Does the Macaque Monkey Provide a Good Model for Studying Human Executive Control? A Comparative Behavioral Study of Task Switching

PubMed Central

Caselli, Luana; Chelazzi, Leonardo

2011-01-01

The ability to swiftly and smoothly switch from one task set to another is central to intelligent behavior, because it allows an organism to flexibly adapt to ever changing environmental conditions and internal needs. For this reason, researchers interested in executive control processes have often relied on task-switching paradigms as powerful tools to uncover the underlying cognitive and brain architecture. In order to gather fundamental information at the single-cell level, it would be greatly helpful to demonstrate that non-human primates, especially the macaque monkey, share with us similar behavioral manifestations of task-switching and therefore, in all likelihood, similar underlying brain mechanisms. Unfortunately, prior attempts have provided negative results (e.g., Stoet & Snyder, 2003b), in that it was reported that macaques do not show the typical signature of task-switching operations at the behavioral level, represented by switch costs. If confirmed, this would indicate that the macaque cannot be used as a model approach to explore human executive control mechanisms by means of task-switching paradigms. We have therefore decided to re-explore this issue, by conducting a comparative experiment on a group of human participants and two macaque monkeys, whereby we measured and compared performance costs linked to task switching and resistance to interference across the two species. Contrary to what previously reported, we found that both species display robust task switching costs, thus supporting the claim that macaque monkeys provide an exquisitely suitable model to study the brain mechanisms responsible for maintaining and switching task sets. PMID:21720549

Parkinson's Disease Is Associated with Goal Setting Deficits during Task Switching

ERIC Educational Resources Information Center

Meiran, Nachshon; Friedman, Gilad; Yehene, Eynat

2004-01-01

Ten Parkinson's Disease (PD) patients and 10 control participants were tested using a task-switching paradigm in which there was a random task sequence, and the task was cued in every trial. Five PD patients showed a unique error profile. Their performance approximated guessing when accuracy was dependent on correct task identification, and was…

Exploring the repetition bias in voluntary task switching.

PubMed

Mittelstädt, Victor; Dignath, David; Schmidt-Ott, Magdalena; Kiesel, Andrea

2018-01-01

In the voluntary task-switching paradigm, participants are required to randomly select tasks. We reasoned that the consistent finding of a repetition bias (i.e., participants repeat tasks more often than expected by chance) reflects reasonable adaptive task selection behavior to balance the goal of random task selection with the goals to minimize the time and effort for task performance. We conducted two experiments in which participants were provided with variable amount of preview for the non-chosen task stimuli (i.e., potential switch stimuli). We assumed that switch stimuli would initiate some pre-processing resulting in improved performance in switch trials. Results showed that reduced switch costs due to extra-preview in advance of each trial were accompanied by more task switches. This finding is in line with the characteristics of rational adaptive behavior. However, participants were not biased to switch tasks more often than chance despite large switch benefits. We suggest that participants might avoid effortful additional control processes that modulate the effects of preview on task performance and task choice.

The relationship between internet-gaming experience and executive functions measured by virtual environment compared with conventional laboratory multitasks.

PubMed

Chen, Yong-Quan; Hsieh, Shulan

2018-01-01

The aim of this study was to investigate if individuals with frequent internet gaming (IG) experience exhibited better or worse multitasking ability compared with those with infrequent IG experience. The individuals' multitasking abilities were measured using virtual environment multitasks, such as Edinburgh Virtual Errands Test (EVET), and conventional laboratory multitasks, such as the dual task and task switching. Seventy-two young healthy college students participated in this study. They were split into two groups based on the time spent on playing online games, as evaluated using the Internet Use Questionnaire. Each participant performed EVET, dual-task, and task-switching paradigms on a computer. The current results showed that the frequent IG group performed better on EVET compared with the infrequent IG group, but their performance on the dual-task and task-switching paradigms did not differ significantly. The results suggest that the frequent IG group exhibited better multitasking efficacy if measured using a more ecologically valid task, but not when measured using a conventional laboratory multitasking task. The differences in terms of the subcomponents of executive function measured by these task paradigms were discussed. The current results show the importance of the task effect while evaluating frequent internet gamers' multitasking ability.

The relationship between internet-gaming experience and executive functions measured by virtual environment compared with conventional laboratory multitasks

PubMed Central

Chen, Yong-Quan

2018-01-01

The aim of this study was to investigate if individuals with frequent internet gaming (IG) experience exhibited better or worse multitasking ability compared with those with infrequent IG experience. The individuals’ multitasking abilities were measured using virtual environment multitasks, such as Edinburgh Virtual Errands Test (EVET), and conventional laboratory multitasks, such as the dual task and task switching. Seventy-two young healthy college students participated in this study. They were split into two groups based on the time spent on playing online games, as evaluated using the Internet Use Questionnaire. Each participant performed EVET, dual-task, and task-switching paradigms on a computer. The current results showed that the frequent IG group performed better on EVET compared with the infrequent IG group, but their performance on the dual-task and task-switching paradigms did not differ significantly. The results suggest that the frequent IG group exhibited better multitasking efficacy if measured using a more ecologically valid task, but not when measured using a conventional laboratory multitasking task. The differences in terms of the subcomponents of executive function measured by these task paradigms were discussed. The current results show the importance of the task effect while evaluating frequent internet gamers’ multitasking ability. PMID:29879150

Effects of anxiety on task switching: evidence from the mixed antisaccade task.

PubMed

Ansari, Tahereh L; Derakshan, Nazanin; Richards, Anne

2008-09-01

According to the attentional control theory of anxiety (Eysenck, Derakshan, Santos, & Calvo, 2007), anxiety impairs performance on cognitive tasks that involve the shifting function of working memory. This hypothesis was tested using a mixed antisaccade paradigm, in which participants performed single-task and mixed-task versions of the paradigm. The single task involved the completion of separate blocks of anti- and prosaccade trials, whereas in the mixed task, participants completed anti- and prosaccade trials in a random order within blocks. Analysis of switch costs showed that high-anxious individuals did not exhibit the commonly reported paradoxical improvement in saccade latency, whereas low-anxious individuals did. The findings are discussed within the framework of attentional control theory.

Does Task-Set Reconfiguration Create Cognitive Slack?

ERIC Educational Resources Information Center

Gilbert, Sam J.

2005-01-01

C. Oriet and P. Jolicoeur (see record 2003-08747-016) reported 2 experiments in which the perceptual contrast of stimuli was manipulated in a task-switching paradigm. They failed to observe an interaction in the reaction time data between task switching, perceptual contrast, and response-stimulus interval. Using the locus of slack logic, they…

Physiological Aging Influence on Brain Hemodynamic Activity during Task-Switching: A fNIRS Study.

PubMed

Vasta, Roberta; Cutini, Simone; Cerasa, Antonio; Gramigna, Vera; Olivadese, Giuseppe; Arabia, Gennarina; Quattrone, Aldo

2017-01-01

Task-switching (TS) paradigm is a well-known validated tool useful for exploring the neural substrates of cognitive control, in particular the activity of the lateral and medial prefrontal cortex. This work is aimed at investigating how physiological aging influences hemodynamic response during the execution of a color-shape TS paradigm. A multi-channel near infrared spectroscopy (fNIRS) was used to measure hemodynamic activity in 27 young (30.00 ± 7.90 years) and 11 elderly participants (57.18 ± 9.29 years) healthy volunteers (55% male, age range: (19-69) years) during the execution of a TS paradigm. Two holders were placed symmetrically over the left/right hemispheres to record cortical activity [oxy-(HbO) and deoxy-hemoglobin (HbR) concentration] of the dorso-lateral prefrontal cortex (DLPFC), the dorsal premotor cortex (PMC), and the dorso-medial part of the superior frontal gyrus (sFG). TS paradigm requires participants to repeat the same task over a variable number of trials, and then to switch to a different task during the trial sequence. A two-sample t -test was carried out to detect differences in cortical responses between groups. Multiple linear regression analysis was used to evaluate the impact of age on the prefrontal neural activity. Elderly participants were significantly slower than young participants in both color- ( p < 0.01, t = -3.67) and shape-single tasks ( p = 0.026, t = -2.54) as well as switching ( p = 0.026, t = -2.41) and repetition trials ( p = 0.012, t = -2.80). Differences in cortical activation between groups were revealed for HbO mean concentration of switching task in the PMC ( p = 0.048, t = 2.94). In the whole group, significant increases of behavioral performance were detected in switching trials, which positively correlated with aging. Multivariate regression analysis revealed that the HbO mean concentration of switching task in the PMC ( p = 0.01, β = -0.321) and of shape single-task in the sFG ( p = 0.003, β = 0.342) were the best predictors of age effects. Our findings demonstrated that TS might be a reliable instrument to gather a measure of cognitive resources in older people. Moreover, the fNIRS-related brain activity extracted from frontoparietal cortex might become a useful indicator of aging effects.

Transfer of task-switching training in older age: the role of verbal processes.

PubMed

Karbach, Julia; Mang, Sandra; Kray, Jutta

2010-09-01

This study investigated the influence of verbal self-instructions (VSI) on the transfer of task-switching training in older adults (56-78 years). We applied an internally cued switching paradigm in a pretest-training-posttest design. Training-related improvements were not modulated by VSI. Transfer (the pretest-posttest reduction of switch costs) was most pronounced when participants applied the VSI at posttest after practicing the switching task without VSI. The results indicate that in contrast to transfer of executive control training, transfer of (verbal) strategy training seems to be limited and that VSI is most beneficial when the task-switching abilities are already well practiced. (c) 2010 APA, all rights reserved.

Cognitive structure, flexibility, and plasticity in human multitasking-An integrative review of dual-task and task-switching research.

PubMed

Koch, Iring; Poljac, Edita; Müller, Hermann; Kiesel, Andrea

2018-06-01

Numerous studies showed decreased performance in situations that require multiple tasks or actions relative to appropriate control conditions. Because humans often engage in such multitasking activities, it is important to understand how multitasking affects performance. In the present article, we argue that research on dual-task interference and sequential task switching has proceeded largely separately using different experimental paradigms and methodology. In our article we aim at organizing this complex set of research in terms of three complementary research perspectives on human multitasking. One perspective refers to structural accounts in terms of cognitive bottlenecks (i.e., critical processing stages). A second perspective refers to cognitive flexibility in terms of the underlying cognitive control processes. A third perspective emphasizes cognitive plasticity in terms of the influence of practice on human multitasking abilities. With our review article we aimed at highlighting the value of an integrative position that goes beyond isolated consideration of a single theoretical research perspective and that broadens the focus from single experimental paradigms (dual task and task switching) to favor instead a view that emphasizes the fundamental similarity of the underlying cognitive mechanisms across multitasking paradigms. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Event-Related Potential Responses to Task Switching Are Sensitive to Choice of Spatial Filter

PubMed Central

Wong, Aaron S. W.; Cooper, Patrick S.; Conley, Alexander C.; McKewen, Montana; Fulham, W. Ross; Michie, Patricia T.; Karayanidis, Frini

2018-01-01

Event-related potential (ERP) studies using the task-switching paradigm show that multiple ERP components are modulated by activation of proactive control processes involved in preparing to repeat or switch task and reactive control processes involved in implementation of the current or new task. Our understanding of the functional significance of these ERP components has been hampered by variability in their robustness, as well as their temporal and scalp distribution across studies. The aim of this study is to examine the effect of choice of reference electrode or spatial filter on the number, timing and scalp distribution of ERP elicited during task-switching. We compared four configurations, including the two most common (i.e., average mastoid reference and common average reference) and two novel ones that aim to reduce volume conduction (i.e., reference electrode standardization technique (REST) and surface Laplacian) on mixing cost and switch cost effects in cue-locked and target-locked ERP waveforms in 201 healthy participants. All four spatial filters showed the same well-characterized ERP components that are typically seen in task-switching paradigms: the cue-locked switch positivity and target-locked N2/P3 effect. However, both the number of ERP effects associated with mixing and switch cost, and their temporal and spatial resolution were greater with the surface Laplacian transformation which revealed rapid temporal adjustments that were not identifiable with other spatial filters. We conclude that the surface Laplacian transformation may be more suited to characterize EEG signatures of complex spatiotemporal networks involved in cognitive control. PMID:29568260

Disparate bilingual experiences modulate task-switching advantages: A diffusion-model analysis of the effects of interactional context on switch costs.

PubMed

Hartanto, Andree; Yang, Hwajin

2016-05-01

Drawing on the adaptive control hypothesis (Green & Abutalebi, 2013), we investigated whether bilinguals' disparate interactional contexts modulate task-switching performance. Fifty-eight bilinguals within the single-language context (SLC) and 75 bilinguals within the dual-language context (DLC) were compared in a typical task-switching paradigm. Given that DLC bilinguals switch between languages within the same context, while SLC bilinguals speak only one language in one environment and therefore rarely switch languages, we hypothesized that the two groups' stark difference in their interactional contexts of conversational exchanges would lead to differences in switch costs. As predicted, DLC bilinguals showed smaller switch costs than SLC bilinguals. Our diffusion-model analyses suggest that DLC bilinguals' benefits in switch costs are more likely driven by task-set reconfiguration than by proactive interference. Our findings underscore the modulating role of the interactional context of conversational exchanges in task switching. Copyright © 2016 Elsevier B.V. All rights reserved.

Age-related differences in BOLD modulation to cognitive control costs in a multitasking paradigm: Global switch, local switch, and compatibility-switch costs.

PubMed

Nashiro, Kaoru; Qin, Shuo; O'Connell, Margaret A; Basak, Chandramallika

2018-05-15

It is well documented that older adults recruit additional brain regions compared to those recruited by younger adults while performing a wide variety of cognitive tasks. However, it is unclear how such age-related over-recruitment interacts with different types of cognitive control, and whether this over-recruitment is compensatory. To test this, we used a multitasking paradigm, which allowed us to examine age-related over-activation associated with three types of cognitive costs (i.e., global switch, local switch, compatibility-switch costs). We found age-related impairments in global switch cost (GSC), evidenced by slower response times for maintaining and coordinating two tasks vs. performing only one task. However, no age-related declines were observed in either local switch cost (LSC), a cognitive cost associated with switching between the two tasks while maintaining two task loads, or compatibility-switch cost (CSC), a cognitive cost associated with incompatible vs. compatible stimulus-response mappings across the two tasks. The fMRI analyses allowed for identification of distinct cognitive cost-sensitive brain regions associated with GSC and LSC. In fronto-parietal GSC and LSC regions, older adults' increased activations were associated with poorer performance (greater costs), whereas a reverse relationship was observed in younger adults. Older adults also recruited additional fronto-parietal brain regions outside the cognitive cost-sensitive areas, which was associated with poorer performance or no behavioral benefits. Our results suggest that older adults exhibit a combination of inefficient activation within cognitive cost-sensitive regions, specifically the GSC and LSC regions, and non-compensatory over-recruitment in age-sensitive regions. Age-related declines in global switching, compared to local switching, was observed earlier in old age at both neural and behavioral levels. Copyright © 2018 Elsevier Inc. All rights reserved.

Inhibition in task switching: The reliability of the n - 2 repetition cost.

PubMed

Kowalczyk, Agnieszka W; Grange, James A

2017-12-01

The n - 2 repetition cost seen in task switching is the effect of slower response times performing a recently completed task (e.g. an ABA sequence) compared to performing a task that was not recently completed (e.g. a CBA sequence). This cost is thought to reflect cognitive inhibition of task representations and as such, the n - 2 repetition cost has begun to be used as an assessment of individual differences in inhibitory control; however, the reliability of this measure has not been investigated in a systematic manner. The current study addressed this important issue. Seventy-two participants performed three task switching paradigms; participants were also assessed on rumination traits and processing speed-measures of individual differences potentially modulating the n - 2 repetition cost. We found significant n - 2 repetition costs for each paradigm. However, split-half reliability tests revealed that this cost was not reliable at the individual-difference level. Neither rumination tendencies nor processing speed predicted this cost. We conclude that the n - 2 repetition cost is not reliable as a measure of individual differences in inhibitory control.

Switching between Abstract Rules Reflects Disease Severity but Not Dopaminergic Status in Parkinson's Disease

ERIC Educational Resources Information Center

Kehagia, Angie A.; Cools, Roshan; Barker, Roger A.; Robbins, Trevor W.

2009-01-01

This study sought to disambiguate the impact of Parkinson's disease (PD) on cognitive control as indexed by task set switching, by addressing discrepancies in the literature pertaining to disease severity and paradigm heterogeneity. A task set is governed by a rule that determines how relevant stimuli (stimulus set) map onto specific responses…

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

PubMed

Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

2015-07-01

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

Encoding and choice in the task span paradigm.

PubMed

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

2015-03-01

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

Switch Detection in Preschoolers' Cognitive Flexibility

ERIC Educational Resources Information Center

Chevalier, Nicolas; Wiebe, Sandra A.; Huber, Kristina L.; Espy, Kimberly Andrews

2011-01-01

The current study addressed the role of switch detection in cognitive flexibility by testing the effect of transition cues (i.e., cues that directly signal the need to switch or maintain a given task goal) in a cued set-shifting paradigm at 5 years of age. Children performed better, especially on switch trials, when transition cues were combined…

Open- and Closed-Skill Exercise Interventions Produce Different Neurocognitive Effects on Executive Functions in the Elderly: A 6-Month Randomized, Controlled Trial

PubMed Central

Tsai, Chia-Liang; Pan, Chien-Yu; Chen, Fu-Chen; Tseng, Yu-Ting

2017-01-01

This study aimed to explore the effects of open- and closed-skill exercise interventions on the neurocognitive performance of executive functions in the elderly. Sixty-four healthy elderly males were randomly assigned to either a closed-skill (bike riding or brisk walking/jogging, n = 22), open-skill (table tennis, n = 21), or control (n = 21) group. Various neuropsychological [e.g., accuracy rates (AR) and reaction time (RT)] and electrophysiological [e.g., event-related potential (ERP) P3 component] measures were assessed during a variant of the task-switching paradigm, as well as an N-back task at baseline and after either a 6-month exercise intervention or control period. The results showed that, when performing the task-switching paradigm, the two exercise groups relative to control group showed significantly faster RTs in the switch trials after the exercise intervention. However, the RT facilitation in the non-switch and switch trials post-exercise relative to pre-exercise only emerged in the open-skill group. In terms of the N-back task, the two exercise groups significantly increased ARs in the 1-back condition after the exercise intervention, and the beneficial AR effect on the 2-back condition only emerged in the closed-skill group. In addition, the two exercise groups exhibited significantly larger P3 amplitudes on the frontal-to-parietal cortex areas after the exercise intervention relative to the baseline when performing the two cognitive tasks. These neurocognitive results still remained unchanged even when the confounding factors (e.g., cardiorespiratory fitness, social participation, and BMI) were controlled for. The present study concluded that, although 6-month open- and closed-skill exercise interventions facilitate overall electrophysiological effects (i.e., increased ERP P3 amplitudes) on the frontal-to-parietal cortices in the elderly, the two exercise modes produced different levels of neuropsychologically beneficial effects on RTs of the task-switching paradigm (i.e., lessened RTs) and ARs of the N-back task (i.e., enhanced ARs). The distinctive neurocognitive changes induced by open- and closed-skill exercise have implications for task switching and working memory in elderly individuals, especially with such cognitive functioning impairments. PMID:28959200

Switching between univalent task-sets in schizophrenia: ERP evidence of an anticipatory task-set reconfiguration deficit.

PubMed

Karayanidis, Frini; Nicholson, Rebecca; Schall, Ulrich; Meem, Lydia; Fulham, Ross; Michie, Patricia T

2006-10-01

The present study used behavioral and event-related potential (ERP) indices of task-switching to examine whether schizophrenia patients have a specific deficit in anticipatory task-set reconfiguration. Participants switched between univalent tasks in an alternating runs paradigms with blocked response-stimulus interval (RSI) manipulation (150, 300, 600, and 1200ms). Nineteen high functioning people with schizophrenia were compared to controls that were matched for age, gender, education and premorbid IQ estimate. Schizophrenia patients had overall increased RT, but no increase in corrected RT switch cost. In the schizophrenia group, ERPs showed reduced activation of the differential positivity in anticipation of switch trial at the optimal 600ms RSI and reduced activation of the frontal post-stimulus switch negativity at both 600 and 1200ms RSI compared to the control group. Despite no behavioral differences in task switching performance, anticipatory and stimulus-triggered ERP indices of task-switching suggest group differences in processing of switch and repeat trials, especially at longer RSI conditions that for control participants provide opportunity for anticipatory activation of task-set reconfiguration processes. These results are compatible with impaired implementation of endogenously driven processes in schizophrenia and greater reliance on external task cues, especially at long preparation intervals.

The Influence of Feedback on Task-Switching Performance: A Drift Diffusion Modeling Account.

PubMed

Cohen Hoffing, Russell; Karvelis, Povilas; Rupprechter, Samuel; Seriès, Peggy; Seitz, Aaron R

2018-01-01

Task-switching is an important cognitive skill that facilitates our ability to choose appropriate behavior in a varied and changing environment. Task-switching training studies have sought to improve this ability by practicing switching between multiple tasks. However, an efficacious training paradigm has been difficult to develop in part due to findings that small differences in task parameters influence switching behavior in a non-trivial manner. Here, for the first time we employ the Drift Diffusion Model (DDM) to understand the influence of feedback on task-switching and investigate how drift diffusion parameters change over the course of task switch training. We trained 316 participants on a simple task where they alternated sorting stimuli by color or by shape. Feedback differed in six different ways between subjects groups, ranging from No Feedback (NFB) to a variety of manipulations addressing trial-wise vs. Block Feedback (BFB), rewards vs. punishments, payment bonuses and different payouts depending upon the trial type (switch/non-switch). While overall performance was found to be affected by feedback, no effect of feedback was found on task-switching learning. Drift Diffusion Modeling revealed that the reductions in reaction time (RT) switch cost over the course of training were driven by a continually decreasing decision boundary. Furthermore, feedback effects on RT switch cost were also driven by differences in decision boundary, but not in drift rate. These results reveal that participants systematically modified their task-switching performance without yielding an overall gain in performance.

Investigating the relationship between media multitasking and processes involved in task-switching.

PubMed

Alzahabi, Reem; Becker, Mark W; Hambrick, David Z

2017-11-01

Although multitasking with media has increased dramatically in recent years (Rideout, Foehr, & Roberts, 2010), the association between media multitasking and cognitive performance is poorly understood. In addition, the literature on the relationship between media multitasking and task-switching, one measure of cognitive control, has produced mixed results (Alzahabi & Becker, 2013; Minear et al., 2013; Ophir, Nass, & Wagner, 2009). Here we use an individual differences approach to investigate the relationship between media multitasking and task-switching performance by first examining the structure of task-switching and identifying the latent factors that contribute to switch costs. Participants performed a series of 3 different task-switching paradigms, each designed to isolate the effects of a specific putative mechanism (e.g., advanced preparation) related to task-switching performance, as well as a series of surveys to measure media multitasking and intelligence. The results suggest that task-switching performance is related to 2 somewhat independent factors, namely an advanced preparation factor and passive decay factor. In addition, multitasking with media was related to a faster ability to prepare for tasks, resulting in faster task-switching performance without a cost to accuracy. Media multitasking and intelligence were both unrelated to passive decay factors. These findings are consistent with a 2-component model of task-switching (Sohn & Anderson, 2001), as well as an automatic/executive framework of cognitive control (Schneider & Shiffrin, 1977). (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The effect of pain on task switching: pain reduces accuracy and increases reaction times across multiple switching paradigms.

PubMed

Attridge, Nina; Keogh, Edmund; Eccleston, Christopher

2016-10-01

Pain disrupts attention, which may have negative consequences for daily life for people with acute or chronic pain. It has been suggested that switching between tasks may leave us particularly susceptible to pain-related attentional disruption, because we need to disengage our attention from one task before shifting it onto another. Switching tasks typically elicit lower accuracies and/or longer reaction times when participants switch to a new task compared with repeating the same task, and pain may exacerbate this effect. We present 3 studies to test this hypothesis. In study 1, participants completed 2 versions of an alternating runs switching task under pain-free and thermal pain-induction conditions. Pain did not affect performance on either task. In studies 2 and 3, we examined 7 versions of the switching task using large general population samples, experiencing a variety of naturally occurring pain conditions, recruited and tested on the internet. On all tasks, participants with pain had longer reaction times on both switch and repeat trials compared with participants without pain, but pain did not increase switch costs. In studies 2 and 3, we also investigated the effects of type of pain, duration of pain, and analgesics on task performance. We conclude that pain has a small dampening effect on performance overall on switching tasks. This suggests that pain interrupts attention even when participants are engaged in a trial, not only when attention has been disengaged for shifting to a new task set.

