; Themanson, Jason R.; Pontifex, Matthew B.; Castelli, Darla M.
The relationship between aerobic fitness and executive control was assessed in 38 higher- and lower-fit children (M[subscript age] = 9.4 years), grouped according to their performance on a field test of aerobic capacity. Participants performed a flanker task requiring variable amounts of executive control while event-related brain potential…
Coleman, James R; Watson, Jason M; Strayer, David L
The present study investigated individual differences in information processing following errant behavior. Participants were initially classified as high or as low working memory capacity using the Operation Span Task. In a subsequent session, they then performed a high congruency version of the flanker task under both speed and accuracy stress. We recorded ERPs and behavioral measures of accuracy and response time in the flanker task with a primary focus on processing following an error. The error-related negativity was larger for the high working memory capacity group than for the low working memory capacity group. The positivity following an error (Pe) was modulated to a greater extent by speed-accuracy instruction for the high working memory capacity group than for the low working memory capacity group. These data help to explicate the neural bases of individual differences in working memory capacity and cognitive control. © 2017 Society for Psychophysiological Research.
Jan W. De Fockert
Full Text Available There are multiple ways in which working memory can influence selective attention. Aside from the content-specific effects of working memory on selective attention, whereby attention is more likely to be directed towards information that matches the contents of working memory, the mere level of load on working memory has also been shown to have an effect on selective attention. Specifically, high load on working memory is associated with increased processing of irrelevant information. In most demonstrations of the effect to-date, this has led to impaired target performance, leaving open the possibility that the effect partly reflects an increase in general task difficulty under high load. Here we show that working memory load can result in a performance gain when processing of distracting information aids target performance. The facilitation in the detection of a low-contrast Gabor stimulus in the presence of collinear flanking Gabors was greater when load on a concurrent working memory task was high, compared to low. This finding suggests that working memory can interact with selective attention at an early stage in visual processing.
O'Connor, Patrick J; Tomporowski, Phillip D; Dishman, Rodney K
The aim of this study was to examine whether people differed in change in performance across the first five blocks of an online flanker task and whether those trajectories of change were associated with self-reported aerobic or resistance exercise frequency according to age. A total of 8752 men and women aged 13-89 completed a lifestyle survey and five 45-s games (each game was a block of ~46 trials) of an online flanker task. Accuracy of the congruent and incongruent flanker stimuli was analyzed using latent class and growth curve modeling adjusting for time between blocks, whether the blocks occurred on the same or different days, education, smoking, sleep, caffeinated coffee and tea use, and Lumosity training status ("free play" or part of a "daily brain workout"). Aerobic and resistance exercise were unrelated to first block accuracies. For the more cognitively demanding incongruent flanker stimuli, aerobic activity was positively related to the linear increase in accuracy [B=0.577%, 95% confidence interval (CI), 0.112 to 1.25 per day above the weekly mean of 2.8 days] and inversely related to the quadratic deceleration of accuracy gains (B=-0.619% CI, -1.117 to -0.121 per day). An interaction of aerobic activity with age indicated that active participants younger than age 45 had a larger linear increase and a smaller quadratic deceleration compared to other participants. Age moderates the association between self-reported aerobic, but not self-reported resistance, exercise and changes in cognitive control that occur with practice during incongruent presentations across five blocks of a 45-s online, flanker task.
Rey-Mermet, Alodie; Meier, Beat
The purpose of the present study was to determine how long-lasting the post-conflict slowing following incongruent stimuli is. In previous research, incongruent stimuli have been used to induce a conflict because they have relevant features for two different response alternatives. So far, the post-conflict slowing following incongruent stimuli has mainly been assessed up to one trial. In the first two experiments, we assessed the persistence of the post-conflict slowing across several trials. To this end, we presented a few incongruent stimuli among non-conflict stimuli. The results showed a consistent slowing for the first few trials immediately following the incongruent trials. In addition, a sporadic slowing was still found on later trials. In two subsequent experiments, we investigated to what extent the infrequency of incongruent trials - rather than their conflict - induced this slowing. To determine this, we used the same design as in the first two experiments, but we presented non-conflict stimuli as infrequent stimuli. The results showed a slowing on one subsequent trial, ruling out the possibility that the post-conflict slowing following incongruent trials was only caused by infrequency. Together, the findings of the present study indicate that the conflict induced by incongruent trials can have a longer lasting impact on subsequent trials than previously thought.
Heike Eichele; Tom Eichele; Tom Eichele; Tom Eichele; Lynn Marquardt; Steinunn Adolfsdottir; Kenneth Hugdahl; Kenneth Hugdahl; Kenneth Hugdahl; Lin Sørensen; Lin Sørensen; Kerstin J. Plessen; Kerstin J. Plessen; Kerstin J. Plessen
Background: Tourette Syndrome (TS) is a neurodevelopmental disorder with childhood-onset, with a typical decline in tic severity, as well as an increasing ability to suppress tics in late childhood and adolescence. These processes develop in parallel with general improvement of self-regulatory abilities, and performance monitoring during this age-span. Hence, changes in performance monitoring over time might provide insight into the regulation of tics in children and adolescents with TS.Metho...
Huyser, Chaim; Veltman, Dick J.; Wolters, Lidewij H.; de Haan, Else; Boer, Frits
Background: Heightened error and conflict monitoring are considered central mechanisms in obsessive-compulsive disorder (OCD) and are associated with anterior cingulate cortex (ACC) function. Pediatric obsessive-compulsive patients provide an opportunity to investigate the development of this area and its associations with psychopathology.…
Eichele, Heike; Eichele, Tom; Marquardt, Lynn
Background: Tourette Syndrome (TS) is a neurodevelopmental disorder with childhood-onset, with a typical decline in tic severity, as well as an increasing ability to suppress tics in late childhood and adolescence. These processes develop in parallel with general improvement of self......-regulatory abilities, and performance monitoring during this age-span. Hence, changes in performance monitoring over time might provide insight into the regulation of tics in children and adolescents with TS. Method: We measured reaction time, reaction time variability, accuracy, and event-related potentials (ERP...... largely persisted. In terms of ERP, the early P3 developed earlier in children with TS compared with controls at the first assessment, but trajectories converged with maturation. ERP component amplitudes correlated with worst-ever tic scores. Conclusions: Merging trajectories between children with TS...
Ward, Richard T; Smith, Shelby L; Kraus, Brian T; Allen, Anna V; Moses, Michael A; Simon-Dack, Stephanie L
Trait anxiety has been shown to cause significant impairments on attentional tasks. Current research has identified alpha band frequency differences between low-trait and high-trait anxious individuals. Here, we further investigated the underlying alpha band frequency differences between low-trait and high-trait anxious individuals during their resting state and the completion of an inhibition executive functioning task. Using human participants and quantitative electroencephalographic recordings, we measured alpha band frequency in individuals both high and low in trait anxiety during their resting state, and while they completed an Eriksen Flanker Task. Results indicated that high-trait anxious individuals exhibit a desynchronization in alpha band frequency from a resting state to when they complete the Eriksen Flanker Task. This suggests that high-trait anxious individuals maintain fewer attentional resources at rest and must martial resources for task performance as compared with low-trait anxious individuals, who appear to maintain stable cognitive resources between rest and task performance. These findings add to the cognitive neuroscience literature surrounding the role of alpha band frequency in low-trait and high-trait anxious individuals.
Wylie, S A; van den Wildenberg, W P M; Ridderinkhof, K R; Bashore, T R; Powell, V D; Manning, C A; Wooten, G F
Studies that used conflict paradigms such as the Eriksen Flanker task show that many individuals with Parkinson's disease (PD) have pronounced difficulty resolving the conflict that arises from the simultaneous activation of mutually exclusive responses. This finding fits well with contemporary views that postulate a key role for the basal ganglia in action selection. The present experiment aims to specify the cognitive processes that underlie action selection deficits among PD patients in the context of variations in speed-accuracy strategy. PD patients (n=28) and healthy controls (n=17) performed an arrow version of the flanker task under task instructions that either emphasized speed or accuracy of responses. Reaction time (RT) and accuracy rates decreased with speed compared to accuracy instructions, although to a lesser extent for the PD group. Differences in flanker interference effects among PD and healthy controls depended on speed-accuracy strategy. Compared to the healthy controls, PD patients showed larger flanker interference effects under speed stress. RT distribution analyses suggested that PD patients have greater difficulty suppressing incorrect response activation when pressing for speed. These initial findings point to an important interaction between strategic and computational aspects of interference control in accounting for cognitive impairments of PD. The results are also compatible with recent brain imaging studies that demonstrate basal ganglia activity to co-vary with speed-accuracy adjustments.
Wendt, Mike; Kiesel, Andrea
Interference evoked by distractor stimulus information, such as flankers in the Eriksen task, is reduced when the proportion of conflicting stimuli is increased. This modulation is sensitive to contextual cues such as stimulus location or color, suggesting attentional adjustment to conflict contingencies on the basis of context information. In the present study, we explored whether conflict adjustment is modulated by temporal variation of conflict likelihood. To this end, we associated low and high proportions of conflict stimuli with foreperiods of different lengths. Flanker interference was higher with foreperiods associated with low conflict proportions, suggesting that participants use the foreperiod as a contextual cue for attentional adjustment. We conjecture that participants initially adopt the strategy useful for conflict contingencies associated with short foreperiods, and then readjust during the trial, in the absence of any additional exogenous cue, when the imperative stimulus has not occurred during a certain time interval.
Tobia, Valentina; Fasola, Anna; Lupieri, Alice; Marzocchi, Gian Marco
This study aimed to explore the spatial numerical association of response codes (SNARC), the flanker, and the numerical distance effects in children with mathematical difficulties. From a sample of 720 third, fourth, and fifth graders, 60 children were selected and divided into the following three groups: typically developing children (TD; n = 29), children with mathematical difficulties only (MD only; n = 21), and children with mathematical and reading difficulties (MD+RD; n = 10). Children were tested with a numerical Eriksen task that was built to assess SNARC, numerical distance, and flanker (first and second order congruency) effects. Children with MD only showed stronger SNARC and second order congruency effects than did TD children, whereas the numerical distance effects were similar across the three groups. Finally, the first order congruency effect was associated with reading difficulties. These results showed that children with mathematical difficulties with or without reading difficulties were globally more impaired when spatial incompatibilities were presented. © Hammill Institute on Disabilities 2014.
McKay, Cameron C.; van den Berg, Berry; Woldorff, Marty G.
In visual conflict tasks (e.g., Stroop or flanker), response times (RTs) are generally longer on incongruent trials relative to congruent ones. Two event-related-potential (ERP) components classically associated with the processing of stimulus conflict are the fronto-central, incongruency-related negativity (Ninc) and the posterior late-positive complex (LPC), which are derived from the ERP difference waves for incongruent minus congruent trials. It has been questioned, however, whether these effects, or other neural measures of incongruency (e.g., fMRI responses in the anterior cingulate), reflect true conflict processing, or whether such effects derive mainly from differential time-on-task. To address this question, we leveraged high-temporal-resolution ERP measures of brain activity during two behavioral tasks. The first task, a modified Erikson flanker paradigm (with congruent and incongruent trials), was used to evoke the classic RT and ERP effects associated with conflict. In the second, a non-conflict comparison condition, participants visually discriminated a single stimulus (with easy and hard discrimination conditions). Behaviorally, the parameters were titrated to yield similar RT effects of conflict and difficulty (27 ms). Neurally, both within-task contrasts showed an initial fronto-central negative-polarity wave (N2-latency effect), but they then diverged. In the difficulty difference wave, the initial negativity led directly into the posterior LPC, whereas in the incongruency contrast the initial negativity was followed a by a second fronto-central negative peak (Ninc), which was then followed by a considerably longer-latency LPC. These results provide clear evidence that the longer processing for incongruent stimulus inputs do not just reflect time-on-task or difficulty, but include a true conflict-processing component. PMID:28017818
Full Text Available A latent variable study examined whether different classes of working-memory tasks measure the same general construct of working-memory capacity (WMC. Data from 270 subjects were used to examine the relationship between Binding, Updating, Recall-N-back, and Complex Span tasks, and the relations of WMC with secondary memory measures, indicators of cognitive control from two response-conflict paradigms (Simon task and Eriksen flanker task, and fluid intelligence. Confirmatory factor analyses support the concept of a general WMC factor. Results from structural-equation modeling show negligible relations of WMC with response-conflict resolution, and very strong relations of WMC with secondary memory and fluid intelligence. The findings support the hypothesis that individual differences in WMC reflect the ability to build, maintain and update arbitrary bindings.
Donohue, Sarah E.; Appelbaum, Lawrence G.; McKay, Cameron C.; Woldorff, Marty G.
Both stimulus and response conflict can disrupt behavior by slowing response times and decreasing accuracy. Although several neural activations have been associated with conflict processing, it is unclear how specific any of these are to the type of stimulus conflict or the amount of response conflict. Here, we recorded electrical brain activity, while manipulating the type of stimulus conflict in the task (spatial [Flanker] versus semantic [Stroop]) and the amount of response conflict (two versus four response choices). Behaviorally, responses were slower to incongruent versus congruent stimuli across all task and response types, along with overall slowing for higher response-mapping complexity. The earliest incongruency-related neural effect was a short-duration frontally-distributed negativity at ~200 ms that was only present in the Flanker spatial-conflict task. At longer latencies, the classic fronto-central incongruency-related negativity ‘Ninc’ was observed for all conditions, which was larger and ~100 ms longer in duration with more response options. Further, the onset of the motor-related lateralized readiness potential (LRP) was earlier for the two vs. four response sets, indicating that smaller response sets enabled faster motor-response preparation. The late positive complex (LPC) was present in all conditions except the two-response Stroop task, suggesting this late conflict-related activity is not specifically related to task type or response-mapping complexity. Importantly, across tasks and conditions, the LRP onset at or before the conflict-related Ninc, indicating that motor preparation is a rapid, automatic process that interacts with the conflict-detection processes after it has begun. Together, these data highlight how different conflict-related processes operate in parallel and depend on both the cognitive demands of the task and the number of response options. PMID:26827917
Eichele, Heike; Eichele, Tom; Bjelland, Ingvar
BACKGROUND: Tourette syndrome (TS) is a childhood-onset neurodevelopmental disorder and its impact on cognitive development needs further study. Evidence from neuropsychological, neuroimaging and electrophysiological studies suggests that the decline in tic severity and the ability to suppress tics...... relate to the development of self-regulatory functions in late childhood and adolescence. Hence, tasks measuring performance monitoring might provide insight into the regulation of tics in children with TS. METHOD: Twenty-five children with TS, including 14 with comorbid Attention-deficit/ hyperactivity...... disorder (ADHD), 39 children with ADHD and 35 typically developing children aged 8-12 years were tested with a modified Eriksen-Flanker task during a 34-channel electroencephalography (EEG) recording. Task performance, as well as stimulus-locked and response-locked event-related potentials (ERP) were...
van Gaal, Simon; Lamme, Victor A F; Ridderinkhof, K Richard
In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked) or unconsciously (strongly masked primes). We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition.
Simon van Gaal
Full Text Available In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked or unconsciously (strongly masked primes. We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition.
Huyser, C.; Veltman, D.J.; Wolters, L.H.; de Haan, E.; Boer, F.
Background: Heightened error and conflict monitoring are considered central mechanisms in obsessive-compulsive disorder (OCD) and are associated with anterior cingulate cortex (ACC) function. Pediatric obsessive-compulsive patients provide an opportunity to investigate the development of this area
Huyser, C.; Veltman, D.J.; Wolters, L.H.; de Haan, E.; de Boer, F.
Background: Heightened error and conflict monitoring are considered central mechanisms in obsessive-compulsive disorder (OCD) and are associated with anterior cingulate cortex (ACC) function. Pediatric obsessive-compulsive patients provide an opportunity to investigate the development of this area
Huyser, Chaim; Veltman, Dick J.; Wolters, Lidewij H.; de Haan, Else; Boer, Frits
Heightened error and conflict monitoring are considered central mechanisms in obsessive-compulsive disorder (OCD) and are associated with anterior cingulate cortex (ACC) function. Pediatric obsessive-compulsive patients provide an opportunity to investigate the development of this area and its
Ligeza, Tomasz S; Wyczesany, Miroslaw
The detection of cognitive conflict is thought to trigger adjustments in executive control. It has been recently shown that cognitive conflict increases processing of stimuli that are relevant to the ongoing task and that these modulations are exerted by the dorsolateral prefrontal cortex (DLPFC). However, it is still unclear whether such control influences are unspecific and might also affect the processing of task-irrelevant stimuli. The aim of the study was to examine if cognitive conflict affects processing of neutral and negative, task-irrelevant pictures. Participants responded to congruent (non-conflict) or to incongruent (conflict-eliciting) trials of a modified flanker task. Each response was followed by a presentation of a neutral or negative picture. The late positive potential (LPP) in response to picture presentation was used to assess the level of picture processing after conflict vs non-conflict trials. Connectivity between the DLPFC and attentional and perceptual areas during picture presentation was analysed to check if the DLPFC might be a source of these modulations. ERP results showed an effect of cognitive conflict only on processing of negative pictures: LPP in response to negative pictures was increased after conflict trials, whereas LPP in response to neutral pictures remained unchanged. Cortical connectivity analysis showed that conflict trials intensified information flow from the DLPFC towards attentional and perceptual regions. Results suggest that cognitive conflict increases processing of task-irrelevant stimuli; however, they must display high biological salience. Increase in cognitive control exerted by the DLPFC over attentional and perceptual regions is a probable mechanism of the effect. Copyright © 2017 Elsevier B.V. All rights reserved.
van Steenbergen, Henk; Band, Guido P H; Hommel, Bernhard
Sequential modulation of congruency effects in conflict tasks indicates that cognitive control quickly adapts to changing task demands. We investigated in four experiments how this behavioral congruency-sequence effect relates to different levels of perceived task difficulty in a flanker and a Stroop task. In addition, online measures of pupil diameter were used as a physiological index of effort mobilization. Consistent with motivational accounts predicting that increased levels of perceived task difficulty will increase effort mobilization only up to a certain limit, reliable dynamic conflict-driven adjustment in cognitive control was only observed when task difficulty was relatively low. Instead, tasks tentatively associated with high levels of difficulty showed no or reversed conflict adaptation. Although the effects could not be linked consistently to effects in self-reported task difficulty in all experiments, regression analyses showed associations between perceived task difficulty and conflict adaptation in some of the experiments, which provides some initial evidence for an inverted U-shape relationship between perceived difficulty and adaptations in cognitive control. Furthermore, high levels of task difficulty were associated with a conflict-driven reduction in pupil dilation, suggesting that pupil dilation can be used as a physiological marker of mental overload. Our findings underscore the importance of developing models that are grounded in motivational accounts of cognitive control.
Henk eVan Steenbergen
Full Text Available Sequential modulation of congruency effects in conflict tasks indicates that cognitive control quickly adapts to changing task demands. We investigated in four experiments how this behavioral congruency-sequence effect relates to different levels of perceived task difficulty in a flanker and a Stroop task. In addition, online measures of pupil diameter were used as a physiological index of effort mobilization. Consistent with motivational accounts predicting that increased levels of perceived task difficulty will increase effort mobilization only up to a certain limit, reliable dynamic conflict-driven adjustment in cognitive control was only observed when task difficulty was relatively low. Instead, tasks tentatively associated with high levels of difficulty showed no or reversed conflict adaptation. Although the effects could not be linked consistently to effects in self-reported task difficulty in all experiments, regression analyses showed associations between perceived task difficulty and conflict adaptation in some of the experiments, which provides some initial evidence for an inverted U-shape relationship between perceived difficulty and adaptations in cognitive control. Furthermore, high levels of task difficulty were associated with a conflict-driven reduction in pupil dilation, suggesting that pupil dilation can be used as a physiological marker of mental overload. Our findings underscore the importance of developing models that are grounded in motivational accounts of cognitive control.
Liu, Tongran; Xiao, Tong; Jiannong, Shi
The current study investigated whether adolescents with different intellectual levels have different conflict adaptation processes. Adolescents with high and average IQ abilities were enrolled, and their behavioral responses and event-related potentials (ERPs) were recorded during a modified...... Eriksen flanker task. Both groups showed reliable conflict adaptation effects (CAE) with regard to the reaction time (RT), and they showed a faster response to the cC condition than to the iC condition and faster response to the iI condition than to the cI condition. The IQ-related findings showed...... that high IQ adolescents had shorter RTs than their average-IQ counterparts in the cI, iC, and iI conditions, with smaller RT-CAE values. These findings indicated that high IQ adolescents had superior conflict adaptation processes. The electrophysiological findings showed that the cI condition required more...
Have, Mona; Nielsen, Jacob Have; Gejl, Anne Kær
was a 9-month classroom-based PA program that involved integration of PA into the math lessons delivered by the schools' math teachers. The primary study outcome was change in math achievement, measured by a 45-minute standardized math test. Secondary outcomes were change in executive function (using...... a modified Eriksen flanker task and the Behavior Rating Inventory of Executive Function (BRIEF) questionnaire filled out by the parents), creativity (using the Torrance Tests of Creative Thinking, TTCT), aerobic fitness (by the Andersen intermittent shuttle-run test) and body mass index. PA during math...... lessons and total PA (including time spent outside school) were assessed using accelerometry. Math teachers used Short Message Service (SMS)-tracking to report on compliance with the PA intervention and on their motivation for implementing PA in math lessons. Parents used SMS-tracking to register...
Huang, Tao; Tarp, Jakob; Domazet, Sidsel Louise
OBJECTIVE: To examine the associations of adiposity and aerobic fitness with executive function and math performance in Danish adolescents. STUDY DESIGN: Cross-sectional analyses were conducted with data on 525 adolescents attending sixth and seventh grades from 14 schools in the 5 main regions...... of Denmark. A modified Eriksen flanker task was used to assess inhibitory control, a key aspect of executive function. Academic performance was assessed by a customized math test. Aerobic fitness was assessed by an intermittent shuttle-run test (Andersen test). RESULTS: Body mass index (BMI) was negatively......). Aerobic fitness was positively associated with math score (P math score (P > .05). CONCLUSIONS: These results suggest that aerobic fitness is positively associated with both inhibitory control and math performance in adolescents. Adiposity is negatively...
Clayson, Peter E; Larson, Michael J
Psychiatric and neurologic disorders are associated with deficits in the postconflict recruitment of cognitive control. The primary aim of this study was to validate the relationship between cognitive functioning and indices of conflict adaptation. Event-related potentials were obtained from 89 healthy individuals who completed an Eriksen flanker task. Neuropsychological domains tested included memory, verbal fluency, and attention/executive functioning. Behavioral measures and N2 amplitudes showed significant conflict adaptation (i.e., previous-trial congruencies influenced current-trial measures). Higher scores on the attention/executive functioning and verbal fluency domains were associated with larger incongruent-trial N2 conflict adaptation; measures of cognitive functioning were not related to behavioral indices. This study provides initial validation of N2 conflict adaptation effects as cognitive function-related aspects of cognitive control. Copyright © 2012 Society for Psychophysiological Research.
Zheng, Ya; Sheng, Wenbin; Xu, Jing; Zhang, Yuanyuan
Sensation seeking is defined by a strong need for varied, novel, complex, and intense stimulation, and a willingness to take risks for such experience. Several theories propose that the insensitivity to negative consequences incurred by risks is one of the hallmarks of sensation-seeking behaviors. In this study, we investigated the time course of error processing in sensation seeking by recording event-related potentials (ERPs) while high and low sensation seekers performed an Eriksen flanker task. Whereas there were no group differences in ERPs to correct trials, sensation seeking was associated with a blunted error-related negativity (ERN), which was female-specific. Further, different subdimensions of sensation seeking were related to ERN amplitude differently. These findings indicate that the relationship between sensation seeking and error processing is sex-specific. Copyright © 2014 Society for Psychophysiological Research.
Full Text Available Task-irrelevant salient stimuli involuntarily capture attention and can lead to distraction from an ongoing task, especially in children with ADHD. However, there has been tentative evidence that the presentation of novel sounds can have beneficial effects on cognitive performance. In the present study, we aimed to investigate the influence of novel sounds compared to no sound and a repeatedly presented standard sound on attentional performance in children and adolescents with and without ADHD. We therefore had 32 patients with ADHD and 32 typically developing children and adolescents (8 to 13 years executed a flanker task in which each trial was preceded either by a repeatedly presented standard sound (33%, an unrepeated novel sound (33% or no auditory stimulation (33%. Task-irrelevant novel sounds facilitated attentional performance similarly in children with and without ADHD, as indicated by reduced omission error rates, reaction times, and reaction time variability without compromising performance accuracy. By contrast, standard sounds, while also reducing omission error rates and reaction times, led to increased commission error rates. Therefore, the beneficial effect of novel sounds exceeds cueing of the target display by potentially increased alerting and/or enhanced behavioral control.
Kanske, Philipp; Kotz, Sonja A
Coherent behavior depends on attentional control that detects and resolves conflict between opposing actions. The current functional magnetic resonance imaging study tested the hypothesis that emotion triggers attentional control to speed up conflict processing in particularly salient situations. Therefore, we presented emotionally negative and neutral words in a version of the flanker task. In response to conflict, we found activation of the dorsal anterior cingulate cortex (ACC) and of the amygdala for emotional stimuli. When emotion and conflict coincided, a region in the ventral ACC was activated, which resulted in faster conflict processing in reaction times. Emotion also increased functional connectivity between the ventral ACC and activation of the dorsal ACC and the amygdala in conflict trials. These data suggest that the ventral ACC integrates emotion and conflict and prioritizes the processing of conflict in emotional trials. This adaptive mechanism ensures rapid detection and resolution of conflict in potentially threatening situations signaled by emotional stimuli. Copyright © 2010 Wiley-Liss, Inc.
Blask, Katarina; Walther, Eva; Frings, Christian
We investigated in two experiments whether selective attention processes modulate evaluative conditioning (EC). Based on the fact that the typical stimuli in an EC paradigm involve an affect-laden unconditioned stimulus (US) and a neutral conditioned stimulus (CS), we started from the assumption that learning might depend in part upon selective attention to the US. Attention to the US was manipulated by including a variant of the Eriksen flanker task in the EC paradigm. Similarly to the original Flanker paradigm, we implemented a target-distracter logic by introducing the CS as the task-relevant stimulus (i.e. the target) to which the participants had to respond and the US as a task-irrelevant distracter. Experiment 1 showed that CS-US congruence modulated EC if the CS had to be selected against the US. Specifically, EC was more pronounced for congruent CS-US pairs as compared to incongruent CS-US pairs. Experiment 2 disentangled CS-US congruence and CS-US compatibility and suggested that it is indeed CS-US stimulus congruence rather than CS-US response compatibility that modulates EC.
Rajendra D Badgaiyan
Full Text Available It is unclear whether attention deficit hyperactive disorder (ADHD is a hypodopaminergic or hyperdopaminergic condition. Different sets of data suggest either hyperactive or hypoactive dopamine system. Since indirect methods used in earlier studies have arrived at contradictory conclusions, we directly measured the tonic and phasic release of dopamine in ADHD volunteers. The tonic release in ADHD and healthy control volunteers was measured and compared using dynamic molecular imaging technique. The phasic release during performance of Eriksen's flanker task was measured in the two groups using single scan dynamic molecular imaging technique. In these experiments volunteers were positioned in a positron emission tomography (PET camera and administered a dopamine receptor ligand (11C-raclopride intravenously. After the injection PET data were acquired dynamically while volunteers either stayed still (tonic release experiments or performed the flanker task (phasic release experiments. PET data were analyzed to measure dynamic changes in ligand binding potential (BP and other receptor kinetic parameters. The analysis revealed that at rest the ligand BP was significantly higher in the right caudate of ADHD volunteers suggesting reduced tonic release. During task performance significantly lower ligand BP was observed in the same area, indicating increased phasic release. In ADHD tonic release of dopamine is attenuated and the phasic release is enhanced in the right caudate. By characterizing the nature of dysregulated dopamine neurotransmission in ADHD, the results explain earlier findings of reduced or increased dopaminergic activity.
Fan, Lingxia; Yu, Huan; Zhang, Xuemin; Feng, Qing; Sun, Mengdan; Xu, Mengsi
The present study explored the attentional processing mechanisms of gaze and arrow cues in two different types of conflict tasks. In Experiment 1, participants performed a flanker task in which gaze and arrow cues were presented as central targets or bilateral distractors. The congruency between the direction of the target and the distractors was manipulated. Results showed that arrow distractors greatly interfered with the attentional processing of gaze, while the processing of arrow direction was immune to conflict from gaze distractors. Using a spatial compatibility task, Experiment 2 explored the conflict effects exerted on gaze and arrow processing by their relative spatial locations. When the direction of the arrow was in conflict with its spatial layout on screen, response times were slowed; however, the encoding of gaze was unaffected by spatial location. In general, processing to an arrow cue is less influenced by bilateral gaze cues but is affected by irrelevant spatial information, while processing to a gaze cue is greatly disturbed by bilateral arrows but is unaffected by irrelevant spatial information. Different effects on gaze and arrow cues by different types of conflicts may reflect two relatively distinct specific modes of the attentional process.
de Fockert, Jan W.; Caparos, Serge; Linnell, Karina J.; Davidoff, Jules
Background In visual processing, there are marked cultural differences in the tendency to adopt either a global or local processing style. A remote culture (the Himba) has recently been reported to have a greater local bias in visual processing than Westerners. Here we give the first evidence that a greater, and remarkable, attentional selectivity provides the basis for this local bias. Methodology/Principal Findings In Experiment 1, Eriksen-type flanker interference was measured in the Himba and in Western controls. In both groups, responses to the direction of a task-relevant target arrow were affected by the compatibility of task-irrelevant distractor arrows. However, the Himba showed a marked reduction in overall flanker interference compared to Westerners. The smaller interference effect in the Himba occurred despite their overall slower performance than Westerners, and was evident even at a low level of perceptual load of the displays. In Experiment 2, the attentional selectivity of the Himba was further demonstrated by showing that their attention was not even captured by a moving singleton distractor. Conclusions/Significance We argue that the reduced distractibility in the Himba is clearly consistent with their tendency to prioritize the analysis of local details in visual processing. PMID:22046275
Huang, Tao; Tarp, Jakob; Domazet, Sidsel Louise; Thorsen, Anne Kær; Froberg, Karsten; Andersen, Lars Bo; Bugge, Anna
To examine the associations of adiposity and aerobic fitness with executive function and math performance in Danish adolescents. Cross-sectional analyses were conducted with data on 525 adolescents attending sixth and seventh grades from 14 schools in the 5 main regions of Denmark. A modified Eriksen flanker task was used to assess inhibitory control, a key aspect of executive function. Academic performance was assessed by a customized math test. Aerobic fitness was assessed by an intermittent shuttle-run test (Andersen test). Body mass index (BMI) was negatively associated with accuracy on incongruent trials during the flanker task (P = .005). A higher BMI was associated with a larger accuracy interference score (P = .01). Similarly, waist circumference (WC) was negatively associated with accuracy on incongruent trials (P = .008). A higher WC was associated with a larger reaction time (RT) interference score (P = .02) and accuracy interference score (P = .009). Higher aerobic fitness was associated with a faster RT on congruent trials (P = .009) and incongruent trials (P = .003). Higher aerobic fitness was associated with a smaller RT interference score (P = .04). Aerobic fitness was positively associated with math score (P math score (P > .05). These results suggest that aerobic fitness is positively associated with both inhibitory control and math performance in adolescents. Adiposity is negatively associated with inhibitory control in adolescents. Adiposity is not associated with math performance. Copyright © 2015 Elsevier Inc. All rights reserved.
Tapia, Evelina; Breitmeyer, Bruno G.; Jacob, Jane; Broyles, Elizabeth C.
Flanker congruency effects were measured in a masked flanker task to assess the properties of spatial attention during conscious and nonconscious processing of form, color, and conjunctions of these features. We found that (1) consciously and nonconsciously processed colored shape distractors (i.e., flankers) produce flanker congruency effects;…
Cognitive task analysis is defined as the extension of traditional task analysis techniques to yield information about the knowledge, thought processes and goal structures that underlie observable task performance. Cognitive task analyses are conducted for a wide variety of purposes, including the
Wager, Erica; Peterson, Mary A; Folstein, Jonathan R; Scalf, Paige E
Successful attentional function requires inhibition of distracting information (e.g., Deutsch & Deutsch, 1963). Similarly, perceptual segregation of the visual world into figure and ground entails ground suppression (e.g., Likova & Tyler, 2008; Peterson & Skow, 2008). Here, we ask whether the suppressive processes of attention and perception-distractor inhibition and ground suppression-interact to more effectively insulate task performance from interfering information. We used a variant of the Eriksen flanker paradigm to assess the efficacy of distractor inhibition. Participants indicated the right/left orientation of a central arrow, which could be flanked by congruent, neutral, or incongruent stimuli. We manipulated the degree to which the ground region of a display was suppressed and measured the influence of this manipulation on the efficacy with which participants could inhibit responses from incongruent flankers. Greater ground suppression reduced the influence on target identification of interfering, incongruent information, but not that of facilitative, congruent information. These data are the first to show that distractor inhibition interacts with ground suppression to improve attentional function.
Braarud, Per Oeivind; Brendryen, Haavar
The current approach to mental workload assessment in process control was evaluated in 3 previous HAMMLAB studies, by analysing the relationship between workload related measures and performance. The results showed that subjective task complexity rating was related to team's control room performance, that mental effort (NASA-TLX) was weakly related to performance, and that overall activity level was unrelated to performance. The results support the argument that general cognitive measures, i.e., mental workload, are weakly related to performance in the process control domain. This implies that other workload concepts than general mental workload are needed for valid assessment of human reliability and for valid assessment of control room configurations. An assessment of task load in process control suggested that how effort is used to handle task demand is more important then the level of effort invested to solve the task. The report suggests two main workload related concepts with a potential as performance predictors in process control: task requirements, and the work style describing how effort is invested to solve the task. The task requirements are seen as composed of individual task demand and team demand. In a similar way work style are seen as composed of individual task management and teamwork style. A framework for the development of the concepts is suggested based on a literature review and experiences from HAMMLAB research. It is suggested that operational definitions of workload concepts should be based on observable control room behaviour, to assure a potential for developing performance-shaping factors. Finally an explorative analysis of teamwork measures and performance in one study indicated that teamwork concepts are related to performance. This lends support to the suggested development of team demand and teamwork style as elements of a framework for the analysis of workload in process control. (Author)
Sørensen, Torben; Hansen, Poul Erik
Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...
An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching from a manager, the junior employee only has information about his past performance. Based on his past performance, a talented junior who has performed a difficult task sometimes decides to leave the...
This slide presentation reviews the Functional Task Test (FTT), an interdisciplinary testing regimen that has been developed to evaluate astronaut postflight functional performance and related physiological changes. The objectives of the project are: (1) to develop a set of functional tasks that represent critical mission tasks for the Constellation Program, (2) determine the ability to perform these tasks after space flight, (3) Identify the key physiological factors that contribute to functional decrements and (4) Use this information to develop targeted countermeasures.
An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching
Yow, W. Quin; Li, Xiaoqian
Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition) on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-years-old English–Mandarin bilinguals performed four computerized executive function (EF) tasks (Stroop, Eriksen flanker, number–letter switching, and n-back task) that measure the EF components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages) on the Stroop and number–letter task (mixing cost only), indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related EFs such as inhibiting prepotent responses and global set-shifting. PMID:25767451
Yow, W Quin; Li, Xiaoqian
Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition) on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-years-old English-Mandarin bilinguals performed four computerized executive function (EF) tasks (Stroop, Eriksen flanker, number-letter switching, and n-back task) that measure the EF components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages) on the Stroop and number-letter task (mixing cost only), indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related EFs such as inhibiting prepotent responses and global set-shifting.
W. Quin eYow
Full Text Available Recent studies revealed inconsistent evidences of a bilingual advantage in executive processing. One potential source of explanation is the multifaceted experience of the bilinguals in these studies. This study seeks to test whether bilinguals who engage in language selection more frequently would perform better in executive control tasks than those bilinguals who engage in language selection less frequently. We examined the influence of the degree of bilingualism (i.e., language proficiency, frequency of use of two languages, and age of second language acquisition on executive functioning in bilingual young adults using a comprehensive battery of executive control tasks. Seventy-two 18- to 25-year-old English-Mandarin bilinguals performed four computerized executive function tasks (Stroop, Eriksen flanker, number-letter switching and n-back task that measure the executive function components: inhibition, mental-set shifting, and information updating and monitoring. Results from multiple regression analyses, structural equation modeling, and bootstrapping supported the positive association between age of second language acquisition and the interference cost in the Stroop task. Most importantly, we found a significant effect of balanced bilingualism (balanced usage of and balanced proficiency in two languages on the Stroop and number-letter task (mixing cost only, indicating that a more balanced use and a more balanced level of proficiency in two languages resulted in better executive control skills in the adult bilinguals. We did not find any significant effect of bilingualism on flanker or n-back task. These findings provided important insights to the underlying mechanisms of the bilingual cognitive advantage hypothesis, demonstrating that regular experience with extensive practice in controlling attention to their two language systems results in better performance in related executive functions such as inhibiting prepotent responses and global
Smid, Henderikus G O M; Bruggeman, Richard; Martens, Sander
Schizophrenia is thought to be associated with impairments of executive functions, among which conflict control functions play an important role. The available evidence, however, suggests that conflict control is intact in schizophrenia, despite being based on methods that have successfully unveiled conflict control problems in other disorders. Differences between schizophrenia patients and healthy controls in stimulus perception, selective attention, alertness, processing speed and reaction time variability may have been previously overlooked. By controlling for these potential confounders, the present experiments were aimed to be more rigorous tests of the hypothesis that psychosis and schizophrenia are associated with impairments of conflict control. To that end, 27 healthy controls and 53 recent-onset psychosis patients with (n = 27) and without schizophrenia (n = 26) with comparable age, intelligence, and education level, performed three iconic conflict control tasks: the Simon task, the Eriksen flanker task, and the Stroop task, all equipped with neutral trials, and analyzed for various potential confounders. They further performed a battery of standard neuropsychological tests. Schizophrenia patients showed no increased conflict effects in any of the 3 tasks for any alternative measures used. Nonschizophrenia patients only showed abnormally increased response competition in the Simon task. All patients nevertheless demonstrated impaired control of attention and verbal memory. These findings indicate that the type of conflict control engaged by conflict tasks is intact in recent-onset schizophrenia, suggesting that a major component of executive function is spared in schizophrenia. We discuss these findings in terms of proactive and reactive control. (c) 2016 APA, all rights reserved.
The Transport Task Force (TTF) was initiated as a broad-based US magnetic fusion community activity during the fall of 1988 to focus attention on and encourage development of an increased understanding of anomalous transport in tokamaks. The overall TTF goal is to make progress on Characterizing, Understanding and Identifying how to Reduce plasma transport in tokamaks -- to CUIR transport
Ruchsow, M; Groen, G; Kiefer, M; Buchheim, A; Walter, H; Martius, P; Reiter, M; Hermle, L; Spitzer, M; Ebert, D; Falkenstein, M
Borderline personality disorder (BPD) has been related to a dysfunction of anterior cingulate cortex, amygdala, and prefrontal cortex and has been associated clinically with impulsivity, affective instability, and significant interpersonal distress. We examined 17 patients with BPD and 17 age-, sex-, and education matched control participants with no history of Axis I or II psychopathology using event-related potentials (ERPs). Participants performed a hybrid flanker-Go/Nogo task while multichannel EEG was recorded. Our study focused on two ERP components: the Nogo-N2 and the Nogo-P3, which have been discussed in the context of response inhibition and response conflict. ERPs were computed on correct Go trials (button press) and correct Nogo trials (no button press), separately. Groups did not differ with regard to the Nogo-N2. However, BPD patients showed reduced Nogo-P3 amplitudes. For the entire group (n = 34) we found a negative correlation with the Barratt Impulsiveness Scale (BIS-10) and Becks's depression inventory (BDI). The present study is the first to examine Nogo-N2 and Nogo-P3 in BPD and provides further evidence for impaired response inhibition in BPD patients.
"Photographing money" is a self-service model under the mobile Internet. The task pricing is reasonable, related to the success of the commodity inspection. First of all, we analyzed the position of the mission and the membership, and introduced the factor of membership density, considering the influence of the number of members around the mission on the pricing. Multivariate regression of task location and membership density using MATLAB to establish the mathematical model of task pricing. At the same time, we can see from the life experience that membership reputation and the intensity of the task will also affect the pricing, and the data of the task success point is more reliable. Therefore, the successful point of the task is selected, and its reputation, task density, membership density and Multiple regression of task positions, according to which a nhew task pricing program. Finally, an objective evaluation is given of the advantages and disadvantages of the established model and solution method, and the improved method is pointed out.
Minichilli, Alessandro; Zattoni, Alessandro; Nielsen, Sabina
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....
Gäde, Maria; Hall, Mark; Huurdeman, Hugo
, 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...
Loriaux, E.F.; Jehee, J.N.T.
Report on CRP-OSS Task 4.1.1. ''Survey of existing documentation relevant to this programme's goals'' and report on CRP-OSS Task 4.1.2. ''Survey of existing Operator Support Systems and the experience with them'' are presented. 2 tabs
Roberts, Katherine L; Hall, Deborah A
Cognitive control over conflicting information has been studied extensively using tasks such as the color-word Stroop, flanker, and spatial conflict task. Neuroimaging studies typically identify a fronto-parietal network engaged in conflict processing, but numerous additional regions are also reported. Ascribing putative functional roles to these regions is problematic because some may have less to do with conflict processing per se, but could be engaged in specific processes related to the chosen stimulus modality, stimulus feature, or type of conflict task. In addition, some studies contrast activation on incongruent and congruent trials, even though a neutral baseline is needed to separate the effect of inhibition from that of facilitation. In the first part of this article, we report a systematic review of 34 neuroimaging publications, which reveals that conflict-related activity is reliably reported in the anterior cingulate cortex and bilaterally in the lateral prefrontal cortex, the anterior insula, and the parietal lobe. In the second part, we further explore these candidate "conflict" regions through a novel functional magnetic resonance imaging experiment, in which the same group of subjects perform related visual and auditory Stroop tasks. By carefully controlling for the same task (Stroop), the same to-be-ignored stimulus dimension (word meaning), and by separating out inhibitory processes from those of facilitation, we attempt to minimize the potential differences between the two tasks. The results provide converging evidence that the regions identified by the systematic review are reliably engaged in conflict processing. Despite carefully matching the Stroop tasks, some regions of differential activity remained, particularly in the parietal cortex. We discuss some of the task-specific processes which might account for this finding.
Poljac, E.; Bekkering, H.
The present study investigated how the activation of previous tasks interferes with the execution of future tasks as a result of temporal manipulations. Color and shape matching tasks were organized in runs of two trials each. The tasks were specified by a cue presented before a task run, cueing
Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld
The objectives of this work is to develop a task light for office lighting that fulfils the minimum requirements of the European standard EN12464 - 1 : Light and lighting – Lighting of work places, Part 1: Indoor workplaces and the Danish standard DS 700 : Lys og belysning I arbejdsrum , or more...... specifically the requirements that apply to the work area and the immediate surrounding area. By providing a task light that fulfils the requirements for task lighting and the immediate surrounding area, the general lighting only needs to provide the illuminance levels required for background lighting...... and thereby a reduction in installed power for general lighting of about 40 % compared to the way illuminance levels are designed in an office environment in Denmark today. This lighting strategy is useful when the placement of the task area is not defined in the space before the lighting is design ed...
Rajendra D Badgaiyan
Full Text Available Inhibition of unwanted response is an important function of the executive system. Since the inhibitory system is impaired in patients with dysregulated dopamine system, we examined dopamine neurotransmission in the human brain during processing of a task of executive inhibition. The experiment used a recently developed dynamic molecular imaging technique to detect and map dopamine released during performance of a modified Eriksen's flanker task. In this study, young healthy volunteers received an intravenous injection of a dopamine receptor ligand ((11C-raclopride after they were positioned in the PET camera. After the injection, volunteers performed the flanker task under Congruent and Incongruent conditions in a single scan session. They were required to inhibit competing options to select an appropriate response in the Incongruent but not in the Congruent condition. The PET data were dynamically acquired during the experiment and analyzed using two variants of the simplified reference region model. The analysis included estimation of a number of receptor kinetic parameters before and after initiation of the Incongruent condition. We found increase in the rate of ligand displacement (from receptor sites and decrease in the ligand binding potential in the Incongruent condition, suggesting dopamine release during task performance. These changes were observed in small areas of the putamen and caudate bilaterally but were most significant on the dorsal aspect of the body of left caudate. The results provide evidence of dopaminergic processing of executive inhibition and demonstrate that neurochemical changes associated with cognitive processing can be detected and mapped in a single scan session using dynamic molecular imaging.
A poster presentation for the SHC BOSC review will summarize the research efforts under Sustainable and Healthy Communities Research Program (SHC) in the Contaminated Sediment Task within the Contaminated Sites Project. For the Task, Problem Summary & Decision Context; Task O...
Lien, Mei-Ching; Ruthruff, Eric
This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms.…
Hamel, W.R.; Osborn, J.
Many nuclear projects such as environmental restoration and waste management challenges involve radiation or other hazards that will necessitate the use of remote operations that protect human workers from dangerous exposures. Remote work is far more costly to execute than what workers could accomplish directly with conventional tools and practices because task operations are slow and tedious due to difficulties of remote manipulation and viewing. Decades of experience within the nuclear remote operations community show that remote tasks may take hundreds of times longer than hands-on work; even with state-of-the-art force- reflecting manipulators and television viewing, remote task performance execution is five to ten times slower than equivalent direct contact work. Thus the requirement to work remotely is a major cost driver in many projects. Modest improvements in the work efficiency of remote systems can have high payoffs by reducing the completion time of projects. Additional benefits will accrue from improved work quality and enhanced safety
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....
has remained much the same within the last 10 years. However, how the core task has been organized has changed considerable under the influence of various “organizing devices”. The paper focusses on how organizing devices such as risk assessment, output-focus, effect orientation, and treatment...... projects influence the organization of core tasks within the tax administration. The paper shows that the organizational transformations based on the use of these devices have had consequences both for the overall collection of revenue and for the employees’ feeling of “making a difference”. All in all...
Temares, M. Lewis; Lutheran, Joseph A.
Operations tasking for data center management is discussed. The original and revised organizational structures of the data center at the University of Miami are also described. The organizational strategy addresses the functions that should be performed by the data center, anticipates the specialized skills required, and addresses personnel…
Laenger, C. J., Sr.
The engineering tasks performed in response to needs articulated by clinicians are described. Initial contacts were made with these clinician-technology requestors by the Southwest Research Institute NASA Biomedical Applications Team. The basic purpose of the program was to effectively transfer aerospace technology into functional hardware to solve real biomedical problems.
India's Telecom Story is now well known · Indian Operators become an enviable force · At the same time · India Amongst the Leaders · Unfinished Tasks as Operators · LightGSM ON: Innovation for Rural Area from Midas · Broadband Access Options for India · Broadband driven by DSL: still too slow · Is Wireless the answer?
This paper describes a multi-task monitor program for microprocessors. Although written for the Intel 8085, it incorporates features that would be beneficial for implementation in other microprocessors used in controlling and monitoring experiments and accelerators. The monitor places permanent programs (tasks) arbitrarily located throughout ROM in a priority ordered queue. The programmer is provided with the flexibility to add new tasks or modified versions of existing tasks, without having to comply with previously defined task boundaries or having to reprogram all of ROM. Scheduling of tasks is triggered by timers, outside stimuli (interrupts), or inter-task communications. Context switching time is of the order of tenths of a milllisecond
Zinchenko, A; Al-Amin, M M; Alam, M M; Mahmud, W; Kabir, N; Reza, H M; Burne, T H J
Attentional bias to affective information and reduced cognitive control may maintain the symptoms of post-traumatic stress disorder (PTSD) and impair cognitive functioning. However, the role of content specificity of affective stimuli (e.g., trauma-related, emotional trauma-unrelated) in the observed attentional bias and cognitive control is less clear, as this has not been tested simultaneously before. Therefore, we examined the content specificity of attentional bias to threat in PTSD. PTSD participants (survivors of a multistory factory collapse, n=30) and matched controls (n=30) performed an Eriksen Flanker task. They identified the direction of a centrally presented target arrow, which was flanked by several task-irrelevant distractor arrows pointed to the same (congruent) or opposite direction (incongruent). Additionally, participants were presented with a picture of a face (neutral, emotional) or building (neutral=normal, emotional=collapsed multistory factory) as a task-irrelevant background image. We found that PTSD participants produced overall larger conflict effects and longer reaction times (RT) to emotional than to neutral stimuli relative to their healthy counterparts. Moreover, PTSD, but not healthy participants showed a stimulus specific dissociation in processing emotional stimuli. Emotional faces elicited longer RTs compared to neutral faces, while emotional buildings elicited faster responses, compared to neutral buildings. PTSD patients show a content-sensitive attentional bias to emotional information and impaired cognitive control. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available Sedentarism is considered an independent cardiovascular risk factor. Thus, the present study investigated the effects of employing standing desks in classrooms on cognitive function. The intervention class (IG; n = 19 was supplied with standing desks and balance pads for 11 weeks. The control class (CG; n = 19 received lessons as usual. Standing time was assessed objectively (accelerometers and subjectively (self-report sheets, external classroom observers. The impact of standing on the digit span task and Eriksen flanker task was analysed. The standing time of the IG was higher during the school day in comparison to the CG (lesson: p = 0.004; break: p = 0.003. The intra-class correlation coefficient between self-reports and external observation was high (ICC = 0.94. The IG improved slightly on the Digit Span Task compared to CG. Employing standing desks for at least 1 h per school day serves as a feasible and effective opportunity to improve cognitive function.
Eichele, Heike; Eichele, Tom; Bjelland, Ingvar; Høvik, Marie F; Sørensen, Lin; van Wageningen, Heidi; Worren, Marius Kalsås; Hugdahl, Kenneth; Plessen, Kerstin J
Tourette syndrome (TS) is a childhood-onset neurodevelopmental disorder and its impact on cognitive development needs further study. Evidence from neuropsychological, neuroimaging and electrophysiological studies suggests that the decline in tic severity and the ability to suppress tics relate to the development of self-regulatory functions in late childhood and adolescence. Hence, tasks measuring performance monitoring might provide insight into the regulation of tics in children with TS. Twenty-five children with TS, including 14 with comorbid Attention-deficit/ hyperactivity disorder (ADHD), 39 children with ADHD and 35 typically developing children aged 8-12 years were tested with a modified Eriksen-Flanker task during a 34-channel electroencephalography (EEG) recording. Task performance, as well as stimulus-locked and response-locked event-related potentials (ERP) were analyzed and compared across groups. Participants did not differ in their behavioral performance. Children with TS showed higher amplitudes of an early P3 component of the stimulus-locked ERPs in ensemble averages and in separate trial outcomes, suggesting heightened orienting and/or attention during stimulus evaluation. In response-locked averages, children with TS had a slightly higher positive complex before the motor response, likely also reflecting a late P3. Groups did not differ in post-response components, particularly in the error-related negativity (ERN) and error-related positivity (Pe). These findings suggest that children with TS may employ additional attentional resources as a compensatory mechanism to maintain equal behavioral performance.
Dean, Angela J; Bor, William; Adam, Kareen; Bowling, Francis G; Bellgrove, Mark A
Epidemiological research links aggression to low serum concentrations of omega-3 fatty acids, such as those found in fish oil. However, no studies have specifically examined whether fish oil supplementation can reduce the frequency and severity of impulsive aggression in children with disruptive behavior disorders. Children presenting with impulsive aggression and meeting research criteria for diagnosis of disruptive behavior disorders were randomized to receive either: 1) Fish oil capsules (4 g daily) for 6 weeks followed by placebo (identical-looking capsules) for 6 weeks; or 2) placebo for 6 weeks, followed by fish oil for 6 weeks, in a double-blind, crossover design. Primary outcomes were the Children's Aggression Scale and the Modified Overt Aggression Scale. Secondary outcomes included emotional and behavioral functioning (Strengths and Difficulties Questionnaire [SDQ]), hyperactivity symptoms (Attention-Deficit/Hyperactivity Disorder [ADHD] Rating Scale), family functioning (Family Assessment Device), and cognitive functioning (Stop Signal Task, Trail-Making Task, and Eriksen Flanker Task). Serum concentrations of omega-3 and omega-6 fatty acids were measured at baseline, and at 6 and 12 weeks. Twenty-one children participated (81% male; mean age 10.3±2.2 years; range 7-14). Fish oil treatment increased serum concentrations of eicosapentanoic acid (F=14.76, pConduct Subscale, F=4.34, p=0.06). Fish oil treatment was associated with an improvement in one rating of hyperactivity (SDQ Hyperactivity Subscale, F=2.22, pchildren with disruptive behavior disorders.
The International Task Force on Prevention of Nuclear Terrorism was formed in 1985 under the auspices of the Nuclear Control Institute. This report is a consensus report of the 26 task force members - all members not necessarily agreeing on every point and all wordings, but in each case a substantial majority did agree. First, the report defines the threat, then establishes the priorities. Short-term recommendations are presented on: (1) protecting nuclear weapons; (2) protecting nuclear materials; (3) protecting nuclear facilities; (4) intelligence programs; (5) civil liberties concerns; (6) controlling nuclear transfers; (7) US - Soviet cooperation; (8) arms control initiatives; (9) convention of physical protection of nuclear material; (10) role of emergency management programs; and (11) role of the media. Brief long-term recommendations are included on (1) international measures, and (2) emerging nuclear technologies. An Appendix, Production of Nuclear Materials Usable in Weapons is presented for further consideration (without recommendations)
Dohn, Anders Høeg
. The rostering process is non-trivial and especially when service is required around the clock, rostering may involve considerable effort from a designated planner. Therefore, in order to minimize costs and overstaffing, to maximize the utilization of available staff, and to ensure a high level of satisfaction...... as possible to the available staff, while respecting various requirements and rules and while including possible transportation time between tasks. This thesis presents a number of industrial applications in rostering and task scheduling. The applications exist within various contexts in health care....... Mathematical and logic-based models are presented for the problems considered. Novel components are added to existing models and the modeling decisions are justified. In one case, the model is solved by a simple, but efficient greedy construction heuristic. In the remaining cases, column generation is applied...
This paper focuses on the unique aspects of the Fernald Citizens Task Force process that have contributed to a largely successful public participation effort at Fernald. The Fernald Citizens Task Force passed quickly by many procedural issues. Instead, the Task Force concentrated on (a) educating itself about the site, its problems, and possible solutions, and (b) choosing a directed way to approach its mandate: To make recommendations on several open-quotes big pictureclose quotes issues, including future use of the site, cleanup levels, waste disposition, and cleanup priorities. This paper presents the approach used at Fernald for establishing and running a focused site-specific advisory board, the key issues that have been faced, and how these issues were resolved. The success of Fernald in establishing a strong and functioning site-specific advisory board serves as a useful model for other DOE facilities, although the Fernald model is just one of many approaches that can be taken. However, the approach presented here has worked extremely well for Fernald
One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...
Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.
The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.
This document describes the computing tasks of the LHCb computing system. It also describes the logistics of the dataflow between the tasks and the detailed requirements for each task, in particular the data sizes and CPU power requirements. All data sizes are calculated assuming that the LHCb experiment will take data about 107 s per year at a frequency of 200 Hz, which gives 2 \\Theta 109 real events per year. The raw event size should not exceed 100 kB (200 TB per year). We will have to generate about 109 MonteCarlo events per year. The current MonteCarlo simulation program based on the GEANT3.21 package requires about 12 s to produce an average event (all CPU times are normalised to a 1000 MIPS processor). The size of an average MonteCarlo event will be about 200 kB (100 TB per year) of simulated data (without the hits). We will start to use the GEANT4 package in 1998. Rejection factors of 8 and 25 are required in the Level-2 and Level-3 triggers respectively, to reduce the frequency of events to 200 Hz. T...
This paper is concerned with Task Analysis as the basis for ergonomic design to reduce human error rates, rather than for predicting human error rates. Task Analysis techniques usually provide a set of categories for describing sub tasks, and a framework describing the relations between sub-tasks. Both the task type categories and their organisation have implications for optimum interface and training design. In this paper, the framework needed for considering the most complex tasks faced by operators in process industries is discussed such as fault management in unexpected situations, and what is likely to minimise human error in these circumstances. (author)
Orrell, Dean H., II
Previous research had shown the effect of noise on a single communication task. This research has been criticized as not being representative of a real world situation since subjects allocated all of their attention to only one task. In the present study, the effect of adding a loading task to a standard noise-communication paradigm was investigated. Subjects performed both a communication task (Modified Rhyme Test; House et al. 1965) and a short term memory task (Sternberg, 1969) in simulated levels of aircraft noise (95, 105 and 115 dB overall sound pressure level (OASPL)). Task loading was varied with Sternberg's task by requiring subjects to memorize one, four, or six alphanumeric characters. Simulated aircraft noise was varied between levels of 95, 105 and 115 dB OASPL using a pink noise source. Results show that the addition of Sternberg's task and little effect on the intelligibility of the communication task while response time for the communication task increased.
Full Text Available The human brain is adapted to integrate the information from multiple sensory modalities into coherent, robust representations of the objects and events in the external world. A large body of empirical research has demonstrated the ubiquitous nature of the interactions that take place between vision and touch, with the former typically dominating over the latter. Many studies have investigated the influence of visual stimuli on the processing of tactile stimuli (and vice versa. Other studies, meanwhile, have investigated the effect of directing a participant’s gaze either toward or else away from the body-part receiving the target tactile stimulation. Other studies, by contrast, have compared performance in those conditions in which the participant’s eyes have been open versus closed. We start by reviewing the research that has been published to date demonstrating the influence of vision on the processing of tactile targets, that is, on those stimuli that have to be attended or responded to. We outline that many – but not all – of the visuotactile interactions that have been observed to date may be attributable to the direction of spatial attention. We then move on to focus on the crossmodal influence of vision, as well as of the direction of gaze, on the processing of tactile distractors. We highlight the results of those studies demonstrating the influence of vision, rather than gaze direction (i.e., the direction of overt spatial attention, on tactile distractor processing (e.g., tactile variants of the negative-priming or flanker task. The conclusion is that no matter how vision of a tactile distractor is engaged, the result would appear to be the same, namely that tactile distractors are processed more thoroughly.
Lin Shuzi; Zhang Bingyun; Zhao Weiren
The task-to-task communication is used in the Institute of High Energy Physics. The BES (Beijing Spectrometer) uses the communication mode to take some of the BEPC (Beijing Electron Positron Collider) running parameters needed by BES experiments in a periodic time. The authors describe the principle of transparent task-to-task communication and how to use it in BES on-line data acquisition system
Wang, Feihong; Algina, James; Snyder, Patricia; Cox, Martha
We examined children's task engagement during a challenging puzzle task in the presence of their primary caregivers by using a representative sample of rural children from six high-poverty counties across two states. Weighted longitudinal confirmatory factor analysis and structural equation modeling were used to identify a task engagement factor…
Tanaka, Y; Yamaoka, K
This study investigated the relationship between task difficulty and blink activity, which includes blink rate, blink amplitude, and blink duration. Two kinds of tasks established two levels of difficulty. In Exp. 1, a mental arithmetic task was used to examine the relationship. Analysis showed that blink rate for a difficult task was significantly higher than that for an easier one. In Exp. 2, a letter-search task (hiragana Japanese alphabet) was used while the other conditions were the same as those in Exp. 1; however, the results of this experiment were not influenced by the difficulty of the task. As results indicate that blink rate is related to not only difficulty but also the nature of the task, the nature of the task is probably dependent on a mechanism in information processing. The results for blink amplitude and blink duration showed no systematic change during either experiment.
The accomplishments of the task group studies over the past year are reviewed. The purposes of biological investigations, in the context of subseabed disposal, are: an evaluation of the dose to man; an estimation of effects on the ecosystem; and an estimation of the influence of organisms on and as barriers to radionuclide migration. To accomplish these ends, the task group adopted the following research goals: (1) acquire more data on biological accumulation of specific radionuclides, such as those of Tc, Np, Ra, and Sr; (2) acquire more data on transfer coefficients from sediment to organism; (3) Calculate mass transfer rates, construct simple models using them, and estimate collective dose commitment; (4) Identify specific pathways or transfer routes, determine the rates of transfer, and make dose limit calculations with simple models; (5) Calculate dose rates to and estimate irradiation effects on the biota as a result of waste emplacement, by reference to background irradiation calculations. (6) Examine the effect of the biota on altering sediment/water radionuclide exchange; (7) Consider the biological data required to address different accident scenarios; (8) Continue to provide the basic biological information for all of the above, and ensure that the system analysis model is based on the most realistic and up-to-date concepts of marine biologists; and (9) Ensure by way of free exchange of information that the data used in any model are the best currently available
Smith, Janette L; Mattick, Richard P; Sufani, Christopher
Difficulties in monitoring ongoing behaviour may be linked to real-life problematic drinking behaviours. Prior research suggests female heavy drinkers in particular display greater cognitive control deficits. Here, we examine trial-to-trial behavioural adaptations in a conflict monitoring task, relative to drinking behaviour and sex. Heavy drinkers (n=31, 16 male) and controls (n=35, 18 male) completed an Eriksen flanker task while brain electrical activity was recorded. For reaction time, error rates, and N2 and P3 amplitude of the event-related potential, trial-to-trial conflict adaptation was evidenced by a differential response to the current (congruent vs. incongruent) trials dependent on the identity of the previous trial. For the proportion of errors, heavy drinkers showed increased conflict adaptation compared to controls. Conflict adaptation for N2 (indexing monitoring) was larger for female heavy drinkers than controls, and the opposite was observed for males. There were no interactions involving group or sex for the P3 (indexing inhibition). The results suggest a compensatory response, such that heavy drinkers are required to increase performance monitoring in order to achieve the same behavioural outcome as controls. We also confirm the importance of sex as a factor in the relationship between behavioural control and heavy alcohol use. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Full Text Available Abstract Background It is currently unclear whether the function of brain regions associated with executive cognitive processing are independently associated with reduced physiological falls risk. If these are related, it would suggest that the development of interventions targeted at improving executive neurocognitive function would be an effective new approach for reducing physiological falls risk in seniors. Methods We performed a secondary analysis of 73 community-dwelling senior women aged 65 to 75 years old who participated in a 12-month randomized controlled trial of resistance training. Functional MRI data were acquired while participants performed a modified Eriksen Flanker Task - a task of selective attention and conflict resolution. Brain volumes were obtained using MRI. Falls risk was assessed using the Physiological Profile Assessment (PPA. Results After accounting for baseline age, experimental group, baseline PPA score, and total baseline white matter brain volume, baseline activation in the left frontal orbital cortex extending towards the insula was negatively associated with reduced physiological falls risk over the 12-month period. In contrast, baseline activation in the paracingulate gyrus extending towards the anterior cingulate gyrus was positively associated with reduced physiological falls risk. Conclusions Baseline activation levels of brain regions underlying response inhibition and selective attention were independently associated with reduced physiological falls risk. This suggests that falls prevention strategies may be facilitated by incorporating intervention components - such as aerobic exercise - that are specifically designed to induce neurocognitive plasticity. Trial Registration ClinicalTrials.gov Identifier: NCT00426881
Dean, B; Rombos, P [Wardrop (W.L.) and Associates Ltd., Winnipeg, MB (Canada)
Two methodologies for maintenance task selection, Reliability Centre Maintenance (RCM) and Degradation Mode Analysis (DMA), are compared with regard to application in the nuclear industry and potential for application at CANDU nuclear power plants. RCM is the favoured one of the two methodologies. It is more thorough than DMA, is well supported within the US nuclear industry, and - with experience in application - is gaining cost effectiveness. There is interest in the use of RCM in other nations, including France and Japan, and it is already being implemented at Bruce A NGS and Bruce B NGS in Canada. DMA lags behind RCM in development and currently there is little experience to support claims of major benefits at reduced cost. Significant advantages over RCM need to be demonstrated if DMA is to gain acceptance in the nuclear industry. (author). 41 refs., 7 tabs., 8 figs.
Dean, B.; Rombos, P.
Two methodologies for maintenance task selection, Reliability Centre Maintenance (RCM) and Degradation Mode Analysis (DMA), are compared with regard to application in the nuclear industry and potential for application at CANDU nuclear power plants. RCM is the favoured one of the two methodologies. It is more thorough than DMA, is well supported within the US nuclear industry, and - with experience in application - is gaining cost effectiveness. There is interest in the use of RCM in other nations, including France and Japan, and it is already being implemented at Bruce A NGS and Bruce B NGS in Canada. DMA lags behind RCM in development and currently there is little experience to support claims of major benefits at reduced cost. Significant advantages over RCM need to be demonstrated if DMA is to gain acceptance in the nuclear industry. (author). 41 refs., 7 tabs., 8 figs
We present a method for Cognitive Task Analysis that guides the early stages of software development, aiming at an optimal cognitive load for operators of process control systems. The method is based on a practical theory of cognitive task load and support. In addition to the classical measure
Milgram, N; Marshevsky, S; Sadeh, C
The relationships among five aspects of academic procrastination--behavioral delay, personal upset about the delay, task aversiveness, task capability, and the desire to reduce behavioral delay--were investigated in 10th-grade Israeli students (N = 195). Upset about delay was weakly related to delay itself, and--unlike delay--was strongly related to perceived capability to perform academic tasks and to the desire to change delaying behavior. Students delayed more on academic tasks labeled unpleasant than pleasant, were neutral in between, and were correspondingly more upset about the former than the latter. They more frequently acknowledged reasons for academic procrastination that were less threatening to their self-image (e.g., problems in time management) than reasons that were more threatening (e.g., lack of ability). Interest in reducing delay is related more to self-perceived ability to handle tasks than to time spent procrastinating or reasons given for procrastinating.
Larson, Michael J; South, Mikle; Clayson, Peter E; Clawson, Ann
Youth diagnosed with autism spectrum disorders (ASD) often show deficits in cognitive control processes, potentially contributing to characteristic difficulties monitoring and regulating behavior. Modification of performance following conflict can be measured by examining conflict adaptation, the adjustment of cognitive resources based on previous-trial conflict. The electrophysiological correlates of these processes can be measured using the N2, a stimulus-locked component of the event-related potential (ERP). High-density ERPs and behavioral data [i.e. response times (RTs) and error rates] were acquired while 28 youth with ASD and 36 typically developing controls completed a modified Eriksen flanker task. Behaviorally, groups showed similar conflict adaptation effects; youth with ASD showed larger RT slowing on switch trials. For electrophysiology, controls demonstrated larger N2 amplitudes for incongruent (high-conflict) trials following congruent (low-conflict) trials than for incongruent trials following incongruent trials. Importantly, youth with ASD showed no such differences in N2 amplitude based on previous-trial conflict. Lack of electrophysiological conflict adaptation effects in youth with ASD indicates irregular neural processing associated with conflict adaptation. Individuals with ASD show declines in level of conflict evaluation and adaptation. Future research is necessary to accurately characterize and understand the behavioral implications of these cognitive control deficits relative to diagnostic severity, anxiety, and personality. © 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.
Forster, Sarah E; Carter, Cameron S; Cohen, Jonathan D; Cho, Raymond Y
Mechanisms by which the brain monitors and modulates performance are an important focus of recent research. The conflict-monitoring hypothesis posits that the ACC detects conflict between competing response pathways which, in turn, signals for enhanced control. The N2, an ERP component that has been localized to ACC, has been observed after high conflict stimuli. As a candidate index of the conflict signal, the N2 would be expected to be sensitive to the degree of response conflict present, a factor that depends on both the features of external stimuli and the internal control state. In the present study, we sought to explore the relationship between N2 amplitude and these variables through use of a modified Eriksen flankers task in which target-distracter compatibility was parametrically varied. We hypothesized that greater target-distracter incompatibility would result in higher levels of response conflict, as indexed by both behavior and the N2 component. Consistent with this prediction, there were parametric degradations in behavioral performance and increases in N2 amplitudes with increasing incompatibility. Further, increasingly incompatible stimuli led to the predicted parametric increases in control on subsequent incompatible trials as evidenced by enhanced performance and reduced N2 amplitudes. These findings suggest that the N2 component and associated behavioral performance are finely sensitive to the degree of response conflict present and to the control adjustments that result from modulations in conflict.
Liu, Tongran; Xiao, Tong; Shi, Jiannong; Zhao, Daheng; Liu, Jizhong
Conflict control is an important cognitive ability in human behavioral regulation. The Eriksen flanker task was employed to explore the neural correlation between conflict control and intelligence with the aid of event-related potential (ERP) techniques. Two groups of early adolescents with different intellectual levels participated in the current study (an intellectually gifted group of 20 children vs. an intellectually average group of 21 children, with mean scores of 43 vs. 35.7 in Cattell's Culture Fair Test, respectively). Behavioral results indicate that the gifted children had better conflict control performances, with increased accuracy and faster response speeds than the intellectually average children. Electrophysiological results further show that the gifted children had more efficient N2 activations during conflict monitoring processing, faster P3 responses over frontal regions, and stronger P3 activations over central-parietal regions during attentional control processing. The difference waveform analysis showed that the gifted children had the weakest N2d activations when elicited by multiple conflicts. N2d amplitudes can be used to distinguish a stimulus conflict from a response conflict, and P3d amplitudes can be used to separate multiple conflicts from a single conflict. The results support the neural efficiency hypothesis of intelligence and shed light on the close relationship between conflict control ability and human intelligence. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
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.