Is Set Shifting Really Impaired in Trait Anxiety? Only When Switching Away from an Effortfully Established Task Set

PubMed Central

Gustavson, Daniel E.; Altamirano, Lee J.; Johnson, Daniel P.; Whisman, Mark A.; Miyake, Akira

2016-01-01

The current study investigated whether trait anxiety was systematically related to task-set shifting performance, using a task-switching paradigm in which one task was more attentionally demanding than the other. Specifically, taking advantage of a well-established phenomenon known as asymmetric switch costs, we tested the hypothesis that the association between trait anxiety and task-set shifting is most clearly observed when individuals must switch away from a more attentionally demanding task for which it was necessary to effortfully establish an appropriate task set. Ninety-one young adults completed an asymmetric switching task and trait-level mood questionnaires. Results indicated that higher levels of trait anxiety were systematically associated with greater asymmetry in reaction-time (RT) switch costs. Specifically, the RT costs for switching from the more attentionally demanding task to the less demanding task were significantly greater with higher levels of trait anxiety, whereas the RT costs for switching in the opposite direction were not significantly associated with trait anxiety levels. Further analyses indicated that these associations were not attributable to comorbid dysphoria or worry. These results suggest that levels of trait anxiety may not be related to general set-shifting ability per se, but, rather, that anxiety-specific effects may primarily be restricted to when one must efficiently switch away from (or let go of) an effortfully established task set. PMID:27429194

Crossmodal attention switching: auditory dominance in temporal discrimination tasks.

PubMed

Lukas, Sarah; Philipp, Andrea M; Koch, Iring

2014-11-01

Visual stimuli are often processed more efficiently than accompanying stimuli in another modality. In line with this "visual dominance", earlier studies on attentional switching showed a clear benefit for visual stimuli in a bimodal visual-auditory modality-switch paradigm that required spatial stimulus localization in the relevant modality. The present study aimed to examine the generality of this visual dominance effect. The modality appropriateness hypothesis proposes that stimuli in different modalities are differentially effectively processed depending on the task dimension, so that processing of visual stimuli is favored in the dimension of space, whereas processing auditory stimuli is favored in the dimension of time. In the present study, we examined this proposition by using a temporal duration judgment in a bimodal visual-auditory switching paradigm. Two experiments demonstrated that crossmodal interference (i.e., temporal stimulus congruence) was larger for visual stimuli than for auditory stimuli, suggesting auditory dominance when performing temporal judgment tasks. However, attention switch costs were larger for the auditory modality than for visual modality, indicating a dissociation of the mechanisms underlying crossmodal competition in stimulus processing and modality-specific biasing of attentional set. Copyright © 2014 Elsevier B.V. All rights reserved.

Functional brain and age-related changes associated with congruency in task switching

PubMed Central

Eich, Teal S.; Parker, David; Liu, Dan; Oh, Hwamee; Razlighi, Qolamreza; Gazes, Yunglin; Habeck, Christian; Stern, Yaakov

2016-01-01

Alternating between completing two simple tasks, as opposed to completing only one task, has been shown to produce costs to performance and changes to neural patterns of activity, effects which are augmented in old age. Cognitive conflict may arise from factors other than switching tasks, however. Sensorimotor congruency (whether stimulus-response mappings are the same or different for the two tasks) has been shown to behaviorally moderate switch costs in older, but not younger adults. In the current study, we used fMRI to investigate the neurobiological mechanisms of response-conflict congruency effects within a task switching paradigm in older (N=75) and younger (N=62) adults. Behaviorally, incongruency moderated age-related differences in switch costs. Neurally, switch costs were associated with greater activation in the dorsal attention network for older relative to younger adults. We also found that older adults recruited an additional set of brain areas in the ventral attention network to a greater extent than did younger adults to resolve congruency-related response-conflict. These results suggest both a network and an age-based dissociation between congruency and switch costs in task switching. PMID:27520472

Reward sensitivity modulates brain activity in the prefrontal cortex, ACC and striatum during task switching.

PubMed

Fuentes-Claramonte, Paola; Ávila, César; Rodríguez-Pujadas, Aina; Ventura-Campos, Noelia; Bustamante, Juan C; Costumero, Víctor; Rosell-Negre, Patricia; Barrós-Loscertales, Alfonso

2015-01-01

Current perspectives on cognitive control acknowledge that individual differences in motivational dispositions may modulate cognitive processes in the absence of reward contingencies. This work aimed to study the relationship between individual differences in Behavioral Activation System (BAS) sensitivity and the neural underpinnings involved in processing a switching cue in a task-switching paradigm. BAS sensitivity was hypothesized to modulate brain activity in frontal regions, ACC and the striatum. Twenty-eight healthy participants underwent fMRI while performing a switching task, which elicited activity in fronto-striatal regions during the processing of the switch cue. BAS sensitivity was negatively associated with activity in the lateral prefrontal cortex, anterior cingulate cortex and the ventral striatum. Combined with previous results, our data indicate that BAS sensitivity modulates the neurocognitive processes involved in task switching in a complex manner depending on task demands. Therefore, individual differences in motivational dispositions may influence cognitive processing in the absence of reward contingencies.

Reward Sensitivity Modulates Brain Activity in the Prefrontal Cortex, ACC and Striatum during Task Switching

PubMed Central

Fuentes-Claramonte, Paola; Ávila, César; Rodríguez-Pujadas, Aina; Ventura-Campos, Noelia; Bustamante, Juan C.; Costumero, Víctor; Rosell-Negre, Patricia; Barrós-Loscertales, Alfonso

2015-01-01

Current perspectives on cognitive control acknowledge that individual differences in motivational dispositions may modulate cognitive processes in the absence of reward contingencies. This work aimed to study the relationship between individual differences in Behavioral Activation System (BAS) sensitivity and the neural underpinnings involved in processing a switching cue in a task-switching paradigm. BAS sensitivity was hypothesized to modulate brain activity in frontal regions, ACC and the striatum. Twenty-eight healthy participants underwent fMRI while performing a switching task, which elicited activity in fronto-striatal regions during the processing of the switch cue. BAS sensitivity was negatively associated with activity in the lateral prefrontal cortex, anterior cingulate cortex and the ventral striatum. Combined with previous results, our data indicate that BAS sensitivity modulates the neurocognitive processes involved in task switching in a complex manner depending on task demands. Therefore, individual differences in motivational dispositions may influence cognitive processing in the absence of reward contingencies. PMID:25875640

Switching between simple cognitive tasks: the interaction of top-down and bottom-up factors

NASA Technical Reports Server (NTRS)

Ruthruff, E.; Remington, R. W.; Johnston, J. C.

2001-01-01

How do top-down factors (e.g., task expectancy) and bottom-up factors (e.g., task recency) interact to produce an overall level of task readiness? This question was addressed by factorially manipulating task expectancy and task repetition in a task-switching paradigm. The effects of expectancy and repetition on response time tended to interact underadditively, but only because the traditional binary task-repetition variable lumps together all switch trials, ignoring variation in task lag. When the task-recency variable was scaled continuously, all 4 experiments instead showed additivity between expectancy and recency. The results indicated that expectancy and recency influence different stages of mental processing. One specific possibility (the configuration-execution model) is that task expectancy affects the time required to configure upcoming central operations, whereas task recency affects the time required to actually execute those central operations.

Are the deficits in navigational abilities present in the Williams syndrome related to deficits in the backward inhibition?

PubMed Central

Foti, Francesca; Sdoia, Stefano; Menghini, Deny; Mandolesi, Laura; Vicari, Stefano; Ferlazzo, Fabio; Petrosini, Laura

2015-01-01

Williams syndrome (WS) is associated with a distinct profile of relatively proficient skills within the verbal domain compared to the severe impairment of visuo-spatial processing. Abnormalities in executive functions and deficits in planning ability and spatial working memory have been described. However, to date little is known about the influence of executive function deficits on navigational abilities in WS. This study aimed at analyzing in WS individuals a specific executive function, the backward inhibition (BI) that allows individuals to flexibly adapt to continuously changing environments. A group of WS individuals and a mental age- and gender-matched group of typically developing children were subjected to three task-switching experiments requiring visuospatial or verbal material to be processed. Results showed that WS individuals exhibited clear BI deficits during visuospatial task-switching paradigms and normal BI effect during verbal task-switching paradigm. Overall, the present results suggest that the BI involvement in updating environment representations during navigation may influence WS navigational abilities. PMID:25852605

Switch Detection in Preschoolers’ Cognitive Flexibility

PubMed Central

Chevalier, Nicolas; Wiebe, Sandra A.; Huber, Kristina L.; Espy, Kimberly Andrews

2011-01-01

The present study addressed the role of switch detection in cognitive flexibility by testing the effect of transition cues (i.e., cues that directly signal the need to switch or maintain a given task goal) in a cued set-shifting paradigm at age 5. Children performed better, especially on switch trials, when transition cues were combined with traditional task cues (i.e., cues that directly signal the relevant task on a given trial), relative to conditions without transition cues. This effect was not influenced by explicit knowledge of transition cues or transition cue transparency, suggesting transition cues did not need to be semantically processed to be beneficial. These findings reveal that young children’s difficulties in set-shifting situations partially stem from failures to monitor for the need to switch. PMID:21353678

Is set shifting really impaired in trait anxiety? Only when switching away from an effortfully established task set.

PubMed

Gustavson, Daniel E; Altamirano, Lee J; Johnson, Daniel P; Whisman, Mark A; Miyake, Akira

2017-02-01

The current study investigated whether trait anxiety was systematically related to task-set shifting performance, using a task-switching paradigm in which 1 task was more attentionally demanding than the other. Specifically, taking advantage of a well-established phenomenon known as asymmetric switch costs, we tested the hypothesis that the association between trait anxiety and task-set shifting is most clearly observed when individuals must switch away from a more attentionally demanding task for which it was necessary to effortfully establish an appropriate task set. Ninety-one young adults completed an asymmetric switching task and trait-level mood questionnaires. Results indicated that higher levels of trait anxiety were systematically associated with greater asymmetry in reaction time (RT) switch costs. Specifically, the RT costs for switching from the more attentionally demanding task to the less demanding task were significantly greater with higher levels of trait anxiety, whereas the RT costs for switching in the opposite direction were not significantly associated with trait anxiety levels. Further analyses indicated that these associations were not attributable to comorbid dysphoria or worry. These results suggest that levels of trait anxiety may not be related to general set-shifting ability per se, but, rather, that anxiety-specific effects may primarily be restricted to when one must efficiently switch away from (or let go of) an effortfully established task set. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Cognitive caching promotes flexibility in task switching: evidence from event-related potentials.

PubMed

Lange, Florian; Seer, Caroline; Müller, Dorothea; Kopp, Bruno

2015-12-08

Time-consuming processes of task-set reconfiguration have been shown to contribute to the costs of switching between cognitive tasks. We describe and probe a novel mechanism serving to reduce the costs of task-set reconfiguration. We propose that when individuals are uncertain about the currently valid task, one task set is activated for execution while other task sets are maintained at a pre-active state in cognitive cache. We tested this idea by assessing an event-related potential (ERP) index of task-set reconfiguration in a three-rule task-switching paradigm involving varying degrees of task uncertainty. In high-uncertainty conditions, two viable tasks were equally likely to be correct whereas in low-uncertainty conditions, one task was more likely than the other. ERP and performance measures indicated substantial costs of task-set reconfiguration when participants were required to switch away from a task that had been likely to be correct. In contrast, task-set-reconfiguration costs were markedly reduced when the previous task set was chosen under high task uncertainty. These results suggest that cognitive caching of alternative task sets adds to human cognitive flexibility under high task uncertainty.

Cognitive caching promotes flexibility in task switching: evidence from event-related potentials

PubMed Central

Lange, Florian; Seer, Caroline; Müller, Dorothea; Kopp, Bruno

2015-01-01

Time-consuming processes of task-set reconfiguration have been shown to contribute to the costs of switching between cognitive tasks. We describe and probe a novel mechanism serving to reduce the costs of task-set reconfiguration. We propose that when individuals are uncertain about the currently valid task, one task set is activated for execution while other task sets are maintained at a pre-active state in cognitive cache. We tested this idea by assessing an event-related potential (ERP) index of task-set reconfiguration in a three-rule task-switching paradigm involving varying degrees of task uncertainty. In high-uncertainty conditions, two viable tasks were equally likely to be correct whereas in low-uncertainty conditions, one task was more likely than the other. ERP and performance measures indicated substantial costs of task-set reconfiguration when participants were required to switch away from a task that had been likely to be correct. In contrast, task-set-reconfiguration costs were markedly reduced when the previous task set was chosen under high task uncertainty. These results suggest that cognitive caching of alternative task sets adds to human cognitive flexibility under high task uncertainty. PMID:26643146

Touchscreen-paradigm for mice reveals cross-species evidence for an antagonistic relationship of cognitive flexibility and stability

PubMed Central

Richter, S. Helene; Vogel, Anne S.; Ueltzhöffer, Kai; Muzzillo, Chiara; Vogt, Miriam A.; Lankisch, Katja; Armbruster-Genç, Diana J. N.; Riva, Marco A.; Fiebach, Christian J.; Gass, Peter; Vollmayr, Barbara

2014-01-01

The abilities to either flexibly adjust behavior according to changing demands (cognitive flexibility) or to maintain it in the face of potential distractors (cognitive stability) are critical for adaptive behavior in many situations. Recently, a novel human paradigm has found individual differences of cognitive flexibility and stability to be related to common prefrontal networks. The aims of the present study were, first, to translate this paradigm from humans to mice and, second, to test conceptual predictions of a computational model of prefrontal working memory mechanisms, the Dual State Theory, which assumes an antagonistic relation between cognitive flexibility and stability. Mice were trained in a touchscreen-paradigm to discriminate visual cues. The task involved “ongoing” and cued “switch” trials. In addition distractor cues were interspersed to test the ability to resist distraction, and an ambiguous condition assessed the spontaneous switching between two possible responses without explicit cues. While response times did not differ substantially between conditions, error rates (ER) increased from the “ongoing” baseline condition to the most complex condition, where subjects were required to switch between two responses in the presence of a distracting cue. Importantly, subjects switching more often spontaneously were found to be more distractible by task irrelevant cues, but also more flexible in situations, where switching was required. These results support a dichotomy of cognitive flexibility and stability as predicted by the Dual State Theory. Furthermore, they replicate critical aspects of the human paradigm, which indicates the translational potential of the testing procedure and supports the use of touchscreen procedures in preclinical animal research. PMID:24834036

Selective attention to perceptual dimensions and switching between dimensions.

PubMed

Meiran, Nachshon; Dimov, Eduard; Ganel, Tzvi

2013-02-01

In the present experiments, the question being addressed was whether switching attention between perceptual dimensions and selective attention to dimensions are processes that compete over a common resource? Attention to perceptual dimensions is usually studied by requiring participants to ignore a never-relevant dimension. Selection failure (Garner's Interference, GI) is indicated by poorer performance in the filtering condition (when this dimension varies) as compared with baseline (when it is fixed). Switching between perceptual dimensions is usually studied with the task switching paradigm. In the present experiments, attention switching was manipulated by using single-task blocks and blocks in which participants switched between tasks or dimensions in reaction to task cues, and attention to dimensions was assessed by including a third, never-relevant dimension that was either fixed or varied randomly. In Experiments 1 (long cue-target interval, CTI) and 2 (short CTI), the tasks involved shape and color and the never-relevant dimension (texture) was chosen to be separable from them. In Experiments 3 (long CTI) and 4 (short CTI), the tasks involved shape and brightness and the never-relevant dimension, saturation, was chosen to be separable from shape and integral with brightness. Task switching did not generate GI but a short CTI did. Thus, switching and filtering generally do not compete over central limited resources unless under tight time pressure. Experiment 3 shows GI in the brightness task but not in the shape task, suggesting that participants switched their attention between brightness and shape when they switched tasks. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Switch Costs Occur at Lemma Stage When Bilinguals Name Digits: Evidence from Language-Switching and Event-Related Potentials.

PubMed

Chang, Song; Xie, Jiushu; Li, Li; Wang, Ruiming; Liu, Ming

2016-01-01

Switch costs are generally found in language switching tasks. However, the locus where switch costs occur during bilingual language production remains unclear. Several studies that used a cued language-switching paradigm have attempted to investigate this question in bilingual language production, but researchers have not reached a consensus. Moreover, we are interested in where switch costs occur when language selection occurs after lemma activation. Previous studies have not investigated this question because most previous studies presented language cues before or along with the stimuli. Therefore, we used a modified cued language-switching paradigm with a combined event-related potentials (ERPs) technique to explore the locus of switch costs during bilingual language production. The cue and stimulus were separated and presented in two different presentation sequences in which Indonesian-Chinese bilingual speakers were instructed to name digits in their L1 or L2 according to the color of the cue. The ERPs related to the cue and stimulus for two presentation sequences were measured. In the stimulus-cue sequence, the analysis that was time-locked to cues revealed a reversed switch cost as early as 220 ms after the cue onset; furthermore, a switch cost was shown in L1 with a late stage post-cue onset. The results suggested that when language selection occurred after lemma activation, the switch costs mainly occurred at the lemma selection stage. In the cue-stimulus sequence, the analysis that was time-locked to cues did not reveal significant main effects of switching, whereas the analysis that was time-locked to digits yielded a switch cost, again indicating that switch costs mainly occurred at the lemma selection stage rather than at the language task schema competition stage. Overall, our results indicated that when bilinguals spoke digits aloud in the language switching task, switch costs mainly occurred at the lemma selection stage.

Age-related decline in task switching is linked to both global and tract-specific changes in white matter microstructure.

PubMed

Jolly, Todd A D; Cooper, Patrick S; Rennie, Jaime L; Levi, Christopher R; Lenroot, Rhoshel; Parsons, Mark W; Michie, Patricia T; Karayanidis, Frini

2017-03-01

Task-switching performance relies on a broadly distributed frontoparietal network and declines in older adults. In this study, they investigated whether this age-related decline in task switching performance was mediated by variability in global or regional white matter microstructural health. Seventy cognitively intact adults (43-87 years) completed a cued-trials task switching paradigm. Microstructural white matter measures were derived using diffusion tensor imaging (DTI) analyses on the diffusion-weighted imaging (DWI) sequence. Task switching performance decreased with increasing age and radial diffusivity (RaD), a measure of white matter microstructure that is sensitive to myelin structure. RaD mediated the relationship between age and task switching performance. However, the relationship between RaD and task switching performance remained significant when controlling for age and was stronger in the presence of cardiovascular risk factors. Variability in error and RT mixing cost were associated with RaD in global white matter and in frontoparietal white matter tracts, respectively. These findings suggest that age-related increase in mixing cost may result from both global and tract-specific disruption of cerebral white matter linked to the increased incidence of cardiovascular risks in older adults. Hum Brain Mapp 38:1588-1603, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Default mode network abnormalities during state switching in attention deficit hyperactivity disorder.

PubMed

Sidlauskaite, J; Sonuga-Barke, E; Roeyers, H; Wiersema, J R

2016-02-01

Individuals with attention deficit hyperactivity disorder (ADHD) display excess levels of default mode network (DMN) activity during goal-directed tasks, which are associated with attentional disturbances and performance decrements. One hypothesis is that this is due to attenuated down-regulation of this network during rest-to-task switching. A second related hypothesis is that it may be associated with right anterior insula (rAI) dysfunction - a region thought to control the actual state-switching process. These hypotheses were tested in the current fMRI study in which 19 adults with ADHD and 21 typically developing controls undertook a novel state-to-state switching paradigm. Advance cues signalled upcoming switches between rest and task periods and switch-related anticipatory modulation of DMN and rAI was measured. To examine whether rest-to-task switching impairments may be a specific example of a more general state regulation deficit, activity upon task-to-rest cues was also analysed. Against our hypotheses, we found that the process of down-regulating the DMN when preparing to switch from rest to task was unimpaired in ADHD and that there was no switch-specific deficit in rAI modulation. However, individuals with ADHD showed difficulties up-regulating the DMN when switching from task to rest. Rest-to-task DMN attenuation seems to be intact in adults with ADHD and thus appears unrelated to excess DMN activity observed during tasks. Instead, individuals with ADHD exhibit attenuated up-regulation of the DMN, hence suggesting disturbed re-initiation of a rest state.

Categorization difficulty modulates the mediated route for response selection in task switching.

PubMed

Schneider, Darryl W

2017-12-22

Conflict during response selection in task switching is indicated by the response congruency effect: worse performance for incongruent targets (requiring different responses across tasks) than for congruent targets (requiring the same response). The effect can be explained by dual-task processing in a mediated route for response selection, whereby targets are categorized with respect to both tasks. In the present study, the author tested predictions for the modulation of response congruency effects by categorization difficulty derived from a relative-speed-of-processing hypothesis. Categorization difficulty was manipulated for the relevant and irrelevant task dimensions in a novel spatial task-switching paradigm that involved judging the locations of target dots in a grid, without repetition of dot configurations. Response congruency effects were observed and they varied systematically with categorization difficulty (e.g., being larger when irrelevant categorization was easy than when it was hard). These results are consistent with the relative-speed-of-processing hypothesis and suggest that task-switching models that implement variations of the mediated route for response selection need to address the time course of categorization.

The Role of Working Memory Gating in Task Switching: A Procedural Version of the Reference-Back Paradigm

PubMed Central

Kessler, Yoav

2017-01-01

Models of working memory (WM) suggest that the contents of WM are separated from perceptual input by a gate, that enables shielding information against interference when closed, and allows for rapid updating when open. Recent work in the declarative WM domain provided evidence for this notion, demonstrating the behavioral cost of opening and closing the gate. The goal of the present work was to examine gating in procedural WM, namely in a task-switching experiment. In each trial, participants were presented with a digit and a task cue, indicating whether the required task was a parity or a magnitude decision. Critically, a colored frame around the stimulus indicated whether the task cue was relevant (attend trials), or whether it had to be ignored, and the previous task set should be applied regardless of the present cue (ignore trials). Switching between tasks, and between ignore and attend trials, was manipulated. The results of two experiments demonstrated that the cost of gate opening was eliminated in task switching trials, implying that both processes operate in parallel. PMID:29312095

Evidence against mood-congruent attentional bias in Major Depressive Disorder.

PubMed

Cheng, Philip; Preston, Stephanie D; Jonides, John; Mohr, Alicia Hofelich; Thummala, Kirti; Casement, Melynda; Hsing, Courtney; Deldin, Patricia J

2015-12-15

Depression is consistently associated with biased retrieval and interpretation of affective stimuli, but evidence for depressive bias in earlier cognitive processing, such as attention, is mixed. In five separate experiments, individuals with depression (three experiments with clinically diagnosed major depression, two experiments with dysphoria measured via the Beck Depression Inventory) completed three tasks designed to elicit depressive biases in attention, including selective attention, attentional switching, and attentional inhibition. Selective attention was measured using a modified emotional Stroop task, while attentional switching and inhibition was examined via an emotional task-switching paradigm and an emotional counter task. Results across five different experiments indicate that individuals with depression perform comparably with healthy controls, providing corroboration that depression is not characterized by biases in attentional processes. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Too Much of a Good Thing: Stronger Bilingual Inhibition Leads to Larger Lag-2 Task Repetition Costs

ERIC Educational Resources Information Center

Prior, Anat

2012-01-01

Inhibitory control and monitoring abilities of Hebrew-English bilingual and English monolingual university students were compared, in a paradigm requiring participants to switch between performing three distinct tasks. Inhibitory control was gauged by lag-2 task repetition costs, namely decreased performance on the final trial of sequences of type…

Task conflict effect in task switching.

PubMed

Braverman, Ami; Meiran, Nachshon

2010-11-01

A part of action preparation is deciding what the relevant task is. This task-decision process is conceptually separate from response selection. To show this, the authors manipulated task conflict in a spatial task-switching paradigm, using conflict stimuli that appeared during trials with univalent targets (affording 1 task). The conflict stimuli afforded task identity because they were used as task cues with bivalent targets (affording 2 tasks) that were intermixed with the univalent targets. Thus, for univalent targets, irrelevant stimuli either caused low task conflict or high task conflict. In three experiments, the authors found poorer performance in high task conflict trials than in low task conflict trials. Task conflict was introduced during target appearance (Experiment 1) or task preparation (Experiments 2 and 3). In the latter case, the task conflict effect decreased with increasing task preparation time showing that task preparation involves task decision.

Neural substrates of cognitive switching and inhibition in a face processing task.

PubMed

Piguet, Camille; Sterpenich, Virginie; Desseilles, Martin; Cojan, Yann; Bertschy, Gilles; Vuilleumier, Patrik

2013-11-15

We frequently need to change our current occupation, an operation requiring additional effortful cognitive demands. Switching from one task to another may involve two distinct processes: inhibition of the previously relevant task-set, and initiation of a new one. Here we tested whether these two processes are underpinned by separate neural substrates, and whether they differ depending on the nature of the task and the emotional content of stimuli. We used functional magnetic resonance imaging in healthy human volunteers who categorize emotional faces according to three different judgment rules (color, gender, or emotional expression). Our paradigm allowed us to separate neural activity associated with inhibition and switching based on the sequence of the tasks required on successive trials. We found that the bilateral medial superior parietal lobule and left intraparietal sulcus showed consistent activation during switching regardless of the task. On the other hand, no common region was activated (or suppressed) as a consequence of inhibition across all tasks. Rather, task-specific effects were observed in brain regions that were more activated when switching to a particular task but less activated after inhibition of the same task. In addition, compared to other conditions, the emotional task elicited a similar switching cost but lower inhibition cost, accompanied by selective decrease in the anterior cingulate cortex when returning to this task shortly after inhibiting it. These results demonstrate that switching relies on domain-general processes mediated by postero-medial parietal areas, engaged across all tasks, but also provide novel evidence that task inhibition produces domain-specific decreases as a function of particular task demands, with only the latter inhibition component being modulated by emotional information. Copyright © 2013 Elsevier Inc. All rights reserved.