Dongen, van K.; Maanen, van P.P.
Future platforms are envisioned in which human-machine teams are able to share and trade tasks as demands in situations change. It seems that human-machine coordination has not received the attention it deserves by past and present approaches to task allocation. In this paper a simple way to make
Korst, J.H.M.; Aarts, E.H.L.; Lenstra, J.K.
We consider the problem of nonpreemptively scheduling periodic tasks on a minimum number of identical processors, assuming that some slack is allowed in the time between successive executions of a periodic task. We prove that the problem is NP-hard in the strong sense. Necessary and sufficient
Shitova, Natalia; Roelofs, Ardi; Schriefers, Herbert; Bastiaansen, Marcel; Schoffelen, Jan-Mathijs
Accumulating evidence suggests that spoken word production requires different amounts of top-down control depending on the prevailing circumstances. For example, during Stroop-like tasks, the interference in response time (RT) is typically larger following congruent trials than following incongruent trials. This effect is called the Gratton effect, and has been taken to reflect top-down control adjustments based on the previous trial type. Such control adjustments have been studied extensively in Stroop and Eriksen flanker tasks (mostly using manual responses), but not in the picture-word interference (PWI) task, which is a workhorse of language production research. In one of the few studies of the Gratton effect in PWI, Van Maanen and Van Rijn (2010) examined the effect in picture naming RTs during dual-task performance. Based on PWI effect differences between dual-task conditions, they argued that the functional locus of the PWI effect differs between post-congruent trials (i.e., locus in perceptual and conceptual encoding) and post-incongruent trials (i.e., locus in word planning). However, the dual-task procedure may have contaminated the results. We therefore performed an electroencephalography (EEG) study on the Gratton effect in a regular PWI task. We observed a PWI effect in the RTs, in the N400 component of the event-related brain potentials, and in the midfrontal theta power, regardless of the previous trial type. Moreover, the RTs, N400, and theta power reflected the Gratton effect. These results provide evidence that the PWI effect arises at the word planning stage following both congruent and incongruent trials, while the amount of top-down control changes depending on the previous trial type. Copyright © 2017 Elsevier Ltd. All rights reserved.
Tieges, Zoe; Snel, Jan; Kok, Albert; Wijnen, Jasper G.; Lorist, Monicque M.; Ridderinkhof, K. Richard
We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials
Schlienz, Nicolas J; Hawk, Larry W
Smoking abstinence is theorized to increase smoking reinforcement and decrease nondrug reinforcement. A separate literature demonstrates the detrimental effects of abstinence on cognition. The present study integrates these two areas by examining the separate and combined effects of reinforcement and smoking abstinence on behavior and a neurophysiological index of response monitoring (ie, error-related negativity [ERN]) during a cognitive task. After a screening visit, adult smokers attended two laboratory visits, once while smoking and once while abstinent. Participants completed a flanker task under cigarette-, money-, and no-reinforcement conditions. The initial 15 participants had an easier reaction time (RT) requirement; to ensure sufficient error rates for ERN computation, a harder RT deadline was employed for the remaining 21 participants. Smoking abstinence reduced speeded accuracy and ERN amplitude only among participants tested with the harder RT deadline. Cigarette and money reinforcement each increased speeded accuracy and ERN amplitude compared to no reinforcement. The effect of cigarette reinforcement tended to be greater during abstinence for speeded accuracy but not the ERN. The effect of money reinforcement was unaffected by abstinence. The impact of smoking abstinence on reinforcement may depend on task demands. However, the effects of cigarette and money reinforcement generalize well from operant paradigms to cognitive tasks, fostering integration between the two literatures. Results provided modest evidence of abstinence-induced increases in smoking reinforcement; the absence of abstinence-induced reductions in nondrug reinforcement is consistent with recent work in suggesting that such effects are limited to a subset of sensory reinforcers. This study draws attention to the need for greater integration of reinforcement and cognition to better understand the mechanisms that contribute to smoking relapse. Results emphasize thoughtful
Sarri, Margarita; Greenwood, Richard; Kalra, Lalit; Driver, Jon
Unilateral neglect involves deficits of spatial exploration and awareness that do not always affect a fixed portion of extrapersonal space, but may vary with current stimulation and possibly with task demands. Here, we assessed any ‘top-down’, task-related influences on visual neglect, with novel experimental variants of the cancellation test. Many different versions of the cancellation test are used clinically, and can differ in the extent of neglect revealed, though the exact factors determ...
This document contains information relating to Category B, C, and D generic technical activities. The specific information provided for each task includes the reactor type to which the generic issue applies, the NRC division with lead responsibility and a description of the problem to be addressed by the task. Also provided in this document is a listing of Category A generic technical activities and definitions of Priority Categories A, B, C, and D
Kramer, A. F.; Wickens, C. D.; Donchin, E.
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.
The fundamental properties of quantum information and its applications to computing and cryptography have been greatly illuminated by considering information-theoretic tasks that are provably possible or impossible within non-relativistic quantum mechanics. I describe here a general framework for defining tasks within (special) relativistic quantum theory and illustrate it with examples from relativistic quantum cryptography and relativistic distributed quantum computation. The framework gives a unified description of all tasks previously considered and also defines a large class of new questions about the properties of quantum information in relation to Minkowski causality. It offers a way of exploring interesting new fundamental tasks and applications, and also highlights the scope for a more systematic understanding of the fundamental information-theoretic properties of relativistic quantum theory. (paper)
Guenter, Hannes; van Emmerik, Hetty; Schreurs, Bert; Kuypers, Tom; van Iterson, Ad; Notelaers, Guy
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. PMID:28190944
This report provides a summary of progress for the project open-quotes Evaluation of the Geologic Relations and Seismotectonic Stability of the Yucca Mountain Area, Nevada Nuclear Waste Site Investigation (NNWSI).close quotes A similar report was previously provided for the period of 1 October 1991 to 30 September 1992. The report initially covers the activities of the General Task and is followed by sections that describe the progress of the other ongoing tasks
sociological factors pertaining to social structures and values. For example, telecommuting , job-sharing, and families’ attempts to decrease the amount...achievement strivings (actively working hard to achieve goals), and poly- chronicity ( the preference for working on more than one task at a time) with MT...Joslyn note (2000), this description of ADM makes it sound exceedingly easy. However, nothing could be farther from the truth . The task qualifies as an MT
Small, D.E.; McDonald, M.J.
With a goal of producing faster, safer, and cheaper technologies for nuclear waste cleanup, Sandia is actively developing and extending intelligent systems technologies. Graphical Programming is a key technology for robotic waste cleanup that Sandia is developing for this goal. This paper describes Sancho, Sandia most advanced Graphical Programming supervisory software. Sancho, now operational on several robot systems, incorporates all of Sandia's recent advances in supervisory control. Sancho, developed to rapidly apply Graphical Programming on a diverse set of robot systems, uses a general set of tools to implement task and operational behavior. Sancho can be rapidly reconfigured for new tasks and operations without modifying the supervisory code. Other innovations include task-based interfaces, event-based sequencing, and sophisticated GUI design. These innovations have resulted in robot control programs and approaches that are easier and safer to use than teleoperation, off-line programming, or full automation
Longstreet, Phil; Xiao, Xiao; Sarker, Saonee
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....
Lim, Hayoung A; Watson, Angela L
Music is widely recognized as a motivating stimulus. Investigators have examined the use of music to improve a variety of motivation-related outcomes; however, these studies have focused primarily on passive music listening rather than active participation in musical activities. To examine the influence of participation in musical tasks and unique participant characteristics on energetic arousal. We used a one-way Welch's ANOVA to examine the influence of musical participation (i.e., a non-musical control and four different musical task conditions) upon energetic arousal. In addition, ancillary analyses of participant characteristics including personality, age, gender, sleep, musical training, caffeine, nicotine, and alcohol revealed their possible influence upon pretest and posttest energetic arousal scores. Musical participation yielded a significant relationship with energetic arousal, F(4, 55.62) = 44.38, p = .000, estimated ω2 = 0.60. Games-Howell post hoc pairwise comparisons revealed statistically significant differences between five conditions. Descriptive statistics revealed expected differences between introverts' and extraverts' energetic arousal scores at the pretest, F(1, 115) = 6.80, p = .010, partial η2= .06; however, mean differences failed to reach significance at the posttest following musical task participation. No other measured participant characteristics yielded meaningful results. Passive tasks (i.e., listening to a story or song) were related to decreased energetic arousal, while active musical tasks (i.e., singing, rhythm tapping, and keyboard playing) were related to increased energetic arousal. Musical task participation appeared to have a differential effect for individuals with certain personality traits (i.e., extroverts and introverts).
Berkowitz, Evan; Jansen, Gustav R.; McElvain, Kenneth; Walker-Loud, André
High Performance Computing is often performed on scarce and shared computing resources. To ensure computers are used to their full capacity, administrators often incentivize large workloads that are not possible on smaller systems. Measurements in Lattice QCD frequently do not scale to machine-size workloads. By bundling tasks together we can create large jobs suitable for gigantic partitions. We discuss METAQ and mpi_jm, software developed to dynamically group computational tasks together, that can intelligently backfill to consume idle time without substantial changes to users' current workflows or executables.
Full Text Available High Performance Computing is often performed on scarce and shared computing resources. To ensure computers are used to their full capacity, administrators often incentivize large workloads that are not possible on smaller systems. Measurements in Lattice QCD frequently do not scale to machine-size workloads. By bundling tasks together we can create large jobs suitable for gigantic partitions. We discuss METAQ and mpi_jm, software developed to dynamically group computational tasks together, that can intelligently backfill to consume idle time without substantial changes to users’ current workflows or executables.
Nielsen, Jan; Jacobsen, Claus Haugaard; Mathiesen, Birgit Bork
were confronted with complicated jobs, e.g., group, internal and interdisciplinary supervision, but were not prepared, i.e. trained, prior to these tasks. These findings imply that more training is needed for novice supervisors. Preferably, this training should be introduced before, or at least...... Questionnaire covering a wide range of items on professional development, experience, and practice. In this paper we focus on background data (experience, training and practice), specifically the tasks and training of the respondents as novice supervisors. The results show, that a majority of novice supervisors...
... of the Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and... Community Preventive Services Task Force (Task Force). The in-person Task Force meeting is being replaced by... CDC's ability to complete the necessary scientific and logistical support for the meeting. The Task...
... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...
... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...
... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... Services Task Force (Task Force). The Task Force is independent and nonfederal. Its members are nationally.... The Task Force was convened in 1996 by the Department of Health and Human Services (HHS) to assess the...
T. Tsikrika (Theodora); J. Kludas
htmlabstractThe wikipedia image retrieval task at ImageCLEF provides a testbed for the system-oriented evaluation of visual information retrieval from a collection of Wikipedia images. The aim is to investigate the effectiveness of retrieval approaches that exploit textual and visual evidence in the
Daro, Phil; Burkhardt, Hugh
We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."
Holmes, C. P.; Kinter, J. L.; Beebe, R. F.; Feigelson, E.; Hurlburt, N. E.; Mentzel, C.; Smith, G.; Tino, C.; Walker, R. J.
Two years ago NASA established the Ad Hoc Big Data Task Force (BDTF - https://science.nasa.gov/science-committee/subcommittees/big-data-task-force), an advisory working group with the NASA Advisory Council system. The scope of the Task Force included all NASA Big Data programs, projects, missions, and activities. The Task Force focused on such topics as exploring the existing and planned evolution of NASA's science data cyber-infrastructure that supports broad access to data repositories for NASA Science Mission Directorate missions; best practices within NASA, other Federal agencies, private industry and research institutions; and Federal initiatives related to big data and data access. The BDTF has completed its two-year term and produced several recommendations plus four white papers for NASA's Science Mission Directorate. This presentation will discuss the activities and results of the TF including summaries of key points from its focused study topics. The paper serves as an introduction to the papers following in this ESSI session.
Schmid, Petra C; Kleiman, Tali; Amodio, David M
Social anxiety--the fear of social embarrassment and negative evaluation by others--ranks among people's worst fears, and it is often thought to impair task performance. We investigated the neurocognitive processes through which trait social anxiety relates to task performance, proposing a model of the joint contributions of reactive control, theoretically associated with conflict monitoring and activity of the dorsal anterior cingulate cortex (dACC), and proactive control, theoretically associated with top-down regulation and activity of the dorsolateral prefrontal cortex (dlPFC). Participants varying in their degree of trait social anxiety completed the Eriksen flanker task while electroencephalography (EEG) was recorded. Task-related left dlPFC activity was indexed by relative left prefrontal EEG (inverse alpha), and conflict-related dACC activity was indexed by the N2r component of the event-related potential. Stronger activity in both regions predicted better response control, and greater social anxiety was associated with worse response control. Furthermore, for all participants, greater left prefrontal EEG activity predicted better behavioral control, but for high social anxiety participants only, greater N2r responses also predicted behavioral control. This pattern suggests that low social anxiety individuals engaged a proactive control process, driven by dlPFC activity, whereas high social anxiety individuals relied additionally on a reactive control process, driven by conflict-related dACC activity. These findings support a model of control that involves different patterns of interplay between proactive and reactive strategies and may help to explain self-regulatory impairments in social anxiety. Copyright © 2015 Elsevier Ltd. All rights reserved.
Sosic-Vasic, Zrinka; Ulrich, Martin; Ruchsow, Martin; Vasic, Nenad; Grön, Georg
The present study investigated the association between traits of the Five Factor Model of Personality (Neuroticism, Extraversion, Openness for Experiences, Agreeableness, and Conscientiousness) and neural correlates of error monitoring obtained from a combined Eriksen-Flanker-Go/NoGo task during event-related functional magnetic resonance imaging in 27 healthy subjects. Individual expressions of personality traits were measured using the NEO-PI-R questionnaire. Conscientiousness correlated positively with error signaling in the left inferior frontal gyrus and adjacent anterior insula (IFG/aI). A second strong positive correlation was observed in the anterior cingulate gyrus (ACC). Neuroticism was negatively correlated with error signaling in the inferior frontal cortex possibly reflecting the negative inter-correlation between both scales observed on the behavioral level. Under present statistical thresholds no significant results were obtained for remaining scales. Aligning the personality trait of Conscientiousness with task accomplishment striving behavior the correlation in the left IFG/aI possibly reflects an inter-individually different involvement whenever task-set related memory representations are violated by the occurrence of errors. The strong correlations in the ACC may indicate that more conscientious subjects were stronger affected by these violations of a given task-set expressed by individually different, negatively valenced signals conveyed by the ACC upon occurrence of an error. Present results illustrate that for predicting individual responses to errors underlying personality traits should be taken into account and also lend external validity to the personality trait approach suggesting that personality constructs do reflect more than mere descriptive taxonomies.
Full Text Available The present study investigated the association between traits of the Five Factor Model of Personality (Neuroticism, Extraversion, Openness for Experiences, Agreeableness, and Conscientiousness and neural correlates of error monitoring obtained from a combined Eriksen-Flanker-Go/NoGo task during event-related functional magnetic resonance imaging in 27 healthy subjects. Individual expressions of personality traits were measured using the NEO-PI-R questionnaire. Conscientiousness correlated positively with error signaling in the left inferior frontal gyrus and adjacent anterior insula (IFG/aI. A second strong positive correlation was observed in the anterior cingulate gyrus (ACC. Neuroticism was negatively correlated with error signaling in the inferior frontal cortex possibly reflecting the negative inter-correlation between both scales observed on the behavioral level. Under present statistical thresholds no significant results were obtained for remaining scales. Aligning the personality trait of Conscientiousness with task accomplishment striving behavior the correlation in the left IFG/aI possibly reflects an inter-individually different involvement whenever task-set related memory representations are violated by the occurrence of errors. The strong correlations in the ACC may indicate that more conscientious subjects were stronger affected by these violations of a given task-set expressed by individually different, negatively valenced signals conveyed by the ACC upon occurrence of an error. Present results illustrate that for predicting individual responses to errors underlying personality traits should be taken into account and also lend external validity to the personality trait approach suggesting that personality constructs do reflect more than mere descriptive taxonomies.
Sanbonmatsu, David M.; Strayer, David L.; Medeiros-Ward, Nathan; Watson, Jason M.
The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are ...
Sanbonmatsu, David M; Strayer, David L; Medeiros-Ward, Nathan; Watson, Jason M
The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.
David M Sanbonmatsu
Full Text Available The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants' perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation--high levels of impulsivity and sensation seeking--reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control--low scorers on the Operation Span task and persons high in impulsivity--tended to report higher levels of multi-tasking activity.
Sanbonmatsu, David M.; Strayer, David L.; Medeiros-Ward, Nathan; Watson, Jason M.
The present study examined the relationship between personality and individual differences in multi-tasking ability. Participants enrolled at the University of Utah completed measures of multi-tasking activity, perceived multi-tasking ability, impulsivity, and sensation seeking. In addition, they performed the Operation Span in order to assess their executive control and actual multi-tasking ability. The findings indicate that the persons who are most capable of multi-tasking effectively are not the persons who are most likely to engage in multiple tasks simultaneously. To the contrary, multi-tasking activity as measured by the Media Multitasking Inventory and self-reported cell phone usage while driving were negatively correlated with actual multi-tasking ability. Multi-tasking was positively correlated with participants’ perceived ability to multi-task ability which was found to be significantly inflated. Participants with a strong approach orientation and a weak avoidance orientation – high levels of impulsivity and sensation seeking – reported greater multi-tasking behavior. Finally, the findings suggest that people often engage in multi-tasking because they are less able to block out distractions and focus on a singular task. Participants with less executive control - low scorers on the Operation Span task and persons high in impulsivity - tended to report higher levels of multi-tasking activity. PMID:23372720
Gurrin, Cathal; Joho, Hideo; Hopfgartner, Frank; Zhou, Liting; Albatal, Rami
In this paper we review the NTCIR12-Lifelog pilot task,\\ud which ran at NTCIR-12. We outline the test collection employed,\\ud along with the tasks, the eight submissions and the\\ud findings from this pilot task. We finish by suggesting future\\ud plans for the task.
Na, J. C.; Park, J. H.; Lee, S. K.; Kim, J. K.; Kim, E. S.; Cho, S. B.; Kang, J. S.
This report describes task analysis methodology for advanced HSI designs. Task analyses was performed by using procedure-based hierarchical task analysis and task decomposition methods. The results from the task analysis were recorded in a database. Using the TA results, we developed static prototype of advanced HSI and human factors engineering verification and validation methods for an evaluation of the prototype. In addition to the procedure-based task analysis methods, workload estimation based on the analysis of task performance time and analyses for the design of information structure and interaction structures will be necessary
Stephanie A. Kazanas; Kendra M. Van Valkenburg; Jeanette Altarriba
This study was designed to investigate the impact of survival processing with a novel task for this paradigm: the Stroop color-naming task. As the literature is mixed with regard to task generalizability, with survival processing promoting better memory for words, but not better memory for faces or paired associates, these types of task investigations are important to a growing field of research. Using the Stroop task provides a unique contribution, as identifying items by color is an importa...
interruption. A cognitive model we discuss below explains this effect in terms of increases in performance speed having the effect of compressing memory for...performance, and pilot data suggest that the task can distinguish between cognitive processes that are impaired by sleep deprivation and those that are...David Z. Hambrick Technical contact: Erik M. Altmann Michigan State University Department of Psychology 316 Physics Rd, Room 298A East Lansing
Edwards, Harold C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ibanez, Daniel Alejandro [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
This report documents the ASC/ATDM Kokkos deliverable "Production Portable Dy- namic Task DAG Capability." This capability enables applications to create and execute a dynamic task DAG ; a collection of heterogeneous computational tasks with a directed acyclic graph (DAG) of "execute after" dependencies where tasks and their dependencies are dynamically created and destroyed as tasks execute. The Kokkos task scheduler executes the dynamic task DAG on the target execution resource; e.g. a multicore CPU, a manycore CPU such as Intel's Knights Landing (KNL), or an NVIDIA GPU. Several major technical challenges had to be addressed during development of Kokkos' Task DAG capability: (1) portability to a GPU with it's simplified hardware and micro- runtime, (2) thread-scalable memory allocation and deallocation from a bounded pool of memory, (3) thread-scalable scheduler for dynamic task DAG, (4) usability by applications.
Schaffer, Bryan S.; Manegold, Jennifer G.
The authors investigated the antecedents of team task cohesiveness in service learning classroom environments. Focusing on task commitment and task attraction as key dependent variables representing cohesiveness, and task interdependence as the primary independent variable, the authors position three important task action phase processes as…
Halvorson, Kimberly M.; Ebner, Herschel; Hazeltine, Eliot
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…
... Community Preventive Services Task Force (Task Force) AGENCY: Centers for Disease Control and Prevention... September 17, 2013, announcing the next meeting of the Community Preventive Services Task Force (Task Force... the Task Force to consider the findings of systematic reviews and issue findings and recommendations...
Hart, S. G.; Shively, R. J.; Vidulich, M. A.; Miller, R. C.
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.
Berchicci, M; Pontifex, M B; Drollette, E S; Pesce, C; Hillman, C H; Di Russo, F
The association between a fit body and a fit brain in children has led to a rise of behavioral and neuroscientific research. Yet, the relation of cardiorespiratory fitness on premotor neurocognitive preparation with early visual processing has received little attention. Here, 41 healthy, lower and higher fit preadolescent children were administered a modified version of the Eriksen flanker task while electroencephalography (EEG) and behavioral measures were recorded. Event-related potentials (ERPs) locked to the stimulus onset with an earlier than usual baseline (-900/-800 ms) allowed investigation of both the usual post-stimulus (i.e., the P1, N1 and P2) as well as the pre-stimulus ERP components, such as the Bereitschaftspotential (BP) and the prefrontal negativity (pN component). At the behavioral level, aerobic fitness was associated response accuracy, with higher fit children being more accurate than lower fit children. Fitness-related differences selectively emerged at prefrontal brain regions during response preparation, with larger pN amplitude for higher than lower fit children, and at early perceptual stages after stimulus onset, with larger P1 and N1 amplitudes in higher relative to lower fit children. Collectively, the results suggest that the benefits of being aerobically fit appear at the stage of cognitive preparation prior to stimulus presentation and the behavioral response during the performance of a task that challenges cognitive control. Further, it is likely that enhanced activity in prefrontal brain areas may improve cognitive control of visuo-motor tasks, allowing for stronger proactive inhibition and larger early allocation of selective attention resources on relevant external stimuli. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.
Full Text Available Background: Tourette syndrome (TS is a childhood-onset neurodevelopmental disorder and its impact on cognitive development needs further study. Evidence from neuropsychological, neuroimaging and electrophysiological studies suggest that the decline in tic severity and the ability to suppress tics relate to the development of self-regulatory functions in late childhood and adolescence. Hence, tasks measuring performance monitoring might provide insight into the regulation of tics in children with TS. Method: Twenty-five children with TS, including 14 with comorbid Attention-deficit/hyperactivity disorder (ADHD, 39 children with ADHD and 35 typically developing children aged 8-12 years were tested with a modified Eriksen-Flanker task during a 34-channel electroencephalography (EEG recording. Task performance, as well as stimulus-locked and response-locked event-related potentials (ERP were analyzed and compared across groups. Results: Participants did not differ in their behavioral performance. Children with TS showed higher amplitudes of an early P3 component of the stimulus-locked ERPs in ensemble averages and in separate trial outcomes, suggesting heightened orienting and/or attention during stimulus evaluation. In response-locked averages, children with TS had a slightly higher positive complex before the motor response, likely also reflecting a late P3. Groups did not differ in post-response components, particularly in the error-related negativity (ERN and error-related positivity (Pe.Conclusions: These findings suggest that children with TS may employ additional attentional resources as a compensatory mechanism to maintain equal behavioral performance.
Full Text Available We used functional magnetic resonance imaging to investigate brain activations during nine different dual tasks in which the participants were required to simultaneously attend to concurrent streams of spoken syllables and written letters. They performed a phonological, spatial or simple (speaker-gender or font-shade discrimination task within each modality. We expected to find activations associated specifically with dual tasking especially in the frontal and parietal cortices. However, no brain areas showed systematic dual task enhancements common for all dual tasks. Further analysis revealed that dual tasks including component tasks that were according to Baddeley’s model modality atypical, that is, the auditory spatial task or the visual phonological task, were not associated with enhanced frontal activity. In contrast, for other dual tasks, activity specifically associated with dual tasking was found in the left or bilateral frontal cortices. Enhanced activation in parietal areas, however, appeared not to be specifically associated with dual tasking per se, but rather with intermodal attention switching. We also expected effects of dual tasking in left frontal supramodal phonological processing areas when both component tasks required phonological processing and in right parietal supramodal spatial processing areas when both tasks required spatial processing. However, no such effects were found during these dual tasks compared with their component tasks performed separately. Taken together, the current results indicate that activations during dual tasks depend in a complex manner on specific demands of component tasks.
The main functions and tasks for Civil Emergency Planning Directorate of NATO are presented. As a support and complement of United Nations Europ-Atlantic Partnership Council established a regional arrangement - a Europ-Atlantic Disaster Response capability with Coordination Center at NATO headquarters. Responsibility for disaster response is with the stricken nation while Europ-Atlantic Partnership Council role is one of coordination rather than direction. Europ-Atlantic Disaster Response Coordination Center act as focal point for information sharing on disaster assistance request among Europ-Atlantic Partnership Council countries. NATO Civil Emergency Planning Directorate consists of representatives from Europ-Atlantic Partnership Council countries and United Nations liaison officer
van der Lubbe, Robert Henricus Johannes; Jaśkowski, Piotr; Wauschkuhn, Bernd; Verleger, Rolf
Examined the influence of strategy for a simple response task, a choice-by-location task, and the Simon task by varying time pressure in 11 Ss (mean age 28 yrs). Besides reaction time (RT) and accuracy, we measured response force and derived two measures from the event-related EEG potential to form
Mitchell, Rachel L. C.
Previous studies of the Stroop task propose two key mediators: the prefrontal and cingulate cortices but hints exist of functional specialization within these regions. This study aimed to examine the effect of task modality upon the prefrontal and cingulate response by examining the response to colour, number, and shape Stroop tasks whilst BOLD…
Schulz, Hans-Jörg; Nocke, Thomas; Heitzler, Magnus; Schumann, Heidrun
Knowledge about visualization tasks plays an important role in choosing or building suitable visual representations to pursue them. Yet, tasks are a multi-faceted concept and it is thus not surprising that the many existing task taxonomies and models all describe different aspects of tasks, depending on what these task descriptions aim to capture. This results in a clear need to bring these different aspects together under the common hood of a general design space of visualization tasks, which we propose in this paper. Our design space consists of five design dimensions that characterize the main aspects of tasks and that have so far been distributed across different task descriptions. We exemplify its concrete use by applying our design space in the domain of climate impact research. To this end, we propose interfaces to our design space for different user roles (developers, authors, and end users) that allow users of different levels of expertise to work with it.
... USPSTF Our Members Conflict of Interest Disclosures Task Force Resources Our Partners Reports to Congress Contact Us ... effort to make the U.S. Preventive Services Task Force (USPSTF) recommendations clearer and its processes more transparent, ...
Smirmaul, B P; Dos Santos, R V; Da Silva Neto, L V
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.
Huntsinger, Jeffrey R.
The current research challenges the common view that positive affect and negative affect generate a broadened or narrowed attentional focus, respectively. Contrary to this view, two studies found that the link between affect and attentional focus as measured by a traditional flanker task (Study 1) and a modified flanker task (Study 2) reflects…
Rousculp, Christopher L [Los Alamos National Laboratory
Task Order 10 formalizes a collaboration in high explosive pulsed power (HEPP) experiments between LANL and VNIIEF. The focus is the VNIIEF disk explosive magnetic generator (DEMG) technology. The task order outlines a sequence of tasks and deliverables culminating in an experiment which takes place in the US utilizing US explosives and a Russian DEMG. This talk summarizes task order 10. It gives a brief history and present status in terms of the proposed high pressure EOS experiment (ALT-3).
Lawson, Anton E.; Nordland, Floyd H.
Investigated was the hypothesis that conservation tasks are unifactor by administering eight different conservation tasks to 96 seventh-grade science students and performing a principal component analysis on the data. Results indicated that conservation tasks may measure up to three different components of cognitive thought. (SL)
A nucleus of multi-tasking operating systems has been implemented on a Motorola 6800 microprocessor. This control structure, called a Task Manager, is appropriate for those real-time systems which are required to handle several different asynchronous events. The general concept of a Task Manager is described. A specific implementation for a Motorola 6800 microprocessor is given and its usage defined
Rusch, Frank R.; And Others
Verbal sequence training was used to teach a moderately mentally retarded woman to sequence job-related tasks. Learning to say the tasks in the proper sequence resulted in the employee performing her tasks in that sequence, and the employee was capable of mediating her own work behavior when scheduled changes occurred. (Author/JDD)
The study addresses the question of what makes a mathematical task interesting to the 9th year students. Semi-structured interviews were carried out with 15 students of purposive selection of the 9th year. The students were asked to recall a task they found interesting and engaging during the past three years. An analysis of the tasks was made…
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.
Meiran, Nachshon; Hsieh, Shulan; Dimov, Eduard
Task switching requires maintaining readiness to execute any task of a given set of tasks. However, when tasks switch, the readiness to execute the now-irrelevant task generates interference, as seen in the task rule incongruence effect. Overcoming such interference requires fine-tuned inhibition that impairs task readiness only minimally. In an experiment involving 2 object classification tasks and 2 location classification tasks, the authors show that irrelevant task rules that generate response conflicts are inhibited. This competitor rule suppression (CRS) is seen in response slowing in subsequent trials, when the competing rules become relevant. CRS is shown to operate on specific rules without affecting similar rules. CRS and backward inhibition, which is another inhibitory phenomenon, produced additive effects on reaction time, suggesting their mutual independence. Implications for current formal theories of task switching as well as for conflict monitoring theories are discussed. (c) 2010 APA, all rights reserved
Kimura, Takehide; Kaneko, Fuminari; Nagahata, Keita; Shibata, Eriko; Aoki, Nobuhiro
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.
The National Council of Radiation Protection and Measurements (NCRP) has recently established a Task Group on Soil Contamination to describe and evaluate the migration pathways and modes of radiation exposure that can potentially arise due to radioactive contamination of soil. The purpose of this paper is to describe the scientific principles for evaluation of soil contamination which can be used as a basis for derivation of soil contamination limits for specific situations. This paper describes scenarios that can lead to soil contamination, important characteristics of soil contamination, the subsequent migration pathways and exposure modes, and the application of principles in the report in deriving soil contamination limits. The migration pathways and exposure modes discussed in this paper include: direct radiation exposure; and exhalation of gases
Rabella, Mireia; Grasa, Eva; Corripio, Iluminada; Romero, Sergio; Mañanas, Miquel Àngel; Antonijoan, Rosa M; Münte, Thomas F; Pérez, Víctor; Riba, Jordi
Schizotypal personality disorder (SPD) is a schizophrenia-spectrum disorder characterized by odd or bizarre behavior, strange speech, magical thinking, unusual perceptual experiences, and social anhedonia. Schizophrenia proper has been associated with anomalies in dopaminergic neurotransmission and deficits in neurophysiological markers of self-monitoring, such as low amplitude in cognitive event-related brain potentials (ERPs) like the error-related negativity (ERN), and the error positivity (Pe). These components occur after performance errors, rely on adequate fronto-striatal function, and are sensitive to dopaminergic modulation. Here we postulated that analogous to observations in schizophrenia, SPD individuals would show deficits in self-monitoring, as measured by the ERN and the Pe. We also assessed the capacity of dopaminergic antagonists to reverse these postulated deficits. We recorded the electroencephalogram (EEG) from 9 SPD individuals and 12 healthy controls in two separate experimental sessions while they performed the Eriksen Flanker Task, a classical task recruiting behavioral monitoring. Participants received a placebo or 1 mg risperidone according to a double-blind randomized design. After placebo, SPD individuals showed slower reaction times to hits, longer correction times following errors and reduced ERN and Pe amplitudes. While risperidone impaired performance and decreased ERN and Pe in the control group, it led to behavioral improvements and ERN amplitude increases in the SPD individuals. These results indicate that SPD individuals show deficits in self-monitoring analogous to those in schizophrenia. These deficits can be evidenced by neurophysiological measures, suggest a dopaminergic imbalance, and can be reverted by dopaminergic antagonists.
Broekkamp, H.; Dijk, van E.; Brekelmans, J.M.G.; Mainhard, T.; Brok, den P.J.
Students who perceive assigned academic tasks as more clear perform better on these tasks. Moreover, it has been shown that "task clarity" (as experienced by students) varies across teachers. Apparently, some teachers are more effective than other teachers in communicating tasks. There is, however,
Forrest, Charlotte L. D.; Monsell, Stephen; McLaren, Ian P. L.
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,…
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…
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.…
Strobach, Tilo; Schütz, Anja; Schubert, Torsten
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
Strobach, Tilo; Schütz, Anja; Schubert, Torsten
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.
Soo Ji Kim
Full Text Available Given the interplay between cognitive and motor functions during walking, cognitive demands required during gait have been investigated with regard to dual task performance. Along with the needs to understand how the type of concurrent task while walking affects gait performance, there are calls for diversified dual tasks that can be applied to older adults with varying levels of cognitive decline. Therefore, this study aimed to examine how rhythm-motor tasks affect dual task performance and gait control, compared to a traditional cognitive-motor task. Also, it examined whether rhythm-motor tasks are correlated with traditional cognitive-motor task performance and cognitive measures. Eighteen older adults without cognitive impairment participated in this study. Each participant was instructed to walk at self-paced tempo without performing a concurrent task (single walking task and walk while separately performing two types of concurrent tasks: rhythm-motor and cognitive-motor tasks. Rhythm-motor tasks included instrument playing (WalkIP, matching to rhythmic cueing (WalkRC, and instrument playing while matching to rhythmic cueing (WalkIP+RC. The cognitive-motor task involved counting forward by 3s (WalkCount.f3. In each condition, dual task costs (DTC, a measure for how dual tasks affect gait parameters, were measured in terms of walking speed and stride length. The ratio of stride length to walking speed, a measure for dynamic control of gait, was also examined. The results of this study demonstrated that the task type was found to significantly influence these measures. Rhythm-motor tasks were found to interfere with gait parameters to a lesser extent than the cognitive-motor task (WalkCount.f3. In terms of ratio measures, stride length remained at a similar level, walking speed greatly decreased in the WalkCount.f3 condition. Significant correlations between dual task-related measures during rhythm-motor and cognitive-motor tasks support the
Laumann, Karin; Braarud, Per Oeivind; Svengren, Haakan
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)
Hall, E. J.; Topp, D. A.; Delaney, R. A.
The overall objective of this study was to develop a 3-D numerical analysis for compressor casing treatment flowfields. The current version of the computer code resulting from this study is referred to as ADPAC (Advanced Ducted Propfan Analysis Codes-Version 7). This report is intended to serve as a computer program user's manual for the ADPAC code developed under Tasks 6 and 7 of the NASA Contract. The ADPAC program is based on a flexible multiple- block grid discretization scheme permitting coupled 2-D/3-D mesh block solutions with application to a wide variety of geometries. Aerodynamic calculations are based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. Steady flow predictions are accelerated by a multigrid procedure. An iterative implicit algorithm is available for rapid time-dependent flow calculations, and an advanced two equation turbulence model is incorporated to predict complex turbulent flows. The consolidated code generated during this study is capable of executing in either a serial or parallel computing mode from a single source code. Numerous examples are given in the form of test cases to demonstrate the utility of this approach for predicting the aerodynamics of modem turbomachinery configurations.
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.
Vriesenga, Mark R.; Peleg, K.; Sklansky, Jack
Machine vision systems analyze image data to carry out automation tasks. Our interest is in machine vision systems that rely on models to achieve their designed task. When the model is interrogated from an a priori menu of questions, the model need not be complete. Instead, the machine vision system can use a partial model that contains a large amount of information in regions of interest and less information elsewhere. We propose an adaptive modeling scheme for machine vision, called task-focused modeling, which constructs a model having just sufficient detail to carry out the specified task. The model is detailed in regions of interest to the task and is less detailed elsewhere. This focusing effect saves time and reduces the computational effort expended by the machine vision system. We illustrate task-focused modeling by an example involving real-time micropropagation of plants in automated agriculture.
Madsen, Ida E H; Tripathi, Manisha; Borritz, Marianne
OBJECTIVES: According to the "stress-as-offense-to-self" perspective, work tasks that are considered unnecessary or unreasonable - so-called "illegitimate work tasks" - are likely to elicit stress-reactions. Previous studies, mostly cross-sectional, have shown that illegitimate tasks are associated...... with increased self-reported stress, cortisol, and counterproductive work behavior. In this article, we examine the prospective association between unnecessary work tasks, one type of illegitimate work tasks, and mental health among Danish human service workers. Further, we explore whether this association...... is modified by sex, age, occupational position, and baseline mental health status. METHODS: The data were obtained from self-administered questionnaires from 1351 Danish human service workers in three waves of data-collection during 1999-2005. We measured unnecessary work tasks by a single item, and assessed...
During the past few years the nuclear industry has become concerned with predicting human performance in nuclear power plants. One of the best means available at the present time to make sure that training, procedures, job performance aids and plant hardware match the capabilities and limitations of personnel is by performing a detailed analysis of the tasks required in each job position. The approved method for this type of analysis is referred to as job or task analysis. Job analysis is a broader type of analysis and is usually thought of in terms of establishing overall performance objectives, and in establishing a basis for position descriptions. Task analysis focuses on the building blocks of task performance, task elements, and places them within the context of specific performance requirements including time to perform, feedback required, special tools used, and required systems knowledge. The use of task analysis in the nuclear industry has included training validation, preliminary risk screening, and procedures development
Wickens, Christopher D.; Larish, Inge; Contorer, Aaron
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.
Epling, Samantha L; Russell, Paul N; Helton, William S
Cognitive resource theory is a common explanation for both the performance decline in vigilance tasks, known as the vigilance decrement, and the limited ability to perform multiple tasks simultaneously. The limited supply of cognitive resources may be utilized faster than they are replenished resulting in a performance decrement, or may need to be allocated among multiple tasks with some performance cost. Researchers have proposed both domain-specific, for example spatial versus verbal processing resources, and domain general cognitive resources. One challenge in testing the domain specificity of cognitive resources in vigilance is the current lack of difficult semantic vigilance tasks which reliably produce a decrement. In the present research, we investigated whether the vigilance decrement was found in a new abbreviated semantic discrimination vigilance task, and whether there was a performance decrement in said vigilance task when paired with a word recall task, as opposed to performed individually. As hypothesized, a vigilance decrement in the semantic vigilance task was found in both the single-task and dual-task conditions, along with reduced vigilance performance in the dual-task condition and reduced word recall in the dual-task condition. This is consistent with cognitive resource theory. The abbreviated semantic vigilance task will be a useful tool for researchers interested in determining the specificity of cognitive resources utilized in vigilance tasks.
Wrightson, J G; Smeeton, N J
During dual-task gait, changes in the stride-to-stride variability of stride time (STV) are suggested to represent the allocation of cognitive control to walking . However, contrasting effects have been reported for overground and treadmill walking, which may be due to differences in the relative difficulty of the dual task. Here we compared the effect of overground and treadmill dual-task walking on STV in 18 healthy adults. Participants walked overground and on a treadmill for 120s during single-task (walking only) and dual-task (walking whilst performing serial subtractions in sevens) conditions. Dual-task effects on STV, cognitive task (serial subtraction) performance and perceived task difficulty were compared between walking modalities. STV was increased during overground dual-task walking, but was unchanged during treadmill dual-task walking. There were no differences in cognitive task performance or perceived task difficulty. These results show that gait is controlled differently during overground and treadmill dual-task walking. However, these differences are not solely due to differences in task difficulty, and may instead represent modality dependent control strategies. Copyright © 2017 Elsevier B.V. All rights reserved.
Asame, Hajime; Endo, Isao; Kotosaka, Shin-ya; Takata, Shozo; Hiraoka, Hiroyuki; Kohda, Takehisa; Matsumoto, Akihiro; Yamagishi, Kiichiro.
The adaptability evaluation of maintenance robots to autonomous plants has been discussed. In this paper, a new concept of autonomous plant with maintenance robots are introduced, and a framework of autonomous maintenance system is proposed. Then, task-oriented evaluation of robot arms is discussed for evaluating their adaptability to maintenance tasks, and a new criterion called operability is proposed for adaptability evaluation. The task-oriented evaluation system is implemented and applied to structural design of robot arms. Using genetic algorithm, an optimal structure adaptable to a pump disassembly task is obtained. (author)
Agrawal, Pankaj; Pradhan, B
We introduce the notion of a task-oriented maximally entangled state (TMES). This notion depends on the task for which a quantum state is used as the resource. TMESs are the states that can be used to carry out the task maximally. This concept may be more useful than that of a general maximally entangled state in the case of a multipartite system. We illustrate this idea by giving an operational definition of maximally entangled states on the basis of communication tasks of teleportation and superdense coding. We also give examples and a procedure to obtain such TMESs for n-qubit systems.
Balzan, Ryan P; Ephraums, Rachel; Delfabbro, Paul; Andreou, Christina
Previous research involving the probabilistic reasoning 'beads task' has consistently demonstrated a jumping-to-conclusions (JTC) bias, where individuals with delusions make decisions based on limited evidence. However, recent studies have suggested that miscomprehension may be confounding the beads task. The current study aimed to test the conventional beads task against a conceptually simpler probabilistic reasoning "box task" METHODS: One hundred non-clinical participants completed both the beads task and the box task, and the Peters et al. Delusions Inventory (PDI) to assess for delusion-proneness. The number of 'draws to decision' was assessed for both tasks. Additionally, the total amount of on-screen evidence was manipulated for the box task, and two new box task measures were assessed (i.e., 'proportion of evidence requested' and 'deviation from optimal solution'). Despite being conceptually similar, the two tasks did not correlate, and participants requested significantly less information on the beads task relative to the box task. High-delusion-prone participants did not demonstrate hastier decisions on either task; in fact, for box task, this group was observed to be significantly more conservative than low-delusion-prone group. Neither task was incentivized; results need replication with a clinical sample. Participants, and particularly those identified as high-delusion-prone, displayed a more conservative style of responding on the novel box task, relative to the beads task. The two tasks, whilst conceptually similar, appear to be tapping different cognitive processes. The implications of these results are discussed in relation to the JTC bias and the theoretical mechanisms thought to underlie it. Copyright © 2016 Elsevier Ltd. All rights reserved.
Deprez, Sabine; Vandenbulcke, Mathieu; Peeters, Ron; Emsell, Louise; Amant, Frederic; Sunaert, Stefan
Insight into the neural architecture of multitasking is crucial when investigating the pathophysiology of multitasking deficits in clinical populations. Presently, little is known about how the brain combines dual-tasking with a concurrent short-term memory task, despite the relevance of this mental operation in daily life and the frequency of complaints related to this process, in disease. In this study we aimed to examine how the brain responds when a memory task is added to dual-tasking. Thirty-three right-handed healthy volunteers (20 females, mean age 39.9 ± 5.8) were examined with functional brain imaging (fMRI). The paradigm consisted of two cross-modal single tasks (a visual and auditory temporal same-different task with short delay), a dual-task combining both single tasks simultaneously and a multi-task condition, combining the dual-task with an additional short-term memory task (temporal same-different visual task with long delay). Dual-tasking compared to both individual visual and auditory single tasks activated a predominantly right-sided fronto-parietal network and the cerebellum. When adding the additional short-term memory task, a larger and more bilateral frontoparietal network was recruited. We found enhanced activity during multitasking in components of the network that were already involved in dual-tasking, suggesting increased working memory demands, as well as recruitment of multitask-specific components including areas that are likely to be involved in online holding of visual stimuli in short-term memory such as occipito-temporal cortex. These results confirm concurrent neural processing of a visual short-term memory task during dual-tasking and provide evidence for an effective fMRI multitasking paradigm. © 2013 Elsevier Ltd. All rights reserved.
Gordey, T [ConocoPhillips Canada Resources Corp., Calgary, AB (Canada); Sunstrum, M [Enform, Calgary, AB (Canada)
Worker absenteeism due to substance abuse costs the Alberta economy approximately $720 million a year. It is estimated that 20 per cent of all drivers in fatal crashes were using alcohol, and the use of cannabis and cocaine in Alberta has more than doubled over the last 15 years. In addition, 1 in 10 Alberta workers have reported using alcohol while at work and 4 per cent have reported using alcohol 4 hours prior to coming to work during the previous 12 months. In an effort to ensure appropriate health and safety for workers in the Canadian petroleum industry, 6 trade associations in the sector have joined together as the Enform Alcohol and Drug Initiative and are now working to develop a common approach to drug and alcohol guidelines and workplace rules. The task group will determine if existing policies and guidelines are sufficient to ensure a safe workplace and will consider standardizing the testing, application and rehabilitation of workers with respect to the use of drugs and alcohol. In the past, disciplinary actions have often been reversed because employers have not been consistent or did not follow established alcohol and drug policies or test to specific standards. Various work rules for inappropriate alcohol and drug use were reviewed, as well as education and communication strategies regarding policy content. Standards for testing criteria were discussed, as well as issues concerning duty-to-accommodate circumstances. An excerpt of concentration standards was presented. It was concluded that a matrix for companies to assess and determine safety sensitive positions is needed. refs., tabs., figs.
Gordey, T.; Sunstrum, M.
Worker absenteeism due to substance abuse costs the Alberta economy approximately $720 million a year. It is estimated that 20 per cent of all drivers in fatal crashes were using alcohol, and the use of cannabis and cocaine in Alberta has more than doubled over the last 15 years. In addition, 1 in 10 Alberta workers have reported using alcohol while at work and 4 per cent have reported using alcohol 4 hours prior to coming to work during the previous 12 months. In an effort to ensure appropriate health and safety for workers in the Canadian petroleum industry, 6 trade associations in the sector have joined together as the Enform Alcohol and Drug Initiative and are now working to develop a common approach to drug and alcohol guidelines and workplace rules. The task group will determine if existing policies and guidelines are sufficient to ensure a safe workplace and will consider standardizing the testing, application and rehabilitation of workers with respect to the use of drugs and alcohol. In the past, disciplinary actions have often been reversed because employers have not been consistent or did not follow established alcohol and drug policies or test to specific standards. Various work rules for inappropriate alcohol and drug use were reviewed, as well as education and communication strategies regarding policy content. Standards for testing criteria were discussed, as well as issues concerning duty-to-accommodate circumstances. An excerpt of concentration standards was presented. It was concluded that a matrix for companies to assess and determine safety sensitive positions is needed. refs., tabs., figs
Aerojet Rocketdyne (AR) has developed an innovative gasifier concept incorporating advanced technologies in ultra-dense phase dry feed system, rapid mix injector, and advanced component cooling to significantly improve gasifier performance, life, and cost compared to commercially available state-of-the-art systems. A key feature of the AR gasifier design is the transition from the gasifier outlet into the quench zone, where the raw syngas is cooled to ~ 400°C by injection and vaporization of atomized water. Earlier pilot plant testing revealed a propensity for the original gasifier outlet design to accumulate slag in the outlet, leading to erratic syngas flow from the outlet. Subsequent design modifications successfully resolved this issue in the pilot plant gasifier. In order to gain greater insight into the physical phenomena occurring within this zone, AR developed a cold flow simulation apparatus with Coanda Research & Development with a high degree of similitude to hot fire conditions with the pilot scale gasifier design, and capable of accommodating a scaled-down quench zone for a demonstration-scale gasifier. The objective of this task was to validate similitude of the cold flow simulation model by comparison of pilot-scale outlet design performance, and to assess demonstration scale gasifier design feasibility from testing of a scaled-down outlet design. Test results did exhibit a strong correspondence with the two pilot scale outlet designs, indicating credible similitude for the cold flow simulation device. Testing of the scaled-down outlet revealed important considerations in the design and operation of the demonstration scale gasifier, in particular pertaining to the relative momentum between the downcoming raw syngas and the sprayed quench water and associated impacts on flow patterns within the quench zone. This report describes key findings from the test program, including assessment of pilot plant configuration simulations relative to actual
Beard, D.S.; Klose, W.; Shimamoto, S.; Vecsey, G.
A multinational program of cooperative research, development, demonstrations, and exchanges of information on superconducting magnets for fusion was initiated in 1977 under an IEA agreement. The first major step in the development of TF magnets was called the Large Coil Task. Participants in LCT were the U.S. DOE, EURATOM, JAERI, and the Departement Federal de l'Interieur of Switzerland. The goals of LCT were to obtain experimental data, to demonstrate reliable operation of large superconducting coils, and to prove design principles and fabrication techniques being considered for the toroidal magnets of thermonuclear reactors. These goals were to be accomplished through coordinated but largely independent design, development, and construction of six test coils, followed by collaborative testing in a compact toroidal test array at fields of 8 T and higher. Under the terms of the IEA Agreement, the United States built and operated the test facility at Oak Ridge and provided three test coils. The other participants provided one coil each. Information on design and manufacturing and all test data were shared by all. The LCT team of each participant included a government laboratory and industrial partners or contractors. The last coil was completed in 1985, and the test assembly was completed in October of that year. Over the next 23 months, the six-coil array was cooled down and extensive testing was performed. Results were gratifying, as tests achieved design-point performance and well beyond. (Each coil reached a peak field of 9 T.) Experiments elucidated coil behavior, delineated limits of operability, and demonstrated coil safety. (orig./KP)
Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan
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…
Spingath, Elsie Y.; Kang, Hyun Sug; Plummer, Thane; Blake, David T.
Adult learning-induced sensory cortex plasticity results in enhanced action potential rates in neurons that have the most relevant information for the task, or those that respond strongly to one sensory stimulus but weakly to its comparison stimulus. Current theories suggest this plasticity is caused when target stimulus evoked activity is enhanced by reward signals from neuromodulatory nuclei. Prior work has found evidence suggestive of nonselective enhancement of neural responses, and suppression of responses to task distractors, but the differences in these effects between detection and discrimination have not been directly tested. Using cortical implants, we defined physiological responses in macaque somatosensory cortex during serial, matched, detection and discrimination tasks. Nonselective increases in neural responsiveness were observed during detection learning. Suppression of responses to task distractors was observed during discrimination learning, and this suppression was specific to cortical locations that sampled responses to the task distractor before learning. Changes in receptive field size were measured as the area of skin that had a significant response to a constant magnitude stimulus, and these areal changes paralleled changes in responsiveness. From before detection learning until after discrimination learning, the enduring changes were selective suppression of cortical locations responsive to task distractors, and nonselective enhancement of responsiveness at cortical locations selective for target and control skin sites. A comparison of observations in prior studies with the observed plasticity effects suggests that the non-selective response enhancement and selective suppression suffice to explain known plasticity phenomena in simple spatial tasks. This work suggests that differential responsiveness to task targets and distractors in primary sensory cortex for a simple spatial detection and discrimination task arise from nonselective
Elsie Y Spingath
Full Text Available Adult learning-induced sensory cortex plasticity results in enhanced action potential rates in neurons that have the most relevant information for the task, or those that respond strongly to one sensory stimulus but weakly to its comparison stimulus. Current theories suggest this plasticity is caused when target stimulus evoked activity is enhanced by reward signals from neuromodulatory nuclei. Prior work has found evidence suggestive of nonselective enhancement of neural responses, and suppression of responses to task distractors, but the differences in these effects between detection and discrimination have not been directly tested. Using cortical implants, we defined physiological responses in macaque somatosensory cortex during serial, matched, detection and discrimination tasks. Nonselective increases in neural responsiveness were observed during detection learning. Suppression of responses to task distractors was observed during discrimination learning, and this suppression was specific to cortical locations that sampled responses to the task distractor before learning. Changes in receptive field size were measured as the area of skin that had a significant response to a constant magnitude stimulus, and these areal changes paralleled changes in responsiveness. From before detection learning until after discrimination learning, the enduring changes were selective suppression of cortical locations responsive to task distractors, and nonselective enhancement of responsiveness at cortical locations selective for target and control skin sites. A comparison of observations in prior studies with the observed plasticity effects suggests that the non-selective response enhancement and selective suppression suffice to explain known plasticity phenomena in simple spatial tasks. This work suggests that differential responsiveness to task targets and distractors in primary sensory cortex for a simple spatial detection and discrimination task arise from
... individual task order, accounting and appropriation data. (e) The Contractor shall provide acknowledgement of... conflict between the requirements of the task order and the Contractor's approved task plan, the task order...
Full Text Available Why is the human brain fundamentally limited when attempting to execute two tasks at the same time or in close succession? Two classical paradigms, psychological refractory period (PRP and task switching, have independently approached this issue, making significant advances in our understanding of the architecture of cognition. Yet, there is an apparent contradiction between the conclusions derived from these two paradigms. The PRP paradigm, on the one hand, suggests that the simultaneous execution of two tasks is limited solely by a passive structural bottleneck in which the tasks are executed on a first-come, first-served basis. The task-switching paradigm, on the other hand, argues that switching back and forth between task configurations must be actively controlled by a central executive system (the system controlling voluntary, planned, and flexible action. Here we have explicitly designed an experiment mixing the essential ingredients of both paradigms: task uncertainty and task simultaneity. In addition to a central bottleneck, we obtain evidence for active processes of task setting (planning of the appropriate sequence of actions and task disengaging (suppression of the plan set for the first task in order to proceed with the next one. Our results clarify the chronometric relations between these central components of dual-task processing, and in particular whether they operate serially or in parallel. On this basis, we propose a hierarchical model of cognitive architecture that provides a synthesis of task-switching and PRP paradigms.
Koch, Iring; Rumiati, Raffaella I
Three dual-task experiments examined the influence of processing a briefly presented visual object for deferred verbal report on performance in an unrelated auditory-manual reaction time (RT) task. RT was increased at short stimulus-onset asynchronies (SOAs) relative to long SOAs, showing that memory consolidation processes can produce a functional processing bottleneck in dual-task performance. In addition, the experiments manipulated the spatial compatibility of the orientation of the visual object and the side of the speeded manual response. This cross-task compatibility produced relative RT benefits only when the instruction for the visual task emphasized overlap at the level of response codes across the task sets (Experiment 1). However, once the effective task set was in place, it continued to produce cross-task compatibility effects even in single-task situations ("ignore" trials in Experiment 2) and when instructions for the visual task did not explicitly require spatial coding of object orientation (Experiment 3). Taken together, the data suggest a considerable degree of task-set inertia in dual-task performance, which is also reinforced by finding costs of switching task sequences (e.g., AC --> BC vs. BC --> BC) in Experiment 3.
de Pater, I.E.; van Vianen, A.E.M.; Fischer, A.H.; van Ginkel, W.P.
Purpose - The purpose of this paper is to examine: gender differences in the choice to perform challenging tasks, gender differences in the actual performance of challenging tasks, and the impact of challenging experiences on supervisors' evaluations of individuals' potential for career advancement.
DeAcetis, Louis A.; Schmidt, Oron; Krishen, Kumar
A method of simulating equipment using ADA tasks is discussed. Individual units of equipment are coded as concurrently running tasks that monitor and respond to input signals. This technique has been used in a simulation of the space-to-ground Communications and Tracking subsystem of Space Station Freedom.
Full Text Available Computing the optimal geometric structure of manipulators is one of the most intricate problems in contemporary robot kinematics. Robotic manipulators are designed and built to perform certain predetermined tasks. There is a very close relationship between the structure of the manipulator and its kinematic performance. It is therefore important to incorporate such task requirements during the design and synthesis of the robotic manipulators. Such task requirements and performance constraints can be specified in terms of the required end-effector positions, orientations and velocities along the task trajectory. In this work, we present a comprehensive method to develop the optimal geometric structure (DH parameters of a non-redundant six degree of freedom serial manipulator from task descriptions. In this work we define, develop and test a methodology to design optimal manipulator configurations based on task descriptions. This methodology is devised to investigate all possible manipulator configurations that can satisfy the task performance requirements under imposed joint constraints. Out of all the possible structures, the structures that can reach all the task points with the required orientations are selected. Next, these candidate structures are tested to see whether they can attain end-effector velocities in arbitrary directions within the user defined joint constraints, so that they can deliver the best kinematic performance. Additionally least power consuming configurations are also identified.
The result of the study revealed that head teachers' decision-making strategy and head teachers' leadership style have significant influence on teachers' task performance in the sampled schools. And that head teachers' communication skills significantly relates to teachers' task performance in the area. Based on this result, ...
Erkan, D.; Derksen, R.; Levy, R.; Machin, S.; Ortel, T.; Pierangeli, S.; Roubey, R.; Lockshin, M.
The Antiphospholipid Syndrome (APS) Clinical Research Task Force (CRTF) was one of six Task Forces developed by the 13(th) International Congress on Antiphospholipid Antibodies (aPL) organization committee with the purpose of: a) evaluating the limitations of APS clinical research and developing
Bos, J; Mulder, LJM; van Ouwerkerk, RJ; Maarse, FJ; Akkerman, AE; Brand, AN; Mulder, LJM
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
Crump, Matthew J C; Logan, Gordon D
Contextual cues signaling task likelihood or the likelihood of task repetition are known to modulate the size of switch costs. We follow up on the finding by Leboe, Wong, Crump, and Stobbe (2008) that location cues predictive of the proportion of switch or repeat trials modulate switch costs. Their design employed one cue per task, whereas our experiment employed two cues per task, which allowed separate assessment of modulations to the cue-repetition benefit, a measure of lower level cue-encoding processes, and to the task-alternation cost, a measure of higher level processes representing task-set information. We demonstrate that location information predictive of switch proportion modulates performance at the level of task-set representations. Furthermore, we demonstrate that contextual control occurs even when subjects are unaware of the associations between context and switch likelihood. We discuss the notion that contextual information provides rapid, unconscious control over the extent to which prior task-set representations are retrieved in the service of guiding online performance.
Belkin, Nicholas J.; Bogers, Toine; Kamps, Jaap; Kelly, Diane; Koolen, Marijn; Yilmaz, Emine
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
Programming education and contests have introduced software to help evaluation by executing submitted taskwork. We present the notion of a task package as a unit for collecting, storing, archiving, and exchanging all information concerning a programming task. We also describe a specific format for
Pannebakker, Merel Mathilde
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
The work plan and objectives of this task are designed to support the acceleration of safe implementation of hydrogen infrastructure through coordinated international collaborations and hydrogen safety knowledge dissemination.......The work plan and objectives of this task are designed to support the acceleration of safe implementation of hydrogen infrastructure through coordinated international collaborations and hydrogen safety knowledge dissemination....
Zenasni, Franck; Lubart, Todd
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.…
Lake County Area Vocational Center, Grayslake, IL.
The duties and tasks found in these task lists form the basis of instructional content for secondary, postsecondary, and adult occupational training programs for industrial occupations. The industrial occupations are divided into eight clusters. The clusters and occupations are: construction cluster (bricklayer, carpenter, building maintenance…
Lin, Binbin; Yang, Sen; Zhang, Chiyuan; Ye, Jieping; He, Xiaofei
Multi-task learning (MTL) aims to improve generalization performance by learning multiple related tasks simultaneously and identifying the shared information among tasks. Most of existing MTL methods focus on learning linear models under the supervised setting. We propose a novel semi-supervised and nonlinear approach for MTL using vector fields. A vector field is a smooth mapping from the manifold to the tangent spaces which can be viewed as a directional derivative of functions on the manifold. We argue that vector fields provide a natural way to exploit the geometric structure of data as well as the shared differential structure of tasks, both of which are crucial for semi-supervised multi-task learning. In this paper, we develop multi-task vector field learning (MTVFL) which learns the predictor functions and the vector fields simultaneously. MTVFL has the following key properties. (1) The vector fields MTVFL learns are close to the gradient fields of the predictor functions. (2) Within each task, the vector field is required to be as parallel as possible which is expected to span a low dimensional subspace. (3) The vector fields from all tasks share a low dimensional subspace. We formalize our idea in a regularization framework and also provide a convex relaxation method to solve the original non-convex problem. The experimental results on synthetic and real data demonstrate the effectiveness of our proposed approach.
Liu, An; Wang, Weiqi; Shang, Shuo; Li, Qing; Zhang, Xiangliang
Spatial crowdsourcing (SC) outsources tasks to a set of workers who are required to physically move to specified locations and accomplish tasks. Recently, it is emerging as a promising tool for emergency management, as it enables efficient and cost
Bialystok, Ellen; Craik, Fergus I M; Stefurak, Taresa
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.
van Vijfeijken, H.; Kleingeld, A.; van Tuijl, H.; Algera, J.A.; Thierry, Hk.
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
Vijfeijken, van H.T.G.A.; Kleingeld, P.A.M.; Tuijl, van H.F.J.M.; Algera, J.A.; Thierry, H.
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
Hart, Stephen W (Inventor); Yamokoski, John D. (Inventor); Wightman, Brian J (Inventor); Dinh, Duy Paul (Inventor); Gooding, Dustin R (Inventor)
A system for developing distributed robot application-level software includes a robot having an associated control module which controls motion of the robot in response to a commanded task, and a robot task commander (RTC) in networked communication with the control module over a network transport layer (NTL). The RTC includes a script engine(s) and a GUI, with a processor and a centralized library of library blocks constructed from an interpretive computer programming code and having input and output connections. The GUI provides access to a Visual Programming Language (VPL) environment and a text editor. In executing a method, the VPL is opened, a task for the robot is built from the code library blocks, and data is assigned to input and output connections identifying input and output data for each block. A task sequence(s) is sent to the control module(s) over the NTL to command execution of the task.
Blackman, H.S.; Gertman, D.I.; Petersen, R.J.
Task analyses were used to assist in identifying improvements needed in the training curriculum for selected positions at the Power Burst Facility (PBF). Four positions were examined: Experiment Power Reactor Operator, Experiment (EPRO-Ex); Experiment Power Reactor Operator, Plant (EPRO-P); Experiment Power Reactor Operator, Console (EPRO-Co), and Shift Supervisor (SS). A complete position task listing and core of tasks defined in terms of (a) level of difficulty to perform, (b) severity of consequence if performed improperly, and (c) associated error probability were identified by each position. The systems, academic, and administrative knowledge needed by job incumbents to perform each task was noted. Strategies for teaching the knowledge associated with these tasks are presented
Leung, Vitus Joseph; Bunde, David P.; Ebbers, Johnathan; Price, Nicholas W.; Swank, Matthew.; Feer, Stefan P.; Rhodes, Zachary D.
This paper examines task mapping algorithms for non-contiguously allocated parallel jobs. Several studies have shown that task placement affects job running time for both contiguously and non-contiguously allocated jobs. Traditionally, work on task mapping either uses a very general model where the job has an arbitrary communication pattern or assumes that jobs are allocated contiguously, making them completely isolated from each other. A middle ground between these two cases is the mapping problem for non-contiguous jobs having a specific communication pattern. We propose several task mapping algorithms for jobs with a stencil communication pattern and evaluate them using experiments and simulations. Our strategies improve the running time of a MiniApp by as much as 30% over a baseline strategy. Furthermore, this improvement increases markedly with the job size, demonstrating the importance of task mapping as systems grow toward exascale.
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.
Emalee J. W. Quickel
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.
Kiesel, Andrea; Steinhauser, Marco; Wendt, Mike; Falkenstein, Michael; Jost, Kerstin; Philipp, Andrea M.; Koch, Iring
The task-switching paradigm offers enormous possibilities to study cognitive control as well as task interference. The current review provides an overview of recent research on both topics. First, we review different experimental approaches to task switching, such as comparing mixed-task blocks with single-task blocks, predictable task-switching…
Smith, Rebekah E; Hunt, R Reed
Remembering to perform an action in the future, called prospective memory, often shows age-related differences in favor of young adults when tested in the laboratory. Recently Smith, Horn, and Bayen (2012; Aging, Neuropsychology, and Cognition, 19, 495) embedded a PM task in an ongoing color-matching task and manipulated the difficulty of the ongoing task by varying the number of colors on each trial of the task. Smith et al. found that age-related differences in PM performance (lower PM performance for older adults relative to young adults) persisted even when older adults could perform the ongoing task as well or better than the young adults. The current study investigates a possible explanation for the pattern of results reported by Smith et al. by including a manipulation of task emphasis: for half of the participants the prospective memory task was emphasize, while for the other half the ongoing color-matching task was emphasized. Older adults performed a 4-color version of the ongoing color-matching task, while young adults completed either the 4-color or a more difficult 6-color version of the ongoing task. Older adults failed to perform as well as the young adults on the prospective memory task regardless of task emphasis, even when older adults were performing as well or better than the young adults on the ongoing color-matching task. The current results indicate that the lack of an effect of ongoing task load on prospective memory task performance is not due to a perception that one or the other task is more important than the other.
Hanna, Gregory L.; Carrasco, Melisa; Harbin, Shannon M.; Nienhuis, Jenna K.; LaRosa, Christina E.; Chen, Poyu; Fitzgerald, Kate D.; Gehring, William J.
Objective The error-related negativity (ERN) is a negative deflection in the event-related potential following an incorrect response, which is often increased in patients with obsessive-compulsive disorder (OCD). However, the relationship of the ERN to comorbid tic disorders has not been examined in patients with OCD. This study compared ERN amplitudes in patients with tic-related OCD, patients with non-tic-related OCD, and healthy controls. Method The ERN, correct response negativity, and error number were measured during an Eriksen flanker task to assess performance monitoring in 44 youth with a lifetime diagnosis of OCD and 44 matched healthy controls ranging in age from 10 to 19 years. Nine youth with OCD had a lifetime history of tics. Results ERN amplitudewas significantly increased in OCD patients compared to healthy controls. ERN amplitude was significantly larger in patients with non-tic-related OCD than either patients with tic-related OCD or controls. ERN amplitude had a significant negative correlation with age in healthy controls but not patients with OCD. Instead, in patients with non-tic-related OCD, ERN amplitude had a significant positive correlation with age at onset of OCD symptoms. ERN amplitude in patients was unrelated to OCD symptom severity, current diagnostic status, or treatment effects. Conclusions The results provide further evidence of increased error-related brain activity in pediatric OCD. The difference in the ERN between patients with tic-related and non-tic-related OCD provides preliminary evidence of a neurobiological difference between these two OCD subtypes. The results indicate the ERN is a trait-like measure that may serve as a biomarker for non-tic-related OCD. PMID:22917203
Bugge, Anna; Tarp, Jakob; Østergaard, Lars; Domazet, Sidsel Louise; Andersen, Lars Bo; Froberg, Karsten
The aim of the study; LCoMotion - Learning, Cognition and Motion was to develop, document, and evaluate a multi-component physical activity (PA) intervention in public schools in Denmark. The primary outcome was cognitive function. Secondary outcomes were academic skills, body composition, aerobic fitness and PA. The primary aim of the present paper was to describe the rationale, design and methods of the LCoMotion study. LCoMotion was designed as a cluster-randomized controlled study. Fourteen schools from all five regions in Denmark participated. All students from 6th and 7th grades were invited to participate (n = 869) and consent was obtained for 87% (n = 759). Baseline measurements were obtained in November/December 2013 and follow-up measurements in May/June 2014. The intervention lasted five months and consisted of a "package" of three main components: PA during academic lessons, PA during recess and PA homework. Furthermore a cycling campaign was conducted during the intervention period. Intervention schools should endeavor to ensure that students were physically active for at least 60 min every school day. Cognitive function was measured by a modified Eriksen flanker task and academic skills by a custom made mathematics test. PA was objectively measured by accelerometers (ActiGraph, GT3X and GT3X+) and aerobic fitness assessed by an intermittent shuttle-run test (the Andersen intermittent running test). Furthermore, compliance with the intervention was assessed by short message service (SMS)-tracking and questionnaires were delivered to students, parents and teachers. LCoMotion has ability to provide new insights on the effectiveness of a multicomponent intervention on cognitive function and academic skills in 6th and 7th grade students. Clinicaltrials.gov: NCT02012881 (10/10/2013).
Domazet, Sidsel L; Tarp, Jakob; Huang, Tao; Gejl, Anne Kær; Andersen, Lars Bo; Froberg, Karsten; Bugge, Anna
To examine objectively measured physical activity level, organized sports participation and active commuting to school in relation to mathematic performance and inhibitory control in adolescents. The design was cross-sectional. A convenient sample of 869 sixth and seventh grade students (12-14 years) was invited to participate in the study. A total of 568 students fulfilled the inclusion criteria and comprised the final sample for this study. Mathematic performance was assessed by a customized test and inhibitory control was assessed by a modified Eriksen flanker task. Physical activity was assessed with GT3X and GT3X+ accelerometers presented in sex-specific quartiles of mean counts per minute and mean minutes per day in moderate-to-vigorous physical activity. Active commuting and sports participation was self-reported. Mixed model regression was applied. Total physical activity level was stratified by bicycling status in order to bypass measurement error subject to the accelerometer. Non-cyclists in the 2nd quartile of counts per minute displayed a higher mathematic score, so did cyclists in the 2nd and 3rd quartile of moderate-to-vigorous physical activity relative to the least active quartile. Non-cyclists in the 3rd quartile of counts per minute had an improved reaction time and cyclists in the 2nd quartile of counts per minute and moderate-to-vigorous physical activity displayed an improved accuracy, whereas non-cyclists in the 2nd quartile of counts per minute showed an inferior accuracy relative to the least active quartile. Bicycling to school and organized sports participation were positively associated with mathematic performance. Sports participation and bicycling were positively associated with mathematic performance. Results regarding objectively measured physical activity were mixed. Although, no linear nor dose-response relationship was observed there was no indication of a higher activity level impairing the scholastic or cognitive performance.