Social task switching: On the automatic social engagement of executive functions.

PubMed

Dudarev, Veronica; Hassin, Ran R

2016-01-01

Humans are quintessentially social, yet much of cognitive psychology has focused on the individual, in individual settings. The literature on joint action is one of the most prominent exceptions. Joint-action research studies the sociality of our mental representations by examining how the tasks of other people around us affect our own task performance. In this paper we go beyond examining whether we represent others and their tasks, by asking whether we also automatically do their tasks with them, even if they require effortful executive functions. To this end we examine one of the core executive functions, shifting, in a new paradigm that allows us to investigate task-switching in a joint-action setup. Copyright © 2015 Elsevier B.V. All rights reserved.

On the origins of the task mixing cost in the cuing task-switching paradigm.

PubMed

Rubin, Orit; Meiran, Nachshon

2005-11-01

Poorer performance in conditions involving task repetition within blocks of mixed tasks relative to task repetition within blocks of single task is called mixing cost (MC). In 2 experiments exploring 2 hypotheses regarding the origins of MC, participants either switched between cued shape and color tasks, or they performed them as single tasks. Experiment 1 supported the hypothesis that mixed-tasks trials require the resolution of task ambiguity by showing that MC existed only with ambiguous stimuli that afforded both tasks and not with unambiguous stimuli affording only 1 task. Experiment 2 failed to support the hypothesis that holding multiple task sets in working memory (WM) generates MC by showing that systematic manipulation of the number of stimulus-response rules in WM did not affect MC. The results emphasize the role of competition management between task sets during task control.

Dissociable effects of game elements on motivation and cognition in a task-switching training in middle childhood

PubMed Central

Dörrenbächer, Sandra; Müller, Philipp M.; Tröger, Johannes; Kray, Jutta

2014-01-01

Although motivational reinforcers are often used to enhance the attractiveness of trainings of cognitive control in children, little is known about how such motivational manipulations of the setting contribute to separate gains in motivation and cognitive-control performance. Here we provide a framework for systematically investigating the impact of a motivational video-game setting on the training motivation, the task performance, and the transfer success in a task-switching training in middle-aged children (8–11 years of age). We manipulated both the type of training (low-demanding/single-task training vs. high-demanding/task-switching training) as well as the motivational setting (low-motivational/without video-game elements vs. high-motivational/with video-game elements) separately from another. The results indicated that the addition of game elements to a training setting enhanced the intrinsic interest in task practice, independently of the cognitive demands placed by the training type. In the task-switching group, the high-motivational training setting led to an additional enhancement of task and switching performance during the training phase right from the outset. These motivation-induced benefits projected onto the switching performance in a switching situation different from the trained one (near-transfer measurement). However, in structurally dissimilar cognitive tasks (far-transfer measurement), the motivational gains only transferred to the response dynamics (speed of processing). Hence, the motivational setting clearly had a positive impact on the training motivation and on the paradigm-specific task-switching abilities; it did not, however, consistently generalize on broad cognitive processes. These findings shed new light on the conflation of motivation and cognition in childhood and may help to refine guidelines for designing adequate training interventions. PMID:25431564

Task inhibition, conflict, and the n-2 repetition cost: A combined computational and empirical approach.

PubMed

Sexton, Nicholas J; Cooper, Richard P

2017-05-01

Task inhibition (also known as backward inhibition) is an hypothesised form of cognitive inhibition evident in multi-task situations, with the role of facilitating switching between multiple, competing tasks. This article presents a novel cognitive computational model of a backward inhibition mechanism. By combining aspects of previous cognitive models in task switching and conflict monitoring, the model instantiates the theoretical proposal that backward inhibition is the direct result of conflict between multiple task representations. In a first simulation, we demonstrate that the model produces two effects widely observed in the empirical literature, specifically, reaction time costs for both (n-1) task switches and n-2 task repeats. Through a systematic search of parameter space, we demonstrate that these effects are a general property of the model's theoretical content, and not specific parameter settings. We further demonstrate that the model captures previously reported empirical effects of inter-trial interval on n-2 switch costs. A final simulation extends the paradigm of switching between tasks of asymmetric difficulty to three tasks, and generates novel predictions for n-2 repetition costs. Specifically, the model predicts that n-2 repetition costs associated with hard-easy-hard alternations are greater than for easy-hard-easy alternations. Finally, we report two behavioural experiments testing this hypothesis, with results consistent with the model predictions. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Guessing versus Choosing an Upcoming Task

PubMed Central

Kleinsorge, Thomas; Scheil, Juliane

2016-01-01

We compared the effects of guessing vs. choosing an upcoming task. In a task-switching paradigm with four tasks, two groups of participants were asked to either guess or choose which task will be presented next under otherwise identical conditions. The upcoming task corresponded to participants’ guesses or choices in 75 % of the trials. However, only participants in the Choosing condition were correctly informed about this, whereas participants in the Guessing condition were told that tasks were determined at random. In the Guessing condition, we replicated previous findings of a pronounced reduction of switch costs in case of incorrect guesses. This switch cost reduction was considerably less pronounced with denied choices in the Choosing condition. We suggest that in the Choosing condition, the signaling of prediction errors associated with denied choices is attenuated because a certain proportion of denied choices is consistent with the overall representation of the situation as conveyed by task instructions. In the Guessing condition, in contrast, the mismatch of guessed and actual task is resolved solely on the level of individual trials by strengthening the representation of the actual task. PMID:27047423

Lifelong Bilingualism Maintains Neural Efficiency for Cognitive Control in Aging

PubMed Central

Gold, Brian T.; Kim, Chobok; Johnson, Nathan F.; Kryscio, Richard J.; Smith, Charles D.

2013-01-01

Recent behavioral data have shown that lifelong bilingualism can maintain youthful cognitive control abilities in aging. Here, we provide the first direct evidence of a neural basis for the bilingual cognitive control boost in aging. Two experiments were conducted, using a perceptual task switching paradigm, and including a total of 110 participants. In Experiment 1, older adult bilinguals showed better perceptual switching performance than their monolingual peers. In Experiment 2, younger and older adult monolinguals and bilinguals completed the same perceptual task switching experiment while fMRI was performed. Typical age-related performance reductions and fMRI activation increases were observed. However, like younger adults, bilingual older adults outperformed their monolingual peers while displaying decreased activation in left lateral frontal cortex and cingulate cortex. Critically, this attenuation of age-related over-recruitment associated with bilingualism was directly correlated with better task switching performance. In addition, the lower BOLD response in frontal regions accounted for 82% of the variance in the bilingual task switching reaction time advantage. These results suggest that lifelong bilingualism offsets age-related declines in the neural efficiency for cognitive control processes. PMID:23303919

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

PubMed Central

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

2013-01-01

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

Dissociative Global and Local Task-Switching Costs Across Younger Adults, Middle-Aged Adults, Older Adults, and Very Mild Alzheimer Disease Individuals

PubMed Central

Huff, Mark J.; Balota, David A.; Minear, Meredith; Aschenbrenner, Andrew J.; Duchek, Janet M.

2015-01-01

A task-switching paradigm was used to examine differences in attentional control across younger adults, middle-aged adults, healthy older adults, and individuals classified in the earliest detectable stage of Alzheimer's disease (AD). A large sample of participants (570) completed a switching task in which participants were cued to classify the letter (consonant/vowel) or number (odd/even) task-set dimension of a bivalent stimulus (e.g., A 14), respectively. A Pure block consisting of single-task trials and a Switch block consisting of nonswitch and switch trials were completed. Local (switch vs. nonswitch trials) and global (nonswitch vs. pure trials) costs in mean error rates, mean response latencies, underlying reaction time distributions, along with stimulus-response congruency effects were computed. Local costs in errors were group invariant, but global costs in errors systematically increased as a function of age and AD. Response latencies yielded a strong dissociation: Local costs decreased across groups whereas global costs increased across groups. Vincentile distribution analyses revealed that the dissociation of local and global costs primarily occurred in the slowest response latencies. Stimulus-response congruency effects within the Switch block were particularly robust in accuracy in the very mild AD group. We argue that the results are consistent with the notion that the impaired groups show a reduced local cost because the task sets are not as well tuned, and hence produce minimal cost on switch trials. In contrast, global costs increase because of the additional burden on working memory of maintaining two task sets. PMID:26652720

Deficient saccadic inhibition in Asperger's disorder and the social-emotional processing disorder

PubMed Central

Manoach, D; Lindgren, K; Barton, J

2004-01-01

Background: Both Asperger's disorder and the social-emotional processing disorder (SEPD), a form of non-verbal learning disability, are associated with executive function deficits. SEPD has been shown to be associated with deficient saccadic inhibition. Objective: To study two executive functions in Asperger's disorder and SEPD, inhibition and task switching, using a single saccadic paradigm. Methods: 22 control subjects and 27 subjects with developmental social processing disorders—SEPD, Asperger's disorder, or both syndromes—performed random sequences of prosaccades and antisaccades. This design resulted in four trial types, prosaccades and antisaccades, that were either repeated or switched. The design allowed the performance costs of inhibition and task switching to be isolated. Results: Subjects with both Asperger's disorder and SEPD showed deficient inhibition, as indicated by increased antisaccade errors and a disproportionate increase in latency for antisaccades relative to prosaccades. In contrast, task switching error and latency costs were normal and unrelated to the costs of inhibition. Conclusions: This study replicates the finding of deficient saccadic inhibition in SEPD, extends it to Asperger's disorder, and implicates prefrontal cortex dysfunction in these syndromes. The finding of intact task switching shows that executive function deficits in Asperger's disorder and SEPD are selective and suggests that inhibition and task switching are mediated by distinct neural networks. PMID:15548490

A developmental neuroimaging investigation of the change paradigm

PubMed Central

Thomas, Laura A.; Hall, Julie M.; Skup, Martha; Jenkins, Sarah E.; Pine, Daniel S.; Leibenluft, Ellen

2010-01-01

This neuroimaging study examines the development of cognitive flexibility using the Change task in a sample of youths and adults. The Change task requires subjects to inhibit a prepotent response and substitute an alternate response, and the task incorporates an algorithm that adjusts task difficulty in response to subject performance. Data from both groups combined show a network of prefrontal and parietal areas that are active during the task. For adults vs. youths, a distributed network was more active for successful change trials versus go, baseline, or unsuccessful change trials. This network included areas involved in rule representation, retrieval (lateral PFC), and switching (medial PFC and parietal regions). These results are consistent with data from previous task-switching experiments and inform developmental understandings of cognitive flexibility. PMID:21159096

Cognitive rigidity in unipolar depression and obsessive compulsive disorder: examination of task switching, Stroop, working memory updating and post-conflict adaptation.

PubMed

Meiran, Nachshon; Diamond, Gary M; Toder, Doron; Nemets, Boris

2011-01-30

Obsessive compulsive disorder (OCD) and depressive rumination are both characterized by cognitive rigidity. We examined the performance of 17 patients (9 suffering from unipolar depression [UD] without OCD, and 8 suffering from OCD without UD), and 17 control participants matched on age, gender, language and education, on a battery covering the four main executive functions. Results indicated that, across both disorders, patients required more trials to adjust to single-task conditions after experiencing task switching, reflecting slow disengagement from switching mode, and showed abnormal post-conflict adaptation of processing mode following high conflict Stroop trials in comparison to controls. Rumination, which was elevated in UD and not in OCD, was associated with poor working memory updating and less task preparation. The results show that OCD and UD are associated with similar cognitive rigidity in the presently tested paradigms. Copyright © 2010 Elsevier Ltd. All rights reserved.

Developmental changes in using verbal self-cueing in task-switching situations: the impact of task practice and task-sequencing demands.

PubMed

Kray, Jutta; Gaspard, Hanna; Karbach, Julia; Blaye, Agnès

2013-01-01

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.

Attention switching after dietary brain 5-HT challenge in high impulsive subjects.

PubMed

Markus, C Rob; Jonkman, Lisa M

2007-09-01

High levels of impulsivity have adverse effects on performance in cognitive tasks, particularLy in those tasks that require high attention investment. Furthermore, both animal and human research has indicated that reduced brain serotonin (5-HT) function is associated with increases in impulsive behaviour or decreased inhibition ability, but the effects of 5-HT challenge have not yet been investigated in subjects vulnerable to impulsivity. The present study aimed to investigate whether subjects with high trait impulsivity perform worse than low impulsive subjects in a task switching paradigm in which they have to rapidly shift their attention between two response rules, and to investigate the influence of a 5-HT enhancing diet. Healthy subjects with high ( n = 19) and low (n = 18) trait impulsivity scores participated in a double-blind placebo-controlled study. All subjects performed the attention switch task in the morning following breakfast containing either tryptophan-rich alpha-lactalbumin (4.8 g/100 g TRP) or placebo protein (1.4 g/100 g TRP). Whereas there were no baseline differences between high and low impulsive subjects in task switching abilities, high impulsive subjects made significantly more switch errors and responded slower after dietary 5-HT stimulation, whereas no dietary effects were found on task switching performance in low-impulsive subjects. The deterioration in task switching performance induced by the 5-HT enhancing diet in high impulsive subjects was suggested to be established by general arousal/attention-reducing effects of 5-HT, which might have a larger impact in high impulsive subjects due to either different brain circuitry involved in task switching in this group or lower baseline arousal levels.

Schizophrenia patients show task switching deficits consistent with N-methyl-d-aspartate system dysfunction but not global executive deficits: implications for pathophysiology of executive dysfunction in schizophrenia.

PubMed

Wylie, Glenn R; Clark, E A; Butler, P D; Javitt, D C

2010-05-01

Schizophrenia is associated with cognitive processing deficits, including deficits in executive processing, that represent a core component of the disorder. In the Task Switching Test, subjects view ambiguous stimuli and must alternate between competing rules to generate correct responses. Subjects show worse performance (prolonged response time and/or increased error rates) on the first response after a switch than on subsequent responses ("switch costs"), as well as performing worse when stimuli are incongruent as opposed to congruent ("congruence costs"). Finally, subjects show worse performance in the dual vs single task condition ("mixing costs"). In monkeys, the N-methyl-D-aspartate (NMDA) antagonist ketamine has been shown to increase congruence but not switch costs. Here, subjects viewed colored letters and had to respond alternately based upon letter (X vs O) or color (red vs blue). Switch, congruence and mixing costs were calculated. Patients with schizophrenia (n = 16) and controls (n = 17) showed similar switch costs, consistent with prior literature. Patients nevertheless showed increased congruence and mixing costs. In addition, relative to controls, patients showed worse performance across conditions in the letter vs color tasks, suggesting deficits in form vs color processing. Overall, while confirming executive dysfunction in schizophrenia, this study indicates that not all aspects of executive control are impaired and that the task switching paradigm may be useful for evaluating neurochemical vs neuroanatomic hypotheses of schizophrenia.

Reactive control processes contributing to residual switch cost and mixing cost across the adult lifespan.

PubMed

Whitson, Lisa R; Karayanidis, Frini; Fulham, Ross; Provost, Alexander; Michie, Patricia T; Heathcote, Andrew; Hsieh, Shulan

2014-01-01

In task-switching paradigms, performance is better when repeating the same task than when alternating between tasks (switch cost) and when repeating a task alone rather than intermixed with another task (mixing cost). These costs remain even after extensive practice and when task cues enable advanced preparation (residual costs). Moreover, residual reaction time mixing cost has been consistently shown to increase with age. Residual switch and mixing costs modulate the amplitude of the stimulus-locked P3b. This mixing effect is disproportionately larger in older adults who also prepare more for and respond more cautiously on these "mixed" repeat trials (Karayanidis et al., 2011). In this paper, we analyze stimulus-locked and response-locked P3 and lateralized readiness potentials to identify whether residual switch and mixing cost arise from the need to control interference at the level of stimulus processing or response processing. Residual mixing cost was associated with control of stimulus-level interference, whereas residual switch cost was also associated with a delay in response selection. In older adults, the disproportionate increase in mixing cost was associated with greater interference at the level of decision-response mapping and response programming for repeat trials in mixed-task blocks. These findings suggest that older adults strategically recruit greater proactive and reactive control to overcome increased susceptibility to post-stimulus interference. This interpretation is consistent with recruitment of compensatory strategies to compensate for reduced repetition benefit rather than an overall decline on cognitive flexibility.

Reactive control processes contributing to residual switch cost and mixing cost across the adult lifespan

PubMed Central

Whitson, Lisa R.; Karayanidis, Frini; Fulham, Ross; Provost, Alexander; Michie, Patricia T.; Heathcote, Andrew; Hsieh, Shulan

2014-01-01

In task-switching paradigms, performance is better when repeating the same task than when alternating between tasks (switch cost) and when repeating a task alone rather than intermixed with another task (mixing cost). These costs remain even after extensive practice and when task cues enable advanced preparation (residual costs). Moreover, residual reaction time mixing cost has been consistently shown to increase with age. Residual switch and mixing costs modulate the amplitude of the stimulus-locked P3b. This mixing effect is disproportionately larger in older adults who also prepare more for and respond more cautiously on these “mixed” repeat trials (Karayanidis et al., 2011). In this paper, we analyze stimulus-locked and response-locked P3 and lateralized readiness potentials to identify whether residual switch and mixing cost arise from the need to control interference at the level of stimulus processing or response processing. Residual mixing cost was associated with control of stimulus-level interference, whereas residual switch cost was also associated with a delay in response selection. In older adults, the disproportionate increase in mixing cost was associated with greater interference at the level of decision-response mapping and response programming for repeat trials in mixed-task blocks. These findings suggest that older adults strategically recruit greater proactive and reactive control to overcome increased susceptibility to post-stimulus interference. This interpretation is consistent with recruitment of compensatory strategies to compensate for reduced repetition benefit rather than an overall decline on cognitive flexibility. PMID:24817859

Doing many things at a time: Lack of power decreases the ability to multitask.

PubMed

Cai, Ran Alice; Guinote, Ana

2017-09-01

Three studies investigated the effects of power on the ability to pursue multiple, concomitant goals, also known as multitasking. It was predicted that powerless participants will show lower multitasking ability than control and powerful participants. Study 1 focused on self-reported ability to multitask in a sample of executives and subordinate employees. Studies 2 and 3 investigated the ability to dual-task and to switch between tasks, respectively, using dual-task and task-switching paradigms. Across the studies, powerless individuals were less able to effectively multitask compared with control and powerful participants, suggesting that the detrimental effects of lack of power extend beyond single-task environments, shown in past research, into multitasking environments. Underlying mechanisms are discussed. © 2017 The British Psychological Society.

Cognitive Control and Language across the Life Span: Does Labeling Improve Reactive Control?

ERIC Educational Resources Information Center

Lucenet, Joanna; Blaye, Agnès; Chevalier, Nicolas; Kray, Jutta

2014-01-01

How does cognitive control change with age, and what are the processes underlying these changes? This question has been extensively studied using versions of the task-switching paradigm, which allow participants to actively prepare for the upcoming task (Kray, Eber, & Karbach, 2008). Little is known, however, about age-related changes in this…

Across-task priming revisited: response and task conflicts disentangled using ex-Gaussian distribution analysis.

PubMed

Moutsopoulou, Karolina; Waszak, Florian

2012-04-01

The differential effects of task and response conflict in priming paradigms where associations are strengthened between a stimulus, a task, and a response have been demonstrated in recent years with neuroimaging methods. However, such effects are not easily disentangled with only measurements of behavior, such as reaction times (RTs). Here, we report the application of ex-Gaussian distribution analysis on task-switching RT data and show that conflict related to stimulus-response associations retrieved after a switch of tasks is reflected in the Gaussian component. By contrast, conflict related to the retrieval of stimulus-task associations is reflected in the exponential component. Our data confirm that the retrieval of stimulus-task and -response associations affects behavior differently. Ex-Gaussian distribution analysis is a useful tool for pulling apart these different levels of associative priming that are not distinguishable in analyses of RT means.

An information theory account of late frontoparietal ERP positivities in cognitive control.

PubMed

Barceló, Francisco; Cooper, Patrick S

2018-03-01

ERP research on task switching has revealed distinct transient and sustained positive waveforms (latency circa 300-900 ms) while shifting task rules or stimulus-response (S-R) mappings. However, it remains unclear whether such switch-related positivities show similar scalp topography and index context-updating mechanisms akin to those posed for domain-general (i.e., classic P300) positivities in many task domains. To examine this question, ERPs were recorded from 31 young adults (18-30 years) while they were intermittently cued to switch or repeat their perceptual categorization of Gabor gratings varying in color and thickness (switch task), or else they performed two visually identical control tasks (go/no-go and oddball). Our task cueing paradigm examined two temporarily distinct stages of proactive rule updating and reactive rule execution. A simple information theory model helped us gauge cognitive demands under distinct temporal and task contexts in terms of low-level S-R pathways and higher-order rule updating operations. Task demands modulated domain-general (indexed by classic oddball P3) and switch positivities-indexed by both a cue-locked late positive complex and a sustained positivity ensuing task transitions. Topographic scalp analyses confirmed subtle yet significant split-second changes in the configuration of neural sources for both domain-general P3s and switch positivities as a function of both the temporal and task context. These findings partly meet predictions from information estimates, and are compatible with a family of P3-like potentials indexing functionally distinct neural operations within a common frontoparietal "multiple demand" system during the preparation and execution of simple task rules. © 2016 Society for Psychophysiological Research.

The effect of episodic retrieval on inhibition in task switching.

PubMed

Grange, James A; Kowalczyk, Agnieszka W; O'Loughlin, Rory

2017-08-01

Inhibition in task switching is inferred from n-2 repetition costs: the observation that ABA task switching sequences are responded to slower than CBA sequences. This is thought to reflect the persisting inhibition of Task A, which slows reactivation attempts. Mayr (2002) reported an experiment testing a critical noninhibitory account of this effect, namely episodic retrieval: If the trial parameters for Task A match across an ABA sequence, responses should be facilitated because of priming from episodic retrieval; a cost would occur if trial parameters mismatch. In a rule-switching paradigm, Mayr reported no significant difference in n-2 repetition cost when the trial parameters repeated or switched across an ABA sequence, in clear contrast to the episodic retrieval account. What remains unclear is whether successful episodic retrieval modulates the n-2 repetition cost. Across 3 experiments-including a close replication of Mayr-we find clear evidence of reduced n-2 task repetition costs when episodic retrieval is controlled. We find that the effect of episodic retrieval on the n-2 task repetition cost is increased when the cue-task relationship is made more abstract, suggesting the effect is because of interference in establishing the relevant attentional set. We also demonstrate that the episodic retrieval effect is not influenced by retrieval of low-level, perceptual, elements. Together, the data suggest the n-2 task repetition cost-typically attributable to an inhibitory mechanism-also reflects episodic retrieval effects. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Age-related processing strategies and go–nogo effects in task-switching: an ERP study

PubMed Central

Gaál, Zsófia A.; Czigler, István

2015-01-01

We studied cognitive and age-related changes in three task-switching (TS) paradigms: (1) informatively cued TS with go stimuli, (2) informatively cued TS with go and nogo stimuli, (3) non-informatively cued TS with go and nogo stimuli. This design allowed a direct comparison, how informative and non-informative cues influenced preparatory processes, and how nogo stimuli changed the context of the paradigm and cognitive processing in different aging groups. Beside the behavioral measures [reaction time (RT), error rate], event-related potentials (ERPs) were registered to the cue and target stimuli in young (N = 39, mean age = 21.6 ± 1.6 years) and older (N = 40, mean age = 65.7 ± 3.2 years) adults. The results provide evidence for declining performance in the older group: they had slower RT, less hits, more erroneous responses, higher mixing costs and decreased amplitude of ERP components than the participants of the younger group. In the task without the nogo stimuli young adults kept the previous task-set active that could be seen in shorter RT and larger amplitude of cue-locked late positivity (P3b) in task repeat (TR) trials compared to task switch trials. If both go and nogo stimuli were presented, similar RTs and P3b amplitudes appeared in the TR and TS trials. In the complex task situations older adults did not evolve an appropriate task representation and task preparation, as indicated by the lack of cue-locked P3b, CNV, and target-locked P3b. We conclude that young participants developed explicit representation of task structures, but the presence of nogo stimuli had marked effects on such representation. On the other hand, older people used only implicit control strategy to solve the task, hence the basic difference between the age groups was their strategy of task execution. PMID:26029072

Measuring the interrelations among multiple paradigms of visual attention: an individual differences approach.