Sidsel L Domazet
Full Text Available To examine objectively measured physical activity level, organized sports participation and active commuting to school in relation to mathematic performance and inhibitory control in adolescents.The design was cross-sectional. A convenient sample of 869 sixth and seventh grade students (12-14 years was invited to participate in the study. A total of 568 students fulfilled the inclusion criteria and comprised the final sample for this study. Mathematic performance was assessed by a customized test and inhibitory control was assessed by a modified Eriksen flanker task. Physical activity was assessed with GT3X and GT3X+ accelerometers presented in sex-specific quartiles of mean counts per minute and mean minutes per day in moderate-to-vigorous physical activity. Active commuting and sports participation was self-reported. Mixed model regression was applied. Total physical activity level was stratified by bicycling status in order to bypass measurement error subject to the accelerometer.Non-cyclists in the 2nd quartile of counts per minute displayed a higher mathematic score, so did cyclists in the 2nd and 3rd quartile of moderate-to-vigorous physical activity relative to the least active quartile. Non-cyclists in the 3rd quartile of counts per minute had an improved reaction time and cyclists in the 2nd quartile of counts per minute and moderate-to-vigorous physical activity displayed an improved accuracy, whereas non-cyclists in the 2nd quartile of counts per minute showed an inferior accuracy relative to the least active quartile. Bicycling to school and organized sports participation were positively associated with mathematic performance.Sports participation and bicycling were positively associated with mathematic performance. Results regarding objectively measured physical activity were mixed. Although, no linear nor dose-response relationship was observed there was no indication of a higher activity level impairing the scholastic or cognitive
Choudhary, Dnyanraj; Bhattacharyya, Sauvik; Bose, Sekhar
Cognitive decline is often associated with the aging process. Ashwagandha (Withania somnifera (L.) Dunal) has long been used in the traditional Ayurvedic system of medicine to enhance memory and improve cognition. This pilot study was designed to evaluate the efficacy and safety of ashwagandha (Withania somnifera (L.) Dunal) in improving memory and cognitive functioning in adults with mild cognitive impairment (MCI). A prospective, randomized, double-blind, placebo-controlled study was conducted in 50 adults. Subjects were treated with either ashwagandha-root extract (300 mg twice daily) or placebo for eight weeks. After eight weeks of study, the ashwagandha treatment group demonstrated significant improvements compared with the placebo group in both immediate and general memory, as evidenced by Wechsler Memory Scale III subtest scores for logical memory I (p = 0.007), verbal paired associates I (p = 0.042), faces I (p = 0.020), family pictures I (p = 0.006), logical memory II (p = 0.006), verbal paired associates II (p = 0.031), faces II (p = 0.014), and family pictures II (p = 0.006). The treatment group also demonstrated significantly greater improvement in executive function, sustained attention, and information-processing speed as indicated by scores on the Eriksen Flanker task (p = 0.002), Wisconsin Card Sort test (p = 0.014), Trail-Making test part A (p = 0.006), and the Mackworth Clock test (p = 0.009). Ashwagandha may be effective in enhancing both immediate and general memory in people with MCI as well as improving executive function, attention, and information processing speed.
Huang, Tao; Gejl, Anne Kær; Froberg, Karsten
Objectives To examine objectively measured physical activity level, organized sports participation and active commuting to school in relation to mathematic performance and inhibitory control in adolescents. Methods The design was cross-sectional. A convenient sample of 869 sixth and seventh grade students (12–14 years) was invited to participate in the study. A total of 568 students fulfilled the inclusion criteria and comprised the final sample for this study. Mathematic performance was assessed by a customized test and inhibitory control was assessed by a modified Eriksen flanker task. Physical activity was assessed with GT3X and GT3X+ accelerometers presented in sex-specific quartiles of mean counts per minute and mean minutes per day in moderate-to-vigorous physical activity. Active commuting and sports participation was self-reported. Mixed model regression was applied. Total physical activity level was stratified by bicycling status in order to bypass measurement error subject to the accelerometer. Results Non-cyclists in the 2nd quartile of counts per minute displayed a higher mathematic score, so did cyclists in the 2nd and 3rd quartile of moderate-to-vigorous physical activity relative to the least active quartile. Non-cyclists in the 3rd quartile of counts per minute had an improved reaction time and cyclists in the 2nd quartile of counts per minute and moderate-to-vigorous physical activity displayed an improved accuracy, whereas non-cyclists in the 2nd quartile of counts per minute showed an inferior accuracy relative to the least active quartile. Bicycling to school and organized sports participation were positively associated with mathematic performance. Conclusions Sports participation and bicycling were positively associated with mathematic performance. Results regarding objectively measured physical activity were mixed. Although, no linear nor dose-response relationship was observed there was no indication of a higher activity level impairing the
Patino, Luis R; Adler, Caleb M; Mills, Neil P; Strakowski, Stephen M; Fleck, David E; Welge, Jeffrey A; DelBello, Melissa P
To examine conflict monitoring and conflict-driven adaptation in individuals at familial risk for developing bipolar disorder. We recruited 24 adolescents who had a parent with bipolar disorder and 23 adolescents with healthy parents. Participants completed an arrow version of the Eriksen Flanker Task that included trials with three levels of conflict: neutral, congruent, and incongruent flanks. Differences in performance were explored based upon the level of conflict in the current and previous trials. Individuals at risk for developing bipolar disorder performed more slowly than youth with healthy parents in all trials. Analyses evaluating sequential effects revealed that at-risk subjects responded more slowly than youth of healthy parents for all trial types when preceded by an incongruent trial, for incongruent trials preceded by congruent trials, and for neutral and congruent trials when preceded by neutral trials. In contrast to the comparison group, at-risk adolescents failed to display a response time advantage for incongruent trials preceded by an incongruent trial. When removing subjects with attention-deficit hyperactivity disorder (ADHD), differences between groups in response time fell below significant level, but a difference in sequence modulation remained significant. Subjects at risk for bipolar disorder also displayed greater intra-subject response time variability for incongruent and congruent trials compared with the comparison adolescents. No differences in response accuracy were observed between groups. Adolescents at risk for developing bipolar disorder displayed specific deficits in cognitive flexibility, which might be useful as a potential marker related to the development of bipolar disorder. © 2013 John Wiley and Sons A/S. Published by Blackwell Publishing Ltd.
Hanna, Gregory L; Carrasco, Melisa; Harbin, Shannon M; Nienhuis, Jenna K; LaRosa, Christina E; Chen, Poyu; Fitzgerald, Kate D; Gehring, William J
The error-related negativity (ERN) is a negative deflection in the event-related potential after an incorrect response, which is often increased in patients with obsessive-compulsive disorder (OCD). However, the relation of the ERN to comorbid tic disorders has not been examined in patients with OCD. This study compared ERN amplitudes in patients with tic-related OCD, patients with non-tic-related OCD, and healthy controls. The ERN, correct response negativity, and error number were measured during an Eriksen flanker task to assess performance monitoring in 44 youth with a lifetime diagnosis of OCD and 44 matched healthy controls ranging in age from 10 to 19 years. Nine youth with OCD had a lifetime history of tics. ERN amplitude was significantly increased in patients with OCD compared with healthy controls. ERN amplitude was significantly larger in patients with non-tic-related OCD than in patients with tic-related OCD or controls. ERN amplitude had a significant negative correlation with age in healthy controls but not in patients with OCD. Instead, in patients with non-tic-related OCD, ERN amplitude had a significant positive correlation with age at onset of OCD symptoms. ERN amplitude in patients was unrelated to OCD symptom severity, current diagnostic status, or treatment effects. The results provide further evidence of increased error-related brain activity in pediatric OCD. The difference in the ERN between patients with tic-related and those with non-tic-related OCD provides preliminary evidence of a neurobiological difference between these two OCD subtypes. The results indicate the ERN is a trait-like measurement that may serve as a biomarker for non-tic-related OCD. Copyright © 2012 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.
Farmer, George D.; Janssen, C.P.|info:eu-repo/dai/nl/412781654; Nguyen, Anh T; Brumby, Duncan P.
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.
Corbalan, Gemma; Kester, Liesbeth; van Merrienboer, Jeroen J. G.
Complex skill acquisition by performing authentic learning tasks is constrained by limited working memory capacity [Baddeley, A. D. (1992). Working memory. "Science, 255", 556-559]. To prevent cognitive overload, task difficulty and support of each newly selected learning task can be adapted to the learner's competence level and perceived task…
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…
Skehan, Peter; Xiaoyue, Bei; Qian, Li; Wang, Zhan
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…
Azkarai, Agurtzane; García Mayo, María del Pilar
Research has shown that tasks provide second language (L2) learners with many opportunities to learn the L2. Task repetition has been claimed to benefit L2 learning since familiarity with procedure and/or content gives learners the chance to focus on more specific aspects of language. Most research on task repetition has focused on adult…
Kray, Jutta; Gaspard, Hanna; Karbach, Julia; Blaye, Agnès
In this study we examined whether developmental changes in using verbal self-cueing for task-goal maintenance are dependent on the amount of task practice and task-sequencing demands. To measure task-goal maintenance we applied a switching paradigm in which children either performed only task A or B in single-task blocks or switched between them on every second trial in mixed-task blocks. Task-goal maintenance was determined by comparing the performance between both blocks (mixing costs). The influence of verbal self-cueing was measured by instructing children to either name the next task aloud or not to verbalize during task preparation. Task-sequencing demands were varied between groups whereas one group received spatial task cues to support keeping track of the task sequence, while the other group did not. We also varied by the amount of prior practice in task switching while one group of participants practiced task switching first, before performing the task naming in addition, and the other group did it vice versa. Results of our study investigating younger (8–10 years) and older children (11–13 years) revealed no age differences in beneficial effects of verbal self-cueing. In line with previous findings, children showed reduced mixing costs under task-naming instructions and under conditions of low task-sequence demands (with the presence of spatial task cues). Our results also indicated that these benefits were only obtained for those groups of children that first received practice in task switching alone with no additional verbalization instruction. These findings suggest that internal task-cueing strategies can be efficiently used in children but only if they received prior practice in the underlying task so that demands on keeping and coordinating various instructions are reduced. Moreover, children benefitted from spatial task cues for better task-goal maintenance only if no verbal task-cueing strategy was introduced first. PMID:24381566
Ewolds, Harald E; Bröker, Laura; de Oliveira, Rita F; Raab, Markus; Künzell, Stefan
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.
Stephanie A. Kazanas
Full Text Available This study was designed to investigate the impact of survival processing with a novel task for this paradigm: the Stroop color-naming task. As the literature is mixed with regard to task generalizability, with survival processing promoting better memory for words, but not better memory for faces or paired associates, these types of task investigations are important to a growing field of research. Using the Stroop task provides a unique contribution, as identifying items by color is an important evolutionary adaptation and not specific to humans as is the case with word recall. Our results indicate that survival processing, with its accompanying survival-relevance rating task, remains the best mnemonic strategy for word memory. However, our results also indicate that presenting the survival passage does not motivate better color-naming performance than color-naming alone. In addition, survival processing led to a larger amount of Stroop interference, though not significantly larger than the other conditions. Together, these findings suggest that considering one’s survival when performing memory and attention-based tasks does not enhance cognitive performance generally, although greater allocation of attentional resources to color-incongruent concrete objects could be considered adaptive. These findings support the notion that engaging in deeper processing via survival-relevance ratings may preserve these words across a variety of experimental manipulations.
Full Text Available Abstract We present the preparation, resources, results and analysis of three tasks of the BioNLP Shared Task 2011: the main tasks on Infectious Diseases (ID and Epigenetics and Post-translational Modifications (EPI, and the supporting task on Entity Relations (REL. The two main tasks represent extensions of the event extraction model introduced in the BioNLP Shared Task 2009 (ST'09 to two new areas of biomedical scientific literature, each motivated by the needs of specific biocuration tasks. The ID task concerns the molecular mechanisms of infection, virulence and resistance, focusing in particular on the functions of a class of signaling systems that are ubiquitous in bacteria. The EPI task is dedicated to the extraction of statements regarding chemical modifications of DNA and proteins, with particular emphasis on changes relating to the epigenetic control of gene expression. By contrast to these two application-oriented main tasks, the REL task seeks to support extraction in general by separating challenges relating to part-of relations into a subproblem that can be addressed by independent systems. Seven groups participated in each of the two main tasks and four groups in the supporting task. The participating systems indicated advances in the capability of event extraction methods and demonstrated generalization in many aspects: from abstracts to full texts, from previously considered subdomains to new ones, and from the ST'09 extraction targets to other entities and events. The highest performance achieved in the supporting task REL, 58% F-score, is broadly comparable with levels reported for other relation extraction tasks. For the ID task, the highest-performing system achieved 56% F-score, comparable to the state-of-the-art performance at the established ST'09 task. In the EPI task, the best result was 53% F-score for the full set of extraction targets and 69% F-score for a reduced set of core extraction targets, approaching a level
Yamamoto, Naohide; Incera, Sara; McLennan, Conor T.
In a reverse Stroop task, observers respond to the meaning of a color word irrespective of the color in which the word is printed—for example, the word red may be printed in the congruent color (red), an incongruent color (e.g., blue), or a neutral color (e.g., white). Although reading of color words in this task is often thought to be neither facilitated by congruent print colors nor interfered with incongruent print colors, this interference has been detected by using a response method that does not give any bias in favor of processing of word meanings or processing of print colors. On the other hand, evidence for the presence of facilitation in this task has been scarce, even though this facilitation is theoretically possible. By modifying the task such that participants respond to a stimulus color word by pointing to a corresponding response word on a computer screen with a mouse, the present study investigated the possibility that not only interference but also facilitation would take place in a reverse Stroop task. Importantly, in this study, participants’ responses were dynamically tracked by recording the entire trajectories of the mouse. Arguably, this method provided richer information about participants’ performance than traditional measures such as reaction time and accuracy, allowing for more detailed (and thus potentially more sensitive) investigation of facilitation and interference in the reverse Stroop task. These trajectories showed that the mouse’s approach toward correct response words was significantly delayed by incongruent print colors but not affected by congruent print colors, demonstrating that only interference, not facilitation, was present in the current task. Implications of these findings are discussed within a theoretical framework in which the strength of association between a task and its response method plays a critical role in determining how word meanings and print colors interact in reverse Stroop tasks. PMID:27199881
Gulbinaite, Rasa; van Viegen, Tara; Wieling, Martijn; Cohen, Michael X; VanRullen, Rufin
Rhythmic visual stimulation ("flicker") is primarily used to "tag" processing of low-level visual and high-level cognitive phenomena. However, preliminary evidence suggests that flicker may also entrain endogenous brain oscillations, thereby modulating cognitive processes supported by those brain rhythms. Here we tested the interaction between 10 Hz flicker and endogenous alpha-band (∼10 Hz) oscillations during a selective visuospatial attention task. We recorded EEG from human participants (both genders) while they performed a modified Eriksen flanker task in which distractors and targets flickered within (10 Hz) or outside (7.5 or 15 Hz) the alpha band. By using a combination of EEG source separation, time-frequency, and single-trial linear mixed-effects modeling, we demonstrate that 10 Hz flicker interfered with stimulus processing more on incongruent than congruent trials (high vs low selective attention demands). Crucially, the effect of 10 Hz flicker on task performance was predicted by the distance between 10 Hz and individual alpha peak frequency (estimated during the task). Finally, the flicker effect on task performance was more strongly predicted by EEG flicker responses during stimulus processing than during preparation for the upcoming stimulus, suggesting that 10 Hz flicker interfered more with reactive than proactive selective attention. These findings are consistent with our hypothesis that visual flicker entrained endogenous alpha-band networks, which in turn impaired task performance. Our findings also provide novel evidence for frequency-dependent exogenous modulation of cognition that is determined by the correspondence between the exogenous flicker frequency and the endogenous brain rhythms. SIGNIFICANCE STATEMENT Here we provide novel evidence that the interaction between exogenous rhythmic visual stimulation and endogenous brain rhythms can have frequency-specific behavioral effects. We show that alpha-band (10 Hz) flicker impairs stimulus
Sochenkova, A.; Sochenkov, I.; Makovetskii, A.; Vokhmintsev, A.; Melnikov, A.
Computer vision tasks are remaining very important for the last couple of years. One of the most complicated problems in computer vision is face recognition that could be used in security systems to provide safety and to identify person among the others. There is a variety of different approaches to solve this task, but there is still no universal solution that would give adequate results in some cases. Current paper presents following approach. Firstly, we extract an area containing face, then we use Canny edge detector. On the next stage we use convolutional neural networks (CNN) to finally solve face recognition and person identification task.
Barrett, Harrison H.; Myers, Kyle J.; Devaney, Nicholas; Dainty, J. C.; Caucci, Luca
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.
AD-A7l 43 ANALYSIS OF HUMAN COMMUNICATION DURING ASSEMBLY TASKS in1(U) CRNEGIE-MELLO UNIY PITTSBURGH PA ROBOTICS INST UNCLSSIIEDK S BARBER ET AL...ao I Dur~~~~IngAbcbyTs; 7c .S:in i lSAo .0. Analysis of Human Communication During Assembly Tasks K. Suzanne Barber and Gerald J. Agin CMU-RI-TR-86-1...TYPE or REPORT & PE-Rioo CevCZaz Analysis of Human Communication During Assembly Inlterim Tasks I . PERFORMING 00RG. REPORT NUMBER 1. £UT~oOR~e) IL
Remacle, J.; Quoidbach, G.
The concept of 'computerized management' of plant intervention tasks was developed by TRACTEBEL in 1983 for the Belgian power plants of ELECTRABEL. The main objective of the 'Computerized Management of Plant Intervention Tasks' is to help the staff of a nuclear or a conventional power plant in planning, organizing, and carrying out any (preventive or corrective) maintenance task. It consists of a group of interconnected functional modules acting on a unique and homogeneous data base. A short description of 3 modules is given, i.e., the 'User' Module, the 'Equipment' Module and the 'Periodic Procedure' Module. (Z.S.)
Heilskov-Hansen, Thomas; Svendsen, Susanne Wulff; Thomsen, Jane Frølund
OBJECTIVES: Sex differences in occupational biomechanical exposures may be part of the explanation why musculoskeletal complaints and disorders tend to be more common among women than among men. We aimed to determine possible sex differences in task distribution and task-specific postures...... correction were used to evaluate sex differences. RESULTS: Statistically significant (psex differences were revealed in task proportions, but the proportions differed by less than 4%. For task exposures, no statistically significant sex differences were found. CONCLUSIONS: Only minor sex differences...... and movements of the upper extremities among Danish house painters, and to establish sex-specific task exposure matrices. METHODS: To obtain task distributions, we sent out a questionnaire to all members of the Painters' Union in Denmark (N = 9364), of whom 53% responded. Respondents reported their task...
TASHMANOV E.B.; МАМАTOV М.S.
In this paper we consider the relationship of control tasks and image compression losses. The main idea of this approach is to allocate structural lines simplified image and further compress the selected data
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...
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...
Ergonomics is the study of physical interaction between humans and their working environment. The objective of this study was to characterize the performance of spinal anaesthesia in an acute hospital setting, applying ergonomic task analysis.
Developing communicative competence through thinking tasks - Experimenting with Thinking Approach in Danish as Second Language ClassroomSession on Innovations in the classroom, a presentation. Abstract for the conference Creativity & Thinking Skills in Learning, teaching & Management. Riga 19......-20 September 2014 Elina Maslo, Aarhus University, Department of Education, firstname.lastname@example.org Summary: The goal of this presentation is to present some of the experiences with thinking tasks in the Danish language classroom, conducted in the Nordplus Nordic Language Project “Problem solving tasks for learning...... of Danish as second and foreign language in transformative learning spaces”. Two teachers have developed and tried out some thinking tasks in their classrooms, with the aim to foster the development of students´ communicative competence. The learning processes from two classrooms will be analysed...
This report describes the work conducted in Task 10 of the V2I Safety Applications Development Project. The work was performed by the University of Michigan Transportation Research Institute (UMTRI) under contract to the Crash Avoidance Metrics Partn...
Higginbotham, Matthew T
In this monograph, by analyzing the UN, NATO and the US Army's evolving Modular Logistics Doctrine, the author integrates the key areas from each doctrine into a multinational logistics joint task force (MLJTF) organization...
Chow, Michael; Macnamara, Brooke N; Conway, Andrew R A
In a series of four experiments, we explored what conditions are sufficient to produce a phonological similarity facilitation effect in working memory span tasks. By using the same set of memoranda, but differing the secondary-task requirements across experiments, we showed that a phonological similarity facilitation effect is dependent upon the semantic relationship between the memoranda and the secondary-task stimuli, and is robust to changes in the representation, ordering, and pool size of the secondary-task stimuli. These findings are consistent with interference accounts of memory (Brown, Neath, & Chater, Psychological Review, 114, 539-576, 2007; Oberauer, Lewandowsky, Farrell, Jarrold, & Greaves, Psychonomic Bulletin & Review, 19, 779-819, 2012), whereby rhyming stimuli provide a form of categorical similarity that allows distractors to be excluded from retrieval at recall.
Full Text Available This paper presents our proposal and the implementation of an algorithm for automated refactoring of context-free grammars. Rather than operating under some domain-specific task, in our approach refactoring is perfomed on the basis of a refactoring task defined by its user. The algorithm and the corresponding refactoring system are called mARTINICA. mARTINICA is able to refactor grammars of arbitrary size and structural complexity. However, the computation time needed to perform a refactoring task with the desired outcome is highly dependent on the size of the grammar. Until now, we have successfully performed refactoring tasks on small and medium-size grammars of Pascal-like languages and parts of the Algol-60 programming language grammar. This paper also briefly introduces the reader to processes occurring in grammar refactoring, a method for describing desired properties that a refactored grammar should fulfill, and there is a discussion of the overall significance of grammar refactoring.
May 15, 1991 ... ergonomic selection, and was associated with the evolution of increasing behavioural ... The sequence in which tasks are perfonned by workers, .... space, providing a pictorial representation of the association between the ...
Schneider, Nathan; Hovy, Dirk; Johannsen, Anders Trærup
This task combines the labeling of multiword expressions and supersenses (coarse-grained classes) in an explicit, yet broad-coverage paradigm for lexical semantics. Nine systems participated; the best scored 57.7% F1 in a multi-domain evaluation setting, indicating that the task remains largely...... unresolved. An error analysis reveals that a large number of instances in the data set are either hard cases, which no systems get right, or easy cases, which all systems correctly solve....
Pannebakker, Merel Mathilde
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...
Park, Jin Kyun; Jung, Won Dea [KAERI, Daejeon (Korea, Republic of)
Estimating the likelihood of human error in a reliable manner is really important for enhancing the safety of a large process control system such as Nuclear Power Plants (NPPs). In this regard, from the point of view of Probabilistic Safety Assessment (PSA), various kinds of Human Reliability Analysis (HRA) methods have been used for several decades in order to systematically evaluate the effect of human error on the safety of NPPs. However, one of the recurrence issues is to determine the level of an important Performance Shaping Factor (PSF) by using a clear and objective manner with respect to the context of a given task. Unfortunately, there is no such criterion for a certain PSF such as the complexity of a task. For this reason, in this study, an objective criterion that is helpful for identifying a complicated task is suggested based on the Task Complexity (TACOM) measure. To this end, subjective difficulty scores rated by high speed train drivers are collected. After that, subjective difficulty scores are compared with the associated TACOM scores being quantified based on tasks to be conducted by high speed train drivers. As a result, it is expected that high speed train drivers feel a significant difficulty when they are faced with tasks of which the TACOM scores are greater than 4.2. Since TACOM measure is a kind of general tool to quantify the complexity of tasks to be done by human operators, it is promising to conclude that this value can be regarded as a common threshold representing what a complicated task is.
This paper discusses an integrated robot assembly task planning system architecture. In such an integrated system, the robot motion commands produced from the planning system can be validated before done-loading for actual execution.......This paper discusses an integrated robot assembly task planning system architecture. In such an integrated system, the robot motion commands produced from the planning system can be validated before done-loading for actual execution....
This paper provides a simple theoretical framework based on a new type of human capital introduced by Gibbons and Waldman (2004), called task-specific training, to understand job design. Mainly, in the presence of task-specific training, promotions might result ex-post in the underutilization of human capital and thus firms at the time of designing jobs should attempt to diversify this risk.
López, S Guerra; Fuster, J Iglesias; Reyes, M Martín; Collazo, T M Bravo; Quiñones, R Mendoza; Berazain, A Reyes; Rodríguez, M A Pedroso; Días de Villarvilla, T; Bobés, M Antonieta; Valdés-Sosa, M
In recent years, reports of attentional deficits in schizophrenic patients and in their biological relatives have rapidly increased, including an important effort to search for the endophenotypes in order to link specific genes to this illness. Posner et al. developed a test, the Attention Network Test (ANT), to study the neural networks. This test provides a separate measure for each one of the three anatomically-defined attention networks (alerting, orienting and executive control). In this paper, we investigate the attentional performance in 32 schizophrenic patients, 29 unaffected first degree relatives and 29 healthy controls using the ANT through a study of family association. We have studied the efficiency of the segregated executive control, alerting and orienting networks by measuring how response latencies (reaction time) were modified by the cue position and the flanking stimuli. We also studied the familial association of these attentional alterations. The ANOVA revealed main effects of flanker and cue condition and a significant interaction effect between flanker and groups studied. The schizophrenic patients and their relatives had a longer median reaction time than the control group. The probands and their relatives significantly differed from the healthy controls in terms of their conflict resolution; however, the alerting network appeared to be conserved. Our results support the thesis of a specific attentional deficit in schizophrenia and show the segregation of the three attentional networks. The family association of these reported alterations supports the idea of a potential endophenotype in schizophrenia.
Vatansever, D; Menon, D K; Manktelow, A E; Sahakian, B J; Stamatakis, E A
Initially described as task-induced deactivations during goal-directed paradigms of high attentional load, the unresolved functionality of default mode regions has long been assumed to interfere with task performance. However, recent evidence suggests a potential default mode network involvement in fulfilling cognitive demands. We tested this hypothesis in a finger opposition paradigm with task and fixation periods which we compared with an independent resting state scan using functional magnetic resonance imaging and a comprehensive analysis pipeline including activation, functional connectivity, behavioural and graph theoretical assessments. The results indicate task specific changes in the default mode network topography. Behaviourally, we show that increased connectivity of the posterior cingulate cortex with the left superior frontal gyrus predicts faster reaction times. Moreover, interactive and dynamic reconfiguration of the default mode network regions' functional connections illustrates their involvement with the task at hand with higher-level global parallel processing power, yet preserved small-world architecture in comparison with rest. These findings demonstrate that the default mode network does not disengage during this paradigm, but instead may be involved in task relevant processing. Copyright © 2015 Elsevier Inc. All rights reserved.
Liebel, Spencer W; Clark, Uraina S; Xu, Xiaomeng; Riskin-Jones, Hannah H; Hawkshead, Brittany E; Schwarz, Nicolette F; Labbe, Donald; Jerskey, Beth A; Sweet, Lawrence H
Our objective was to determine whether a Symbol Search paradigm developed for functional magnetic resonance imaging (FMRI) is a reliable and valid measure of cognitive processing speed (CPS) in healthy older adults. As all older adults are expected to experience cognitive declines due to aging, and CPS is one of the domains most affected by age, establishing a reliable and valid measure of CPS that can be administered inside an MR scanner may prove invaluable in future clinical and research settings. We evaluated the reliability and construct validity of a newly developed FMRI Symbol Search task by comparing participants' performance in and outside of the scanner and to the widely used and standardized Symbol Search subtest of the Wechsler Adult Intelligence Scale (WAIS). A brief battery of neuropsychological measures was also administered to assess the convergent and discriminant validity of the FMRI Symbol Search task. The FMRI Symbol Search task demonstrated high test-retest reliability when compared to performance on the same task administered out of the scanner (r=.791; pSymbol Search (r=.717; pSymbol Search task were also observed. The FMRI Symbol Search task is a reliable and valid measure of CPS in healthy older adults and exhibits expected sensitivity to the effects of age on CPS performance.
Hak, Sovannara; Mansard, Nicolas; Stasse, Olivier; Laumond, Jean Paul
Efficient methods to perform motion recognition have been developed using statistical tools. Those methods rely on primitive learning in a suitable space, for example, the latent space of the joint angle and/or adequate task spaces. Learned primitives are often sequential: A motion is segmented according to the time axis. When working with a humanoid robot, a motion can be decomposed into parallel subtasks. For example, in a waiter scenario, the robot has to keep some plates horizontal with one of its arms while placing a plate on the table with its free hand. Recognition can thus not be limited to one task per consecutive segment of time. The method presented in this paper takes advantage of the knowledge of what tasks the robot is able to do and how the motion is generated from this set of known controllers, to perform a reverse engineering of an observed motion. This analysis is intended to recognize parallel tasks that have been used to generate a motion. The method relies on the task-function formalism and the projection operation into the null space of a task to decouple the controllers. The approach is successfully applied on a real robot to disambiguate motion in different scenarios where two motions look similar but have different purposes.
When designing real-time systems, it is often desirable to schedule execution of software tasks based on the occurrence of events. The events may be clock ticks, interrupts from a hardware device, or software signals from other software tasks. If the nature of the events, is well understood, this scheduling is normally a static part of the system design. If the nature of the events is not completely understood, or is expected to change over time, it may be necessary to provide a mechanism for adjusting the scheduling of the software tasks. RHIC front-end computers (FECs) provide such a mechanism. The goals in designing this mechanism were to be as independent as possible of the underlying operating system, to allow for future expansion of the mechanism to handle new types of events, and to allow easy configuration. Some considerations which steered the design were programming paradigm (object oriented vs. procedural), programming language, and whether events are merely interesting moments in time, or whether they intrinsically have data associated with them. The design also needed to address performance and robustness tradeoffs involving shared task contexts, task priorities, and use of interrupt service routine (ISR) contexts vs. task contexts. This paper will explore these considerations and tradeoffs
Alexander, Eric; Gleicher, Michael
Topic modeling, a method of statistically extracting thematic content from a large collection of texts, is used for a wide variety of tasks within text analysis. Though there are a growing number of tools and techniques for exploring single models, comparisons between models are generally reduced to a small set of numerical metrics. These metrics may or may not reflect a model's performance on the analyst's intended task, and can therefore be insufficient to diagnose what causes differences between models. In this paper, we explore task-centric topic model comparison, considering how we can both provide detail for a more nuanced understanding of differences and address the wealth of tasks for which topic models are used. We derive comparison tasks from single-model uses of topic models, which predominantly fall into the categories of understanding topics, understanding similarity, and understanding change. Finally, we provide several visualization techniques that facilitate these tasks, including buddy plots, which combine color and position encodings to allow analysts to readily view changes in document similarity.
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.
Christian P Janssen
Full Text Available We investigate how good people are at multitasking by comparing behavior to a prediction of the optimal strategy for dividing attention between two concurrent tasks. In our experiment, 24 participants had to interleave entering digits on a keyboard with controlling a randomly moving cursor with a joystick. The difficulty of the tracking task was systematically varied as a within-subjects factor. Participants were also exposed to different explicit reward functions that varied the relative importance of the tracking task relative to the typing task (between-subjects. Results demonstrate that these changes in task characteristics and monetary incentives, together with individual differences in typing ability, influenced how participants choose to interleave tasks. This change in strategy then affected their performance on each task. A computational cognitive model was used to predict performance for a wide set of alternative strategies for how participants might have possibly interleaved tasks. This allowed for predictions of optimal performance to be derived, given the constraints placed on performance by the task and cognition. A comparison of human behavior with the predicted optimal strategy shows that participants behaved near optimally. Our findings have implications for the design and evaluation of technology for multitasking situations, as consideration should be given to the characteristics of the task, but also to how different users might use technology depending on their individual characteristics and their priorities.
Schuch, Stefanie; Grange, James A
Task inhibition is considered to facilitate switching to a new task and is assumed to decay slowly over time. Hence, more persisting inhibition needs to be overcome when returning to a task after one intermediary trial (ABA task sequence) than when returning after two or more intermediary trials (CBA task sequence). Schuch and Grange (J Exp Psychol Learn Mem Cogn 41:760-767, 2015) put forward the hypothesis that there is higher task conflict in ABA than CBA sequences, leading to increased cognitive control in the subsequent trial. They provided evidence that performance is better in trials following ABA than following CBA task sequences. Here, this effect of the previous task sequence ("N-3 effect") is further investigated by varying the cue-stimulus interval (CSI), allowing for short (100 ms) or long (900 ms) preparation time for the upcoming task. If increased cognitive control after ABA involves a better preparation for the upcoming task, the N-3 effect should be larger with long than short CSI. The results clearly show that this is not the case. In Experiment 1, the N-3 effect was smaller with long than short CSI; in Experiment 2, the N-3 effect was not affected by CSI. Diffusion model analysis confirmed previous results in the literature (regarding the effect of CSI and of the ABA-CBA difference); however, the N-3 effect was not unequivocally associated with any of the diffusion model parameters. In exploratory analysis, we also tested the alternative hypothesis that the N-3 effect involves more effective task shielding, which would be reflected in reduced congruency effects in trials following ABA, relative to trials following CBA; congruency effects did not differ between these conditions. Taken together, we can rule out two potential explanations of the N-3 effect: Neither is this effect due to enhanced task preparation, nor to more effective task shielding.
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.
Gathmann, Bettina; Schiebener, Johannes; Wolf, Oliver T.; Brand, Matthias
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
Benjamin Andrew Parris
Full Text Available In the present study participants completed two blocks of the Stroop task, one in which the Response-Stimulus Interval (RSI was 3500ms and one in which RSI was 200ms. It was expected that, in line with previous research, the shorter RSI would induce a low Task Conflict context by increasing focus on the colour identification goal in the Stroop task. Based on previous research showing the role of Task Conflict in the presence or absence Stroop facilitation, this was expected to lead to the novel finding of an increase in facilitation and simultaneous decrease in interference. Such a finding would be problematic for models of Stroop effects that predict these indices of performance should be affected in tandem. A crossover interaction is reported supporting these predictions. As predicted, the shorter RSI resulted in incongruent and congruent trial RTs decreasing relative to a static neutral baseline condition; hence interference decreased as facilitation increased. An explanatory model (expanding on the work of Goldfarb, Henik and colleagues is presented that: 1 Shows how under certain conditions the predictions from single mechanism models hold true (i.e. when Task conflict is held constant; 2 Shows how it is possible that interference can be affected by an experimental manipulation that leaves facilitation apparently untouched and; 3 Predicts that facilitation cannot be independently affected by an experimental manipulation.