PubMed

Huang, Liqiang; Mo, Lei; Li, Ying

2012-04-01

A large part of the empirical research in the field of visual attention has focused on various concrete paradigms. However, as yet, there has been no clear demonstration of whether or not these paradigms are indeed measuring the same underlying construct. We collected a very large data set (nearly 1.3 million trials) to address this question. We tested 257 participants on nine paradigms: conjunction search, configuration search, counting, tracking, feature access, spatial pattern, response selection, visual short-term memory, and change blindness. A fairly general attention factor was identified. Some of the participants were also tested on eight other paradigms. This general attention factor was found to be correlated with intelligence, visual marking, task switching, mental rotation, and Stroop task. On the other hand, a few paradigms that are very important in the attention literature (attentional capture, consonance-driven orienting, and inhibition of return) were found to be dissociated from this general attention factor.

Neurophysiological signature of effective anticipatory task-set control: a task-switching investigation.

PubMed

Lavric, Aureliu; Mizon, Guy A; Monsell, Stephen

2008-09-01

Changing between cognitive tasks requires a reorganization of cognitive processes. Behavioural evidence suggests this can occur in advance of the stimulus. However, the existence or detectability of an anticipatory task-set reconfiguration process remains controversial, in part because several neuroimaging studies have not detected extra brain activity during preparation for a task switch relative to a task repeat. In contrast, electrophysiological studies have identified potential correlates of preparation for a task switch, but their interpretation is hindered by the scarcity of evidence on their relationship to performance. We aimed to: (i) identify the brain potential(s) reflecting effective preparation for a task-switch in a task-cuing paradigm that shows clear behavioural evidence for advance preparation, and (ii) characterize this activity by means of temporal segmentation and source analysis. Our results show that when advance preparation was effective (as indicated by fast responses), a protracted switch-related component, manifesting itself as widespread posterior positivity and concurrent right anterior negativity, preceded stimulus onset for approximately 300 ms, with sources primarily in the left lateral frontal, right inferior frontal and temporal cortices. When advance preparation was ineffective (as implied by slow responses), or made impossible by a short cue-stimulus interval (CSI), a similar component, with lateral prefrontal generators, peaked approximately 300 ms poststimulus. The protracted prestimulus component (which we show to be distinct from P3 or contingent negative variation, CNV) also correlated over subjects with a behavioural measure of preparation. Furthermore, its differential lateralization for word and picture cues was consistent with a role for verbal self-instruction in preparatory task-set reconfiguration.

Game-based training of flexibility and attention improves task-switch performance: near and far transfer of cognitive training in an EEG study.

PubMed

Olfers, Kerwin J F; Band, Guido P H

2018-01-01

There is a demand for ways to enhance cognitive flexibility, as it can be a limiting factor for performance in daily life. Video game training has been linked to advantages in cognitive functioning, raising the question if training with video games can promote cognitive flexibility. In the current study, we investigated if game-based computerized cognitive training (GCCT) could enhance cognitive flexibility in a healthy young adult sample (N = 72), as measured by task-switch performance. Three GCCT schedules were contrasted, which targeted: (1) cognitive flexibility and task switching, (2) attention and working memory, or (3) an active control involving basic math games, in twenty 45-min sessions across 4-6 weeks. Performance on an alternating-runs task-switch paradigm during pretest and posttest sessions indicated greater overall reaction time improvements after both flexibility and attention training as compared to control, although not related to local switch cost. Flexibility training enhanced performance in the presence of distractor-related interference. In contrast, attention training was beneficial when low task difficulty undermined sustained selective attention. Furthermore, flexibility training improved response selection as indicated by a larger N2 amplitude after training as compared to control, and more efficient conflict monitoring as indicated by reduced Nc/CRN and larger Pe amplitude after training. These results provide tentative support for the efficacy of GCCT and suggest that an ideal training might include both task switching and attention components, with maximal task diversity both within and between training games.

A developmental neuroimaging investigation of the change paradigm.

PubMed

Thomas, Laura A; Hall, Julie M; Skup, Martha; Jenkins, Sarah E; Pine, Daniel S; Leibenluft, Ellen

2011-01-01

This neuroimaging study examines the development of cognitive flexibility using the Change task in a sample of youths and adults. The Change task requires subjects to inhibit a prepotent response and substitute an alternative response, and the task incorporates an algorithm that adjusts task difficulty in response to subject performance. Data from both groups combined show a network of prefrontal and parietal areas that are active during the task. For adults vs. youths, a distributed network was more active for successful change trials versus go, baseline, or unsuccessful change trials. This network included areas involved in rule representation, retrieval (lateral PFC), and switching (medial PFC and parietal regions). These results are consistent with data from previous task-switching experiments and inform developmental understandings of cognitive flexibility. Published 2010. This article is a US Government work and is in the public domain in the USA.

Caudate Nucleus Volume Mediates the Link between Cardiorespiratory Fitness and Cognitive Flexibility in Older Adults

PubMed Central

Verstynen, Timothy D.; Lynch, Brighid; Miller, Destiny L.; Voss, Michelle W.; Prakash, Ruchika Shaurya; Chaddock, Laura; Basak, Chandramallika; Szabo, Amanda; Olson, Erin A.; Wojcicki, Thomas R.; Fanning, Jason; Gothe, Neha P.; McAuley, Edward; Kramer, Arthur F.; Erickson, Kirk I.

2012-01-01

The basal ganglia play a central role in regulating the response selection abilities that are critical for mental flexibility. In neocortical areas, higher cardiorespiratory fitness levels are associated with increased gray matter volume, and these volumetric differences mediate enhanced cognitive performance in a variety of tasks. Here we examine whether cardiorespiratory fitness correlates with the volume of the subcortical nuclei that make up the basal ganglia and whether this relationship predicts cognitive flexibility in older adults. Structural MRI was used to determine the volume of the basal ganglia nuclei in a group of older, neurologically healthy individuals (mean age 66 years, N = 179). Measures of cardiorespiratory fitness (VO2max), cognitive flexibility (task switching), and attentional control (flanker task) were also collected. Higher fitness levels were correlated with higher accuracy rates in the Task Switching paradigm. In addition, the volume of the caudate nucleus, putamen, and globus pallidus positively correlated with Task Switching accuracy. Nested regression modeling revealed that caudate nucleus volume was a significant mediator of the relationship between cardiorespiratory fitness, and task switching performance. These findings indicate that higher cardiorespiratory fitness predicts better cognitive flexibility in older adults through greater grey matter volume in the dorsal striatum. PMID:22900181

Functional Roles of Neural Preparatory Processes in a Cued Stroop Task Revealed by Linking Electrophysiology with Behavioral Performance.

PubMed

Wang, Chao; Ding, Mingzhou; Kluger, Benzi M

2015-01-01

It is well established that cuing facilitates behavioral performance and that different aspects of instructional cues evoke specific neural preparatory processes in cued task-switching paradigms. To deduce the functional role of these neural preparatory processes the majority of studies vary aspects of the experimental paradigm and describe how these variations alter markers of neural preparatory processes. Although these studies provide important insights, they also have notable limitations, particularly in terms of understanding the causal or functional relationship of neural markers to cognitive and behavioral processes. In this study, we sought to address these limitations and uncover the functional roles of neural processes by examining how variability in the amplitude of neural preparatory processes predicts behavioral performance to subsequent stimuli. To achieve this objective 16 young adults were recruited to perform a cued Stroop task while their brain activity was measured using high-density electroencephalography. Four temporally overlapping but functionally and topographically distinct cue-triggered event related potentials (ERPs) were identified: 1) A left-frontotemporal negativity (250-700 ms) that was positively associated with word-reading performance; 2) a midline-frontal negativity (450-800 ms) that was positively associated with color-naming and incongruent performance; 3) a left-frontal negativity (450-800 ms) that was positively associated with switch trial performance; and 4) a centroparietal positivity (450-800 ms) that was positively associated with performance for almost all trial types. These results suggest that at least four dissociable cognitive processes are evoked by instructional cues in the present task, including: 1) domain-specific task facilitation; 2) switch-specific task-set reconfiguration; 3) preparation for response conflict; and 4) proactive attentional control. Examining the relationship between ERPs and behavioral performance provides a functional link between neural markers and the cognitive processes they index.

Flexible conflict management: conflict avoidance and conflict adjustment in reactive cognitive control.

PubMed

Dignath, David; Kiesel, Andrea; Eder, Andreas B

2015-07-01

Conflict processing is assumed to serve two crucial, yet distinct functions: Regarding task performance, control is adjusted to overcome the conflict. Regarding task choice, control is harnessed to bias decision making away from the source of conflict. Despite recent theoretical progress, until now two lines of research addressed these conflict-management strategies independently of each other. In this research, we used a voluntary task-switching paradigm in combination with response interference tasks to study both strategies in concert. In Experiment 1, participants chose between two univalent tasks on each trial. Switch rates increased following conflict trials, indicating avoidance of conflict. Furthermore, congruency effects in reaction times and error rates were reduced following conflict trials, demonstrating conflict adjustment. In Experiment 2, we used bivalent instead of univalent stimuli. Conflict adjustment in task performance was unaffected by this manipulation, but conflict avoidance was not observed. Instead, task switches were reduced after conflict trials. In Experiment 3, we used tasks comprising univalent or bivalent stimuli. Only tasks with univalent revealed conflict avoidance, whereas conflict adjustment was found for all tasks. On the basis of established theories of cognitive control, an integrative process model is described that can account for flexible conflict management. (c) 2015 APA, all rights reserved.

Cardiovascular fitness and executive control during task-switching: an ERP study.

PubMed

Scisco, Jenna L; Leynes, P Andrew; Kang, Jie

2008-07-01

Cardiovascular fitness recently has been linked to executive control function in older adults. The present study examined the relationship between cardiovascular fitness and executive control in young adults using event-related potentials (ERPs). Participants completed a two-part experiment. In part one, a graded exercise test (GXT) was administered using a cycle ergometer to obtain VO(2)max, a measure of maximal oxygen uptake. High-fit participants had VO(2)max measures at or above the 70th percentile based on age and sex, and low-fit participants had VO(2)max measures at or below the 30th percentile. In part two, a task-switching paradigm was used to investigate executive control. Task-switching trials produced slower response times and greater amplitude for both the P3a and P3b components of the ERP relative to a non-switch trial block. No ERP components varied as a function of fitness group. These findings, combined with results from previous research, suggest that the relationship between greater cardiovascular fitness and better cognitive function emerges after early adulthood.

Video game practice optimizes executive control skills in dual-task and task switching situations.

PubMed

Strobach, Tilo; Frensch, Peter A; Schubert, Torsten

2012-05-01

We examined the relation of action video game practice and the optimization of executive control skills that are needed to coordinate two different tasks. As action video games are similar to real life situations and complex in nature, and include numerous concurrent actions, they may generate an ideal environment for practicing these skills (Green & Bavelier, 2008). For two types of experimental paradigms, dual-task and task switching respectively; we obtained performance advantages for experienced video gamers compared to non-gamers in situations in which two different tasks were processed simultaneously or sequentially. This advantage was absent in single-task situations. These findings indicate optimized executive control skills in video gamers. Similar findings in non-gamers after 15 h of action video game practice when compared to non-gamers with practice on a puzzle game clarified the causal relation between video game practice and the optimization of executive control skills. Copyright © 2012 Elsevier B.V. All rights reserved.

Reduced activation in lateral prefrontal cortex and anterior cingulate during attention and cognitive control functions in medication-naïve adolescents with depression compared to controls.

PubMed

Halari, Rozmin; Simic, Mima; Pariante, Carmine M; Papadopoulos, Andrew; Cleare, Anthony; Brammer, Michael; Fombonne, Eric; Rubia, Katya

2009-03-01

There is increasing recognition of major depressive disorder (MDD) in adolescence. In adult MDD, abnormalities of fronto-striatal and fronto-cingulate circuitries mediating cognitive control functions have been implicated in the pathogenesis and been related to problems with controlling negative thoughts. No neuroimaging studies of cognitive control functions, however, exist in paediatric depression. This study investigated whether medication-naïve adolescents with MDD show abnormal brain activation of fronto-striatal and fronto-cingulate networks when performing tasks of attentional and cognitive control. Event-related functional magnetic resonance imaging was used to compare brain activation between 21 medication-naïve adolescents with a first-episode of MDD aged 14-17 years and 21 healthy adolescents, matched for handedness, age, sex, demographics and IQ. Activation paradigms were tasks of selective attention (Simon task), attentional switching (Switch task), and motor response inhibition and error detection (Stop task). In all three tasks, adolescents with depression compared to healthy controls demonstrated reduced activation in task-relevant right dorsolateral (DLPFC), inferior prefrontal cortex (IFC) and anterior cingulate gyrus (ACG). Additional areas of relatively reduced activation were in the parietal lobes during the Stop and Switch tasks, putamen, insula and temporal lobes during the Switch task and precuneus during the Simon task. This study shows first evidence that medication-naïve adolescents with MDD are characterised by abnormal function in ACG and right lateral prefrontal cortex during tasks of attention and performance monitoring, suggesting an early pathogenesis of these functional abnormalities attributed to MDD.

The Effect of Positive Mood on Flexible Processing of Affective Information.

PubMed

Grol, Maud; De Raedt, Rudi

2017-07-17

Recent efforts have been made to understand the cognitive mechanisms underlying psychological resilience. Cognitive flexibility in the context of affective information has been related to individual differences in resilience. However, it is unclear whether flexible affective processing is sensitive to mood fluctuations. Furthermore, it remains to be investigated how effects on flexible affective processing interact with the affective valence of information that is presented. To fill this gap, we tested the effects of positive mood and individual differences in self-reported resilience on affective flexibility, using a task switching paradigm (N = 80). The main findings showed that positive mood was related to lower task switching costs, reflecting increased flexibility, in line with previous findings. In line with this effect of positive mood, we showed that greater resilience levels, specifically levels of acceptance of self and life, also facilitated task set switching in the context of affective information. However, the effects of resilience on affective flexibility seem more complex. Resilience tended to relate to more efficient task switching when negative information was preceded by positive information, possibly because the presentation of positive information, as well as positive mood, can facilitate task set switching. Positive mood also influenced costs associated with switching affective valence of the presented information. This latter effect was indicative of a reduced impact of no longer relevant negative information and more impact of no longer relevant positive information. Future research should confirm these effects of individual differences in resilience on affective flexibility, considering the affective valence of the presented information. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Variability in Proactive and Reactive Cognitive Control Processes Across the Adult Lifespan

PubMed Central

Karayanidis, Frini; Whitson, Lisa Rebecca; Heathcote, Andrew; Michie, Patricia T.

2011-01-01

Task-switching paradigms produce a highly consistent age-related increase in mixing cost [longer response time (RT) on repeat trials in mixed-task than single-task blocks] but a less consistent age effect on switch cost (longer RT on switch than repeat trials in mixed-task blocks). We use two approaches to examine the adult lifespan trajectory of control processes contributing to mixing cost and switch cost: latent variables derived from an evidence accumulation model of choice, and event-related potentials (ERP) that temporally differentiate proactive (cue-driven) and reactive (target-driven) control processes. Under highly practiced and prepared task conditions, aging was associated with increasing RT mixing cost but reducing RT switch cost. Both effects were largely due to the same cause: an age effect for mixed-repeat trials. In terms of latent variables, increasing age was associated with slower non-decision processes, slower rate of evidence accumulation about the target, and higher response criterion. Age effects on mixing costs were evident only on response criterion, the amount of evidence required to trigger a decision, whereas age effects on switch cost were present for all three latent variables. ERPs showed age-related increases in preparation for mixed-repeat trials, anticipatory attention, and post-target interference. Cue-locked ERPs that are linked to proactive control were associated with early emergence of age differences in response criterion. These results are consistent with age effects on strategic processes controlling decision caution. Consistent with an age-related decline in cognitive flexibility, younger adults flexibly adjusted response criterion from trial-to-trial on mixed-task blocks, whereas older adults maintained a high criterion for all trials. PMID:22073037

Hemispheric Asymmetries and Cognitive Flexibility: An ERP and sLORETA Study

ERIC Educational Resources Information Center

Ocklenburg, Sebastian; Gunturkun, Onur; Beste, Christian

2012-01-01

Although functional cerebral asymmetries (FCAs) affect all cognitive domains, their modulation of the efficacy of specific executive functions is largely unexplored. In the present study, we used a lateralized version of the task switching paradigm to investigate the relevance of hemispheric asymmetries for cognitive control processes. Words were…

Sustained and transient attentional processes modulate neural predictors of memory encoding in consecutive time periods

PubMed Central

Padovani, Tullia; Koenig, Thomas; Eckstein, Doris; Perrig, Walter J

2013-01-01

Memory formation is commonly thought to rely on brain activity following an event. Yet, recent research has shown that even brain activity previous to an event can predict later recollection (subsequent memory effect, SME). In order to investigate the attentional sources of the SME, event-related potentials (ERPs) elicited by task cues preceding target words were recorded in a switched task paradigm that was followed by a surprise recognition test. Stay trials, that is, those with the same task as the previous trial, were contrasted with switch trials, which included a task switch compared to the previous trial. The underlying assumption was that sustained attention would be dominant in stay trials and that transient attentional reconfiguration processes would be dominant in switch trials. To determine the SME, local and global statistics of scalp electric fields were used to identify differences between subsequently remembered and forgotten items. Results showed that the SME in stay trials occurred in a time window from 2 to 1 sec before target onset, whereas the SME in switch trials occurred subsequently, in a time window from 1 to 0 sec before target onset. Both SMEs showed a frontal negativity resembling the topography of previously reported effects, which suggests that sustained and transient attentional processes contribute to the prestimulus SME in consecutive time periods. PMID:24381815

Sustained and transient attentional processes modulate neural predictors of memory encoding in consecutive time periods.

PubMed

Padovani, Tullia; Koenig, Thomas; Eckstein, Doris; Perrig, Walter J

2013-07-01

Memory formation is commonly thought to rely on brain activity following an event. Yet, recent research has shown that even brain activity previous to an event can predict later recollection (subsequent memory effect, SME). In order to investigate the attentional sources of the SME, event-related potentials (ERPs) elicited by task cues preceding target words were recorded in a switched task paradigm that was followed by a surprise recognition test. Stay trials, that is, those with the same task as the previous trial, were contrasted with switch trials, which included a task switch compared to the previous trial. The underlying assumption was that sustained attention would be dominant in stay trials and that transient attentional reconfiguration processes would be dominant in switch trials. To determine the SME, local and global statistics of scalp electric fields were used to identify differences between subsequently remembered and forgotten items. Results showed that the SME in stay trials occurred in a time window from 2 to 1 sec before target onset, whereas the SME in switch trials occurred subsequently, in a time window from 1 to 0 sec before target onset. Both SMEs showed a frontal negativity resembling the topography of previously reported effects, which suggests that sustained and transient attentional processes contribute to the prestimulus SME in consecutive time periods.

Task-switching cost and repetition priming: two overlooked confounds in the first-set procedure of the Sternberg paradigm and how they affect memory set-size effects.

PubMed

Jou, Jerwen

2014-10-01

Subjects performed Sternberg-type memory recognition tasks (Sternberg paradigm) in four experiments. Category-instance names were used as learning and testing materials. Sternberg's original experiments demonstrated a linear relation between reaction time (RT) and memory-set size (MSS). A few later studies found no relation, and other studies found a nonlinear relation (logarithmic) between the two variables. These deviations were used as evidence undermining Sternberg's serial scan theory. This study identified two confounding variables in the fixed-set procedure of the paradigm (where multiple probes are presented at test for a learned memory set) that could generate a MSS RT function that was either flat or logarithmic rather than linearly increasing. These two confounding variables were task-switching cost and repetition priming. The former factor worked against smaller memory sets and in favour of larger sets whereas the latter factor worked in the opposite way. Results demonstrated that a null or a logarithmic RT-to-MSS relation could be the artefact of the combined effects of these two variables. The Sternberg paradigm has been used widely in memory research, and a thorough understanding of the subtle methodological pitfalls is crucial. It is suggested that a varied-set procedure (where only one probe is presented at test for a learned memory set) is a more contamination-free procedure for measuring the MSS effects, and that if a fixed-set procedure is used, it is worthwhile examining the RT function of the very first trials across the MSSs, which are presumably relatively free of contamination by the subsequent trials.

Cognitive load selectively influences the interruptive effect of pain on attention.

PubMed

Moore, David J; Eccleston, Christopher; Keogh, Edmund

2017-10-01

Pain is known to interrupt attentional performance. Such interference effects seem to occur preferentially for tasks that are complex and/or difficult. However, few studies have directly manipulated memory load in the context of pain interference to test this view. Therefore, this study examines the effect of experimental manipulations of both memory load and pain on 3 tasks previously found to be sensitive to pain interference. Three experiments were conducted. A different task was examined in each experiment, each comprising of a high- and low-cognitive load versions of the task. Experiment 1 comprised an attention span (n-back) task, experiment 2 an attention switching task, and experiment 3 a divided attention task. Each task was conducted under painful and nonpainful conditions. Within the pain condition, an experimental thermal pain induction protocol was administered at the same time participants completed the task. The load manipulations were successful in all experiments. Pain-related interference occurred under the high-load condition but only for the attention span task. No effect of pain was found on either the attentional switching or divided attention task. These results suggest that while cognitive load may influence the interruptive effect of pain on attention, this effect may be selective. Because pain affected the high-load version of the n-back task but did not interrupt performance on attentional switching or dual-task paradigms, this means that our findings did not completely support our hypotheses. Future research should explore further the parameters and conditions under which pain-related interference occurs.

When and why do old adults outsource control to the environment?

PubMed

Mayr, Ulrich; Spieler, Daniel H; Hutcheon, Thomas G

2015-09-01

Old adults' tendency to rely on information present in the environment rather than internal representations has been frequently noted, but is not well understood. The fade-out paradigm provides a useful model situation to study this internal-to-external shift across the life span: Subjects need to transition from an initial, cued task-switching phase to a fade-out phase where only 1 task remains relevant. Old adults exhibit large response-time "fade-out costs," mainly because they continue to consult the task cues. Here we show that age differences in fade-out costs remain very large even when we insert between the task-switching and the fade-out phase 20 single-task trials without task cues (during which even old adults' performance becomes highly fluent; Experiment 1), but costs in old adults are eliminated when presenting an on-screen instruction to focus on the 1 remaining task at the transition point between the task-switching and fade-out phase (Experiment 2). Furthermore, old adults, but not young adults, also exhibited "fade-in costs" when they were instructed to perform an initial single-task phase that would be followed by the cued task-switching phase (Experiment 3). Combined, these results show that old adults' tendency to overutilize external support is not a problem of perseverating earlier-relevant control settings. Instead, old adults seem less likely to initiate the necessary reconfiguration process when transitioning from 1 phase to the next because they use underspecified task models that lack the higher-level distinction between those contexts that do and that do not require external support. (c) 2015 APA, all rights reserved).

Action-Effect Associations in Voluntary and Cued Task-Switching.

PubMed

Sommer, Angelika; Lukas, Sarah

2017-01-01

The literature of action control claims that humans control their actions in two ways. In the stimulus-based approach, actions are triggered by external stimuli. In the ideomotor approach, actions are elicited endogenously and controlled by the intended goal. In the current study, our purpose was to investigate whether these two action control modes affect task-switching differently. We combined a classical task-switching paradigm with action-effect learning. Both experiments consisted of two experimental phases: an acquisition phase, in which associations between task, response and subsequent action effects were learned and a test phase, in which the effects of these associations were tested on task performance by presenting the former action effects as preceding effects, prior to the task (called practiced effects ). Subjects either chose freely between tasks (ideomotor action control mode) or they were cued as to which task to perform (sensorimotor action control mode). We aimed to replicate the consistency effect (i.e., task is chosen according to the practiced task-effect association) and non-reversal advantage (i.e., better task performance when the practiced effect matches the previously learned task-effect association). Our results suggest that participants acquired stable action-effect associations independently of the learning mode. The consistency effect (Experiment 1) could be shown, independent of the learning mode, but only on the response-level. The non-reversal advantage (Experiment 2) was only evident in the error rates and only for participants who had practiced in the ideomotor action control mode.

Action-Effect Associations in Voluntary and Cued Task-Switching

PubMed Central

Sommer, Angelika; Lukas, Sarah

2018-01-01

The literature of action control claims that humans control their actions in two ways. In the stimulus-based approach, actions are triggered by external stimuli. In the ideomotor approach, actions are elicited endogenously and controlled by the intended goal. In the current study, our purpose was to investigate whether these two action control modes affect task-switching differently. We combined a classical task-switching paradigm with action-effect learning. Both experiments consisted of two experimental phases: an acquisition phase, in which associations between task, response and subsequent action effects were learned and a test phase, in which the effects of these associations were tested on task performance by presenting the former action effects as preceding effects, prior to the task (called practiced effects). Subjects either chose freely between tasks (ideomotor action control mode) or they were cued as to which task to perform (sensorimotor action control mode). We aimed to replicate the consistency effect (i.e., task is chosen according to the practiced task-effect association) and non-reversal advantage (i.e., better task performance when the practiced effect matches the previously learned task-effect association). Our results suggest that participants acquired stable action-effect associations independently of the learning mode. The consistency effect (Experiment 1) could be shown, independent of the learning mode, but only on the response-level. The non-reversal advantage (Experiment 2) was only evident in the error rates and only for participants who had practiced in the ideomotor action control mode. PMID:29387027

Long-Term Memory and the Control of Attentional Control

PubMed Central

Mayr, Ulrich; Kuhns, David; Hubbard, Jason

2014-01-01

Task-switch costs and in particular the switch-cost asymmetry (i.e., the larger costs of switching to a dominant than a non-dominant task) are usually explained in terms of trial-to-trial carry-over of task-specific control settings. Here we argue that task switches are just one example of situations that trigger a transition from working-memory maintenance to updating, thereby opening working memory to interference from long-term memory. We used a new paradigm that requires selecting a spatial location either on the basis of a central cue (i.e., endogenous control of attention) or a peripheral, sudden onset (i.e., exogenous control of attention). We found a strong cost asymmetry that occurred even after short interruptions of otherwise single-task blocks (Exp. 1-3), but that was much stronger when participants had experienced the competing task under conditions of conflict (Exp. 1-2). Experiment 3 showed that the asymmetric costs were due to interruptions per se, rather than to associative interference tied to specific interruption activities. Experiment 4 generalized the basic pattern across interruptions varying in length or control demands and Experiment 5 across primary tasks with response-selection conflict rather than attentional conflict. Combined, the results support a model in which costs of selecting control settings arise when (a) potentially interfering memory traces have been encoded in long-term memory and (b) working-memory is forced from a maintenance mode into an updating mode (e.g., through task interruptions), thereby allowing unwanted retrieval of the encoded memory traces. PMID:24650696

Functional Roles of Neural Preparatory Processes in a Cued Stroop Task Revealed by Linking Electrophysiology with Behavioral Performance

PubMed Central

Wang, Chao; Ding, Mingzhou; Kluger, Benzi M.

2015-01-01

It is well established that cuing facilitates behavioral performance and that different aspects of instructional cues evoke specific neural preparatory processes in cued task-switching paradigms. To deduce the functional role of these neural preparatory processes the majority of studies vary aspects of the experimental paradigm and describe how these variations alter markers of neural preparatory processes. Although these studies provide important insights, they also have notable limitations, particularly in terms of understanding the causal or functional relationship of neural markers to cognitive and behavioral processes. In this study, we sought to address these limitations and uncover the functional roles of neural processes by examining how variability in the amplitude of neural preparatory processes predicts behavioral performance to subsequent stimuli. To achieve this objective 16 young adults were recruited to perform a cued Stroop task while their brain activity was measured using high-density electroencephalography. Four temporally overlapping but functionally and topographically distinct cue-triggered event related potentials (ERPs) were identified: 1) A left-frontotemporal negativity (250-700 ms) that was positively associated with word-reading performance; 2) a midline-frontal negativity (450-800 ms) that was positively associated with color-naming and incongruent performance; 3) a left-frontal negativity (450-800 ms) that was positively associated with switch trial performance; and 4) a centroparietal positivity (450-800 ms) that was positively associated with performance for almost all trial types. These results suggest that at least four dissociable cognitive processes are evoked by instructional cues in the present task, including: 1) domain-specific task facilitation; 2) switch-specific task-set reconfiguration; 3) preparation for response conflict; and 4) proactive attentional control. Examining the relationship between ERPs and behavioral performance provides a functional link between neural markers and the cognitive processes they index. PMID:26230662

Correlates of stimulus-response congruence in the posterior parietal cortex.

PubMed

Stoet, Gijsbert; Snyder, Lawrence H

2007-02-01

Primate behavior is flexible: The response to a stimulus often depends on the task in which it occurs. Here we study how single neurons in the posterior parietal cortex (PPC) respond to stimuli which are associated with different responses in different tasks. Two rhesus monkeys performed a task-switching paradigm. Each trial started with a task cue instructing which of two tasks to perform, followed by a stimulus requiring a left or right button press. For half the stimuli, the associated responses were different in the two tasks, meaning that the task context was necessary to disambiguate the incongruent stimuli. The other half of stimuli required the same response irrespective of task context (congruent). Using this paradigm, we previously showed that behavioral responses to incongruent stimuli are significantly slower than to congruent stimuli. We now demonstrate a neural correlate in the PPC of the additional processing time required for incongruent stimuli. Furthermore, we previously found that 29% of parietal neurons encode the task being performed (task-selective cells). We now report differences in neuronal timing related to congruency in task-selective versus task nonselective cells. These differences in timing suggest that the activity in task nonselective cells reflects a motor command, whereas activity in task-selective cells reflects a decision process.

The cerebellum mediates conflict resolution.

PubMed

Schweizer, Tom A; Oriet, Chris; Meiran, Nachshon; Alexander, Michael P; Cusimano, Michael; Stuss, Donald T

2007-12-01

Regions within the frontal and parietal cortex have been implicated as important neural correlates for cognitive control during conflict resolution. Despite the extensive reciprocal connectivity between the cerebellum and these putatively critical cortical areas, a role for the cerebellum in conflict resolution has never been identified. We used a task-switching paradigm that separates processes related to task-set switching and the management of response conflict independent of motor processing. Eleven patients with chronic, focal lesions to the cerebellum and 11 healthy controls were compared. Patients were slower and less accurate in conditions involving conflict resolution. In the absence of response conflict, however, tasks-witching abilities were not impaired in our patients. The cerebellum may play an important role in coordinating with other areas of cortex to modulate active response states. These results are the first demonstration of impaired conflict resolution following cerebellar lesions in the presence of an intact prefrontal cortex.

Inner speech impairments in autism.

PubMed

Whitehouse, Andrew J O; Maybery, Murray T; Durkin, Kevin

2006-08-01

Three experiments investigated the role of inner speech deficit in cognitive performances of children with autism. Experiment 1 compared children with autism with ability-matched controls on a verbal recall task presenting pictures and words. Experiment 2 used pictures for which the typical names were either single syllable or multisyllable. Two encoding conditions manipulated the use of verbal encoding. Experiment 3 employed a task-switching paradigm for which performance has been shown to be contingent upon inner speech. In Experiment 1, children with autism demonstrated a lower picture-superiority effect compared to controls. In Experiment 2, the children with autism showed a lower word-length effect when pictures were presented alone, but a more substantial word-length effect in a condition requiring overt labelling. In Experiment 3, articulatory suppression affected the task-switching performance of the control participants only. Individuals with autism have limitations in their use of inner speech.

Effects of high-dose ethanol intoxication and hangover on cognitive flexibility.

PubMed

Wolff, Nicole; Gussek, Philipp; Stock, Ann-Kathrin; Beste, Christian

2018-01-01

The effects of high-dose ethanol intoxication on cognitive flexibility processes are not well understood, and processes related to hangover after intoxication have remained even more elusive. Similarly, it is unknown in how far the complexity of cognitive flexibility processes is affected by intoxication and hangover effects. We performed a neurophysiological study applying high density electroencephalography (EEG) recording to analyze event-related potentials (ERPs) and perform source localization in a task switching paradigm which varied the complexity of task switching by means of memory demands. The results show that high-dose ethanol intoxication only affects task switching (i.e. cognitive flexibility processes) when memory processes are required to control task switching mechanisms, suggesting that even high doses of ethanol compromise cognitive processes when they are highly demanding. The EEG and source localization data show that these effects unfold by modulating response selection processes in the anterior cingulate cortex. Perceptual and attentional selection processes as well as working memory processes were only unspecifically modulated. In all subprocesses examined, there were no differences between the sober and hangover states, thus suggesting a fast recovery of cognitive flexibility after high-dose ethanol intoxication. We assume that the gamma-aminobutyric acid (GABAergic) system accounts for the observed effects, while they can hardly be explained by the dopaminergic system. © 2016 Society for the Study of Addiction.

Bilingual Language Switching in the Laboratory versus in the Wild: The Spatiotemporal Dynamics of Adaptive Language Control

PubMed Central

2017-01-01

For a bilingual human, every utterance requires a choice about which language to use. This choice is commonly regarded as part of general executive control, engaging prefrontal and anterior cingulate cortices similarly to many types of effortful task switching. However, although language control within artificial switching paradigms has been heavily studied, the neurobiology of natural switching within socially cued situations has not been characterized. Additionally, although theoretical models address how language control mechanisms adapt to the distinct demands of different interactional contexts, these predictions have not been empirically tested. We used MEG (RRID: NIFINV:nlx_inv_090918) to investigate language switching in multiple contexts ranging from completely artificial to the comprehension of a fully natural bilingual conversation recorded “in the wild.” Our results showed less anterior cingulate and prefrontal cortex involvement for more natural switching. In production, voluntary switching did not engage the prefrontal cortex or elicit behavioral switch costs. In comprehension, while laboratory switches recruited executive control areas, fully natural switching within a conversation only engaged auditory cortices. Multivariate pattern analyses revealed that, in production, interlocutor identity was represented in a sustained fashion throughout the different stages of language planning until speech onset. In comprehension, however, a biphasic pattern was observed: interlocutor identity was first represented at the presentation of the interlocutor and then again at the presentation of the auditory word. In all, our findings underscore the importance of ecologically valid experimental paradigms and offer the first neurophysiological characterization of language control in a range of situations simulating real life to various degrees. SIGNIFICANCE STATEMENT Bilingualism is an inherently social phenomenon, interactional context fully determining language choice. This research addresses the neural mechanisms underlying multilingual individuals' ability to successfully adapt to varying conversational contexts both while speaking and listening. Our results showed that interactional context critically determines language control networks' engagement: switching under external constraints heavily recruited prefrontal control regions, whereas natural, voluntary switching did not. These findings challenge conclusions derived from artificial switching paradigms, which suggested that language switching is intrinsically effortful. Further, our results predict that the so-called bilingual advantage should be limited to individuals who need to control their languages according to external cues and thus would not occur by virtue of an experience in which switching is fully free. PMID:28821648

General Slowing and Education Mediate Task Switching Performance Across the Life-Span

PubMed Central

Moretti, Luca; Semenza, Carlo; Vallesi, Antonino

2018-01-01

Objective: This study considered the potential role of both protective factors (cognitive reserve, CR) and adverse ones (general slowing) in modulating cognitive flexibility in the adult life-span. Method: Ninety-eight individuals performed a task-switching (TS) paradigm in which we adopted a manipulation concerning the timing between the cue and the target. Working memory demands were minimized by using transparent cues. Additionally, indices of cognitive integrity, depression, processing speed and different CR dimensions were collected and used in linear models accounting for TS performance under the different time constraints. Results: The main results showed similar mixing costs and higher switching costs in older adults, with an overall age-dependent effect of general slowing on these costs. The link between processing speed and TS performance was attenuated when participants had more time to prepare. Among the different CR indices, formal education only was associated with reduced switch costs under time pressure. Discussion: Even though CR is often operationalized as a unitary construct, the present research confirms the benefits of using tools designed to distinguish between different CR dimensions. Furthermore, our results provide empirical support to the assumption that processing speed influence on executive performance depends on time constraints. Finally, it is suggested that whether age differences appear in terms of switch or mixing costs depends on working memory demands (which were low in our tasks with transparent cues). PMID:29780341

Switching auditory attention using spatial and non-spatial features recruits different cortical networks.

PubMed

Larson, Eric; Lee, Adrian K C

2014-01-01

Switching attention between different stimuli of interest based on particular task demands is important in many everyday settings. In audition in particular, switching attention between different speakers of interest that are talking concurrently is often necessary for effective communication. Recently, it has been shown by multiple studies that auditory selective attention suppresses the representation of unwanted streams in auditory cortical areas in favor of the target stream of interest. However, the neural processing that guides this selective attention process is not well understood. Here we investigated the cortical mechanisms involved in switching attention based on two different types of auditory features. By combining magneto- and electro-encephalography (M-EEG) with an anatomical MRI constraint, we examined the cortical dynamics involved in switching auditory attention based on either spatial or pitch features. We designed a paradigm where listeners were cued in the beginning of each trial to switch or maintain attention halfway through the presentation of concurrent target and masker streams. By allowing listeners time to switch during a gap in the continuous target and masker stimuli, we were able to isolate the mechanisms involved in endogenous, top-down attention switching. Our results show a double dissociation between the involvement of right temporoparietal junction (RTPJ) and the left inferior parietal supramarginal part (LIPSP) in tasks requiring listeners to switch attention based on space and pitch features, respectively, suggesting that switching attention based on these features involves at least partially separate processes or behavioral strategies. © 2013 Elsevier Inc. All rights reserved.

Serial or overlapping processing in multitasking as individual preference: Effects of stimulus preview on task switching and concurrent dual-task performance.

PubMed

Reissland, Jessika; Manzey, Dietrich

2016-07-01

Understanding the mechanisms and performance consequences of multitasking has long been in focus of scientific interest, but has been investigated by three research lines more or less isolated from each other. Studies in the fields of the psychological refractory period, task switching, and interruptions have scored with a high experimental control, but usually do not give participants many degrees of freedom to self-organize the processing of two concurrent tasks. Individual strategies as well as their impact on efficiency have mainly been neglected. Self-organized multitasking has been investigated in the field of human factors, but primarily with respect to overall performance without detailed investigation of how the tasks are processed. The current work attempts to link aspects of these research lines. All of them, explicitly or implicitly, provide hints about an individually preferred type of task organization, either more cautious trying to work strictly serially on only one task at a time or more daring with a focus on task interleaving and, if possible, also partially overlapping (parallel) processing. In two experiments we investigated different strategies of task organization and their impact on efficiency using a new measure of overall multitasking efficiency. Experiment 1 was based on a classical task switching paradigm with two classification tasks, but provided one group of participants with a stimulus preview of the task to switch to next, enabling at least partial overlapping processing. Indeed, this preview led to a reduction of switch costs and to an increase of dual-task efficiency, but only for a subgroup of participants. They obviously exploited the possibility of overlapping processing, while the others worked mainly serially. While task-sequence was externally guided in the first experiment, Experiment 2 extended the approach by giving the participants full freedom of task organization in concurrent performance of the same tasks. Fine-grained analyses of response scheduling again revealed individual differences regarding the preference for strictly serial processing vs. some sort of task interleaving and overlapping processing. However, neither group showed a striking benefit in dual-task efficiency, although the results show that the costs of multitasking can partly be compensated by overlapping processing. Copyright © 2016 Elsevier B.V. All rights reserved.

Shift Work and Cognitive Flexibility: Decomposing Task Performance.

PubMed

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

2017-04-01

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

A Randomized Controlled ERP Study on the Effects of Multi-Domain Cognitive Training and Task Difficulty on Task Switching Performance in Older Adults.

PubMed

Küper, Kristina; Gajewski, Patrick D; Frieg, Claudia; Falkenstein, Michael

2017-01-01

Executive functions are subject to a marked age-related decline, but have been shown to benefit from cognitive training interventions. As of yet, it is, however, still relatively unclear which neural mechanism can mediate training-related performance gains. In the present electrophysiological study, we examined the effects of multi-domain cognitive training on performance in an untrained cue-based task switch paradigm featuring Stroop color words: participants either had to indicate the word meaning of Stroop stimuli (word task) or perform the more difficult task of color naming (color task). One-hundred and three older adults (>65 years old) were randomly assigned to a training group receiving a 4-month multi-domain cognitive training, a passive no-contact control group or an active (social) control group receiving a 4-month relaxation training. For all groups, we recorded performance and EEG measures before and after the intervention. For the cognitive training group, but not for the two control groups, we observed an increase in response accuracy at posttest, irrespective of task and trial type. No training-related effects on reaction times were found. Cognitive training was also associated with an overall increase in N2 amplitude and a decrease of P2 latency on single trials. Training-related performance gains were thus likely mediated by an enhancement of response selection and improved access to relevant stimulus-response mappings. Additionally, cognitive training was associated with an amplitude decrease in the time window of the target-locked P3 at fronto-central electrodes. An increase in the switch positivity during advance task preparation emerged after both cognitive and relaxation training. Training-related behavioral and event-related potential (ERP) effects were not modulated by task difficulty. The data suggest that cognitive training increased slow negative potentials during target processing which enhanced the N2 and reduced a subsequent P3-like component on both switch and non-switch trials and irrespective of task difficulty. Our findings further corroborate the effectiveness of multi-domain cognitive training in older adults and indicate that ERPs can be instrumental in uncovering the neural processes underlying training-related performance gains.

Getting stuck with pornography? Overuse or neglect of cybersex cues in a multitasking situation is related to symptoms of cybersex addiction.

PubMed

Schiebener, Johannes; Laier, Christian; Brand, Matthias

2015-03-01

Some individuals consume cybersex contents, such as pornographic material, in an addictive manner, which leads to severe negative consequences in private life or work. One mechanism leading to negative consequences may be reduced executive control over cognition and behavior that may be necessary to realize goal-oriented switching between cybersex use and other tasks and obligations of life. To address this aspect,we investigated 104 male participants with an executive multitasking paradigm with two sets: One set consisted of pictures of persons, the other set consisted of pornographic pictures. In both sets the pictures had to be classified according to certain criteria. The explicit goal was to work on all classification tasks to equal amounts, by switching between the sets and classification tasks in a balanced manner. We found that less balanced performance in this multitasking paradigm was associated with a higher tendency towards cybersex addiction. Persons with this tendency often either overused or neglected working on the pornographic pictures. The results indicate that reduced executive control over multitasking performance, when being confronted with pornographic material, may contribute to dysfunctional behaviors and negative consequences resulting from cybersex addiction. However, individuals with tendencies towards cybersex addiction seem to have either an inclination to avoid or to approach the pornographic material, as discussed in motivational models of addiction.

Getting stuck with pornography? Overuse or neglect of cybersex cues in a multitasking situation is related to symptoms of cybersex addiction

PubMed Central

LAIER, CHRISTIAN; BRAND, MATTHIAS

2015-01-01

Background and aims Some individuals consume cybersex contents, such as pornographic material, in an addictive manner, which leads to severe negative consequences in private life or work. One mechanism leading to negative consequences may be reduced executive control over cognition and behavior that may be necessary to realize goal-oriented switching between cybersex use and other tasks and obligations of life. Methods To address this aspect, we investigated 104 male participants with an executive multitasking paradigm with two sets: One set consisted of pictures of persons, the other set consisted of pornographic pictures. In both sets the pictures had to be classified according to certain criteria. The explicit goal was to work on all classification tasks to equal amounts, by switching between the sets and classification tasks in a balanced manner. Results We found that less balanced performance in this multitasking paradigm was associated with a higher tendency towards cybersex addiction. Persons with this tendency often either overused or neglected working on the pornographic pictures. Discussion The results indicate that reduced executive control over multitasking performance, when being confronted with pornographic material, may contribute to dysfunctional behaviors and negative consequences resulting from cybersex addiction. However, individuals with tendencies towards cybersex addiction seem to have either an inclination to avoid or to approach the pornographic material, as discussed in motivational models of addiction. PMID:25786495

The simulated gambling paradigm applied to young adults: an examination of university students' performance.

PubMed

Caroselli, Jerome Silvio; Hiscock, Merrill; Scheibel, Randall S; Ingram, Fred

2006-01-01

Simulated gambling tasks have become popular as sensitive tools for identifying individuals with real-time impairment in decision making. Various clinical samples, especially patients with damage to the ventromedial prefrontal cortex, perform poorly on these tasks. The patients typically persist in choosing risky (disadvantageous) card decks instead of switching to safer (advantageous) decks. In terms of Damasio's (1994) somatic marker hypothesis, the poor performance stems from defective integration of emotional and rational aspects of decision making. Less information is available about performance in healthy populations, particularly young adults. After administering a computerized gambling task to 141 university students, we found that individuals in this population also tend to prefer disadvantageous decks to advantageous decks. The results indicate that performance is governed primarily by the frequency of positive outcomes on a trial-by-trial basis rather than by the accumulation of winnings in the longer term. These findings are discussed in light of the cognitive literature pertaining to the simulated gambling paradigm.

Task frequency influences stimulus-driven effects on task selection during voluntary task switching.

PubMed

Arrington, Catherine M; Reiman, Kaitlin M

2015-08-01

Task selection during voluntary task switching involves both top-down (goal-directed) and bottom-up (stimulus-driven) mechanisms. The factors that shift the balance between these two mechanisms are not well characterized. In the present research, we studied the role that task frequency plays in determining the extent of stimulus-driven task selection. In two experiments, we used the basic paradigm adapted from Arrington (Memory & Cognition, 38, 991-997, 2008), in which the effect of stimulus availability serves as a marker of stimulus-driven task selection. A number and letter appeared on each trial with varying stimulus onset asynchronies, and participants performed either a consonant/vowel or an even/odd judgment. In Experiment 1, participants were instructed as to the relative frequency with which each task was to be performed (i.e., 50/50, 60/40, or 75/25) and were further instructed to make their transitions between tasks unpredictable. In Experiment 2, participants were given no instructions about how to select tasks, resulting in naturally occurring variation in task frequency. With both instructed (Exp. 1) and naturally occurring (Exp. 2) relative task frequencies, the less frequently performed task showed a greater effect of stimulus availability on task selection, suggestive of a larger influence of stimulus-driven mechanisms during task performance for the less frequent task. When goal-directed mechanisms of task choice are engaged less frequently, the relative influence of the stimulus environment increases.

Parsing the roles of the frontal lobes and basal ganglia in task control using multivoxel pattern analysis

PubMed Central

Kehagia, Angie A.; Ye, Rong; Joyce, Dan W.; Doyle, Orla M.; Rowe, James B.; Robbins, Trevor W.

2017-01-01

Cognitive control has traditionally been associated with the prefrontal cortex, based on observations of deficits in patients with frontal lesions. However, evidence from patients with Parkinson’s disease (PD) indicates that subcortical regions also contribute to control under certain conditions. We scanned 17 healthy volunteers while they performed a task switching paradigm that previously dissociated performance deficits arising from frontal lesions in comparison with PD, as a function of the abstraction of the rules that are switched. From a multivoxel pattern analysis by Gaussian Process Classification (GPC), we then estimated the forward (generative) model to infer regional patterns of activity that predict Switch / Repeat behaviour between rule conditions. At 1000 permutations, Switch / Repeat classification accuracy for concrete rules was significant in the basal ganglia, but at chance in the frontal lobe. The inverse pattern was obtained for abstract rules, whereby the conditions were successfully discriminated in the frontal lobe but not in the basal ganglia. This double dissociation highlights the difference between cortical and subcortical contributions to cognitive control and demonstrates the utility of multivariate approaches in investigations of functions that rely on distributed and overlapping neural substrates. PMID:28387585

The system neurophysiological basis of backward inhibition.

PubMed

Zhang, Rui; Stock, Ann-Kathrin; Fischer, Rico; Beste, Christian

2016-12-01

Task switching is regularly required in our everyday life. To succeed in switching, it is important to inhibit the most recently performed task and instead activate the currently relevant task. The process that inhibits a recently performed task when a new task is to be performed is referred to as 'backward inhibition' (BI). While the BI effect has been subject to intense research in cognitive psychology, little is known about the neuronal mechanisms that are related to the BI effect and those that relate to differences in the magnitude of the BI effect. In the current study, we examined the system neurophysiological basis of BI processes using event-related potentials (ERPs) and sLORETA by also taking inter-individual differences in the magnitude of the BI into account. The results suggest that BI processes and inter-individual differences in them strongly depend upon attentional selection mechanisms (reflected by N1-ERP modulations in the current task/trial) mediated via networks consisting of extrastriate occipital areas, the temporo-parietal junction and the inferior frontal gyrus. Other processes and mechanisms related to conflict monitoring, response selection, or the updating, organization and implementation of a new task-set (i.e. N2 and P3 processes) were not shown to be modulated by BI processes and differences in their magnitude, as evoked with a common BI paradigm.

The Minimum Requirements of Language Control: Evidence from Sequential Predictability Effects in Language Switching

ERIC Educational Resources Information Center

Declerck, Mathieu; Koch, Iring; Philipp, Andrea M.

2015-01-01

The current study systematically examined the influence of sequential predictability of languages and concepts on language switching. To this end, 2 language switching paradigms were combined. To measure language switching with a random sequence of languages and/or concepts, we used a language switching paradigm that implements visual cues and…

Efficiency in Rule- vs. Plan-Based Movements Is Modulated by Action-Mode.