Eskevich, Maria; Jones, Gareth J.F.; Chen, Shu; Aly, Robin; Ordelman, Roeland J.F.; Larson, Martha
The Search and Hyperlinking Task was one of the Brave New Tasks at MediaEval 2012. The Task consisted of two sub- tasks which focused on search and linking in retrieval from a collection of semi-professional video content. These tasks followed up on research carried out within the MediaEval 2011
Herz, A.; Jones, B.; Herz, E.; George, D.; Axelrad, P.; Gehly, S.
In Norse Mythology, Heimdall uses his foreknowledge and keen eyesight to keep watch for disaster from his home near the Rainbow Bridge. Orbit Logic and the Colorado Center for Astrodynamics Research (CCAR) at the University of Colorado (CU) have developed the Heimdall System to schedule observations of known and uncharacterized objects and search for new objects from the Maui Space Surveillance Site. Heimdall addresses the current need for automated and optimized SSA sensor tasking driven by factors associated with improved space object catalog maintenance. Orbit Logic and CU developed an initial baseline prototype SSA sensor tasking capability for select sensors at the Maui Space Surveillance Site (MSSS) using STK and STK Scheduler, and then added a new Track Prioritization Component for FiSST-inspired computations for predicted Information Gain and Probability of Detection, and a new SSA-specific Figure-of-Merit (FOM) for optimized SSA sensor tasking. While the baseline prototype addresses automation and some of the multi-sensor tasking optimization, the SSA-improved prototype addresses all of the key elements required for improved tasking leading to enhanced object catalog maintenance. The Heimdall proof-of-concept was demonstrated for MSSS SSA sensor tasking for a 24 hour period to attempt observations of all operational satellites in the unclassified NORAD catalog, observe a small set of high priority GEO targets every 30 minutes, make a sky survey of the GEO belt region accessible to MSSS sensors, and observe particular GEO regions that have a high probability of finding new objects with any excess sensor time. This Heimdall prototype software paves the way for further R&D that will integrate this technology into the MSSS systems for operational scheduling, improve the software's scalability, and further tune and enhance schedule optimization. The Heimdall software for SSA sensor tasking provides greatly improved performance over manual tasking, improved
Zwosta, Katharina; Hommel, Bernhard; Goschke, Thomas; Fischer, Rico
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.
The task of time estimation, an activity occasionally performed by pilots during actual flight, was investigated with the objective of providing human factors investigators with an unobtrusive and minimally loading additional task that is sensitive to differences in flying conditions and flight instrumentation associated with the main task of piloting an aircraft simulator. Previous research indicated that the duration and consistency of time estimates is associated with the cognitive, perceptual, and motor loads imposed by concurrent simple tasks. The relationships between the length and variability of time estimates and concurrent task variables under a more complex situation involving simulated flight were clarified. The wrap-around effect with respect to baseline duration, a consequence of mode switching at intermediate levels of concurrent task distraction, should contribute substantially to estimate variability and have a complex effect on the shape of the resulting distribution of estimates.
Jung, Won Dae; Park, Jink Yun
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.
Forsyth, Darryl K; Burt, Christopher D B
The scheduling component of the time management process was used as a "paradigm" to investigate the allocation of time to future tasks. In three experiments, we compared task time allocation for a single task with the summed time allocations given for each subtask that made up the single task. In all three, we found that allocated time for a single task was significantly smaller than the summed time allocated to the individual subtasks. We refer to this as the segmentation effect. In Experiment 3, we asked participants to give estimates by placing a mark on a time line, and found that giving time allocations in the form of rounded close approximations probably does not account for the segmentation effect. We discuss the results in relation to the basic processes used to allocate time to future tasks and the means by which planning fallacy bias might be reduced.
Full Text Available This paper outlines a framework for task representation and discusses applications to interference tasks in individual and joint settings. The framework is derived from the Theory of Event Coding. This theory regards task sets as transient assemblies of event codes in which stimulus and response codes interact and shape each other in particular ways. On the one hand, stimulus and response codes compete with each other within their respective subsets (horizontal interactions. On the other hand, stimulus and response code cooperate with each other (vertical interactions. Code interactions instantiating competition and cooperation apply to two time scales: on-line performance (i.e., doing the task and off-line implementation (i.e., setting the task. Interference arises when stimulus and response codes overlap in features that are irrelevant for stimulus identification, but relevant for response selection. To resolve this dilemma, the feature profiles of event codes may become restructured in various ways. The framework is applied to three kinds of interference paradigms. Special emphasis is given to joint settings where tasks are shared between two participants. Major conclusions derived from these applications include: (1 Response competition is the chief driver of interference. Likewise, different modes of response competition give rise to different patterns of interference. (2 The type of features in which stimulus and response codes overlap is also a crucial factor. Different types of such features give likewise rise to different patterns of interference. (3 Task sets for joint settings conflate intraindividual conflicts between responses (what, with interindividual conflicts between responding agents (whom. Features of response codes may, therefore, not only address responses, but also responding agents (both physically and socially.
This paper outlines a framework for task representation and discusses applications to interference tasks in individual and joint settings. The framework is derived from the Theory of Event Coding (TEC). This theory regards task sets as transient assemblies of event codes in which stimulus and response codes interact and shape each other in particular ways. On the one hand, stimulus and response codes compete with each other within their respective subsets (horizontal interactions). On the other hand, stimulus and response code cooperate with each other (vertical interactions). Code interactions instantiating competition and cooperation apply to two time scales: on-line performance (i.e., doing the task) and off-line implementation (i.e., setting the task). Interference arises when stimulus and response codes overlap in features that are irrelevant for stimulus identification, but relevant for response selection. To resolve this dilemma, the feature profiles of event codes may become restructured in various ways. The framework is applied to three kinds of interference paradigms. Special emphasis is given to joint settings where tasks are shared between two participants. Major conclusions derived from these applications include: (1) Response competition is the chief driver of interference. Likewise, different modes of response competition give rise to different patterns of interference; (2) The type of features in which stimulus and response codes overlap is also a crucial factor. Different types of such features give likewise rise to different patterns of interference; and (3) Task sets for joint settings conflate intraindividual conflicts between responses (what), with interindividual conflicts between responding agents (whom). Features of response codes may, therefore, not only address responses, but also responding agents (both physically and socially). PMID:26029085
Matthews, John A.J.; Gold, Michael S.
This report summarizes the work of Task A and B for the period 2013-2016. For Task A the work is for direct detection of dark matter with the single-phase liquid argon experiment Mini-CLEAN. For Task B the work is for the search for new physics in the analysis of fluorescence events with the Auger experiment and for the search for the indirect detection of dark matter with the HAWC experiment.
Full Text Available BACKGROUND: The anterior prefrontal cortex (PFC exhibits activation during some cognitive tasks, including episodic memory, reasoning, attention, multitasking, task sets, decision making, mentalizing, and processing of self-referenced information. However, the medial part of anterior PFC is part of the default mode network (DMN, which shows deactivation during various goal-directed cognitive tasks compared to a resting baseline. One possible factor for this pattern is that activity in the anterior medial PFC (MPFC is affected by dynamic allocation of attentional resources depending on task demands. We investigated this possibility using an event related fMRI with a face working memory task. METHODOLOGY/PRINCIPAL FINDINGS: Sixteen students participated in a single fMRI session. They were asked to form a task set to remember the faces (Face memory condition or to ignore them (No face memory condition, then they were given 6 seconds of preparation period before the onset of the face stimuli. During this 6-second period, four single digits were presented one at a time at the center of the display, and participants were asked to add them and to remember the final answer. When participants formed a task set to remember faces, the anterior MPFC exhibited activation during a task preparation period but deactivation during a task execution period within a single trial. CONCLUSIONS/SIGNIFICANCE: The results suggest that the anterior MPFC plays a role in task set formation but is not involved in execution of the face working memory task. Therefore, when attentional resources are allocated to other brain regions during task execution, the anterior MPFC shows deactivation. The results suggest that activation and deactivation in the anterior MPFC are affected by dynamic allocation of processing resources across different phases of processing.
Matthews, John A.J. [Univ. of New Mexico, Albuquerque, NM (United States); Gold, Michael S. [Univ. of New Mexico, Albuquerque, NM (United States)
This report summarizes the work of Task A and B for the period 2013-2016. For Task A the work is for direct detection of dark matter with the single-phase liquid argon experiment Mini-CLEAN. For Task B the work is for the search for new physics in the analysis of fluorescence events with the Auger experiment and for the search for the indirect detection of dark matter with the HAWC experiment.
Buchler, Norbou G; Hoyer, William J; Cerella, John
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.
Entel, Olga; Tzelgov, Joseph; Bereby-Meyer, Yoella; Shahar, Nitzan
In this study, we tested the proposal that the Stroop task involves two conflicts--task conflict and informational conflict. Task conflict was defined as the latency difference between color words and non-letter neutrals, and manipulated by varying the proportion of color words versus non-letter neutrals. Informational conflict was defined as the latency difference between incongruent and congruent trials and manipulated by varying the congruent-to-incongruent trial ratio. We replicated previous findings showing that increasing the ratio of incongruent-to-congruent trials reduces the latency difference between the incongruent and congruent condition (i.e., informational conflict), as does increasing the proportion of color words (i.e., task conflict). A significant under-additive interaction between the two proportion manipulations (congruent vs. incongruent and color words vs. neutrals) indicated that the effects of task conflict and informational conflict were not additive. By assessing task conflict as the contrast between color words and neutrals, we found that task conflict existed in all of our experimental conditions. Under specific conditions, when task conflict dominated behavior by explaining most of the variability between congruency conditions, we also found negative facilitation, thus demonstrating that this effect is a special case of task conflict.
Gaardboe, Rikke; Jonasen, Tanja Svarre; Nyvang, Tom
The purpose of this article is to investigate the relationship between task characteristics, business intelligence (BI) quality, and task compatibility. It is essential to investigate this relationship, as BI often builds up data from the organization's existing information systems, and thus......, is a supplement. In addition, there is a gap within existing research about task characteristics and BI. We conducted a survey of three companies, where 104 BI end users answered the questionnaire. Our findings reveal that BI users who experience high information quality solve difficult tasks, have a specified...
Meiran, Nachshon; Pereg, Maayan
Novel stimulus-response associations are retrieved automatically even without prior practice. Is this true for novel cue-task associations? The experiment involved miniblocks comprising three phases and task switching. In the INSTRUCTION phase, two new stimuli (or familiar cues) were arbitrarily assigned as cues for up-down/right-left tasks performed on placeholder locations. In the UNIVALENT phase, there was no task cue since placeholder's location afforded one task but the placeholders were the stimuli that we assigned as task cues for the following BIVALENT phase (involving target locations affording both tasks). Thus, participants held the novel cue-task associations in memory while executing the UNIVALENT phase. Results show poorer performance in the first univalent trial when the placeholder was associated with the opposite task (incompatible) than when it was compatible, an effect that was numerically larger with newly instructed cues than with familiar cues. These results indicate automatic retrieval of newly instructed cue-task associations.
Strouwen, Carolien; Molenaar, Esther A L M; Keus, Samyra H J; Münks, Liesbeth; Heremans, Elke; Vandenberghe, Wim; Bloem, Bastiaan R; Nieuwboer, Alice
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.
Ahmadian, Mohammad Javad
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…
Lafleur, Alexandre; Laflamme, Jonathan; Leppink, Jimmie; Côté, Luc
Models on pre-assessment learning effects confirmed that task demands stand out among the factors assessors can modify in an assessment to influence learning. However, little is known about which tasks in objective structured clinical examinations (OSCEs) improve students' cognitive and metacognitive processes. Research is needed to support OSCE designs that benefit students' metacognitive strategies when they are studying, reinforcing a hypothesis-driven approach. With that intent, hypothesis-driven physical examination (HDPE) assessments ask students to elicit and interpret findings of the physical exam to reach a diagnosis ("Examine this patient with a painful shoulder to reach a diagnosis"). When studying for HDPE, students will dedicate more time to hypothesis-driven discussions and practice than when studying for a part-task OSCE ("Perform the shoulder exam"). It is expected that the whole-task nature of HDPE will lead to a hypothesis-oriented use of the learning resources, a frequent use of adjustment strategies, and persistence with learning. In a mixed-methods study, 40 medical students were randomly paired and filmed while studying together for two hypothetical OSCE stations. Each 25-min study period began with video cues asking to study for either a part-task OSCE or an HDPE. In a crossover design, sequences were randomized for OSCEs and contents (shoulder or spine). Time-on-task for discussions or practice were categorized as "hypothesis-driven" or "sequence of signs and maneuvers." Content analysis of focus group interviews summarized students' perception of learning resources, adjustment strategies, and persistence with learning. When studying for HDPE, students allocate significantly more time for hypothesis-driven discussions and practice. Students use resources contrasting diagnoses and report persistence with learning. When studying for part-task OSCEs, time-on-task is reversed, spent on rehearsing a sequence of signs and maneuvers. OSCEs with
The main objective of the 'Computerized Management of Plant Intervention Tasks' is to help the staff of a nuclear or a conventional power plant or of any other complex industrial facility (chemical industries, refineries, and so on) in planning, organizing, and carrying out any (preventive or corrective) maintenance task. This 'Computerized Management of Plant Intervention Tasks' is organized around a data base of all plant components in the facility that might be subjected to maintenance or tagout. It allows to manage, by means of intelligent and configurable 'mail service', the course of the intervention requests as well as various treatments of those requests, in a safe and efficient way, adapted to each particular organization. The concept of 'Computerized Management' of plant intervention tasks was developed by BELGATOM in 1983 for the Belgian nuclear power plants of ELECTRABEL. A first implementation of this concept was made at that time for the Doel NPP under the name POPIT (Programming Of Plant Intervention Tasks). In 1988, it was decided to proceed to a functional upgrade of the application, using advanced software and hardware techniques and products, and to realize a second implementation in the Tihange NPP under the name ACM (Application Consignation Maintenance). (author)
In September of 1989 Cooper Nuclear Station began a project to upgrade the Technical Staff Training Program. This project's roots began by performing job and Task Analysis for Technical Staff. While the industry has long been committed to Job and Task Analysis to target performance based instruction for single job positions, this approach was unique in that it was not originally considered appropriate for a group as diverse as Tech Staff. Much to his satisfaction the Job and Task Analysis Project was much less complicated for Technical Staff than the author had imagined. The benefits of performing the Job and Task Analysis for Technical Staff have become increasingly obvious as he pursues lesson plan development and course revisions. The outline for this presentation will be as follows: philosophy adopted; preparation of the job survey document; performing the job analysis; performing task analysis for technical staff and associated pitfalls; clustering objectives for training and comparison to existing program; benefits now and in the future; final phase (comparison to INPO guides and meeting the needs of non-degreed engineering professionals); and conclusion. By focusing on performance based needs for engineers rather than traditional academics for training the author is confident the future Technical Staff Program will meet the challenges ahead and will exceed requirements for accreditation
Kambayashi, Shaw; Uenaka, Junji
In this report, a natural language analyzer and two different task planning systems are described. In 1988, we have introduced a Japanese language analyzer named CS-PARSER for the input interface of the task planning system in the Human Acts Simulation Program (HASP). For the purpose of a high speed analysis, we have modified a dictionary system of the CS-PARSER by using C language description. It is found that the new dictionary system is very useful for a high speed analysis and an efficient maintenance of the dictionary. For the study of the task planning problem, we have modified a story generating system named Micro TALE-SPIN to generate a story written in Japanese sentences. We have also constructed a planning system with natural language interface by using the CS-PARSER. Task planning processes and related knowledge bases of these systems are explained. A concept design for a new task planning system will be also discussed from evaluations of above mentioned systems. (author)
Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan
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.
Full Text Available In educational hypermedia environments, students are often confronted with potential sources of distraction arising from additional information that, albeit interesting, is unrelated to their current task goal. The paper investigates the conditions under which distraction occurs and hampers performance. Based on theories of volitional action control it was hypothesized that interesting information, especially if related to a pending goal, would interfere with task performance only when working on easy, but not on difficult tasks. In Experiment 1, 66 students learned about probability theory using worked examples and solved corresponding test problems, whose task difficulty was manipulated. As a second factor, the presence of interesting information unrelated to the primary task was varied. Results showed that students solved more easy than difficult probability problems correctly. However, the presence of interesting, but task-irrelevant information did not interfere with performance. In Experiment 2, 68 students again engaged in example-based learning and problem solving in the presence of task-irrelevant information. Problem-solving difficulty was varied as a first factor. Additionally, the presence of a pending goal related to the task-irrelevant information was manipulated. As expected, problem-solving performance declined when a pending goal was present during working on easy problems, whereas no interference was observed for difficult problems. Moreover, the presence of a pending goal reduced the time on task-relevant information and increased the time on task-irrelevant information while working on easy tasks. However, as revealed by mediation analyses these changes in overt information processing behavior did not explain the decline in problem-solving performance. As an alternative explanation it is suggested that goal conflicts resulting from pending goals claim cognitive resources, which are then no longer available for learning and
MacPherson, Sarah E; Turner, Martha S; Bozzali, Marco; Cipolotti, Lisa; Shallice, Tim
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.
Hui chuan Wang
Full Text Available For the past decade, translation learning has become one of the main foci for university language students in Taiwan. However, many studies have shown that translation teachers tend to adopt traditional teaching methods without considering class dynamics and student interactions. This paper therefore looks into the interactions in the researcher’s designed cooperative translation task, the Cooperative Translation Task, to see how these interactions helped or hindered students’ translation learning. A small class of 25 translation students and two translation teachers were participants. Videotaping and interviews were conducted in order to investigate the interaction modes and student participants’ perspectives toward each interaction mode. Six interaction modes were found in this task: within group, between group, translator group and comment-giver group, instructor and students, guest teacher and students, and instructor and guest teacher. Based on the results and participants’ responses, suggested teaching guidelines are provided.
Senanayake, Ransalu; Goonetilleke, Ravindra S
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.
Staffelbach, Matthew; Sempolinski, Peter; Kijewski-Correa, Tracy; Thain, Douglas; Wei, Daniel; Kareem, Ahsan; Madey, Gregory
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.
Novogrudska, Rina; Globa, Larysa; Schill, Alexsander; Romaniuk, Ryszard; Wójcik, Waldemar; Karnakova, Gaini; Kalizhanova, Aliya
The paper presents an approach to engineering tasks composition on engineering knowledge portals. The specific features of engineering tasks are highlighted, their analysis makes the basis for partial engineering tasks integration. The formal algebraic system for engineering tasks composition is proposed, allowing to set the context-independent formal structures for engineering tasks elements' description. The method of engineering tasks composition is developed that allows to integrate partial calculation tasks into general calculation tasks on engineering portals, performed on user request demand. The real world scenario «Calculation of the strength for the power components of magnetic systems» is represented, approving the applicability and efficiency of proposed approach.
Alabdulkarim, Saad; Nussbaum, Maury A; Rashedi, Ehsan; Kim, Sunwook; Agnew, Michael; Gardner, Richard
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.
Yamamoto, Naohide; Incera, Sara; McLennan, Conor T.
In a reverse Stroop task, observers respond to the meaning of a color word irrespective of the color in which the word is printed—for example, the word red may be printed in the congruent color (red), an incongruent color (e.g., blue), or a neutral color (e.g., white). Although reading of color words in this task is often thought to be neither facilitated by congruent print colors nor interfered with incongruent print colors, this interference has been detected by using a response method that...
Zazo Rodríguez, Ángel Francisco; Figuerola, Carlos G.; Alonso Berrocal, José Luis
This paper describes our work at CLEF 2007 Robust Task. We have participated in the monolingual (English, French and Portuguese) and the bilingual (English to French) subtask. At CLEF 2006 our research group obtained very good results applying local query expansion using windows of terms in the robust task. This year we have used the same expansion technique, but taking into account some criteria of robustness: MAP, GMAP, MMR, GS@10, P@10, number of failed topics, number of topics bellow 0.1 ...
This manual was developed to assist all DOE contractors in the design and conduct of job task analysis (JTA) for the radiation protection technician. Experience throughout the nuclear industry and the DOE system has indicated that the quality and efficiency in conducting a JTA at most sites is greatly enhanced by using a generic task list for the position, and clearly written guidelines on the JTA process. This manual is designed to provide this information for personnel to use in developing and conducting site-specific JTAs. (VC)
Basten, U.; Stelzel, C.; Fiebach, C.J.
Previous studies on individual differences in intelligence and brain activation during cognitive processing focused on brain regions where activation increases with task demands (task-positive network, TPN). Our study additionally considers brain regions where activation decreases with task demands
Koning, L. de; Maanen, P.P. van; Dongen, K. van
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
Meiran, Nachshon; Hsieh, Shulan; Chang, Chi-Chih
A major challenge for task switching is maintaining a balance between high task readiness and effectively ignoring irrelevant task rules. This calls for finely tuned inhibition that targets only the source of interference without adversely influencing other task-related representations. The authors show that irrelevant task rules generating response conflict are inhibited, causing their inefficient execution on the next trial (indicating the presence of competitor rule suppression[CRS];Meiran, Hsieh, & Dimov, Journal of Experimental Psychology: Learning, Memory and Cognition, 36, 992-1002, 2010). To determine whether CRS influences task rules, rather than target stimuli or responses, the authors focused on the processing of the task cue before the target stimulus was presented and before the response could be chosen. As was predicted, CRS was found in the event-related potentials in two time windows during task cue processing. It was also found in three time windows after target presentation. Source localization analyses suggest the involvement of the right dorsal prefrontal cortex in all five time windows.
Baggett, H. Lane; And Others
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…
Josep Coral Mateu
Full Text Available This article focuses on the characteristics of Physical Education-in-CLIL (PE-in-CLIL tasks. CLIL (Content and Language Integrated Learning is a teaching approach which uses foreign language as a tool to enhance the subject learning process. We connect PE-in-CLIL with key competences and we introduce the CLIL 4Cs framework. We establish the aims of the study, that is; to describe the features of tasks which are most suitable to PE-in-CLIL and identify integrated tasks which appeal most to learners. We use Action-Research and we collect data through diaries. The participants of the study were twenty-six learners of 5th grade of primary school. We described the strategies of rigour and quality applied and we analysed data using a qualitative data analysis software programme (NVivo. In the results, we identify both the tasks that appeal to students and the tasks that are developed successfully. In the conclusions, we provide teaching guidelines to plan successful PE-in-CLIL tasks that appeal to students. At this point, we emphasise tasks that combined both cooperative learning and oracy with motor activity and games. We also declare the necessity of incorporating scaffolding strategies in order to accommodate students’ linguistic needs and facilitate tasks development. Future CLIL research possibilities emerge in the Physical Education field of work.
Overbeek, T.; Boxtel, van Anton; Westerink, J.H.D.M.
Many studies show that respiratory sinus arrhythmia (RSA) decreases while performing cognitive tasks. However, there is uncertainty about the role of contaminating factors such as physical activity and stress-inducing task variables. Different methods to quantify RSA may also contribute to variable
Overbeek, T.J.M.; van Boxtel, A.; Westerink, J.H.D.M.
Many studies show that respiratory sinus arrhythmia (RSA) decreases while performing cognitive tasks. However, there is uncertainty about the role of contaminating factors such as physical activity and stress-inducing task variables. Different methods to quantify RSA may also contribute to variable
Task-Based Language Learning and Teaching has received sustained attention from teachers and researchers for over thirty years. It is a well-established pedagogy that includes the following characteristics: major focus on authentic and real-world tasks, choice of linguistic resources by learners, and a clearly defined non-linguistic outcome. This…
Shriberg, Lawrence D.; Lohmeier, Heather L.; Campbell, Thomas F.; Dollaghan, Christine A.; Green, Jordan R.; Moore, Christopher A.
Purpose: Conceptual and methodological confounds occur when non(sense) word repetition tasks are administered to speakers who do not have the target speech sounds in their phonetic inventories or who habitually misarticulate targeted speech sounds. In this article, the authors (a) describe a nonword repetition task, the Syllable Repetition Task…
McDonough, Kim; Fuentes, César García
This classroom study examines whether English L2 writers' language use differs depending on the writing task (operationalized as paragraph type), and task conditions (operationalized as individual or collaborative writing). The texts written by English L2 university students in Colombia (N = 26) in response to problem/solution and cause/effect…
Detailed logs of students' computer use, during independent study sessions, were captured in an open-access computer laboratory. Each log consisted of a chronological sequence of tasks representing either the application or the Internet domain displayed in the workstation's active window. Each task was classified using a three-tier schema…
Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan
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…
Kormos, Judit; Trebits, Anna
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…
Cox, Moniek G. P. J.; van der Smagt, Jasper J.; Noorman, Maartje; Wiesfeld, Ans C.; Volders, Paul G. A.; van Langen, Irene M.; Atsma, Douwe E.; Dooijes, Dennis; Houweling, Arjan C.; Loh, Peter; Jordaens, Luc; Arens, Yvonne; Cramer, Maarten J.; Doevendans, Pieter A.; van Tintelen, Peter; Wilde, Arthur A. M.; Hauer, Richard N. W.
Background-Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) Diagnostic Task Force Criteria (TFC) proposed in 1994 are highly specific but lack sensitivity. A new international task force modified criteria to improve diagnostic yield. A comparison of diagnosis by 1994 TFC versus
Overbeek, Thérèse J M; van Boxtel, Anton; Westerink, Joyce H D M
Many studies show that respiratory sinus arrhythmia (RSA) decreases while performing cognitive tasks. However, there is uncertainty about the role of contaminating factors such as physical activity and stress-inducing task variables. Different methods to quantify RSA may also contribute to variable results. In 83 healthy subjects, we studied RSA responses to a working memory task requiring varying levels of cognitive control and a perceptual attention task not requiring strong cognitive control. RSA responses were quantified in the time and frequency domain and were additionally corrected for differences in mean interbeat interval and respiration rate, resulting in eight different RSA indices. The two tasks were clearly differentiated by heart rate and facial EMG reference measures. Cognitive control induced inhibition of RSA whereas perceptual attention generally did not. However, the results show several differences between different RSA indices, emphasizing the importance of methodological variables. Age and sex did not influence the results. Copyright © 2014 Elsevier B.V. All rights reserved.
Kalanthroff, Eyal; Davelaar, Eddy J; Henik, Avishai; Goldfarb, Liat; Usher, Marius
The Stroop task is a central experimental paradigm used to probe cognitive control by measuring the ability of participants to selectively attend to task-relevant information and inhibit automatic task-irrelevant responses. Research has revealed variability in both experimental manipulations and individual differences. Here, we focus on a particular source of Stroop variability, the reverse-facilitation (RF; faster responses to nonword neutral stimuli than to congruent stimuli), which has recently been suggested as a signature of task conflict. We first review the literature that shows RF variability in the Stroop task, both with regard to experimental manipulations and to individual differences. We suggest that task conflict variability can be understood as resulting from the degree of proactive control that subjects recruit in advance of the Stroop stimulus. When the proactive control is high, task conflict does not arise (or is resolved very quickly), resulting in regular Stroop facilitation. When proactive control is low, task conflict emerges, leading to a slow-down in congruent and incongruent (but not in neutral) trials and thus to Stroop RF. To support this suggestion, we present a computational model of the Stroop task, which includes the resolution of task conflict and its modulation by proactive control. Results show that our model (a) accounts for the variability in Stroop-RF reported in the experimental literature, and (b) solves a challenge to previous Stroop models-their ability to account for reaction time distributional properties. Finally, we discuss theoretical implications to Stroop measures and control deficits observed in some psychopathologies. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Developmental tasks common to the formation of a reconstituted family are described, particularly the continued mourning of the old family; the formation of a solid marital relationship despite the difficulties presented by past failures and the presence of children; and the formation of sibling alliances across family lines. (Author)
Cameron, Cheryl A.; Beemsterboer, Phyllis L.; Johnson, Lynn A.; Mislevy, Robert J.; Steinberg, Linda S.; Breyer, F. Jay
As part of the development of a scoring algorithm for a simulation-based dental hygiene initial licensure examination, this effort conducted a task analysis of the dental hygiene domain. Broad classes of behaviors that distinguish along the dental hygiene expert-novice continuum were identified and applied to the design of nine paper-based cases…
Wilson, M.; Roos, N.; Huisman, B.; Witteveen, C.
NedTrain is a Dutch company tasked with performing the maintenance of the rolling stock of the national railway company, NS. NedTrain owns several workshops at different locations. The scheduling in one such workshop will be taken as point of departure for the discussion in this paper. After
Bohórquez Suárez, Ingrid Liliana; Gómez Sará, Mary Mily; Medina Mosquera, Sindy Lorena
This study analyzes what characterizes the negotiations of seventh graders at a public school in Bogotá when working in pairs to develop speaking tasks in EFL classes. The inquiry is a descriptive case study that follows the qualitative paradigm. As a result of analyzing the data, we obtained four consecutive steps that characterize students'…
accessible and available to the Veterans Benefits Administration ( VBA ) as soon as possible381; however, because military service records include health...programs are meeting expectations ........................................... 35 Facilitating Access to Health Care...Enduring RW Mission, Facilitating RW Recovery and Transition, and Facilitating Access to Health Care. SUMMARY 2 DoD Recovering Warrior Task Force
Donabedian, Bairj; McKinnon, Sharon M.; Bruns, William J., Jr.
Questions why managers choose one communication medium in preference to another. Proposes a role for social factors in media selection. Finds, employing a large field-collected sample, strong support for Information Richness Theory, a rational-choice model connecting managers' media choice to task characteristics like variety and analyzability.…
Both the standard economic model and bargaining theory make predictions about financial management and the division of household labor between household partners. Using a large Internet survey, we have tested several predictions about task divisions reported by Dutch household partners. The division
The paper describes the organization and management of the Gradual Upgrading of the Bohunice V1 NPP and the principle tasks and scope of activities provided by VUJE Trnava, Inc. It also describes the system of supplies and the system of quality assurance both in the consortium and in subcontractors. (author)
Bondesio, Mike J.
Conflict management has become an integral part of a headmaster's tasks. Headmasters are not required to suppress or resolve conflict, but to manage it. Since 1976, conflict in black schools has increased, and headmasters have had to manage serious and dangerous situations. Unfortunately, there has been little research in conflict management in…
For grades 3-5, our Common Core State Standards-based resource meets the geometry concepts addressed by the NCTM standards and encourages the students to learn and review the concepts in unique ways. Each task sheet is organized around a central problem taken from real-life experiences of the students.
For grades PK-2, our Common Core State Standards-based resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to learn and review the concepts in unique ways. Each task sheet is organized around a central problem taken from real-life experiences of the students.
For grades PK-2, our Common Core State Standards-based resource meets the geometry concepts addressed by the NCTM standards and encourages the students to learn and review the concepts in unique ways. Each task sheet is organized around a central problem taken from real-life experiences of the students.
Shevts, J.; Kunz, Eh.
The task and functions of the radiation-hygiene inspection in Czechoslovakia are presented. The radiation safety related information amounts that are to be presented to the hygiene inspection institutions are determined. The hygiene inspection content and forms at the stages of NPP designing, construction and operation are discussed. The hygiene inspection place is determined within the general radiation safety system [ru
Imants, P.; Greef, T.E. de
Future air traffic is expected to grow increasingly, opening up a gap for task dependent automation and adaptive interfaces, helping the Air Traffic Controller to cope with fluctuating workloads. One of the challenging factors in the application of such intelligent systems concerns the question what
Imants, P.; de Greef, T.F.A.
Future air traffic is expected to grow increasingly, opening up a gap for task dependent automation and adaptive interfaces, helping the Air Traffic Controller to cope with fluctuating workloads. One of the challenging factors in the application of such intelligent systems concerns the question what
Bragg, Leicha A.; Widjaja, Wanty; Loong, Esther Yook-Kin; Vale, Colleen; Herbert, Sandra
Reasoning in mathematics plays a critical role in developing mathematical understandings. In this article, Bragg, Loong, Widjaja, Vale & Herbert explore an adaptation of the Magic V Task and how it was used in several classrooms to promote and develop reasoning skills.
Dankenbring, Chelsey; Capobianco, Brenda M.; Eichinger, David
In this article, the authors provide an overview of engineering and the engineering design process, and describe the steps they took to develop a fifth grade-level, standards-based engineering design task titled "Getting the Dirt on Decomposition." Their main goal was to focus more on modeling the discrete steps they took to create and…
Defining educational objectives is the key to achieving the goal of professional competence in students. The technique of task analysis was selected to determine components of competence in clinical neurology appropriate to the needs of primary care. A survey of neurological problems in general practice revealed that ...
Task 1 Report summarizes on a country-by-country basis the data supplied by the participating states related to nuclear power forecast, spent fuel generation, AR storage capacity, AFR storage capacity, AFR storage and transport systems. Task Reports 2-5 analyse the spent fuel storage and transport situation according to reactor types. Information on the technical description of spent fuel existing storage and transport techniques and techniques under development and on costs is given. Task 6 summarizes the present legal framework for spent fuel management related to licensing, safety, environmental and physical protection, accounting and control of nuclear material by states, non-proliferation of nuclear weapons, assurances for national access to nuclear material contained in spent fuel, and protection of technology. The institutional practice for spent fuel storage and transport is described. For the period up to the year 2025 a prognosis and recommendations related to legal framework and institutional models are given. The special needs of developing countries and industrialized countries with a limited nuclear power programme with respect to spent fuel management are analysed in Task Reports 7 and 8
Anderson, C.; Hushon, J.
From April to August, 1978 MITRE supported the Health Effects Assessment Task Force sponsored by the Office of the Assistant Secretary for the Environment at DOE. The findings of that Task Force are incorporated in this report and include a detailed definition of health effects assessment, a survey of the mandates for health effects assessments within DOE/EV, a review of current DOE-EV health effects assessment activities, an analysis of the constraints affecting the health effects assessment process and a discussion of the Task Force recommendations. Included as appendices are summaries of two workshops conducted by the Task Force to determine the state-of-the-art of health effects assessment and modeling and a review of risk assessment activities in other federal agencies. The primary recommendation of the panel was that an office be designated or created under the Office of the Assistant Secretary for the Environment to coordinate the Health Effects Risk Assessment effort covering up to 40 program and policy areas; a similar need was expressed for the environmental effects assessment area. 1 tab
A.K. Amin (Alia)
htmlabstractThis PhD project aims at understanding and supporting the complex activities of information gathering. To date, most search applications support one aspect of search namely low-level keyword-based search to find documents. However, in reality, users search tasks are often high-level
Consequently the present researchers motivated by this fact set out to determine the level of relationship between occupational maladjustment and task performance of civil servants in Anambra state. Three research questions and one hypothesis guided the study. The design for the study is correlational survey used to ...
Hendriksen, P.; Riemersma, I.J.; Rijkeboer, R.C.; Rondel, M.; Schmal, D.; Smokers, R.T.M.
In Task 2 of the MATADOR-project1 measurement methods have been developed for the evaluation of the energy consumption and emissions of vehicles with advanced propulsion systems, such as battery-electric, hybrid-electric and fuel cell vehicles. Based on an inventory of existing and prospective
Cockpit task management (CTM) involves the initiation, monitoring, prioritizing, and allocation of resources to concurrent tasks as well as termination of multiple concurrent tasks. As aircrews have more tasks to attend to due to reduced crew sizes and the increased complexity of aircraft and the air transportation system, CTM will become a more critical factor in aviation safety. It is clear that many aviation accidents and incidents can be satisfactorily explained in terms of CTM errors, and it is likely that more accidents induced by poor CTM practice will occur in the future unless the issue is properly addressed. The first step in understanding and facilitating CTM behavior was the development of a preliminary, normative theory of CTM which identifies several important CTM functions. From this theory, some requirements for pilot-vehicle interfaces were developed which are believed to facilitate CTM. A prototype PVI was developed which improves CTM performance and currently, a research program is under way that is aimed at developing a better understanding of CTM and facilitating CTM performance through better equipment and procedures.
Bunnell, L.R.; Doremus, L.A.; Topping, J.B.; Duncan, D.R.
The Pacific Northwest Laboratory is conducting the Solid Waste Technology Support Program (SWTSP) for Westinghouse Hanford Company (WHC). Task E is the Container Corrosion Study Portion of the SWTSP that will perform testing to provide defensible data on the corrosion of low-carbon steel, as used in drums to contain chemical and radioactive wastes at the Hanford Site. A second objective of Task E is to provide and test practical alternative materials that have higher corrosion resistance than low-carbon steel. The scope of work for fiscal year (FY) 1993 included initial testing of mild steel specimens buried in Hanford soils or exposed to atmospheric corrosion in metal storage sheds. During FY 1993, progress was made in three areas of Task E. First, exposure of test materials began at the Soil Corrosion Test Site where low-carbon steel specimens were placed in the soil in five test shafts at depths of 9 m (30 ft). Second, the corrosion measurement of low-carbon steel in the soil of two solid waste trenches continued. The total exposure time is ∼ 500 days. Third, an atmospheric corrosion test of low-carbon steel was put initiated in a metal shed (Building 2401-W) in the 200 West Area. This annual report describes the Task E efforts and provides a current status
Cervera, R; Rodríguez-Pintó, I
The Task Force on Catastrophic Antiphospholipid Syndrome (CAPS) aimed to assess the current knowledge on pathogenesis, clinical and laboratory features, diagnosis and classification, precipitating factors and treatment of CAPS. This article summarizes the main aspects of its final report. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
This is a comparative analysis of leadership related to organizational culture and change that occurred at a large Canadian university during a twenty year period 1983-2003. From an institutional development perspective, leadership is characterized as a culture creation and development responsibility. By centering on the tasks of learning culture,…
Lin, Lin; Cockerham, Deborah; Chang, Zhengsi; Natividad, Gloria
As new technologies increase the opportunities for multitasking, the need to understand human capacities for multitasking continues to grow stronger. Is multitasking helping us to be more efficient? This study investigated the multitasking abilities of 168 participants, ages 6-72, by measuring their task accuracy and completion time when they…
W. H. Neuser
The first answer includes both a review of the previous six Congresses as well as a glance at recent Calvin literature; the second answer will be developed in the overview which follows, titled The future tasks of Calvin research.
Bay, Niels; Henningsen, Poul; Eriksen, Morten
The present report is documentation for the work carried out at DTU on the Brite/Euram project No. BE96-3340, contract No. BRPR-CT97-0398, with the title Enhanced Framework for forging design using reliable three-dimensional simulation (EFFORTS). The objective of task 3 is to determine data...
Abbott, Amy L.; Wren, Douglas G.
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…
Biemans, Frank P.; Vissers, C.A.
The design of Manufacturing Planning and Control Systems (MPCSs) — systems that negotiate with Customers and Suppliers to exchange products in return for money in order to generate profit, is discussed. The computational task of MPCS components are systematically specified as a starting point for
Livy, Sharyn; Muir, Tracey; Sullivan, Peter
Productive struggle leads to productive classrooms where students work on complex problems, are encouraged to take risks, can struggle and fail yet still feel good about working on hard problems (Boaler, 2016). Teachers can foster a classroom culture that values and promotes productive struggle by providing students with challenging tasks. These…
Education Commission of the States, Denver, CO.
Because ill-clothed, sick, or hungry migrant children learn poorly, the Task Force has emphasized the migrant health situation in 1979. Migrant workers have a 33% shorter life expectancy, a 25% higher infant mortality rate, and a 25% higher death rate from tuberculosis and other communicable diseases than the national average. Common among…
Geiger, Vince; Forgasz, Helen; Goos, Merrilyn; Bennison, Anne
Numeracy is a fundamental component of the Australian National Curriculum as a General Capability identified in each F-10 subject. In this paper, we consider the principles of design necessary for the development of numeracy tasks specific to subjects other than mathematics--in this case, the subject of English. We explore the nature of potential…
Zilinskas, Raymond A
In the run-up to his reelection, Russian president Vladimir Putin outlined 28 tasks to be undertaken by his administration, including one that commanded the development of weapons based on “genetic principles.” Political pressure must be applied by governments and professional societies to ensure that there is not a modern reincarnation of the Soviet biological warfare program.
Laverty, Megan J.
Philosophers of education regularly undertake the challenging task of defining their field and what it is they do. John White and Harvey Siegel are no exception: Siegel categorizes philosophy of education as a branch of philosophy, and White responds that philosophers of education would do better to adopt a Deweyan perspective. White claims that…
Orasanu, Judith; Tada, Yuri; Kraft, Norbert; Fischer, Ute
Sending astronauts into space, especially on long-durations missions (e.g. three-year missions to Mars), entails enormous risk. Threats include both physical dangers of radiation, bone loss and other consequences of weightlessness, and also those arising from interpersonal problems associated with extended life in a high-risk isolated and confined environment. Before undertaking long-duration missions, NASA seeks to develop technologies to monitor indicators of potentially debilitating stress at both the individual and team level so that countermeasures can be introduced to prevent further deterioration. Doing so requires a better understanding of indicators of team health and performance. To that end, a study of team problem solving in a simulation environment was undertaken to explore effects of team and task stress. Groups of four males (25-45 yrs) engaged in six dynamic computer-based Antarctic search and rescue missions over four days. Both task and team stressors were manipulated. Physiological responses (ECG, respiration rate and amplitude, SCL, EMG, and PPG); communication (voice and email); individual personality and subjective team dynamics responses were collected and related to task performance. Initial analyses found that physiological measures can be used to identify transient stress, predict performance, and reflect subjective workload. Muscle tension and respiration were the most robust predictors. Not only the level of arousal but its variability during engagement in the task is important to consider. In general, less variability was found to be associated with higher levels of performance. Individuals scoring high on specific personality characteristics responded differently to task stress.
Wavering, Albert J.; Lumia, Ron
A major consideration in the design of trajectory generation software for a Flight Telerobotic Servicer (FTS) is that the FTS will be called upon to perform tasks which require a diverse range of manipulator behaviors and capabilities. In a hierarchical control system where tasks are decomposed into simpler and simpler subtasks, the task decomposition module which performs trajectory planning and execution should therefore be able to accommodate a wide range of algorithms. In some cases, it will be desirable to plan a trajectory for an entire motion before manipulator motion commences, as when optimizing over the entire trajectory. Many FTS motions, however, will be highly sensory-interactive, such as moving to attain a desired position relative to a non-stationary object whose position is periodically updated by a vision system. In this case, the time-varying nature of the trajectory may be handled either by frequent replanning using updated sensor information, or by using an algorithm which creates a less specific state-dependent plan that determines the manipulator path as the trajectory is executed (rather than a priori). This paper discusses a number of trajectory generation techniques from these categories and how they may be implemented in a task decompo-sition module of a hierarchical control system. The structure, function, and interfaces of the proposed trajectory gener-ation module are briefly described, followed by several examples of how different algorithms may be performed by the module. The proposed task decomposition module provides a logical structure for trajectory planning and execution, and supports a large number of published trajectory generation techniques.
Yoon, Wan Chul; Park, Ji Soo; Baek, Dong Hyeon; Ham, Dong Han; Kim, Huhn [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)
While task analysis is one of the essential processes for human factors studies, traditional methods reveal weaknesses in dealing with the cognitive aspects, which become more critical in modern complex system. This report proposes a cognitive task analysis (CTA) method for identifying cognitive requirements of operators' tasks in nuclear power plants. The proposed CTA method is characterized by the information-oriented concept and procedure-based approach. The task prescription identifies the information requirements and trace the information flow to reveal the cognitive organization of task procedure with emphasis to the relations among the information requirements. The cognitive requirements are then analyzed in terms of cognitive span of task information, cognitive envelope and working memory relief point of t procedures, and working memory load. The proposed method is relatively simple and, possibly being incorporated in a full task analysis scheme, directly applicable to the design/evaluation of human-machine interfaces and operating procedures. A prototype of a computerized support system is developed for supporting the practicality of the proposed method. (Author) 104 refs., 8 tabs., 7 figs.
González-Villar, Alberto J; Triñanes, Yolanda; Zurrón, Montserrat; Carrillo-de-la-Peña, María T
Although there is evidence for preferential perceptual processing of written emotional information, the effects of attentional manipulations and the time course of affective processing require further clarification. In this study, we attempted to investigate how the emotional content of words modulates cerebral functioning (event-related potentials, ERPs) and behavior (reaction times, RTs) when the content is task-irrelevant (emotional Stroop Task, EST) or task-relevant (emotional categorization task, ECT), in a sample of healthy middle-aged women. In the EST, the RTs were longer for emotional words than for neutral words, and in the ECT, they were longer for neutral and negative words than for positive words. A principal components analysis of the ERPs identified various temporospatial factors that were differentially modified by emotional content. P2 was the first emotion-sensitive component, with enhanced factor scores for negative nouns across tasks. The N2 and late positive complex had enhanced factor scores for emotional relative to neutral information only in the ECT. The results reinforce the idea that written emotional information has a preferential processing route, both when it is task-irrelevant (producing behavioral interference) and when it is task-relevant (facilitating the categorization). After early automatic processing of the emotional content, late ERPs become more emotionally modulated as the level of attention to the valence increases.
Jansen, Reinier J; Sawyer, Ben D; van Egmond, René; de Ridder, Huib; Hancock, Peter A
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.
Frost, David M; Beach, Tyson A C; McGill, Stuart M; Callaghan, Jack P
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.
Yoon, Wan Chul; Park, Ji Soo; Baek, Dong Hyeon; Ham, Dong Han; Kim, Huhn [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)
While task analysis is one of the essential processes for human factors studies, traditional methods reveal weaknesses in dealing with the cognitive aspects, which become more critical in modern complex system. This report proposes a cognitive task analysis (CTA) method for identifying cognitive requirements of operators' tasks in nuclear power plants. The proposed CTA method is characterized by the information-oriented concept and procedure-based approach. The task prescription identifies the information requirements and trace the information flow to reveal the cognitive organization of task procedure with emphasis to the relations among the information requirements. The cognitive requirements are then analyzed in terms of cognitive span of task information, cognitive envelope and working memory relief point of t procedures, and working memory load. The proposed method is relatively simple and, possibly being incorporated in a full task analysis scheme, directly applicable to the design/evaluation of human-machine interfaces and operating procedures. A prototype of a computerized support system is developed for supporting the practicality of the proposed method. (Author) 104 refs., 8 tabs., 7 figs.
Mouthon, A; Ruffieux, J; Wälchli, M; Keller, M; Taube, W
Non-physical balance training has demonstrated to be efficient to improve postural control in young people. However, little is known about the potential to increase corticospinal excitability by mental simulation in lower leg muscles. Mental simulation of isolated, voluntary contractions of limb muscles increase corticospinal excitability but more automated tasks like walking seem to have no or only minor effects on motor-evoked potentials (MEPs) evoked by transcranial magnetic stimulation (TMS). This may be related to the way of performing the mental simulation or the task itself. Therefore, the present study aimed to clarify how corticospinal excitability is modulated during AO+MI, MI and action observation (AO) of balance tasks. For this purpose, MEPs and H-reflexes were elicited during three different mental simulations (a) AO+MI, (b) MI and (c) passive AO. For each condition, two balance tasks were evaluated: (1) quiet upright stance (static) and (2) compensating a medio-lateral perturbation while standing on a free-swinging platform (dynamic). AO+MI resulted in the largest facilitation of MEPs followed by MI and passive AO. MEP facilitation was significantly larger in the dynamic perturbation than in the static standing task. Interestingly, passive observation resulted in hardly any facilitation independent of the task. H-reflex amplitudes were not modulated. The current results demonstrate that corticospinal excitability during mental simulation of balance tasks is influenced by both the type of mental simulation and the task difficulty. As H-reflexes and background EMG were not modulated, it may be argued that changes in excitability of the primary motor cortex were responsible for the MEP modulation. From a functional point of view, our findings suggest best training/rehabilitation effects when combining MI with AO during challenging postural tasks. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Altmann, Erik M.; Gray, Wayne D.
A model of cognitive control in task switching is developed in which controlled performance depends on the system maintaining access to a code in episodic memory representing the most recently cued task. The main constraint on access to the current task code is proactive interference from old task codes. This interference and the mechanisms that…
Lorist, MM; Klein, Martin; Nieuwenhuis, S; De Jong, R; Mulder, G; Meijman, TF
The effects of mental fatigue on planning and preparation for future actions were examined, using a task switching paradigm. Fatigue was induced by "time on task," with subjects performing a switch task continuously for 2 hr. Subjects had to alternate between tasks on every second trial, so that a
... Committee--New Task AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of new task... Rulemaking Advisory Committee (ARAC) a new task to develop a comprehensive program of voluntary accreditation... maintenance program (CAMP). This task addresses, in part, the ARAC recommendation developed by the Commercial...
... Committee--New Task AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of withdrawal of task assignment for the Aviation Rulemaking Advisory Committee (ARAC). SUMMARY: The FAA has withdrawn a task... is to inform the public of the FAA's decision to withdraw this task. FOR FURTHER INFORMATION CONTACT...
... 32 National Defense 5 2010-07-01 2010-07-01 false Commander of a task force. 700.1053 Section 700... Command Detail to Duty § 700.1053 Commander of a task force. (a) A geographic fleet commander, and any other naval commander, may detail in command of a task force, or other task command, any eligible...
Pannebakker, M.M.; Band, G.P.H.; Ridderinkhof, K.R.
Traditionally, dual-task interference has been attributed to the consequences of task load exceeding capacity limitations. However, the current study demonstrates that in addition to task load, the mutual compatibility of the concurrent processes modulates whether 2 tasks can be performed in
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
This Notice announces two industry-wide Task Forces being formed in response to generic exposure data requirements. It contains EPA's policy on a registrant's options for, and responsibilities when joining Task Force as a way to satisfy data requirements.
Howell, David R; Oldham, Jessie R; DiFabio, Melissa; Vallabhajosula, Srikant; Hall, Eric E; Ketcham, Caroline J; Meehan, William P; Buckley, Thomas A
Gait impairments have been documented following sport-related concussion. Whether preexisting gait pattern differences exist among athletes who participate in different sport classifications, however, remains unclear. Dual-task gait examinations probe the simultaneous performance of everyday tasks (ie, walking and thinking), and can quantify gait performance using inertial sensors. The purpose of this study was to compare the single-task and dual-task gait performance of collision/contact and noncontact athletes. A group of collegiate athletes (n = 265) were tested before their season at 3 institutions (mean age= 19.1 ± 1.1 years). All participants stood still (single-task standing) and walked while simultaneously completing a cognitive test (dual-task gait), and completed walking trials without the cognitive test (single-task gait). Spatial-temporal gait parameters were compared between collision/contact and noncontact athletes using MANCOVAs; cognitive task performance was compared using ANCOVAs. No significant single-task or dual-task gait differences were found between collision/contact and noncontact athletes. Noncontact athletes demonstrated higher cognitive task accuracy during single-task standing (P = .001) and dual-task gait conditions (P = .02) than collision/contact athletes. These data demonstrate the utility of a dual-task gait assessment outside of a laboratory and suggest that preinjury cognitive task performance during dual-tasks may differ between athletes of different sport classifications.
Pretz, Jean E; Link, John A
This article presents a Web-based tool for the creation of divergent-thinking and open-ended creativity tasks. A Java program generates HTML forms with PHP scripting that run an Alternate Uses Task and/or open-ended response items. Researchers may specify their own instructions, objects, and time limits, or use default settings. Participants can also be prompted to select their best responses to the Alternate Uses Task (Silvia et al., 2008). Minimal programming knowledge is required. The program runs on any server, and responses are recorded in a standard MySQL database. Responses can be scored using the consensual assessment technique (Amabile, 1996) or Torrance's (1998) traditional scoring method. Adoption of this Web-based tool should facilitate creativity research across cultures and access to eminent creators. The Creative Task Creator may be downloaded from the Psychonomic Society's Archive of Norms, Stimuli, and Data, www.psychonomic.org/archive.
Full Text Available A multisensor scheduling algorithm based on the hybrid task decomposition and modified binary particle swarm optimization (MBPSO is proposed. Firstly, aiming at the complex relationship between sensor resources and tasks, a hybrid task decomposition method is presented, and the resource scheduling problem is decomposed into subtasks; then the sensor resource scheduling problem is changed into the match problem of sensors and subtasks. Secondly, the resource match optimization model based on the sensor resources and tasks is established, which considers several factors, such as the target priority, detecting benefit, handover times, and resource load. Finally, MBPSO algorithm is proposed to solve the match optimization model effectively, which is based on the improved updating means of particle’s velocity and position through the doubt factor and modified Sigmoid function. The experimental results show that the proposed algorithm is better in terms of convergence velocity, searching capability, solution accuracy, and efficiency.
Adrien, J L; Tanguay, P; Barthélémy, C; Martineaú, J; Perrot, A; Hameury, L; Sauvage, D
Many mentally retarded autistic children can understand the concept of object permanence, but, in comparison to developmental-age matched normal children, the behavioral strategies they employ in carrying out the Casati-Lezine Object Permanence Test are deficient and lead to failure. These deficiencies appear unrelated to interference of stereotypic or other bizarre behavior in task performance. Similar problem-solving deficiencies can be found in mentally retarded children who are not autistic, suggesting that the deficiencies themselves are less related to the social-communication deficits of autistic children, but more to the general problem-solving difficulties found in children with a lower developmental quotient. Nevertheless, the qualitative analysis of results shows a tendency in autistic children, despite their better developmental level, to use less coordinated and regular sequences to solve the task than normal or mentally retarded children.
Palmisano, Ignazio; Tamma, Valentina; Payne, Terry; Doran, Paul
Ontology Modularization techniques identify coherent and often reusable regions within an ontology. The ability to identify such modules, thus potentially reducing the size or complexity of an ontology for a given task or set of concepts is increasingly important in the Semantic Web as domain ontologies increase in terms of size, complexity and expressivity. To date, many techniques have been developed, but evaluation of the results of these techniques is sketchy and somewhat ad hoc. Theoretical properties of modularization algorithms have only been studied in a small number of cases. This paper presents an empirical analysis of a number of modularization techniques, and the modules they identify over a number of diverse ontologies, by utilizing objective, task-oriented measures to evaluate the fitness of the modules for a number of statistical classification problems.
Rimvall, M K; Clemmensen, L; Munkholm, A
the Kiddie-SADS-PL. Register data described family history of mental disorders. Exaggerated Theory of Mind functioning (hyper-ToM) was measured by the ToM Storybook Frederik. A total of 145 (10%) children experienced speech illusions (hearing speech in the absence of speech stimuli), of which 102 (70......Auditory verbal hallucinations (AVH) are common during development and may arise due to dysregulation in top-down processing of sensory input. This study was designed to examine the frequency and correlates of speech illusions measured using the White Noise (WN) task in children from the general...... population. Associations between speech illusions and putative risk factors for psychotic disorder and negative affect were examined. A total of 1486 children aged 11–12 years of the Copenhagen Child Cohort 2000 were examined with the WN task. Psychotic experiences and negative affect were determined using...
Scheerer, Ernest W
The Building Task Force, after researching the many options, recommended to the Board of Trustees that, at this time, it is in the best interest of the association and its members to keep the building. In addition to the reasons outlined in the preceding paragraphs, the conclusions drawn by the Task Force can be summarized as follows: 1) This is not the time to make a change as both land and construction costs are high; 2) There is little inventory at this time that would provide a significant improvement over the present building; 3) There is no urgent need to act now; and 4) Cost-effective changes can be made to make the building more valuable to the association.
In most settings, task-based language teaching and testing have been dissociated from each other. That is why this study came to rethink of the learners' views towards awareness and implementation of task-based language teaching through IELTS listening tasks. To these objectives, after sketching instrumentation, the learners were divided into…
Llera, Alberto; Gómez, Vicenç; Kappen, Hilbert J.
Objective. To assess quantitatively the impact of task selection in the performance of brain-computer interfaces (BCI). Approach. We consider the task-pairs derived from multi-class BCI imagery movement tasks in three different datasets. We analyze for the first time the benefits of task selection on a large-scale basis (109 users) and evaluate the possibility of transferring task-pair information across days for a given subject. Main results. Selecting the subject-dependent optimal task-pair among three different imagery movement tasks results in approximately 20% potential increase in the number of users that can be expected to control a binary BCI. The improvement is observed with respect to the best task-pair fixed across subjects. The best task-pair selected for each subject individually during a first day of recordings is generally a good task-pair in subsequent days. In general, task learning from the user side has a positive influence in the generalization of the optimal task-pair, but special attention should be given to inexperienced subjects. Significance. These results add significant evidence to existing literature that advocates task selection as a necessary step towards usable BCIs. This contribution motivates further research focused on deriving adaptive methods for task selection on larger sets of mental tasks in practical online scenarios.
Hollnagel, E.; Edland, A.; Svenson, O.
This report constitutes a contribution to the NKS/RAK-1:3 project on Integrated Sequence Analysis. Following the meeting at Ringhals, the work was proposed to be performed by the following three steps: Task 1. Cognitive Task Analysis of the E-3 procedure. Task 2. Evaluation and revision of task analysis with Ringhals/KSU experts. Task 3. Integration with simulator data. The Cognitive Task Analysis (CTA) of Task 1 uses the Goals-Means Task Analysis (GMTA) method to identify the sequence of tasks and task steps necessary to achieve the goals of the procedure. It is based on material supplied by Ringhals, which describes the E-3 procedure, including the relevant ES and ECA procedures. The analysis further outlines the cognitive demands profile associated with individual task steps as well as with the task as a whole, as an indication of the nominal task load. The outcome of the cognitive task analysis provides a basis for proposing an adequate event tree. This report describes the results from Task 1. The work has included a two-day meeting between the three contributors, as well as the exchange of intermediate results and comments throughout the period. After the initial draft of the report was prepared, an opportunity was given to observe the SGTR scenario in a full-scope training simulator, and to discuss the details with the instructors. This led to several improvements from the initial draft. (EG)
Cocchini, Gianna; Filardi, Maria Serena; Crhonkova, Marcela; Halpern, Andrea R
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.
Macnamara, Brooke N; Frank, David J
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).
Doucet, Gaelle E; He, Xiaosong; Sperling, Michael R; Sharan, Ashwini; Tracy, Joseph I
Resting-state networks (RSNs) show spatial patterns generally consistent with networks revealed during cognitive tasks. However, the exact degree of overlap between these networks has not been clearly quantified. Such an investigation shows promise for decoding altered functional connectivity (FC) related to abnormal language functioning in clinical populations such as temporal lobe epilepsy (TLE). In this context, we investigated the network configurations during a language task and during resting state using FC. Twenty-four healthy controls, 24 right and 24 left TLE patients completed a verb generation (VG) task and a resting-state fMRI scan. We compared the language network revealed by the VG task with three FC-based networks (seeding the left inferior frontal cortex (IFC)/Broca): two from the task (ON, OFF blocks) and one from the resting state. We found that, for both left TLE patients and controls, the RSN recruited regions bilaterally, whereas both VG-on and VG-off conditions produced more left-lateralized FC networks, matching more closely with the activated language network. TLE brings with it variability in both task-dependent and task-independent networks, reflective of atypical language organization. Overall, our findings suggest that our RSN captured bilateral activity, reflecting a set of prepotent language regions. We propose that this relationship can be best understood by the notion of pruning or winnowing down of the larger language-ready RSN to carry out specific task demands. Our data suggest that multiple types of network analyses may be needed to decode the association between language deficits and the underlying functional mechanisms altered by disease. Hum Brain Mapp 38:2540-2552, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1995. Additionally, this inaugural edition of the Task Book includes information for FY 1994 programs. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive Internet web page
D' Ottavio, Ted [Brookhaven National Lab. (BNL), Upton, NY (United States); Kewisch, Jorg [Brookhaven National Lab. (BNL), Upton, NY (United States); Saltmarsh, Chris [Brookhaven National Lab. (BNL), Upton, NY (United States); Sathe, Smita [Brookhaven National Lab. (BNL), Upton, NY (United States); Satogata, Todd [Brookhaven National Lab. (BNL), Upton, NY (United States); Shea, Don [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, Steve [Brookhaven National Lab. (BNL), Upton, NY (United States); Trahern, Garry [Brookhaven National Lab. (BNL), Upton, NY (United States)
The Beam Injection Tests Software Task Force was charged with studying the software needed for the ATR tests, seen as a stepping stone or template for the larger scope of the full RHIC control system. This report outlines our avenues of exploration so far, presents the current analysis and implementation work in progress, and gives recommendations for the future on the ATR and longer time scales.
efficiency, and reliability of a set of available cars. (ConsumerReport (DOMAINSETS (VALUE (car NOMINAL 10) (make NOMINAL ( honda nissan toyota )) (model NOMINAL...important premise of Larkin and Simon’s work is that, when comparing alternative presentations, it is fruitful to characterize graphic-based problem solving...practical real-world tasks. Chapter 6 describes an experiment in which participants were asked to use a set of alternative presertations to compare
Borlund, Pia; Schneider, Jesper Wiborg
The present paper reports on the initial study and the preliminary findings of how the concept of simulated work task situation is reported used in the research literature. The overall objective of the study is in a systematic manner to learn how and for what types of evaluations the concept is a...... to involve the study participants’ own information needs (to function as baseline of search interaction) is generally neglected in the reported studies....
Braarud, Per Oeivind
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
Lacker, D.K.; Porter, B.J.; Watkins, G.
The procedures for evaluation of IND and NDA applications were reviewed by FDA and the state members of the Task Force believe that there is significant progress being made toward expeditious handling of these items. Progress toward publication of the final rule on radiopharmaceuticals has reduced the need for state regulatory activity in investigational aspects of radiopharmaceutical research to the point that the original concept for the training is no longer valid
Orr, Joseph M.; Weissman, Daniel H.
Bottom-up biases are widely thought to influence task choice in the voluntary task switching paradigm. Definitive support for this hypothesis is lacking, however, because task choice and task performance are usually confounded. We therefore revisited this hypothesis using a paradigm in which task choice and task performance are temporally separated. As predicted, participants tended to choose the task that was primed by bottom-up biases. Moreover, such choices were linked to increased switch costs during subsequent task performance. These findings provide compelling evidence that bottom-up biases influence voluntary task choice. They also suggest that succumbing to such biases reflects a reduction of top-down control that persists to influence upcoming task performance. PMID:21713192
Whicker, F.W.; Kirchner, T.B.
The Pathway Analysis Task constituted one of several multi-laboratory efforts to estimate radiation doses to people, considering all important pathways of exposure, from the testing of nuclear devices at the Nevada Test Site (NTS). The primary goal of the Pathway Analysis Task was to predict radionuclide ingestion by residents of Utah, Nevada, and portions of seven other adjoining western states following radioactive fallout deposition from individual events at the NTS. This report provides comprehensive documentation of the activities and accomplishments of Colorado State University's Pathway Analysis Task during the entire period of support (1979--91). The history of the project will be summarized, indicating the principal dates and milestones, personnel involved, subcontractors, and budget information. Accomplishments, both primary and auxiliary, will be summarized with general results rather than technical details being emphasized. This will also serve as a guide to the reports and open literature publications produced, where the methodological details and specific results are documented. Selected examples of results on internal dose estimates are provided in this report because the data have not been published elsewhere
Bangasser, Debra A; Wicks, Brittany; Waxler, David E; Eck, Samantha R
Sustained attention is the ability to monitor intermittent and unpredictable events over a prolonged period of time. This attentional process subserves other aspects of cognition and is disrupted in certain neurodevelopmental, neuropsychiatric, and neurodegenerative disorders. Thus, it is clinically important to identify mechanisms that impair and improve sustained attention. Such mechanisms are often first discovered using rodent models. Therefore, several behavior procedures for testing aspects of sustained attention have been developed for rodents. One, first described by McGaughy and Sarter (1995), called the sustained attention task (SAT), trains rats to distinguish between signal (i.e., brief light presentation) and non-signal trials. The signals are short and thus require careful attention to be perceived. Attentional demands can be increased further by introducing a distractor (e.g., flashing houselight). We have modified this task for touchscreen operant chambers, which are configured with a touchscreen on one wall that can present stimuli and record responses. Here we detail our protocol for SAT in touchscreen chambers. Additionally, we present standard measures of performance in male and female Sprague-Dawley rats. Comparable performance on this task in both sexes highlights its use for attention studies, especially as more researchers are including female rodents in their experimental design. Moreover, the easy implementation of SAT for the increasingly popular touchscreen chambers increases its utility.
Camos, Valérie; Mora, Gérôme; Barrouillet, Pierre
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.
Whicker, F.W.; Kirchner, T.B. [Colorado State Univ., Fort Collins, CO (United States)
The Pathway Analysis Task constituted one of several multi-laboratory efforts to estimate radiation doses to people, considering all important pathways of exposure, from the testing of nuclear devices at the Nevada Test Site (NTS). The primary goal of the Pathway Analysis Task was to predict radionuclide ingestion by residents of Utah, Nevada, and portions of seven other adjoining western states following radioactive fallout deposition from individual events at the NTS. This report provides comprehensive documentation of the activities and accomplishments of Colorado State University`s Pathway Analysis Task during the entire period of support (1979--91). The history of the project will be summarized, indicating the principal dates and milestones, personnel involved, subcontractors, and budget information. Accomplishments, both primary and auxiliary, will be summarized with general results rather than technical details being emphasized. This will also serve as a guide to the reports and open literature publications produced, where the methodological details and specific results are documented. Selected examples of results on internal dose estimates are provided in this report because the data have not been published elsewhere.
Patrick S Cooper
Full Text Available Cognitive control is required in situations that involve uncertainty or change, such as when resolving conflict, selecting responses and switching tasks. Recently, it has been suggested that cognitive control can be conceptualised as a mechanism which prioritises goal-relevant information to deal with uncertainty. This hypothesis has been supported using a paradigm that requires conflict resolution. In this study, we examine whether cognitive control during task switching is also consistent with this notion. We used information theory to quantify the level of uncertainty in different trial types during a cued task-switching paradigm. We test the hypothesis that differences in uncertainty between task repeat and task switch trials can account for typical behavioural effects in task-switching. Increasing uncertainty was associated with less efficient performance (i.e., slower and less accurate, particularly on switch trials and trials that afford little opportunity for advance preparation. Interestingly, both mixing and switch costs were associated with a common episodic control process. These results support the notion that cognitive control may be conceptualised as an information processor that serves to resolve uncertainty in the environment.
Rennie, Jaime L.
Cognitive control is required in situations that involve uncertainty or change, such as when resolving conflict, selecting responses and switching tasks. Recently, it has been suggested that cognitive control can be conceptualised as a mechanism which prioritises goal-relevant information to deal with uncertainty. This hypothesis has been supported using a paradigm that requires conflict resolution. In this study, we examine whether cognitive control during task switching is also consistent with this notion. We used information theory to quantify the level of uncertainty in different trial types during a cued task-switching paradigm. We test the hypothesis that differences in uncertainty between task repeat and task switch trials can account for typical behavioural effects in task-switching. Increasing uncertainty was associated with less efficient performance (i.e., slower and less accurate), particularly on switch trials and trials that afford little opportunity for advance preparation. Interestingly, both mixing and switch costs were associated with a common episodic control process. These results support the notion that cognitive control may be conceptualised as an information processor that serves to resolve uncertainty in the environment. PMID:26107646
Full Text Available In spite of the numerous merits of task-based language instruction as claimed by its supporters in the last few decades, task-supported teaching approach as an alternative was introduced. Since then, there have been controversial debates over the superiority of each of these two approaches. Thus, in the current research project, the purpose was to consider these two teaching approaches in the scope of English language teaching, with the purpose of exploring the most efficient one in an Iranian EFL context. To this end, 120 sophomore students, majoring in English language translation course at Islamic Azad University, Shar-e-Qods branch were selected among 4 intact reading comprehension II classes. Next, they were divided into two experimental groups. The first experimental group received task-based instruction and for the second experimental group, task-trusted teaching approach was applied. The results of the data analyses turned out that task-trusted teaching approach was superior to task-based teaching in teaching reading to EFL learners.
The Transport Task Force has functioned as the primary scientific organization in the area of magnetic-fusion confinement and transport since its inception in 1988. It has defined and set research directions, coordinated broad research efforts, advocated new funding initiatives, and created a highly successful and widely admired interactive culture between experiment, theory and modeling. The Transport Task Force carries out its activities under the direction of its chair and the Executive Committee. The Executive Committee is comprised of the leaders and deputy leaders of the scientific working groups. The working groups are structured and organized according to research needs and priorities and have been organized around the areas of Core Transport, H Mode and Pedestal, Fast Particle Transport, Transient Transport Phenomena, and Modeling and Simulation. A steering committee provides advise on TTF activities. Further information on the working groups and the structure and management of the TTF can be found at http://psfcwww2.psfc.mit.edu/ttf/index.html. The TTF holds an annual workshop. A summary of the workshops held during the period of this report is given in Appendix I. During the period of this report the Transport Task Force was involved in several significant activities. Foremost of these was a sweeping review of the status of transport science, the key research tasks for progress during the next 5-10 years, and a proposal for a funding initiative to ensure application of adequate resources to these problems. The conclusions of this study were incorporated into a white paper, which is copied below in Appendix II. Other significant activities have included the introduction of an extended, ongoing discussion on verification and validation as a requisite for defining and codifying the path toward predictive capability, the orchestration of a gradual shift of focus from ion thermal confinement to electron thermal confinement, and a joining of efforts on edge
Howell, David R; Osternig, Louis R; Chou, Li-Shan
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.