PubMed

Scheib, Jean P P; Stoll, Sarah; Thürmer, J Lukas; Randerath, Jennifer

2018-01-01

The rule/plan motor cognition (RPMC) paradigm elicits visually indistinguishable motor outputs, resulting from either plan- or rule-based action-selection, using a combination of essentially interchangeable stimuli. Previous implementations of the RPMC paradigm have used pantomimed movements to compare plan- vs. rule-based action-selection. In the present work we attempt to determine the generalizability of previous RPMC findings to real object interaction by use of a grasp-to-rotate task. In the plan task, participants had to use prospective planning to achieve a comfortable post-handle rotation hand posture. The rule task used implementation intentions (if-then rules) leading to the same comfortable end-state. In Experiment A, we compare RPMC performance of 16 healthy participants in pantomime and real object conditions of the experiment, within-subjects. Higher processing efficiency of rule- vs. plan-based action-selection was supported by diffusion model analysis. Results show a significant response-time increase in the pantomime condition compared to the real object condition and a greater response-time advantage of rule-based vs. plan-based actions in the pantomime compared to the real object condition. In Experiment B, 24 healthy participants performed the real object RPMC task in a task switching vs. a blocked condition. Results indicate that plan-based action-selection leads to longer response-times and less efficient information processing than rule-based action-selection in line with previous RPMC findings derived from the pantomime action-mode. Particularly in the task switching mode, responses were faster in the rule compared to the plan task suggesting a modulating influence of cognitive load. Overall, results suggest an advantage of rule-based action-selection over plan-based action-selection; whereby differential mechanisms appear to be involved depending on the action-mode. We propose that cognitive load is a factor that modulates the advantageous effect of implementation intentions in motor cognition on different levels as illustrated by the varying speed advantages and the variation in diffusion parameters per action-mode or condition, respectively.

The relation of saturated fats and dietary cholesterol to childhood cognitive flexibility.

PubMed

Khan, Naiman A; Raine, Lauren B; Drollette, Eric S; Scudder, Mark R; Hillman, Charles H

2015-10-01

Identification of health behaviors and markers of physiological health associated with childhood cognitive function has important implications for public health policy targeted toward cognitive health throughout the life span. Although previous studies have shown that aerobic fitness and obesity exert contrasting effects on cognitive flexibility among prepubertal children, the extent to which diet plays a role in cognitive flexibility has received little attention. Accordingly, this study examined associations between saturated fats and cholesterol intake and cognitive flexibility, assessed using a task switching paradigm, among prepubertal children between 7 and 10 years (N = 150). Following adjustment of confounding variables (age, sex, socioeconomic status, IQ, VO2max, and BMI), children consuming diets higher in saturated fats exhibited longer reaction time during the task condition requiring greater amounts of cognitive flexibility. Further, increasing saturated fat intake and dietary cholesterol were correlated with greater switch costs, reflecting impaired ability to maintain multiple task sets in working memory and poorer efficiency of cognitive control processes involved in task switching. These data are among the first to indicate that children consuming diets higher in saturated fats and cholesterol exhibit compromised ability to flexibly modulate their cognitive operations, particularly when faced with greater cognitive challenge. Future longitudinal and intervention studies are necessary to comprehensively characterize the interrelationships between diet, aerobic fitness, obesity, and children's cognitive abilities. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Randomized Controlled ERP Study on the Effects of Multi-Domain Cognitive Training and Task Difficulty on Task Switching Performance in Older Adults

PubMed Central

Küper, Kristina; Gajewski, Patrick D.; Frieg, Claudia; Falkenstein, Michael

2017-01-01

Executive functions are subject to a marked age-related decline, but have been shown to benefit from cognitive training interventions. As of yet, it is, however, still relatively unclear which neural mechanism can mediate training-related performance gains. In the present electrophysiological study, we examined the effects of multi-domain cognitive training on performance in an untrained cue-based task switch paradigm featuring Stroop color words: participants either had to indicate the word meaning of Stroop stimuli (word task) or perform the more difficult task of color naming (color task). One-hundred and three older adults (>65 years old) were randomly assigned to a training group receiving a 4-month multi-domain cognitive training, a passive no-contact control group or an active (social) control group receiving a 4-month relaxation training. For all groups, we recorded performance and EEG measures before and after the intervention. For the cognitive training group, but not for the two control groups, we observed an increase in response accuracy at posttest, irrespective of task and trial type. No training-related effects on reaction times were found. Cognitive training was also associated with an overall increase in N2 amplitude and a decrease of P2 latency on single trials. Training-related performance gains were thus likely mediated by an enhancement of response selection and improved access to relevant stimulus-response mappings. Additionally, cognitive training was associated with an amplitude decrease in the time window of the target-locked P3 at fronto-central electrodes. An increase in the switch positivity during advance task preparation emerged after both cognitive and relaxation training. Training-related behavioral and event-related potential (ERP) effects were not modulated by task difficulty. The data suggest that cognitive training increased slow negative potentials during target processing which enhanced the N2 and reduced a subsequent P3-like component on both switch and non-switch trials and irrespective of task difficulty. Our findings further corroborate the effectiveness of multi-domain cognitive training in older adults and indicate that ERPs can be instrumental in uncovering the neural processes underlying training-related performance gains. PMID:28446870

Selective impairment of masked priming in dual-task performance.

PubMed

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

2011-03-01

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

Working memory load affects repetitive behaviour but not cognitive flexibility in adolescent autism spectrum disorder.

PubMed

Wolff, Nicole; Chmielewski, Witold X; Beste, Christian; Roessner, Veit

2017-03-16

Autism spectrum disorder (ASD) is associated with repetitive and stereotyped behaviour, suggesting that cognitive flexibility may be deficient in ASD. A central, yet not examined aspect to understand possible deficits in flexible behaviour in ASD relates (i) to the role of working memory and (ii) to neurophysiological mechanisms underlying behavioural modulations. We analysed behavioural and neurophysiological (EEG) correlates of cognitive flexibility using a task-switching paradigm with and without working memory load in adolescents with ASD and typically developing controls (TD). Adolescents with ASD versus TD show similar performance in task switching with no memory load, indicating that 'pure' cognitive flexibility is not in deficit in adolescent ASD. However performance during task repetition decreases with increasing memory load. Neurophysiological data reflect the pattern of behavioural effects, showing modulations in P2 and P3 event-related potentials. Working memory demands affect repetitive behaviour while processes of cognitive flexibility are unaffected. Effects emerge due to deficits in preparatory attentional processes and deficits in task rule activation, organisation and implementation of task sets when repetitive behaviour is concerned. It may be speculated that the habitual response mode in ASD (i.e. repetitive behaviour) is particularly vulnerable to additional demands on executive control processes.

The Role of Task-Related Learned Representations in Explaining Asymmetries in Task Switching

PubMed Central

Barutchu, Ayla; Becker, Stefanie I.; Carter, Olivia; Hester, Robert; Levy, Neil L.

2013-01-01

Task switch costs often show an asymmetry, with switch costs being larger when switching from a difficult task to an easier task. This asymmetry has been explained by difficult tasks being represented more strongly and consequently requiring more inhibition prior to switching to the easier task. The present study shows that switch cost asymmetries observed in arithmetic tasks (addition vs. subtraction) do not depend on task difficulty: Switch costs of similar magnitudes were obtained when participants were presented with unsolvable pseudo-equations that did not differ in task difficulty. Further experiments showed that neither task switch costs nor switch cost asymmetries were due to perceptual factors (e.g., perceptual priming effects). These findings suggest that asymmetrical switch costs can be brought about by the association of some tasks with greater difficulty than others. Moreover, the finding that asymmetrical switch costs were observed (1) in the absence of a task switch proper and (2) without differences in task difficulty, suggests that present theories of task switch costs and switch cost asymmetries are in important ways incomplete and need to be modified. PMID:23613919

BDNF mediates improvements in executive function following a 1-year exercise intervention

PubMed Central

Leckie, Regina L.; Oberlin, Lauren E.; Voss, Michelle W.; Prakash, Ruchika S.; Szabo-Reed, Amanda; Chaddock-Heyman, Laura; Phillips, Siobhan M.; Gothe, Neha P.; Mailey, Emily; Vieira-Potter, Victoria J.; Martin, Stephen A.; Pence, Brandt D.; Lin, Mingkuan; Parasuraman, Raja; Greenwood, Pamela M.; Fryxell, Karl J.; Woods, Jeffrey A.; McAuley, Edward; Kramer, Arthur F.; Erickson, Kirk I.

2014-01-01

Executive function declines with age, but engaging in aerobic exercise may attenuate decline. One mechanism by which aerobic exercise may preserve executive function is through the up-regulation of brain-derived neurotropic factor (BDNF), which also declines with age. The present study examined BDNF as a mediator of the effects of a 1-year walking intervention on executive function in 90 older adults (mean age = 66.82). Participants were randomized to a stretching and toning control group or a moderate intensity walking intervention group. BDNF serum levels and performance on a task-switching paradigm were collected at baseline and follow-up. We found that age moderated the effect of intervention group on changes in BDNF levels, with those in the highest age quartile showing the greatest increase in BDNF after 1-year of moderate intensity walking exercise (p = 0.036). The mediation analyses revealed that BDNF mediated the effect of the intervention on task-switch accuracy, but did so as a function of age, such that exercise-induced changes in BDNF mediated the effect of exercise on task-switch performance only for individuals over the age of 71. These results demonstrate that both age and BDNF serum levels are important factors to consider when investigating the mechanisms by which exercise interventions influence cognitive outcomes, particularly in elderly populations. PMID:25566019

A dissociation between stopping and switching actions following a lesion of the pre-supplementary motor area

PubMed Central

Roberts, R. Edward; Husain, Masud

2015-01-01

Introduction Although the pre-supplementary motor area (pre-SMA) is one of the most frequently reported areas of activation in functional imaging studies, the role of this brain region in cognition is still a matter of intense debate. Here we present a patient with a focal lesion of caudal pre-SMA who displays a selective deficit in updating a response plan to switch actions, but shows no impairment when required to withhold a response – stopping. Materials & methods The patient and a control group underwent three tasks designed to measure different aspects of cognitive control and executive function. Results The pre-SMA patient displayed no impairment when responding in the face of distracting stimuli (Eriksen flanker paradigm), or when required to halt an on-going response (STOP task). However, a specific deficit was observed when she was required to rapidly switch between response plans (CHANGE task). Conclusions These findings suggest that the caudal pre-SMA may have a particularly important role in a network of brain regions required for rapidly updating and implementing response plans. The lack of any significant impairment on other measures of cognitive control suggests that this is not likely due to a global deficit in cognitive control. We discuss the implications of these results in the context of current theories of pre-SMA function. PMID:25282056

Selective attentional enhancement and inhibition of fronto-posterior connectivity by the basal ganglia during attention switching.

PubMed

van Schouwenburg, Martine R; den Ouden, Hanneke E M; Cools, Roshan

2015-06-01

The prefrontal cortex and the basal ganglia interact to selectively gate a desired action. Recent studies have shown that this selective gating mechanism of the basal ganglia extends to the domain of attention. Here, we investigate the nature of this action-like gating mechanism for attention using a spatial attention-switching paradigm in combination with functional neuroimaging and dynamic causal modeling. We show that the basal ganglia guide attention by focally releasing inhibition of task-relevant representations, while simultaneously inhibiting task-irrelevant representations by selectively modulating prefrontal top-down connections. These results strengthen and specify the role of the basal ganglia in attention. Moreover, our findings have implications for psychological theorizing by suggesting that inhibition of unattended sensory regions is not only a consequence of mutual suppression, but is an active process, subserved by the basal ganglia. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Multiple-object permanence tracking: limitation in maintenance and transformation of perceptual objects.

PubMed

Saiki, Jun

2002-01-01

Research on change blindness and transsaccadic memory revealed that a limited amount of information is retained across visual disruptions in visual working memory. It has been proposed that visual working memory can hold four to five coherent object representations. To investigate their maintenance and transformation in dynamic situations, I devised an experimental paradigm called multiple-object permanence tracking (MOPT) that measures memory for multiple feature-location bindings in dynamic situations. Observers were asked to detect any color switch in the middle of a regular rotation of a pattern with multiple colored disks behind an occluder. The color-switch detection performance dramatically declined as the pattern rotation velocity increased, and this effect of object motion was independent of the number of targets. The MOPT task with various shapes and colors showed that color-shape conjunctions are not available in the MOPT task. These results suggest that even completely predictable motion severely reduces our capacity of object representations, from four to only one or two.

Efficiency in Rule- vs. Plan-Based Movements Is Modulated by Action-Mode

PubMed Central

Scheib, Jean P. P.; Stoll, Sarah; Thürmer, J. Lukas; Randerath, Jennifer

2018-01-01

The rule/plan motor cognition (RPMC) paradigm elicits visually indistinguishable motor outputs, resulting from either plan- or rule-based action-selection, using a combination of essentially interchangeable stimuli. Previous implementations of the RPMC paradigm have used pantomimed movements to compare plan- vs. rule-based action-selection. In the present work we attempt to determine the generalizability of previous RPMC findings to real object interaction by use of a grasp-to-rotate task. In the plan task, participants had to use prospective planning to achieve a comfortable post-handle rotation hand posture. The rule task used implementation intentions (if-then rules) leading to the same comfortable end-state. In Experiment A, we compare RPMC performance of 16 healthy participants in pantomime and real object conditions of the experiment, within-subjects. Higher processing efficiency of rule- vs. plan-based action-selection was supported by diffusion model analysis. Results show a significant response-time increase in the pantomime condition compared to the real object condition and a greater response-time advantage of rule-based vs. plan-based actions in the pantomime compared to the real object condition. In Experiment B, 24 healthy participants performed the real object RPMC task in a task switching vs. a blocked condition. Results indicate that plan-based action-selection leads to longer response-times and less efficient information processing than rule-based action-selection in line with previous RPMC findings derived from the pantomime action-mode. Particularly in the task switching mode, responses were faster in the rule compared to the plan task suggesting a modulating influence of cognitive load. Overall, results suggest an advantage of rule-based action-selection over plan-based action-selection; whereby differential mechanisms appear to be involved depending on the action-mode. We propose that cognitive load is a factor that modulates the advantageous effect of implementation intentions in motor cognition on different levels as illustrated by the varying speed advantages and the variation in diffusion parameters per action-mode or condition, respectively. PMID:29593612

Does media multitasking always hurt? A positive correlation between multitasking and multisensory integration.

PubMed

Lui, Kelvin F H; Wong, Alan C-N

2012-08-01

Heavy media multitaskers have been found to perform poorly in certain cognitive tasks involving task switching, selective attention, and working memory. An account for this is that with a breadth-biased style of cognitive control, multitaskers tend to pay attention to various information available in the environment, without sufficient focus on the information most relevant to the task at hand. This cognitive style, however, may not cause a general deficit in all kinds of tasks. We tested the hypothesis that heavy media multitaskers would perform better in a multisensory integration task than would others, due to their extensive experience in integrating information from different modalities. Sixty-three participants filled out a questionnaire about their media usage and completed a visual search task with and without synchronous tones (pip-and-pop paradigm). It was found that a higher degree of media multitasking was correlated with better multisensory integration. The fact that heavy media multitaskers are not deficient in all kinds of cognitive tasks suggests that media multitasking does not always hurt.

Task-set switching under cue-based versus memory-based switching conditions in younger and older adults.

PubMed

Kray, Jutta

2006-08-11

Adult age differences in task switching and advance preparation were examined by comparing cue-based and memory-based switching conditions. Task switching was assessed by determining two types of costs that occur at the general (mixing costs) and specific (switching costs) level of switching. Advance preparation was investigated by varying the time interval until the next task (short, middle, very long). Results indicated that the implementation of task sets was different for cue-based switching with random task sequences and memory-based switching with predictable task sequences. Switching costs were strongly reduced under cue-based switching conditions, indicating that task-set cues facilitate the retrieval of the next task. Age differences were found for mixing costs and for switching costs only under cue-based conditions in which older adults showed smaller switching costs than younger adults. It is suggested that older adults adopt a less extreme bias between two tasks than younger adults in situations associated with uncertainty. For cue-based switching with random task sequences, older adults are less engaged in a complete reconfiguration of task sets because of the probability of a further task change. Furthermore, the reduction of switching costs was more pronounced for cue- than memory-based switching for short preparation intervals, whereas the reduction of switch costs was more pronounced for memory- than cue-based switching for longer preparation intervals at least for older adults. Together these findings suggest that the implementation of task sets is functionally different for the two types of task-switching conditions.

Can task-switching training enhance executive control functioning in children with attention deficit/-hyperactivity disorder?

PubMed

Kray, Jutta; Karbach, Julia; Haenig, Susann; Freitag, Christine

2011-01-01

The key cognitive impairments of children with attention deficit/-hyperactivity disorder (ADHD) include executive control functions such as inhibitory control, task-switching, and working memory (WM). In this training study we examined whether task-switching training leads to improvements in these functions. Twenty children with combined type ADHD and stable methylphenidate medication performed a single-task and a task-switching training in a crossover training design. The children were randomly assigned to one of two groups. One group started with the single-task training and then performed the task-switching training and the other group vice versa. The effectiveness of the task-switching training was measured as performance improvements (relative to the single-task training) on a structurally similar but new switching task and on other executive control tasks measuring inhibitory control and verbal WM as well as on fluid intelligence (reasoning). The children in both groups showed improvements in task-switching, that is, a reduction of switching costs, but not in performing the single-tasks across four training sessions. Moreover, the task-switching training lead to selective enhancements in task-switching performance, that is, the reduction of task-switching costs was found to be larger after task-switching than after single-task training. Similar selective improvements were observed for inhibitory control and verbal WM, but not for reasoning. Results of this study suggest that task-switching training is an effective cognitive intervention that helps to enhance executive control functioning in children with ADHD.

Can Task-Switching Training Enhance Executive Control Functioning in Children with Attention Deficit/-Hyperactivity Disorder?

PubMed Central

Kray, Jutta; Karbach, Julia; Haenig, Susann; Freitag, Christine

2012-01-01

The key cognitive impairments of children with attention deficit/-hyperactivity disorder (ADHD) include executive control functions such as inhibitory control, task-switching, and working memory (WM). In this training study we examined whether task-switching training leads to improvements in these functions. Twenty children with combined type ADHD and stable methylphenidate medication performed a single-task and a task-switching training in a crossover training design. The children were randomly assigned to one of two groups. One group started with the single-task training and then performed the task-switching training and the other group vice versa. The effectiveness of the task-switching training was measured as performance improvements (relative to the single-task training) on a structurally similar but new switching task and on other executive control tasks measuring inhibitory control and verbal WM as well as on fluid intelligence (reasoning). The children in both groups showed improvements in task-switching, that is, a reduction of switching costs, but not in performing the single-tasks across four training sessions. Moreover, the task-switching training lead to selective enhancements in task-switching performance, that is, the reduction of task-switching costs was found to be larger after task-switching than after single-task training. Similar selective improvements were observed for inhibitory control and verbal WM, but not for reasoning. Results of this study suggest that task-switching training is an effective cognitive intervention that helps to enhance executive control functioning in children with ADHD. PMID:22291628

Positive Emotion Facilitates Cognitive Flexibility: An fMRI Study

PubMed Central

Wang, Yanmei; Chen, Jie; Yue, Zhenzhu

2017-01-01

Cognitive flexibility is the ability to switch rapidly between multiple goals. By using a task-switching paradigm, the present study investigated how positive emotion affected cognitive flexibility and the underlying neural mechanisms. After viewing pictures of different emotional valence (positive, negative, or neutral), participants discriminated whether a target digit in a specific color was odd or even. After a series of trials, the color of target stimuli was changed, i.e., the switch condition. Switch costs were measured by the increase of reaction times (RTs) in the switch trials compared to those in the repeat trials. Behavior results indicated that switch costs significantly decreased in the positive emotional condition, and increased in the negative emotional condition, compared with those in the neutral condition. Imaging data revealed enhanced activation in the dorsal anterior cingulate cortex (dACC) in switch trials than those in repeat trials. Moreover, the interaction between emotion (positive, negative, neutral) and trial type (repeat vs. switch) was significant. For switch trials, the activation of dACC decreased significantly in the positive condition, while increased significantly in the negative condition compared to neutral condition. By contrast, for repeat trials, no significant difference was observed for the activation of dACC among three emotional conditions. Our results showed that positive emotions could increase the cognitive flexibility and reduce the conflict by decreasing the activation of dACC. PMID:29163255

Functional Disconnectivity during Inter-Task Resting State in Dementia with Lewy Bodies.

PubMed

Chabran, Eléna; Roquet, Daniel; Gounot, Daniel; Sourty, Marion; Armspach, Jean-Paul; Blanc, Frédéric

2018-01-01

Limited research has been done on the functional connectivity in visuoperceptual regions in dementia with Lewy bodies (DLB) patients. This study aimed to investigate the functional connectivity differences between a task condition and an inter-task resting state condition within a visuoperceptual paradigm, in DLB patients compared with Alzheimer disease (AD) patients and healthy elderly control subjects. Twenty-six DLB, 29 AD, and 22 healthy subjects underwent a detailed clinical and neuropsychological examination along with a functional MRI during the different conditions of a visuoperceptual paradigm. Functional images were analyzed using group-level spatial independent component analysis and seed-based connectivity analyses. While the DLB patients scored well and did not differ from the control and AD groups in terms of functional activity and connectivity during the task conditions, they showed decreased functional connectivity in visuoperceptual regions during the resting state condition, along with a temporal impairment of the default-mode network activity. Functional connectivity disturbances were also found within two attentional-executive networks and between these networks and visuoperceptual regions. We found a specific functional profile in the switching between task and resting state conditions in DLB patients. This result could help better characterize functional impairments in DLB and their contribution to several core symptoms of this pathology such as visual hallucinations and cognitive fluctuations. © 2018 S. Karger AG, Basel.

Brain Signal Variability Differentially Affects Cognitive Flexibility and Cognitive Stability.

PubMed

Armbruster-Genç, Diana J N; Ueltzhöffer, Kai; Fiebach, Christian J

2016-04-06

Recent research yielded the intriguing conclusion that, in healthy adults, higher levels of variability in neuronal processes are beneficial for cognitive functioning. Beneficial effects of variability in neuronal processing can also be inferred from neurocomputational theories of working memory, albeit this holds only for tasks requiring cognitive flexibility. However, cognitive stability, i.e., the ability to maintain a task goal in the face of irrelevant distractors, should suffer under high levels of brain signal variability. To directly test this prediction, we studied both behavioral and brain signal variability during cognitive flexibility (i.e., task switching) and cognitive stability (i.e., distractor inhibition) in a sample of healthy human subjects and developed an efficient and easy-to-implement analysis approach to assess BOLD-signal variability in event-related fMRI task paradigms. Results show a general positive effect of neural variability on task performance as assessed by accuracy measures. However, higher levels of BOLD-signal variability in the left inferior frontal junction area result in reduced error rate costs during task switching and thus facilitate cognitive flexibility. In contrast, variability in the same area has a detrimental effect on cognitive stability, as shown in a negative effect of variability on response time costs during distractor inhibition. This pattern was mirrored at the behavioral level, with higher behavioral variability predicting better task switching but worse distractor inhibition performance. Our data extend previous results on brain signal variability by showing a differential effect of brain signal variability that depends on task context, in line with predictions from computational theories. Recent neuroscientific research showed that the human brain signal is intrinsically variable and suggested that this variability improves performance. Computational models of prefrontal neural networks predict differential effects of variability for different behavioral situations requiring either cognitive flexibility or stability. However, this hypothesis has so far not been put to an empirical test. In this study, we assessed cognitive flexibility and cognitive stability, and, besides a generally positive effect of neural variability on accuracy measures, we show that neural variability in a prefrontal brain area at the inferior frontal junction is differentially associated with performance: higher levels of variability are beneficial for the effectiveness of task switching (cognitive flexibility) but detrimental for the efficiency of distractor inhibition (cognitive stability). Copyright © 2016 the authors 0270-6474/16/363978-10$15.00/0.

Working memory costs of task switching.

PubMed

Liefooghe, Baptist; Barrouillet, Pierre; Vandierendonck, André; Camos, Valérie

2008-05-01

Although many accounts of task switching emphasize the importance of working memory as a substantial source of the switch cost, there is a lack of evidence demonstrating that task switching actually places additional demands on working memory. The present study addressed this issue by implementing task switching in continuous complex span tasks with strictly controlled time parameters. A series of 4 experiments demonstrate that recall performance decreased as a function of the number of task switches and that the concurrent load of item maintenance had no influence on task switching. These results indicate that task switching induces a cost on working memory functioning. Implications for theories of task switching, working memory, and resource sharing are addressed.

Is the phonological similarity effect in working memory due to proactive interference?

PubMed

Baddeley, Alan D; Hitch, Graham J; Quinlan, Philip T

2018-04-12

Immediate serial recall of verbal material is highly sensitive to impairment attributable to phonological similarity. Although this has traditionally been interpreted as a within-sequence similarity effect, Engle (2007) proposed an interpretation based on interference from prior sequences, a phenomenon analogous to that found in the Peterson short-term memory (STM) task. We use the method of serial reconstruction to test this in an experiment contrasting the standard paradigm in which successive sequences are drawn from the same set of phonologically similar or dissimilar words and one in which the vowel sound on which similarity is based is switched from trial to trial, a manipulation analogous to that producing release from PI in the Peterson task. A substantial similarity effect occurs under both conditions although there is a small advantage from switching across similar sequences. There is, however, no evidence for the suggestion that the similarity effect will be absent from the very first sequence tested. Our results support the within-sequence similarity rather than a between-list PI interpretation. Reasons for the contrast with the classic Peterson short-term forgetting task are briefly discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The joint effect of bilingualism and ADHD on executive functions.

PubMed

Mor, Billy; Yitzhaki-Amsalem, Sarin; Prior, Anat

2015-06-01

The current study investigated the combined effect of ADHD, previously associated with executive function (EF) deficits, and of bilingualism, previously associated with EF enhancement, on EF. Eighty University students, Hebrew monolinguals and Russian Hebrew bilinguals, with and without ADHD participated. Inhibition tasks were a Numeric Stroop task and a Simon arrows task. Shifting tasks were the Trail Making Test (TMT) and a task-switching paradigm. Participants with ADHD performed worse than controls, but we did not find a bilingual advantage in EF. The negative impact of ADHD was more pronounced for bilinguals than for monolinguals, but only in interference suppression tasks. Bilingual participants with ADHD had the lowest performance. Bilingualism might prove to be an added burden for adults with ADHD, leading to reduced EF abilities. Alternatively, the current findings might be ascribed to over- or under-diagnosis of ADHD due to cultural differences between groups. These issues should be pursued in future research. © 2014 SAGE Publications.

Qualitative Differences between Bilingual Language Control and Executive Control: Evidence from Task-Switching

PubMed Central

Calabria, Marco; Hernández, Mireia; Branzi, Francesca M.; Costa, Albert

2012-01-01

Previous research has shown that highly proficient bilinguals have comparable switch costs in both directions when they switch between languages (L1 and L2), the so-called “symmetrical switch cost” effect. Interestingly, the same symmetry is also present when they switch between L1 and a much weaker L3. These findings suggest that highly proficient bilinguals develop a language control system that seems to be insensitive to language proficiency. In the present study, we explore whether the pattern of symmetrical switch costs in language switching tasks generalizes to a non-linguistic switching task in the same group of highly proficient bilinguals. The end goal of this is to assess whether bilingual language control (bLC) can be considered as subsidiary to domain-general executive control (EC). We tested highly proficient Catalan–Spanish bilinguals both in a linguistic switching task and in a non-linguistic switching task. In the linguistic task, participants named pictures in L1 and L2 (Experiment 1) or L3 (Experiment 2) depending on a cue presented with the picture (a flag). In the non-linguistic task, the same participants had to switch between two card sorting rule-sets (color and shape). Overall, participants showed symmetrical switch costs in the linguistic switching task, but not in the non-linguistic switching task. In a further analysis, we observed that in the linguistic switching task the asymmetry of the switch costs changed across blocks, while in the non-linguistic switching task an asymmetrical switch cost was observed throughout the task. The observation of different patterns of switch costs in the linguistic and the non-linguistic switching tasks suggest that the bLC system is not completely subsidiary to the domain-general EC system. PMID:22275905

Working memory and executive function: the influence of content and load on the control of attention.

PubMed

Hester, Robert; Garavan, Hugh

2005-03-01

In a series of three experiments, increasing working memory (WM) load was demonstrated to reduce the executive control of attention, measured via task-switching and inhibitory control paradigms. Uniquely, our paradigms allowed comparison of the ability to exert executive control when the stimulus was either part of the currently rehearsed memory set or an unrelated distractor item. The results demonstrated a content-specific effect-insofar as switching attention away from, or exerting inhibitory control over, items currently held in WM was especially difficult-compounded by increasing WM load. This finding supports the attentional control theory that active maintenance of competing task goals is critical to executive function and WM capacity; however, it also suggests that the increased salience provided to the contents of WM through active rehearsal exerts a content-specific influence on attentional control. These findings are discussed in relation to cue-induced ruminations, where active rehearsal of evocative information (e.g., negative thoughts in depression or drug-related thoughts in addiction) in WM typically results from environmental cuing. The present study has demonstrated that when information currently maintained in WM is reencountered, it is harder to exert executive control over it. The difficulty with suppressing the processing of these stimuli presumably reinforces the maintenance of these items in WM, due to the greater level of attention they are afforded, and may help to explain how the cue-induced craving/rumination cycle is perpetuated.

Asymmetrical Switch Costs in Children

ERIC Educational Resources Information Center

Ellefson, Michelle R.; Shapiron, Laura R.; Chater, Nick

2006-01-01

Switching between tasks produces decreases in performance as compared to repeating the same task. Asymmetrical switch costs occur when switching between two tasks of unequal difficulty. This asymmetry occurs because the cost is greater when switching to the less difficult task than when switching to the more difficult task. Various theories about…

Automation bias: empirical results assessing influencing factors.

PubMed

Goddard, Kate; Roudsari, Abdul; Wyatt, Jeremy C

2014-05-01

To investigate the rate of automation bias - the propensity of people to over rely on automated advice and the factors associated with it. Tested factors were attitudinal - trust and confidence, non-attitudinal - decision support experience and clinical experience, and environmental - task difficulty. The paradigm of simulated decision support advice within a prescribing context was used. The study employed within participant before-after design, whereby 26 UK NHS General Practitioners were shown 20 hypothetical prescribing scenarios with prevalidated correct and incorrect answers - advice was incorrect in 6 scenarios. They were asked to prescribe for each case, followed by being shown simulated advice. Participants were then asked whether they wished to change their prescription, and the post-advice prescription was recorded. Rate of overall decision switching was captured. Automation bias was measured by negative consultations - correct to incorrect prescription switching. Participants changed prescriptions in 22.5% of scenarios. The pre-advice accuracy rate of the clinicians was 50.38%, which improved to 58.27% post-advice. The CDSS improved the decision accuracy in 13.1% of prescribing cases. The rate of automation bias, as measured by decision switches from correct pre-advice, to incorrect post-advice was 5.2% of all cases - a net improvement of 8%. More immediate factors such as trust in the specific CDSS, decision confidence, and task difficulty influenced rate of decision switching. Lower clinical experience was associated with more decision switching. Age, DSS experience and trust in CDSS generally were not significantly associated with decision switching. This study adds to the literature surrounding automation bias in terms of its potential frequency and influencing factors. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

In Support of a Distinction between Voluntary and Stimulus-Driven Control: A Review of the Literature on Proportion Congruent Effects.

PubMed

Bugg, Julie M; Crump, Matthew J C

2012-01-01

Cognitive control is by now a large umbrella term referring collectively to multiple processes that plan and coordinate actions to meet task goals. A common feature of paradigms that engage cognitive control is the task requirement to select relevant information despite a habitual tendency (or bias) to select goal-irrelevant information. At least since the 1970s, researchers have employed proportion congruent (PC) manipulations to experimentally establish selection biases and evaluate the mechanisms used to control attention. PC manipulations vary the frequency with which irrelevant information conflicts (i.e., is incongruent) with relevant information. The purpose of this review is to summarize the growing body of literature on PC effects across selective attention paradigms, beginning first with Stroop, and then describing parallel effects in flanker and task-switching paradigms. The review chronologically tracks the expansion of the PC manipulation from its initial implementation at the list-wide level, to more recent implementations at the item-specific and context-specific levels. An important theoretical aim is demonstrating that PC effects at different levels (e.g., list-wide vs. item or context-specific) support a distinction between voluntary forms of cognitive control, which operate based on anticipatory information, and relatively automatic or reflexive forms of cognitive control, which are rapidly triggered by the processing of particular stimuli or stimulus features. A further aim is to highlight those PC manipulations that allow researchers to dissociate stimulus-driven control from other stimulus-driven processes (e.g., S-R responding; episodic retrieval). We conclude by discussing the utility of PC manipulations for exploring the distinction between voluntary control and stimulus-driven control in other relevant paradigms.

In Support of a Distinction between Voluntary and Stimulus-Driven Control: A Review of the Literature on Proportion Congruent Effects

PubMed Central

Bugg, Julie M.; Crump, Matthew J. C.

2012-01-01

Cognitive control is by now a large umbrella term referring collectively to multiple processes that plan and coordinate actions to meet task goals. A common feature of paradigms that engage cognitive control is the task requirement to select relevant information despite a habitual tendency (or bias) to select goal-irrelevant information. At least since the 1970s, researchers have employed proportion congruent (PC) manipulations to experimentally establish selection biases and evaluate the mechanisms used to control attention. PC manipulations vary the frequency with which irrelevant information conflicts (i.e., is incongruent) with relevant information. The purpose of this review is to summarize the growing body of literature on PC effects across selective attention paradigms, beginning first with Stroop, and then describing parallel effects in flanker and task-switching paradigms. The review chronologically tracks the expansion of the PC manipulation from its initial implementation at the list-wide level, to more recent implementations at the item-specific and context-specific levels. An important theoretical aim is demonstrating that PC effects at different levels (e.g., list-wide vs. item or context-specific) support a distinction between voluntary forms of cognitive control, which operate based on anticipatory information, and relatively automatic or reflexive forms of cognitive control, which are rapidly triggered by the processing of particular stimuli or stimulus features. A further aim is to highlight those PC manipulations that allow researchers to dissociate stimulus-driven control from other stimulus-driven processes (e.g., S-R responding; episodic retrieval). We conclude by discussing the utility of PC manipulations for exploring the distinction between voluntary control and stimulus-driven control in other relevant paradigms. PMID:23060836

The effects of one night of partial sleep deprivation on executive functions in individuals reporting chronic insomnia and good sleepers.

PubMed

Ballesio, Andrea; Cerolini, Silvia; Ferlazzo, Fabio; Cellini, Nicola; Lombardo, Caterina

2018-02-15

The aim of the present study was to investigate the effects of a partial sleep deprivation night on executive functions in participants reporting chronic insomnia and good sleepers using a Task Switching paradigm. Sixteen participants reporting symptoms of chronic insomnia and sixteen good sleepers were tested after a night of habitual sleep and after a night of partial sleep deprivation (5 h of sleep allowed). The Switch Cost (SC) and the Backward Inhibition (BI) were computed as measures of switching attention and response inhibition, respectively. We observed a marginally significant interaction Night × Group on SC (F (1,29)  = 4.06, p = 0.053), η 2  = 0.123. Fisher's least significant difference (LSD) post-hoc revealed a smaller SC after the sleep deprived night relative to the habitual night for the good sleepers (p = 0.027; M = 192.23 ± 201.81 vs M = 98.99 ± 141.16). Differently, participants with insomnia did not show any change after the two nights. Several limitations must be acknowledged including the use of a convenient sample of university students and the use of a single task of cognitive performance. We found that SC was smaller in the good sleepers after a night of partial sleep deprivation compared to a habitual night, indicating a better switching performance. The insomnia group showed no differences in performance after the two experimental nights. Several factors may account for these results, including increased levels of arousal and cognitive effort during task execution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cue-Independent Task-Specific Representations in Task Switching: Evidence from Backward Inhibition

ERIC Educational Resources Information Center

Altmann, Erik M.

2007-01-01

The compound-cue model of cognitive control in task switching explains switch cost in terms of a switch of task cues rather than of a switch of tasks. The present study asked whether the model generalizes to Lag 2 repetition cost (also known as backward inhibition), a related effect in which the switch from B to A in ABA task sequences is costlier…

Knowing the future: partial foreknowledge effects on the programming of prosaccades and antisaccades.

PubMed

Abegg, Mathias; Manoach, Dara S; Barton, Jason J S

2011-01-01

Foreknowledge about the demands of an upcoming trial may be exploited to optimize behavioural responses. In the current study we systematically investigated the benefits of partial foreknowledge--that is, when some but not all aspects of a future trial are known in advance. For this we used an ocular motor paradigm with horizontal prosaccades and antisaccades. Predictable sequences were used to create three partial foreknowledge conditions: one with foreknowledge about the stimulus location only, one with foreknowledge about the task set only, and one with foreknowledge about the direction of the required response only. These were contrasted with a condition of no-foreknowledge and a condition of complete foreknowledge about all three parameters. The results showed that the three types of foreknowledge affected saccadic efficiency differently. While foreknowledge about stimulus-location had no effect on efficiency, task foreknowledge had some effect and response-foreknowledge was as effective as complete foreknowledge. Foreknowledge effects on switch costs followed a similar pattern in general, but were not specific for switching of the trial attribute for which foreknowledge was available. We conclude that partial foreknowledge has a differential effect on efficiency, most consistent with preparatory activation of a motor schema in advance of the stimulus, with consequent benefits for both switched and repeated trials. Copyright © 2010 Elsevier Ltd. All rights reserved.

schwimmbad: A uniform interface to parallel processing pools in Python

NASA Astrophysics Data System (ADS)

Price-Whelan, Adrian M.; Foreman-Mackey, Daniel

2017-09-01

Many scientific and computing problems require doing some calculation on all elements of some data set. If the calculations can be executed in parallel (i.e. without any communication between calculations), these problems are said to be perfectly parallel. On computers with multiple processing cores, these tasks can be distributed and executed in parallel to greatly improve performance. A common paradigm for handling these distributed computing problems is to use a processing "pool": the "tasks" (the data) are passed in bulk to the pool, and the pool handles distributing the tasks to a number of worker processes when available. schwimmbad provides a uniform interface to parallel processing pools and enables switching easily between local development (e.g., serial processing or with multiprocessing) and deployment on a cluster or supercomputer (via, e.g., MPI or JobLib).

Switch-Independent Task Representations in Frontal and Parietal Cortex.

PubMed

Loose, Lasse S; Wisniewski, David; Rusconi, Marco; Goschke, Thomas; Haynes, John-Dylan

2017-08-16

Alternating between two tasks is effortful and impairs performance. Previous fMRI studies have found increased activity in frontoparietal cortex when task switching is required. One possibility is that the additional control demands for switch trials are met by strengthening task representations in the human brain. Alternatively, on switch trials, the residual representation of the previous task might impede the buildup of a neural task representation. This would predict weaker task representations on switch trials, thus also explaining the performance costs. To test this, male and female participants were cued to perform one of two similar tasks, with the task being repeated or switched between successive trials. Multivoxel pattern analysis was used to test which regions encode the tasks and whether this encoding differs between switch and repeat trials. As expected, we found information about task representations in frontal and parietal cortex, but there was no difference in the decoding accuracy of task-related information between switch and repeat trials. Using cross-classification, we found that the frontoparietal cortex encodes tasks using a generalizable spatial pattern in switch and repeat trials. Therefore, task representations in frontal and parietal cortex are largely switch independent. We found no evidence that neural information about task representations in these regions can explain behavioral costs usually associated with task switching. SIGNIFICANCE STATEMENT Alternating between two tasks is effortful and slows down performance. One possible explanation is that the representations in the human brain need time to build up and are thus weaker on switch trials, explaining performance costs. Alternatively, task representations might even be enhanced to overcome the previous task. Here, we used a combination of fMRI and a brain classifier to test whether the additional control demands under switching conditions lead to an increased or decreased strength of task representations in frontoparietal brain regions. We found that task representations are not modulated significantly by switching processes and generalize across switching conditions. Therefore, task representations in the human brain cannot account for the performance costs associated with alternating between tasks. Copyright © 2017 the authors 0270-6474/17/378033-10$15.00/0.

Stochastic Dynamics Underlying Cognitive Stability and Flexibility

PubMed Central

Ueltzhöffer, Kai; Armbruster-Genç, Diana J. N.; Fiebach, Christian J.

2015-01-01

Cognitive stability and flexibility are core functions in the successful pursuit of behavioral goals. While there is evidence for a common frontoparietal network underlying both functions and for a key role of dopamine in the modulation of flexible versus stable behavior, the exact neurocomputational mechanisms underlying those executive functions and their adaptation to environmental demands are still unclear. In this work we study the neurocomputational mechanisms underlying cue based task switching (flexibility) and distractor inhibition (stability) in a paradigm specifically designed to probe both functions. We develop a physiologically plausible, explicit model of neural networks that maintain the currently active task rule in working memory and implement the decision process. We simplify the four-choice decision network to a nonlinear drift-diffusion process that we canonically derive from a generic winner-take-all network model. By fitting our model to the behavioral data of individual subjects, we can reproduce their full behavior in terms of decisions and reaction time distributions in baseline as well as distractor inhibition and switch conditions. Furthermore, we predict the individual hemodynamic response timecourse of the rule-representing network and localize it to a frontoparietal network including the inferior frontal junction area and the intraparietal sulcus, using functional magnetic resonance imaging. This refines the understanding of task-switch-related frontoparietal brain activity as reflecting attractor-like working memory representations of task rules. Finally, we estimate the subject-specific stability of the rule-representing attractor states in terms of the minimal action associated with a transition between different rule states in the phase-space of the fitted models. This stability measure correlates with switching-specific thalamocorticostriatal activation, i.e., with a system associated with flexible working memory updating and dopaminergic modulation of cognitive flexibility. These results show that stochastic dynamical systems can implement the basic computations underlying cognitive stability and flexibility and explain neurobiological bases of individual differences. PMID:26068119

Age Differences in the Transfer and Maintenance of Practice-Induced Improvements in Task Switching: The Impact of Working-Memory and Inhibition Demands

PubMed Central

Kray, Jutta; Fehér, Balázs

2017-01-01

Recent aging studies on training in task switching found that older adults showed larger improvements to an untrained switching task as younger adults do. However, less clear is what type of cognitive control processes can explain these training gains as participants were trained with a particular type of switching task including bivalent stimuli, requiring high inhibition demands, and no task cues helping them keeping track of the task sequence, and by this, requiring high working-memory (WM) demands. The aims of this study were first to specify whether inhibition, WM, or switching demands are critical for the occurrence of transfer and whether this transfer depends on the degree of overlap between training and transfer situation; and second to assess whether practiced-induced gains in task switching can be maintained over a longer period of time. To this end, we created five training conditions that varied in switching (switching vs. single task training), inhibition (switching training with bivalent or univalent stimuli), and WM demands (switching training with or without task cues). We investigated 81 younger adults and 82 older adults with a pretest-training-posttest design and a follow-up measurement after 6 months. Results indicated that all training and age groups showed improvements in task switching and a differential effect of training condition on improvements to an untrained switching task in younger and older adults. For younger adults, we found larger improvements in task switching for the switching groups than the single-task training group independently of inhibition and WM demands, suggesting that practice in switching is most critical. However, these benefits disappeared after 6 months. In contrast, for older adults training groups practicing task switching under high inhibition demands showed larger improvements to untrained switching tasks than the other groups. Moreover, these benefits were maintained over time. We also found that the transfer of benefits in task switching was larger with greater overlap between training and transfer situation. However, results revealed no evidence for transfer to other untrained cognitive task. Overall, the findings suggest that training in resolving interference while switching between two tasks is most critical for the occurrence of transfer in the elderly. PMID:28367135

Task Inhibition and Response Inhibition in Older vs. Younger Adults: A Diffusion Model Analysis

PubMed Central

Schuch, Stefanie

2016-01-01

Differences in inhibitory ability between older (64–79 years, N = 24) and younger adults (18–26 years, N = 24) were investigated using a diffusion model analysis. Participants performed a task-switching paradigm that allows assessing n−2 task repetition costs, reflecting inhibitory control on the level of tasks, as well as n−1 response-repetition costs, reflecting inhibitory control on the level of responses. N−2 task repetition costs were of similar size in both age groups. Diffusion model analysis revealed that for both younger and older adults, drift rate parameters were smaller in the inhibition condition relative to the control condition, consistent with the idea that persisting task inhibition slows down response selection. Moreover, there was preliminary evidence for task inhibition effects in threshold separation and non-decision time in the older, but not the younger adults, suggesting that older adults might apply different strategies when dealing with persisting task inhibition. N−1 response-repetition costs in mean RT were larger in older than younger adults, but in mean error rates tended to be larger in younger than older adults. Diffusion-model analysis revealed longer non-decision times in response repetitions than response switches in both age groups, consistent with the idea that motor processes take longer in response repetitions than response switches due to persisting response inhibition of a previously executed response. The data also revealed age-related differences in overall performance: Older adults responded more slowly and more accurately than young adults, which was reflected by a higher threshold separation parameter in diffusion model analysis. Moreover, older adults showed larger non-decision times and higher variability in non-decision time than young adults, possibly reflecting slower and more variable motor processes. In contrast, overall drift rate did not differ between older and younger adults. Taken together, diffusion model analysis revealed differences in overall performance between the age groups, as well as preliminary evidence for age differences in dealing with task inhibition, but no evidence for an inhibitory deficit in older age. PMID:27895599

Event-Related Potential Measures of Attention Capture in Adolescent Inpatients With Acute Suicidal Behavior.

PubMed

Tavakoli, Paniz; Boafo, Addo; Dale, Allyson; Robillard, Rebecca; Greenham, Stephanie L; Campbell, Kenneth

2018-01-01

Impaired executive functions, modulated by the frontal lobes, have been suggested to be associated with suicidal behavior. The present study examines one of these executive functions, attentional control, maintaining attention to the task-at-hand. A group of inpatient adolescents with acute suicidal behavior and healthy controls were studied using a passively presented auditory optimal paradigm. This "optimal" paradigm consisted of a series of frequently presented homogenous pure tone "standards" and different "deviants," constructed by changing one or more features of the standard. The optimal paradigm has been shown to be a more time-efficient replacement to the traditional oddball paradigm, which makes it suitable for use in clinical populations. The extent of processing of these "to-be-ignored" auditory stimuli was measured by recording event-related potentials (ERPs). The P3a ERP component is thought to reflect processes associated with the capturing of attention. Rare and novel stimuli may result in an executive decision to switch attention away from the current cognitive task and toward a probe of the potentially more relevant "interrupting" auditory input. On the other hand, stimuli that are quite similar to the standard should not elicit P3a. The P3a has been shown to be larger in immature brains in early compared to later adolescence. An overall enhanced P3a was observed in the suicidal group. The P3a was larger in this group for both the environmental sound and white noise deviants, although only the environmental sound P3a attained significance. Other deviants representing only a small change from the standard did not elicit a P3a in healthy controls. They did elicit a small P3a in the suicidal group. These findings suggest a lowered threshold for the triggering of the involuntary switch of attention in these patients, which may play a role in their reported distractibility. The enhanced P3a is also suggestive of an immature frontal central executive and may provide a promising marker for early identification of some of the risk factors for some of the cognitive difficulties linked to suicidality.

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

PubMed

Arbuthnott, Katherine D; Woodward, Todd S

2002-03-01

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

Task switching in a hierarchical task structure: evidence for the fragility of the task repetition benefit.

PubMed

Lien, Mei-Ching; Ruthruff, Eric

2004-05-01

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. In Experiments 2-5, adjacent task elements were grouped temporally and/or spatially (forming an ensemble) to create a hierarchical task organization. Results indicate that the effect of switching at the ensemble level dominated the effect of switching at the element level. Experiments 6 and 7, using an ensemble of 3 task elements, revealed that the element-level switch cost was virtually absent between ensembles but was large within an ensemble. The authors conclude that the element-level task repetition benefit is fragile and can be eliminated in a hierarchical task organization.

Task switching in a hierarchical task structure: evidence for the fragility of the task repetition benefit

NASA Technical Reports Server (NTRS)

Lien, Mei-Ching; Ruthruff, Eric

2004-01-01

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. In Experiments 2-5, adjacent task elements were grouped temporally and/or spatially (forming an ensemble) to create a hierarchical task organization. Results indicate that the effect of switching at the ensemble level dominated the effect of switching at the element level. Experiments 6 and 7, using an ensemble of 3 task elements, revealed that the element-level switch cost was virtually absent between ensembles but was large within an ensemble. The authors conclude that the element-level task repetition benefit is fragile and can be eliminated in a hierarchical task organization.

Functional split brain in a driving/listening paradigm

PubMed Central

Boly, Melanie; Mensen, Armand; Tononi, Giulio

2016-01-01

We often engage in two concurrent but unrelated activities, such as driving on a quiet road while listening to the radio. When we do so, does our brain split into functionally distinct entities? To address this question, we imaged brain activity with fMRI in experienced drivers engaged in a driving simulator while listening either to global positioning system instructions (integrated task) or to a radio show (split task). We found that, compared with the integrated task, the split task was characterized by reduced multivariate functional connectivity between the driving and listening networks. Furthermore, the integrated information content of the two networks, predicting their joint dynamics above and beyond their independent dynamics, was high in the integrated task and zero in the split task. Finally, individual subjects’ ability to switch between high and low information integration predicted their driving performance across integrated and split tasks. This study raises the possibility that under certain conditions of daily life, a single brain may support two independent functional streams, a “functional split brain” similar to what is observed in patients with an anatomical split. PMID:27911805

Functional split brain in a driving/listening paradigm.

PubMed

Sasai, Shuntaro; Boly, Melanie; Mensen, Armand; Tononi, Giulio

2016-12-13

We often engage in two concurrent but unrelated activities, such as driving on a quiet road while listening to the radio. When we do so, does our brain split into functionally distinct entities? To address this question, we imaged brain activity with fMRI in experienced drivers engaged in a driving simulator while listening either to global positioning system instructions (integrated task) or to a radio show (split task). We found that, compared with the integrated task, the split task was characterized by reduced multivariate functional connectivity between the driving and listening networks. Furthermore, the integrated information content of the two networks, predicting their joint dynamics above and beyond their independent dynamics, was high in the integrated task and zero in the split task. Finally, individual subjects' ability to switch between high and low information integration predicted their driving performance across integrated and split tasks. This study raises the possibility that under certain conditions of daily life, a single brain may support two independent functional streams, a "functional split brain" similar to what is observed in patients with an anatomical split.