Full Text Available In two experiments, subjects responded to on-task probes while reading under dual-task conditions. The secondary task was to monitor the text for occurrences of the letter e. In Experiment 1, reading comprehension was assessed with a multiple-choice recognition test; in Experiment 2, subjects recalled the text. In both experiments, the secondary task replicated the well-known missing-letter effect in which detection of e’s was less effective for the word the. Letter detection was also more effective when subjects were on task, but this effect did not interact with the missing-letter effect. Comprehension was assessed in both the dual-task conditions and in a control single-task conditions. In the single-task conditions, both recognition (Experiment 1 and recall (Experiment 2 was better when subjects were on task, replicating previous research on mind wandering. Surprisingly, though, comprehension under dual-task conditions only showed an effect of being on task when measured with recall; there was no effect on recognition performance. Our interpretation of this pattern of results is that subjects generate their response to on-task probes on the basis of a retrospective assessment of the contents of working memory. Further, we argue that under dual-task conditions, the contents of working memory is not related to the reading processes required for accurate recognition performance. These conclusions have implications for models of text comprehension and for the interpretation of on-task probe responses.
Doumas, Michail; Krampe, Ralf Th
Multitasking is a challenging aspect of human behavior, especially if the concurrently performed tasks are different in nature. Several studies demonstrated pronounced performance decrements (dual-task costs) in older adults for combinations of cognitive and motor tasks. However, patterns of costs among component tasks differed across studies and reasons for participants' resource allocation strategies remained elusive. We investigated young and older adults' multitasking of a working memory task and two sensorimotor tasks, one with low (finger force control) and one with high ecological relevance (postural control). The tasks were performed in single-, dual-, and triple-task contexts. Working memory accuracy was reduced in dual-task contexts with either sensorimotor task and deteriorated further under triple-task conditions. Postural and force performance deteriorated with age and task difficulty in dual-task contexts. However, in the triple-task context with its maximum resource demands, older adults prioritized postural control over both force control and memory. Our results identify ecological relevance as the key factor in older adults' multitasking. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: email@example.com.
Renner, Caroline Ie; Outermans, Jacqueline; Ludwig, Ricarda; Brendel, Christiane; Kwakkel, Gert; Hummelsheim, Horst
To compare the efficacy of intensive daily applied progressive group therapy task training with equally dosed individual progressive task training on self-reported mobility for patients with moderate to severe stroke during inpatient rehabilitation. Randomized controlled clinical trial. In-patient rehabilitation center. A total of 73 subacute patients with stroke who were not able to walk without physical assistance at randomisation. Patients were allocated to group therapy task training (GT) or individual task training (IT). Both interventions were intended to improve walking competency and comprised 30 sessions of 90 minutes over six weeks. Primary outcome was the mobility domain of the Stroke Impact Scale (SIS-3.0). Secondary outcomes were the other domains of SIS-3.0, standing balance, gait speed, walking distance, stair climbing, fatigue, anxiety and depression. No adverse events were reported in either arm of the trial. There were no significant differences between groups for the SIS mobility domain at the end of the intervention (Z= -0.26, P = 0.79). No significant differences between groups were found in gait speed improvements (GT:0.38 ±0.23; IT:0.26±0.35), any other gait related parameters, or in non-physical outcomes such as depression and fatigue. Inpatient group therapy task training for patients with moderate to severe stroke is safe and equally effective as a dose-matched individual task training therapy. Group therapy task training may be delivered as an alternative to individual therapy or as valuable adjunct to increase time spent in gait-related activities. © The Author(s) 2015.
Casner, Stephen M; Schooler, Jonathan W
The objective was to examine the relationship between cockpit automation use and task-related and task-unrelated thought among airline pilots. Studies find that cockpit automation can sometimes relieve pilots of tedious control tasks and afford them more time to think ahead. Paradoxically, automation has also been shown to lead to lesser awareness. These results prompt the question of what pilots think about while using automation. A total of 18 airline pilots flew a Boeing 747-400 simulator while we recorded which of two levels of automation they used. As they worked, pilots were verbally probed about what they were thinking. Pilots were asked to categorize their thoughts as pertaining to (a) a specific task at hand, (b) higher-level flight-related thoughts (e.g.,planning ahead), or (c) thoughts unrelated to the flight. Pilots' performance was also measured. Pilots reported a smaller percentage of task-at-hand thoughts (27% vs. 50%) and a greater percentage of higher-level flight-related thoughts (56% vs. 29%) when using the higher level of automation. However, when all was going according to plan, using either level of automation, pilots also reported a higher percentage of task-unrelated thoughts (21%) than they did when in the midst of an unsuccessful performance (7%). Task-unrelated thoughts peaked at 25% when pilots were not interacting with the automation. Although cockpit automation may provide pilots with more time to think, it may encourage pilots to reinvest only some of this mental free time in thinking flight-related thoughts. This research informs the design of human-automation systems that more meaningfully engage the human operator.
Full Text Available Multi-task learning can extract the correlation of multiple related machine learning problems to improve performance. This paper considers applying the multi-task learning method to learn a single task. We propose a new learning approach, which employs the mixture of expert model to divide a learning task into several related sub-tasks, and then uses the trace norm regularization to extract common feature representation of these sub-tasks. A nonlinear extension of this approach by using kernel is also provided. Experiments conducted on both simulated and real data sets demonstrate the advantage of the proposed approach.
Piil, Jacob Feder; Lundbye-Jensen, Jesper; Trangmar, Steven J
-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...
Liu, Yan-Ci; Yang, Yea-Ru; Tsai, Yun-An; Wang, Ray-Yau
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.
Künstler, E C S; Finke, K; Günther, A; Klingner, C; Witte, O; Bublak, P
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.
The author examines the mechanisms and dynamics of framing effects in risky choices across three distinct task domains (i.e., life-death, public property, and personal money). The choice outcomes of the problems presented in each of the three task domains had a binary structure of a sure thing vs a gamble of equal expected value; the outcomes differed in their framing conditions and the expected values, raging from 6000, 600, 60, to 6, numerically. It was hypothesized that subjects would become more risk seeking, if the sure outcome was below their aspiration level (the minimum requirement). As predicted, more subjects preferred the gamble when facing the life-death choice problems than facing the counterpart problems presented in the other two task domains. Subjects' risk preference varied categorically along the group size dimension in the life-death domain but changed more linearly over the expected value dimension in the monetary domain. Framing effects were observed in 7 of 13 pairs of problems, showing a positive frame-risk aversion and negative frame-risk seeking relationship. In addition, two types of framing effects were theoretically defined and empirically identified. A bidirectional framing effect involves a reversal in risk preference, and occurs when a decision maker's risk preference is ambiguous or weak. Four bidirectional effects were observed; in each case a majority of subjects preferred the sure outcome under a positive frame but the gamble under a negative frame. In contrast, a unidirectional framing effect refers to a preference shift due to the framing of choice outcomes: A majority of subjects preferred one choice outcome (either the sure thing or the gamble) under both framing conditions, with positive frame augmented the preference for the sure thing and negative frame augmented the preference for the gamble. These findings revealed some dynamic regularities of framing effects and posed implications for developing predictive and testable
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.
Zedelius, Claire M; Veling, Harm; Bijleveld, Erik; Aarts, Henk
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.
Annett, J M; Leslie, J C
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.
Spatial crowdsourcing (SC) outsources tasks to a set of workers who are required to physically move to specified locations and accomplish tasks. Recently, it is emerging as a promising tool for emergency management, as it enables efficient and cost-effective collection of critical information in emergency such as earthquakes, when search and rescue survivors in potential ares are required. However in current SC systems, task locations and worker locations are all exposed in public without any privacy protection. SC systems if attacked thus have penitential risk of privacy leakage. In this paper, we propose a protocol for protecting the privacy for both workers and task requesters while maintaining the functionality of SC systems. The proposed protocol is built on partially homomorphic encryption schemes, and can efficiently realize complex operations required during task assignment over encrypted data through a well-designed computation strategy. We prove that the proposed protocol is privacy-preserving against semi-honest adversaries. Simulation on two real-world datasets shows that the proposed protocol is more effective than existing solutions and can achieve mutual privacy-preserving with acceptable computation and communication cost.
Strobach, Tilo; Frensch, Peter A; Schubert, Torsten
We examined the relation of action video game practice and the optimization of executive control skills that are needed to coordinate two different tasks. As action video games are similar to real life situations and complex in nature, and include numerous concurrent actions, they may generate an ideal environment for practicing these skills (Green & Bavelier, 2008). For two types of experimental paradigms, dual-task and task switching respectively; we obtained performance advantages for experienced video gamers compared to non-gamers in situations in which two different tasks were processed simultaneously or sequentially. This advantage was absent in single-task situations. These findings indicate optimized executive control skills in video gamers. Similar findings in non-gamers after 15 h of action video game practice when compared to non-gamers with practice on a puzzle game clarified the causal relation between video game practice and the optimization of executive control skills. Copyright © 2012 Elsevier B.V. All rights reserved.
Ingrid Liliana Bohórquez Suárez
Full Text Available This study analyzes what characterizes the negotiations of seventh graders at a public school in Bogotá when working in pairs to develop speaking tasks in EFL classes. The inquiry is a descriptive case study that follows the qualitative paradigm. As a result of analyzing the data, we obtained four consecutive steps that characterize students’ negotiations: Establishing a connection with a partner to work with, proposing practical alternatives, refusing mates’ propositions, and making practical decisions. Moreover, we found that the constant performance of the process of negotiation provokes students to construct a sociolinguistic identity that allows agreements to emerge.
Alai, Maureen [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Neuscamman, Stephanie [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
LLNL performed fallout and nuclear blast modeling for the 60 cities using the NARAC modeling system and predominant weather patterns determined in a previous Task 4 effort. LLNL performed model simulations and analyses to identify and provide response curves (expressed as two-dimensional contours) for radioactive fallout deposition, transport, population, and blast overpressure as a function of yield, weather, location and time. These contours can then be further combined and correlated with infrastructure and population databases to estimate city specific effects on KPFs such as impacted infrastructure and casualty rates.
Agrawal, Divy; Kruse, Sebastian; Ouzzani, Mourad; Papotti, Paolo; Quiane-Ruiz, Jorge-Arnulfo; Tang, Nan; Zaki, Mohammed J.; Ba, Lamine; Berti-Equille, Laure; Chawla, Sanjay; Elmagarmid, Ahmed; Hammady, Hossam; Idris, Yasser; Kaoudi, Zoi; Khayyat, Zuhair
Many emerging applications, from domains such as healthcare and oil & gas, require several data processing systems for complex analytics. This demo paper showcases Rheem, a framework that provides multi-platform task execution for such applications. It features a three-layer data processing abstraction and a new query optimization approach for multi-platform settings. We will demonstrate the strengths of Rheem by using real-world scenarios from three different applications, namely, machine learning, data cleaning, and data fusion. © 2016 ACM.
Many emerging applications, from domains such as healthcare and oil & gas, require several data processing systems for complex analytics. This demo paper showcases Rheem, a framework that provides multi-platform task execution for such applications. It features a three-layer data processing abstraction and a new query optimization approach for multi-platform settings. We will demonstrate the strengths of Rheem by using real-world scenarios from three different applications, namely, machine learning, data cleaning, and data fusion. © 2016 ACM.
Fountas, Spyros; Blaskmore, Benjamin Simon; Vougioukas, Stavros
decomposed into primitive actions, whichin turn are converted into the tractor directrix. Examples of this method are given forexploring an unknown area and ploughing a field. Results of a simulation of the exploreoperation are presented.Keywords: Autonomous vehicles, route planning, autonomous tractor......A new method is described that can be used to decompose human controlled agriculturaloperations into robotic behaviours embedded in an autonomous tractor. Four main levels havebeen identified: Operation, Task, Optimisation/Behaviour and Primitive actions where eachlevel is subsumed by the level...
Burke, David T; Meleger, Alec; Schneider, Jeffrey C; Snyder, Jim; Dorvlo, Atsu S S; Al-Adawi, Samir
This study tests the relation between eye-movements and thought processing. Subjects were given specific modality tasks (visual, gustatory, kinesthetic) and assessed on whether they responded with distinct eye-movements. Some subjects' eye-movements reflected ongoing thought processing. Instead of a universal pattern, as suggested by the neurolinguistic programming hypothesis, this study yielded subject-specific idiosyncratic eye-movements across all modalities. Included is a discussion of the neurolinguistic programming hypothesis regarding eye-movements and its implications for the eye-movement desensitization and reprocessing theory.
Full Text Available The efficiency of visual tasks involving localization has traditionally been evaluated using forced choice experiments that capitalize on independence across locations to simplify the performance of the ideal observer. However, developments in ideal observer analysis have shown how an ideal observer can be defined for free-localization tasks, where a target can appear anywhere in a defined search region and subjects respond by localizing the target. Since these tasks are representative of many real-world search tasks, it is of interest to evaluate the efficiency of observer performance in them. The central question of this work is whether humans are able to effectively use the information in a free-localization task relative to a similar task where target location is fixed. We use a yes-no detection task at a cued location as the reference for this comparison. Each of the tasks is evaluated using a Gaussian target profile embedded in four different Gaussian noise backgrounds having power-law noise power spectra with exponents ranging from 0 to 3. The free localization task had a square 6.7° search region. We report on two follow-up studies investigating efficiency in a detect-and-localize task, and the effect of processing the white-noise backgrounds. In the fixed-location detection task, we find average observer efficiency ranges from 35% to 59% for the different noise backgrounds. Observer efficiency improves dramatically in the tasks involving localization, ranging from 63% to 82% in the forced localization tasks and from 78% to 92% in the detect-and- localize tasks. Performance in white noise, the lowest efficiency condition, was improved by filtering to give them a power-law exponent of 2. Classification images, used to examine spatial frequency weights for the tasks, show better tuning to ideal weights in the free-localization tasks. The high absolute levels of efficiency suggest that observers are well-adapted to free-localization tasks.
Magvirasari Lestari Linra
Full Text Available Academic procrastination occurs when certain tasks are considered unpleasant, an unpleasant task and the usual delayed them is the task of writing, reading, studying for the exam, meetings, and administrative. The purpose of this study was to determine the relationship of the task aversiveness with academic procrastination. Subject of the study were 100 students out of a population of 516 students of the Faculty of Psychology class of 2012-2014. The method used in this research is quantitative by using Spearman rho as data analysis techniques. The research instrument consists of academic procrastination scale and the scale of the task aversiveness. Based on the results of correlation is known that there is a positive relationship between task aversiveness with academic procrastination with a correlation coefficient r = 0.508; p = 0.000. The results showed that of the 100 students of the Faculty of Psychology University of Makassar has a degree of relationship between task aversiveness with academic procrastination is on the very low category (25, 8%. Area / types of tasks delayed is not necessarily an unpleasant task and otherwise unpleasant task may not be postponed. Area task the highest level of aversive and delays are areas the task of writing and reading. This study illustrates that academic procrastination can be lowered by a change in the mindset of an unpleasant task.
... terms of the definitive task order and agrees to submit a cost proposal with supporting cost or pricing data. If agreement on a definitized task order is not reached by the target date mutually agreed upon...
Zhang, Tianzhu; Ghanem, Bernard; Liu, Si; Ahuja, Narendra
In this paper, we formulate object tracking in a particle filter framework as a multi-task sparse learning problem, which we denote as Multi-Task Tracking (MTT). Since we model particles as linear combinations of dictionary templates
Annett, J M; Cook, N M; Leslie, J C
It has been claimed that olfactory memory is distinct from memory in other modalities. This study investigated the effectiveness of visual and verbal tasks in interfering with olfactory memory and included methodological changes from other recent studies. Subjects were allocated to one of four experimental conditions involving interference tasks [no interference task; visual task; verbal task; visual-plus-verbal task] and presented 15 target odours. Either recognition of the odours or free recall of the odour names was tested on one occasion, either within 15 minutes of presentation or one week later. Recognition and recall performance both showed effects of interference of visual and verbal tasks but there was no effect for time of testing. While the results may be accommodated within a dual coding framework, further work is indicated to resolve theoretical issues relating to task complexity.
Full Text Available This study examined the within-subject stability of 150 participants who performed both a sorting task and a property-generation task over multiple sessions, focusing on three concrete concept categories (food, animals and bathroom products. We hypothesized that (1 the within-subject stability would be higher in the sorting task than in the property-generation task and (2 the nature of the category would influence both the within-subject stability of the classification groups in the sorting task and the properties generated to define these groups. The results show that the within-subject stability of conceptual representations depends both on the task and on the nature of the category. The stability of the representations was greater in the sorting task than in the property-generation task and in the food category. These results are discussed from a longitudinal perspective.
National Aeronautics and Space Administration — Task Analysis (TA) is a fundamental part of NASA system design and validation. TAs are used to produce Master Task Lists that support engineering teams and...
National Aeronautics and Space Administration — The creation of a five-dimensional task analysis visualization (5D-TAV) software tool for Task Analysis and Workload Planning using multi-dimensional visualization...
National Aeronautics and Space Administration — The creation of a five-dimensional task analysis visualization (5D-TAV) software tool for Task Analysis and Workload Planning using multi-dimensional visualization...
... in a complex-skill environment. The subset of task conditions selected were those that involve basic processes of working memory, task monitoring, and differential loads on spatial reasoning and speed of perceiving...
Moray, N.P.; Senders, J.W.; Rhodes, W.
This report presents the results of a research study conducted in support of the human factors engineering program of the Atomic Energy Control Board in Canada. It contains five products which may be used by the Atomic Enegy Control Board in relation to Task Analysis of jobs in CANDU nuclear power plants: 1. a detailed method for preparing for a task analysis; 2. a Task Data Form for recording task analysis data; 3. a detailed method for carrying out task analyses; 4. a guide to assessing alternative methods for performing task analyses, if such are proposed by utilities or consultants; and 5. an annotated bibliography on task analysis. In addition, a short explanation of the origins, nature and uses of task analysis is provided, with some examples of its cost effectiveness. 35 refs
Taura, Kenjiro; Nakashima, Jun; Yokota, Rio; Maruyama, Naoya
This paper describes a task parallel implementation of ExaFMM, an open source implementation of fast multipole methods (FMM), using a lightweight task parallel library MassiveThreads. Although there have been many attempts on parallelizing FMM
Oonk, Marcella; Davis, Christopher J; Krueger, James M; Wisor, Jonathan P; Van Dongen, Hans P A
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.
Gigliotta, Onofrio; Bartolomeo, Paolo; Miglino, Orazio
Neuropsychological phenomena have been modelized mainly, by the mainstream approach, by attempting to reproduce their neural substrate whereas sensory-motor contingencies have attracted less attention. In this work, we introduce a simulator based on the evolutionary robotics platform Evorobot* in order to setting up in silico neuropsychological tasks. Moreover, in this study we trained artificial embodied neurorobotic agents equipped with a pan/tilt camera, provided with different neural and motor capabilities, to solve a well-known neuropsychological test: the cancellation task in which an individual is asked to cancel target stimuli surrounded by distractors. Results showed that embodied agents provided with additional motor capabilities (a zooming/attentional actuator) outperformed simple pan/tilt agents, even those equipped with more complex neural controllers and that the zooming ability is exploited to correctly categorising presented stimuli. We conclude that since the sole neural computational power cannot explain the (artificial) cognition which emerged throughout the adaptive process, such kind of modelling approach can be fruitful in neuropsychological modelling where the importance of having a body is often neglected.
Full Text Available This paper contains developing of a method of solving diagnostic tasks for complex technical objects (STO based on using text models (TMi to describe the functioning of STO. A TMi model is a text description, in normalized form, of all fragments of STO functioning process. The description of TMi is for med using semantic vocabularies of different types, which are generated on the basis of usage of information about all the aspects of STO construction and functioning. Such interpretation description is a subject area for tasks of STO diagnostics. Detection of malfunction and deviations of a functioning process of STO from an established functioning mode is implemented on the basis of analysis of semantic parameters of text description of the STO functioning process in order to determine semantic anomalies which occur in the descriptions of the STO functioning process, as well as in the descriptions of fragments of its functioning. Semantic anomalies occur in case when values of semantic parameters go beyond their established limits.
Gougam, L.A.; Chikhi, A.; Mekideche-Chafa, F.
For several years now, neural network models have enjoyed wide popularity, being applied to problems of regression, classification and time series analysis. Neural networks have been recently seen as attractive tools for developing efficient solutions for many real world problems in function approximation. The latter is a very important task in environments where computation has to be based on extracting information from data samples in real world processes. In a previous contribution, we have used a well known simplified architecture to show that it provides a reasonably efficient, practical and robust, multi-frequency analysis. We have investigated the universal approximation theory of neural networks whose transfer functions are: sigmoid (because of biological relevance), Gaussian and two specified families of wavelets. The latter have been found to be more appropriate to use. The aim of the present contribution is therefore to use a m exican hat wavelet a s transfer function to approximate different tasks relevant and inherent to various applications in physics. The results complement and provide new insights into previously published results on this problem
The Internet is rapidly becoming the standard for communications, information transfer, and information sharing among U.S. Department of Energy (DOE) organizations. It has long been used by the major laboratories, but is now beginning to be used by headquarters staff to communicate with field offices and contractors and as the access point to DOE`s repositories of information. It will soon become key to efficient conduct of operations. Sites without effective access to the Internet will have to rely on secondary, less effective communications. Therefore, the task team believes it is essential that Hanford become a full participant in utilizing this resource. To make this happen an effective access and delivery infrastructure must be provided to DOE and contractor staff and standard ways of doing business on the Internet are required. Much of the technology exists today for robust electronic interchange of information. The use of this technology needs to be expanded and coordinated throughout the DOE and Hanford contractor community. As the use of Internet within DOE is advancing rapidly, it will become the preferred method for communication and information sharing within 5 years. The conclusion of the Internet Inter-Contractor task team is that the use of the Internet is essential to communicate as well as provide and obtain information and knowledge. The Hanford Site must foster, support, and implement necessary changes to the technology infrastructure to improve user access, maintain security, and assure we are effective participants in the networked community.
The Offshore Petroleum Engineering Task Force was established in July 1998 in response to concerns about Newfoundland and Labrador's share of offshore petroleum engineering activity, with the aim of determining the current capability of the local sector, the demand for such companies and individuals until the year 2010, their capability to grow over that time-frame, and requirements in order to achieve that growth. The report summarizes the analysis undertaken by the Task Force as well as the conclusions it reached and associated recommendations. Section two provides an overview of the offshore engineering activity, including its origins, structure, and key success factors, and its also provides a profile of the industry, internationally, in Canada and in Newfoundland. Section three presents an analysis of the future demand for offshore engineering in Newfoundland until 2010, based on three development scenarios. Section four based on a Consulting Engineers of Newfoundland and Labrador (CENL) survey, establishes the present offshore engineering capacity and capabilities within the province. Section five examines current education and training programs and their ability to respond to future demands. Section six summarizes the conclusions of the analysis and presents recommendations designed to facilitate and promote the development of the local offshore engineering industry. 6 figs
Mayfield, C; Moss, S
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.
Boring, Ronald Laurids [Idaho National Laboratory; Joe, Jeffrey Clark [Idaho National Laboratory
In the probabilistic safety assessments (PSAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally, both approaches should arrive at the same set of HFEs. This question remains central as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PSAs tend to be top-down— defined as a subset of the PSA—whereas the HFEs used in petroleum quantitative risk assessments (QRAs) are more likely to be bottom-up—derived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications.
The coming into force of the Single European Act on July 1, 1987, which is to stepwise create a truly frontierless internal market of the European Community up to the year 1992, will have an effect also on the nuclear waste management sector. The goals of the energy policy and fuel cycle policy of the FRG, however, will not be changed by this. The contribution in hand discusses in particular some problems encountered at the back-end of the nuclear fuel cycle, namely nuclear spent fuel reprocessing. Activities in this branch of nuclear industry for more than ten years already have been a joint, European task. Spent fuel elements from West German reactors have been sent for reprocessing to facilities in France and in Great Britain, for example. The task of spent fuel reprocessing in the eyes of the author has a dimension exceeding the scope of the European single market: cooperation in this field for years has been including Switzerland and Sweden, for example, and is likely to include in future some countries of the Eastern Bloc. (orig.) [de
Arellano, Christopher J.; Kram, Rodger
Compared with other species, humans can be very tractable and thus an ideal “model system” for investigating the metabolic cost of locomotion. Here, we review the biomechanical basis for the metabolic cost of running. Running has been historically modeled as a simple spring-mass system whereby the leg acts as a linear spring, storing, and returning elastic potential energy during stance. However, if running can be modeled as a simple spring-mass system with the underlying assumption of perfect elastic energy storage and return, why does running incur a metabolic cost at all? In 1980, Taylor et al. proposed the “cost of generating force” hypothesis, which was based on the idea that elastic structures allow the muscles to transform metabolic energy into force, and not necessarily mechanical work. In 1990, Kram and Taylor then provided a more explicit and quantitative explanation by demonstrating that the rate of metabolic energy consumption is proportional to body weight and inversely proportional to the time of foot-ground contact for a variety of animals ranging in size and running speed. With a focus on humans, Kram and his colleagues then adopted a task-by-task approach and initially found that the metabolic cost of running could be “individually” partitioned into body weight support (74%), propulsion (37%), and leg-swing (20%). Summing all these biomechanical tasks leads to a paradoxical overestimation of 131%. To further elucidate the possible interactions between these tasks, later studies quantified the reductions in metabolic cost in response to synergistic combinations of body weight support, aiding horizontal forces, and leg-swing-assist forces. This synergistic approach revealed that the interactive nature of body weight support and forward propulsion comprises ∼80% of the net metabolic cost of running. The task of leg-swing at most comprises ∼7% of the net metabolic cost of running and is independent of body weight support and forward
Lauring, Jakob; Selmer, Jan
from 489 university staff members showed that age diversity and cultural diversity, representing highly task-related diversity, were positively associated with most of the variables depicting group cohesiveness. On the other hand, gender diversity, illustrating less task-related diversity, seemed......As only very few large-scale studies have investigated multi-cultural university staff and as none of these studies have dealt with diversity and group processes, this survey was directed toward staffs in 16 science departments from three large universities in Denmark. Results based on the response...
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.
Strobach, Tilo; Torsten, Schubert
In dual-task situations, interference between two simultaneous tasks impairs performance. With practice, however, this impairment can be reduced. To identify mechanisms leading to a practice-related improvement in sensorimotor dual tasks, the present review applied the following general hypothesis: Sources that impair dual-task performance at the beginning of practice are associated with mechanisms for the reduction of dual-task impairment at the end of practice. The following types of processes provide sources for the occurrence of this impairment: (a) capacity-limited processes within the component tasks, such as response-selection or motor response stages, and (b) cognitive control processes independent of these tasks and thus operating outside of component-task performance. Dual-task practice studies show that, under very specific conditions, capacity-limited processes within the component tasks are automatized with practice, reducing the interference between two simultaneous tasks. Further, there is evidence that response-selection stages are shortened with practice. Thus, capacity limitations at these stages are sources for dual-task costs at the beginning of practice and are overcome with practice. However, there is no evidence demonstrating the existence of practice-related mechanisms associated with capacity-limited motor-response stages. Further, during practice, there is an acquisition of executive control skills for an improved allocation of limited attention resources to two tasks as well as some evidence supporting the assumption of improved task coordination. These latter mechanisms are associated with sources of dual-task interference operating outside of component task performance at the beginning of practice and also contribute to the reduction of dual-task interference at its end. PMID:28439319
Rofes, A; Spena, G; Miozzo, A; Fontanella, M M; Miceli, G
Multidisciplinary efforts are being made to provide surgical teams with sensitive and specific tasks for language mapping in awake surgery. Researchers and clinicians have elaborated different tasks over time. A fair amount of work has been directed to study the neurofunctional correlates of some of these tasks, and there is recent interest in their standardization. However, little discussion exists on the advantages and disadvantages that each task poses from the perspective of the cognitive neuroscience of language. Such an approach may be a relevant step to assess task validity, to avoid using tasks that tap onto similar processes, and to provide patients with a surgical treatment that ensures maximal tumor resection while avoiding postoperative language deficits. An understanding of the language components that each task entails may also be relevant to improve the current assessments and the ways in which tasks are administered, and to disentangle neurofunctional questions. We reviewed 17 language mapping tasks that have been used in awake surgery. Overt production tasks have been a preferred choice over comprehension tasks. Tasks tapping lexico-semantic processes, particularly object-naming, maintain their role as gold standards. Automated speech tasks are used to detect speech errors and to set the amplitude of the stimulator. Comprehension tasks, reading and writing tasks, and tasks that assess grammatical aspects of language may be regularly administered in the near future. We provide examples of a three-task approach we are administering to patients with prefrontal lesions. We believe that future advances in this area are contingent upon reviewing gold standards and introducing new assessment tools.
Todorov, Ivo; Del Missier, Fabio; Mäntylä, Timo
Coordinating multiple tasks with narrow deadlines is particularly challenging for older adults because of age related decline in cognitive control functions. We tested the hypothesis that multiple task performance reflects age- and gender-related differences in executive functioning and spatial ability. Young and older adults completed a multitasking session with four monitoring tasks as well as separate tasks measuring executive functioning and spatial ability. For both age groups, men excee...
Pasunuru, Ramakanth; Bansal, Mohit
Video captioning, the task of describing the content of a video, has seen some promising improvements in recent years with sequence-to-sequence models, but accurately learning the temporal and logical dynamics involved in the task still remains a challenge, especially given the lack of sufficient annotated data. We improve video captioning by sharing knowledge with two related directed-generation tasks: a temporally-directed unsupervised video prediction task to learn richer context-aware vid...
maintaining the data needed , and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other...actual time. Upon completion of the task, participants filled out questionnaires related to the hedonic and temporal evaluation of the task. Participants...time. Upon completion of the task, participants filled out questionnaires related to the hedonic and temporal evaluation of the task. Participants
Seyeed Mohammad Alavi
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.
Azlyn Ahmad Zawawi, PhD
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.
van der Meere, Jaap; Börger, Norbert A.; Pirila, Silja; Sallee, Floyed
The ability to deal with sources of conflict, that is, interference control, was evaluated in a group of 11 children with first episode Major Depression and a peer control group. To this end, the Eriksen and Schultz (1979) task was used. Here, the participant is presented with a stimulus that
Denis N. Butorin
Full Text Available In the article are been describing technology for manage of testing task in computer program. It was found for recognition of algorithm solution of mathematic task. There are been justifi ed the using hierarchical structure for a special set of testing questions. Also, there has been presented the release of the described tasks in the computer program openSEE.
Denis N. Butorin
In the article are been describing technology for manage of testing task in computer program. It was found for recognition of algorithm solution of mathematic task. There are been justifi ed the using hierarchical structure for a special set of testing questions. Also, there has been presented the release of the described tasks in the computer program openSEE.
Alphen, A. van; Bosse, T.; Frank, I.; Jonker, C.M.; Koeman, F.; Bara, B.G.; Barsalou, L.; Bucciarelli, M.
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
Jackson, Daniel O.; Burch, Alfred Rue
Tasks are viewed as a principled foundation for classroom teaching, social interaction, and language development. This special issue sheds new light on how task-based classroom practices are supported by a diverse range of principles. This introduction describes current trends in classroom practice and pedagogic research in relation to task-based…
Lawson, Anton E.; Nordland, Floyd H.
Some evidence supports the hypothesis that formal operational reasoning ability (at least that measured by Piagetian tasks) is a unified process. The purpose of this research was to determine: (1) if conservation tasks, such as conservation of number, liquid amount, weight and volume, are unifactor; and (2) if conservation tasks form a scale of…
Storme, Martin; Lubart, Todd; Myszkowski, Nils; Cheung, Ping Chung; Tong, Toby; Lau, Sing
This study provides new evidence concerning task specificity in creativity--examining through a cross-cultural perspective the extent to which performance in graphic versus verbal creativity tasks (domain specificity) and in divergent versus convergent creativity tasks (process specificity) are correlated. The relations between different…
Carter, R.J.; Jorgensen, C.C.
An automated tool (TSORT) that can aid training system developers in determining which training strategy should be applied to a particular task and in grouping similar tasks into training categories has been developed. This paper describes the rationale for TSORT's development and addresses its structure, including training categories, task description dimensions, and categorization metrics. It also provides some information on TSORT's application
Bouarfa, L.; Jonker, P.P.; Dankelman, J.
Recognizing and understanding surgical high-level tasks from sensor readings is important for surgical workflow analysis. Surgical high-level task recognition is also a challenging task in ubiquitous computing because of the inherent uncertainty of sensor data and the complexity of the operating
Tsang, Pamela S.; Vidulich, Michael A.
An experiment is described which examined the benefits of distributing the input demands of two tracking tasks as a function of task integrality. Visual and auditory compensatory tracking tasks were utilized. Results indicate that presenting the two tracking signals in two input modalities did not improve time-sharing efficiency. This was attributed to the difficulty insensitivity phenomenon.
Huestegge, Lynn; Koch, Iring
Between-task crosstalk has been discussed as an important source for dual-task costs. In this study, the authors examine concurrently performed saccades and manual responses as a means of studying the role of response-code conflict between 2 tasks. In Experiment 1, participants responded to an imperative auditory stimulus with a left or a right…
Lee, Kyeong-Hwa; Lee, Eun-Jung; Park, Min-Sun
It has been asserted that mathematical tasks play a critical role in the teaching and learning of mathematics. Modification of tasks included in intended curriculum materials, such as textbooks, can be an effective activity for prospective teachers to understand the role of mathematical tasks in the teaching and learning of mathematics; designing…
Hamann, S.; de Jonge, A.
This article introduces the menu task, which can be used to elicit infrequent sounds such as loan phonemes that only occur in a restricted set of words. The menu task is similar to the well-known map task and involves the interaction of two participants to create a menu on the basis of a list of
Carl, Diana R.
Task analysis in human performance technology is used to determine how human performance can be well supported with training, job aids, environmental changes, and other interventions. Early work by Miller (1953) and Gilbert (1969, 1974) addressed cue processing in task execution and recommended cue descriptions in task analysis. Modern task…
Charters, W. W., Jr.
This report compares two approaches to measuring task interdependence, a theoretically fruitful concept for analyzing an organization's technical system. Task interdependence exists among operating personnel in the degree that task performance of one operative constrains, augments, or otherwise poses contingencies for the performance of another.…
Arslanyilmaz, Abdurrahman; Pedersen, Susan
This study examines the effects of subtitled similar task videos on language production by nonnative speakers (NNSs) in an online task-based language learning (TBLL) environment. Ten NNS-NNS dyads collaboratively completed four communicative tasks, using an online TBLL environment specifically designed for this study and a chat tool in…
This study investigated the effect of task type on incidental L2 vocabulary learning. The different tasks investigated in this study differed in terms of repetition of encounters and task involvement load. In a within-subjects design, 72 Iranian learners of English practised 18 target words in three exercise conditions: three ...
Jones, Keith; Pepin, Birgit
Mathematical tasks and tools, including tasks in the form of digital tools, are key resources in mathematics teaching and in mathematics teacher education. Even so, the "design" of mathematical tasks is perceived in different ways: sometimes seen as something distinct from the teaching and learning process, and sometimes as integral to…
... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Task Force on Community Preventive Services Name: Task Force on Community Preventive Services meeting. Times and Dates: 8... by space available. Purpose: The mission of the Task Force is to develop and publish the Guide to...