A new account of the effect of probability on task switching: ERP evidence following the manipulation of switch probability, cue informativeness and predictability

PubMed Central

Nessler, Doreen; Friedman, David; Johnson, Ray

2012-01-01

This task-switching ERP study of 16 young participants investigated whether increased RT slowing on stay trials and faster RTs on switch trials for frequent than infrequent switching are explained by an activation or preparation account. The activation account proposes that task sets are maintained at a higher baseline activation level for frequent switching, necessitating increased task-set updating, as reflected by a larger and/or longer lasting early parietal positivity. The preparation account assumes advance (pre-cue) switch preparation (i.e., task-set reconfiguration), preceding stay and switch trials for frequent switching, as reflected by pre-cue and post-cue late parietal positivities. By and large, the data support the activation account. However, we also found increased, pre-cue task-set updating on frequent stay trials and pre-cue, task-set reconfiguration prior to predictable, frequent switches. These results lead us to propose an extended activation account to explain the effects of switch probability on the executive processes underlying task-switching behavior. PMID:22820040

Task Switching in a Hierarchical Task Structure: Evidence for the Fragility of the Task Repetition Benefit

ERIC Educational Resources Information Center

Lien, Mei-Ching; Ruthruff, Eric

2004-01-01

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.…

Working Memory Costs of Task Switching

ERIC Educational Resources Information Center

Liefooghe, Baptist; Barrouillet, Pierre; Vandierendonck, Andre; Camos, Valerie

2008-01-01

Although many accounts of task switching emphasize the importance of working memory as a substantial source of the switch cost, there is a lack of evidence demonstrating that task switching actually places additional demands on working memory. The present study addressed this issue by implementing task switching in continuous complex span tasks…

Effects of automation and task load on task switching during human supervision of multiple semi-autonomous robots in a dynamic environment.

PubMed

Squire, P N; Parasuraman, R

2010-08-01

The present study assessed the impact of task load and level of automation (LOA) on task switching in participants supervising a team of four or eight semi-autonomous robots in a simulated 'capture the flag' game. Participants were faster to perform the same task than when they chose to switch between different task actions. They also took longer to switch between different tasks when supervising the robots at a high compared to a low LOA. Task load, as manipulated by the number of robots to be supervised, did not influence switch costs. The results suggest that the design of future unmanned vehicle (UV) systems should take into account not simply how many UVs an operator can supervise, but also the impact of LOA and task operations on task switching during supervision of multiple UVs. The findings of this study are relevant for the ergonomics practice of UV systems. This research extends the cognitive theory of task switching to inform the design of UV systems and results show that switching between UVs is an important factor to consider.

Word learning in deaf children with cochlear implants: effects of early auditory experience.

PubMed

Houston, Derek M; Stewart, Jessica; Moberly, Aaron; Hollich, George; Miyamoto, Richard T

2012-05-01

Word-learning skills were tested in normal-hearing 12- to 40-month-olds and in deaf 22- to 40-month-olds 12 to 18 months after cochlear implantation. Using the Intermodal Preferential Looking Paradigm (IPLP), children were tested for their ability to learn two novel-word/novel-object pairings. Normal-hearing children demonstrated learning on this task at approximately 18 months of age and older. For deaf children, performance on this task was significantly correlated with early auditory experience: Children whose cochlear implants were switched on by 14 months of age or who had relatively more hearing before implantation demonstrated learning in this task, but later implanted profoundly deaf children did not. Performance on this task also correlated with later measures of vocabulary size. Taken together, these findings suggest that early auditory experience facilitates word learning and that the IPLP may be useful for identifying children who may be at high risk for poor vocabulary development. © 2012 Blackwell Publishing Ltd.

Word learning in deaf children with cochlear implants: effects of early auditory experience

PubMed Central

Houston, Derek M.; Stewart, Jessica; Moberly, Aaron; Hollich, George; Miyamoto, Richard T.

2013-01-01

Word-learning skills were tested in normal-hearing 12- to 40-month-olds and in deaf 22- to 40-month-olds 12 to 18 months after cochlear implantation. Using the Intermodal Preferential Looking Paradigm (IPLP), children were tested for their ability to learn two novel-word/novel-object pairings. Normal-hearing children demonstrated learning on this task at approximately 18 months of age and older. For deaf children, performance on this task was significantly correlated with early auditory experience: Children whose cochlear implants were switched on by 14 months of age or who had relatively more hearing before implantation demonstrated learning in this task, but later implanted profoundly deaf children did not. Performance on this task also correlated with later measures of vocabulary size. Taken together, these findings suggest that early auditory experience facilitates word learning and that the IPLP may be useful for identifying children who may be at high risk for poor vocabulary development. PMID:22490184

Resolving Task Rule Incongruence during Task Switching by Competitor Rule Suppression

ERIC Educational Resources Information Center

Meiran, Nachshon; Hsieh, Shulan; Dimov, Eduard

2010-01-01

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…

On the role of verbalization during task set selection: switching or serial order control?

PubMed

Bryck, Richard L; Mayr, Ulrich

2005-06-01

Recent task-switching work in which paper-and-pencil administered single-task lists were compared with task-alternation lists has demonstrated large increases in task-switch costs with concurrent articulatory suppression (AS), implicating a crucial role for verbalization during switching (Baddeley, Chincotta, & Adlam, 2001; Emerson & Miyake, 2003). Experiment 1 replicated this result, using computerized assessment, albeit with much smaller effect sizes than in the original reports. In Experiment 2, AS interference was reduced when a sequential cue (spatial location) that indicated the current position in the sequence of task alternations was given. Finally, in Experiment 3, switch trials and no-switch trials were compared within a block of alternating runs of two tasks. Again, AS interference was obtained mainly when the endogenous sequencing demand was high, and it was comparable for no-switch and switch trials. These results suggest that verbalization may be critical for endogenous maintenance and updating of a sequential plan, rather than exclusively for the actual switching process.

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

ERIC Educational Resources Information Center

Schneider, Darryl W.; Logan, Gordon D.

2005-01-01

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

Self-Paced Preparation for a Task Switch Eliminates Attentional Inertia but Not the Performance Switch Cost

ERIC Educational Resources Information Center

Longman, Cai S.; Lavric, Aureliu; Monsell, Stephen

2017-01-01

The performance overhead associated with changing tasks (the "switch cost") usually diminishes when the task is specified in advance but is rarely eliminated by preparation. A popular account of the "residual" (asymptotic) switch cost is that it reflects "task-set inertia": carry-over of task-set parameters from the…

Displaced aggression predicts switching deficits in people with temporal lobe epilepsy.

PubMed

Gul, Amara; Ahmad, Hira

2014-12-01

This study examined the relationship between task-switching abilities and displaced aggression in people with temporal lobe epilepsy (PWE). Participants (35 PWE and 35 healthy controls) performed emotion and gender classification switching tasks. People with temporal lobe epilepsy showed larger switch costs than controls. This result reflected task-switching deficits in PWE. People with temporal lobe epilepsy reported higher anger rumination, revenge planning, and behavioral displaced aggression compared with controls. Displaced aggression was a significant predictor of the task switch costs. It is suggested that displaced aggression is a significant marker of task-switching deficits. Copyright © 2014 Elsevier Inc. All rights reserved.

Revealing the functional neuroanatomy of intrinsic alertness using fMRI: methodological peculiarities.

PubMed

Clemens, Benjamin; Zvyagintsev, Mikhail; Sack, Alexander T; Sack, Alexander; Heinecke, Armin; Willmes, Klaus; Sturm, Walter

2011-01-01

Clinical observations and neuroimaging data revealed a right-hemisphere fronto-parietal-thalamic-brainstem network for intrinsic alertness, and additional left fronto-parietal activity during phasic alertness. The primary objective of this fMRI study was to map the functional neuroanatomy of intrinsic alertness as precisely as possible in healthy participants, using a novel assessment paradigm already employed in clinical settings. Both the paradigm and the experimental design were optimized to specifically assess intrinsic alertness, while at the same time controlling for sensory-motor processing. The present results suggest that the processing of intrinsic alertness is accompanied by increased activity within the brainstem, thalamus, anterior cingulate gyrus, right insula, and right parietal cortex. Additionally, we found increased activation in the left hemisphere around the middle frontal gyrus (BA 9), the insula, the supplementary motor area, and the cerebellum. Our results further suggest that rather minute aspects of the experimental design may induce aspects of phasic alertness, which in turn might lead to additional brain activation in left-frontal areas not normally involved in intrinsic alertness. Accordingly, left BA 9 activation may be related to co-activation of the phasic alertness network due to the switch between rest and task conditions functioning as an external warning cue triggering the phasic alertness network. Furthermore, activation of the intrinsic alertness network during fixation blocks due to enhanced expectancy shortly before the switch to the task block might, when subtracted from the task block, lead to diminished activation in the typical right hemisphere intrinsic alertness network. Thus, we cautiously suggest that--as a methodological artifact--left frontal activations might show up due to phasic alertness involvement and intrinsic alertness activations might be weakened due to contrasting with fixation blocks, when assessing the functional neuroanatomy of intrinsic alertness with a block design in fMRI studies.

Revealing the Functional Neuroanatomy of Intrinsic Alertness Using fMRI: Methodological Peculiarities

PubMed Central

Clemens, Benjamin; Zvyagintsev, Mikhail; Sack, Alexander; Heinecke, Armin; Willmes, Klaus; Sturm, Walter

2011-01-01

Clinical observations and neuroimaging data revealed a right-hemisphere fronto-parietal-thalamic-brainstem network for intrinsic alertness, and additional left fronto-parietal activity during phasic alertness. The primary objective of this fMRI study was to map the functional neuroanatomy of intrinsic alertness as precisely as possible in healthy participants, using a novel assessment paradigm already employed in clinical settings. Both the paradigm and the experimental design were optimized to specifically assess intrinsic alertness, while at the same time controlling for sensory-motor processing. The present results suggest that the processing of intrinsic alertness is accompanied by increased activity within the brainstem, thalamus, anterior cingulate gyrus, right insula, and right parietal cortex. Additionally, we found increased activation in the left hemisphere around the middle frontal gyrus (BA 9), the insula, the supplementary motor area, and the cerebellum. Our results further suggest that rather minute aspects of the experimental design may induce aspects of phasic alertness, which in turn might lead to additional brain activation in left-frontal areas not normally involved in intrinsic alertness. Accordingly, left BA 9 activation may be related to co-activation of the phasic alertness network due to the switch between rest and task conditions functioning as an external warning cue triggering the phasic alertness network. Furthermore, activation of the intrinsic alertness network during fixation blocks due to enhanced expectancy shortly before the switch to the task block might, when subtracted from the task block, lead to diminished activation in the typical right hemisphere intrinsic alertness network. Thus, we cautiously suggest that – as a methodological artifact – left frontal activations might show up due to phasic alertness involvement and intrinsic alertness activations might be weakened due to contrasting with fixation blocks, when assessing the functional neuroanatomy of intrinsic alertness with a block design in fMRI studies. PMID:21984928

Computer usage and task-switching during resident's working day: Disruptive or not?

PubMed

Méan, Marie; Garnier, Antoine; Wenger, Nathalie; Castioni, Julien; Waeber, Gérard; Marques-Vidal, Pedro

2017-01-01

Recent implementation of electronic health records (EHR) has dramatically changed medical ward organization. While residents in general internal medicine use EHR systems half of their working time, whether computer usage impacts residents' workflow remains uncertain. We aimed to observe the frequency of task-switches occurring during resident's work and to assess whether computer usage was associated with task-switching. In a large Swiss academic university hospital, we conducted, between May 26 and July 24, 2015 a time-motion study to assess how residents in general internal medicine organize their working day. We observed 49 day and 17 evening shifts of 36 residents, amounting to 697 working hours. During day shifts, residents spent 5.4 hours using a computer (mean total working time: 11.6 hours per day). On average, residents switched 15 times per hour from a task to another. Task-switching peaked between 8:00-9:00 and 16:00-17:00. Task-switching was not associated with resident's characteristics and no association was found between task-switching and extra hours (Spearman r = 0.220, p = 0.137 for day and r = 0.483, p = 0.058 for evening shifts). Computer usage occurred more frequently at the beginning or ends of day shifts and was associated with decreased overall task-switching. Task-switching occurs very frequently during resident's working day. Despite the fact that residents used a computer half of their working time, computer usage was associated with decreased task-switching. Whether frequent task-switches and computer usage impact the quality of patient care and resident's work must be evaluated in further studies.

Estimated capacity of object files in visual short-term memory is not improved by retrieval cueing.

PubMed

Saiki, Jun; Miyatsuji, Hirofumi

2009-03-23

Visual short-term memory (VSTM) has been claimed to maintain three to five feature-bound object representations. Some results showing smaller capacity estimates for feature binding memory have been interpreted as the effects of interference in memory retrieval. However, change-detection tasks may not properly evaluate complex feature-bound representations such as triple conjunctions in VSTM. To understand the general type of feature-bound object representation, evaluation of triple conjunctions is critical. To test whether interference occurs in memory retrieval for complete object file representations in a VSTM task, we cued retrieval in novel paradigms that directly evaluate the memory for triple conjunctions, in comparison with a simple change-detection task. In our multiple object permanence tracking displays, observers monitored for a switch in feature combination between objects during an occlusion period, and we found that a retrieval cue provided no benefit with the triple conjunction tasks, but significant facilitation with the change-detection task, suggesting that low capacity estimates of object file memory in VSTM reflect a limit on maintenance, not retrieval.

ERP indices of persisting and current inhibitory control: a study of saccadic task switching.

PubMed

Mueller, S C; Swainson, R; Jackson, G M

2009-03-01

Previous studies have found that inhibition of a biologically dominant prepotent response tendency is required during the execution of a less familiar, non-prepotent response. However, the lasting impact of this inhibition and the cognitive mechanisms to flexibly switch between prepotent and non-prepotent responses are poorly understood. We examined the neurophysiological (ERP) correlates of switching between prosaccade and antisaccade responses in 22 healthy volunteers. The behavioural data showed significant switch costs in terms of response latency for the prosaccade task only. These costs occurred exclusively in trials when preparation for the switch was limited to 300 ms, suggesting that inhibition of the prepotent prosaccade task either passively dissipated or was actively overcome during the longer 1000 ms preparation interval. In the neurophysiological data, a late frontal negativity (LFN) was visible during preparation for a switch to the prosaccade task that was absent when switching to the antisaccade task, which may reflect the overcoming of persisting inhibition. During task implementation both saccade types were associated with a late parietal positivity (LPP) for switch relative to repetition trials, possibly indicating attentional reorienting to the switched-to task, and visible only with short preparation intervals. When the prosaccade and antisaccade task were contrasted directly during task implementation, the antisaccade task exhibited increased stimulus-locked N2 and decreased P3 amplitudes indicative of active inhibition. The present findings indicate that neurophysiological markers of persisting and current inhibition can be revealed using a prosaccade/antisaccade-switching task.

Switching between Tasks and Responses: A Developmental Study

ERIC Educational Resources Information Center

Crone, Eveline A.; Bunge, Silvia A.; van der Molen, Maurits W.; Ridderinkhof, K. Richard

2006-01-01

Task switching requires the ability to flexibly switch between task rules and responses, and is sensitive to developmental change. We tested the hypothesis that developmental changes in task switch performance are associated with changes in the facilitating or interfering effect of the previously retrieved stimulus-response (S-R) association.…

Context-dependent switching between proactive and reactive working memory control mechanisms in the right inferior frontal gyrus.

PubMed

Marklund, Petter; Persson, Jonas

2012-11-15

A critical feature of higher cognitive functioning is the capacity to flexibly tailor information processing and behaviors to current situational demands. Recent neurocognitive models have been postulated to account for the dynamic nature of human executive processing by invoking two dissociable cognitive control modes, proactive and reactive control. These may involve partially overlapping, but temporally distinct neural implementation in the prefrontal cortex. Prior brain imaging studies exploring proactive control have mainly used tasks requiring only information about single-items to be retained over unfilled delays. Whether proactive control can also be utilized to facilitate performance in more complex working memory tasks, in which concurrent processing of intervening items and updating is mandatory during contextual cue maintenance remains an open question. To examine this issue and to elucidate the extent to which overlapping neural substrates underlie proactive and reactive control we used fMRI and a modified verbal 3-back paradigm with embedded cues predictive of high-interference trials. This task requires context information to be retained over multiple intervening trials. We found that performance improved with item-specific cues predicting forthcoming lures despite increased working memory load. Temporal dynamics of activation in the right inferior frontal gyrus suggest flexible switching between proactive and reactive control in a context-dependent fashion, with greater sustained responses elicited in the 3-back task involving context maintenance of cue information and greater transient responses elicited in the 3-back task absent of cues. Copyright © 2012 Elsevier Inc. All rights reserved.

Modality-specific effects on crosstalk in task switching: evidence from modality compatibility using bimodal stimulation.

PubMed

Stephan, Denise Nadine; Koch, Iring

2016-11-01

The present study was aimed at examining modality-specific influences in task switching. To this end, participants switched either between modality compatible tasks (auditory-vocal and visual-manual) or incompatible spatial discrimination tasks (auditory-manual and visual-vocal). In addition, auditory and visual stimuli were presented simultaneously (i.e., bimodally) in each trial, so that selective attention was required to process the task-relevant stimulus. The inclusion of bimodal stimuli enabled us to assess congruence effects as a converging measure of increased between-task interference. The tasks followed a pre-instructed sequence of double alternations (AABB), so that no explicit task cues were required. The results show that switching between two modality incompatible tasks increases both switch costs and congruence effects compared to switching between two modality compatible tasks. The finding of increased congruence effects in modality incompatible tasks supports our explanation in terms of ideomotor "backward" linkages between anticipated response effects and the stimuli that called for this response in the first place. According to this generalized ideomotor idea, the modality match between response effects and stimuli would prime selection of a response in the compatible modality. This priming would cause increased difficulties to ignore the competing stimulus and hence increases the congruence effect. Moreover, performance would be hindered when switching between modality incompatible tasks and facilitated when switching between modality compatible tasks.

Dissociating Stimulus-Set and Response-Set in the Context of Task-Set Switching

PubMed Central

Kieffaber, Paul D.; Kruschke, John K.; Cho, Raymond Y.; Walker, Philip M.; Hetrick, William P.

2014-01-01

The primary aim of the present research was to determine how stimulus-set and response-set components of task-set contribute to switch costs and conflict processing. Three experiments are described wherein participants completed an explicitly cued task-switching procedure. Experiment 1 established that task switches requiring a reconfiguration of both stimulus- and response-set incurred larger residual switch costs than task switches requiring the reconfiguration of stimulus-set alone. Between-task interference was also drastically reduced for response-set conflict compared with stimulus-set conflict. A second experiment replicated these findings and demonstrated that stimulus- and response-conflict have dissociable effects on the “decision time” and “motor time” components of total response time. Finally, a third experiment replicated Experiment 2 and demonstrated that the stimulus- and response- components of task switching and conflict processing elicit dissociable neural activity as evidence by event-related brain potentials. PMID:22984990

Eye tracking reveals the cost of switching between self and other perspectives in a visual perspective-taking task.

PubMed

Ferguson, Heather J; Apperly, Ian; Cane, James E

2017-08-01

Previous studies have shown that while people can rapidly and accurately compute their own and other people's visual perspectives, they experience difficulty ignoring the irrelevant perspective when the two perspectives differ. We used the "avatar" perspective-taking task to examine the mechanisms that underlie these egocentric (i.e., interference from their own perspective) and altercentric (i.e., interference from the other person's perspective) tendencies. Participants were eye-tracked as they verified the number of discs in a visual scene according to either their own or an on-screen avatar's perspective. Crucially in some trials the two perspectives were inconsistent (i.e., each saw a different number of discs), while in others they were consistent. To examine the effect of perspective switching, performance was compared for trials that were preceded with the same versus a different perspective cue. We found that altercentric interference can be reduced or eliminated when participants stick with their own perspective across consecutive trials. Our eye-tracking analyses revealed distinct fixation patterns for self and other perspective taking, suggesting that consistency effects in this paradigm are driven by implicit mentalizing of what others can see, and not automatic directional cues from the avatar.

Working memory updating and binding training: Bayesian evidence supporting the absence of transfer.

PubMed

De Simoni, Carla; von Bastian, Claudia C

2018-06-01

As working memory (WM) predicts a wide range of other abilities, it has become a popular target for training interventions. However, its effectiveness to elicit generalized cognitive benefits is still under debate. Previous research yielded inconsistent findings and focused only little on the mechanisms underlying transfer effects. To disentangle training effects on WM capacity and efficiency, we evaluated near transfer to untrained, structurally different WM tasks and far transfer to closely related abilities (i.e., reasoning, processing speed, task switching, and inhibitory control) in addition to process-specific effects on 3 WM mechanisms (i.e., focus switching, removal of WM contents, and interference resolution). We randomly assigned 197 young adults to 1 of 2 experimental groups (updating or item-to-context binding) or to an active control group practicing visual search tasks. Before and after 5 weeks of adaptive training, performance was assessed measuring each of the cognitive processes and abilities of interest with 4 tasks covering verbal-numerical and visual-spatial materials. Despite the relatively large sample size, large practice effects in the trained tasks, and at least moderate correlations between WM training tasks and transfer measures, we found consistent evidence for the absence of any training-induced improvements across all ranges of transfer and mechanisms. Instead, additional analyses of error patterns and self-reported strategy use indicated that WM training encouraged the development of stimulus-specific expertise and use of paradigm-specific strategies. Thus, the results suggest that the WM training interventions examined here enhanced neither WM capacity nor the WM mechanisms assumed to underlie transfer. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

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

PubMed

Picou, Erin M; Ricketts, Todd A

2014-01-01

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

Dissociating Stimulus-Set and Response-Set in the Context of Task-Set Switching

ERIC Educational Resources Information Center

Kieffaber, Paul D.; Kruschke, John K.; Cho, Raymond Y.; Walker, Philip M.; Hetrick, William P.

2013-01-01

The primary aim of the present research was to determine how "stimulus-set" and "response-set" components of task-set contribute to switch costs and conflict processing. Three experiments are described wherein participants completed an explicitly cued task-switching procedure. Experiment 1 established that task switches requiring a reconfiguration…

The Role of Response Repetition in Task Switching

ERIC Educational Resources Information Center

Cooper, Stephen; Mari-Beffa, Paloma

2008-01-01

When switching between tasks, participants are sometimes required to use different response sets for each task. Thus, task switch and response set switch are confounded. In 5 experiments, the authors examined transitions of response within a linear 4-finger arrangement. A random baseline condition was compared with the cuing of specific response…

The Effect of Hierarchical Task Representations on Task Selection in Voluntary Task Switching

ERIC Educational Resources Information Center

Weaver, Starla M.; Arrington, Catherine M.

2013-01-01

The current study explored the potential for hierarchical representations to influence action selection during voluntary task switching. Participants switched between 4 individual task elements. In Experiment 1, participants were encouraged to represent the task elements as grouped within a hierarchy based on experimental manipulations of varying…

A tweaking principle for executive control: neuronal circuit mechanism for rule-based task switching and conflict resolution.

PubMed

Ardid, Salva; Wang, Xiao-Jing

2013-12-11

A hallmark of executive control is the brain's agility to shift between different tasks depending on the behavioral rule currently in play. In this work, we propose a "tweaking hypothesis" for task switching: a weak rule signal provides a small bias that is dramatically amplified by reverberating attractor dynamics in neural circuits for stimulus categorization and action selection, leading to an all-or-none reconfiguration of sensory-motor mapping. Based on this principle, we developed a biologically realistic model with multiple modules for task switching. We found that the model quantitatively accounts for complex task switching behavior: switch cost, congruency effect, and task-response interaction; as well as monkey's single-neuron activity associated with task switching. The model yields several testable predictions, in particular, that category-selective neurons play a key role in resolving sensory-motor conflict. This work represents a neural circuit model for task switching and sheds insights in the brain mechanism of a fundamental cognitive capability.

Overcoming residual interference in mental set switching: Neural correlates and developmental trajectory

PubMed Central

Witt, Suzanne T.; Stevens, Michael C.

2012-01-01

Mental set switching is a key facet of executive control measured behaviorally through reaction time or accuracy (i.e., ‘switch costs’) when shifting among task types. One of several experimentally-dissociable influences on switch costs is ‘task set inertia’, conceptualized as the residual interference conferred when a previous stimulus-response tendency interferes with subsequent stimulus processing on a new task. Task set inertia is thought to represent the passive decay of the previous stimulus-response set from working memory, and its effects decrease with increased interstimulus interval. Closely spaced trials confer high task set inertia, while sparsely spaced trials confer low task set inertia. This functional magnetic resonance imaging (fMRI) study characterized, for the first time, two opposing brain systems engaged to resolve task set inertia: 1) a frontoparietal ‘cortical control’ network for overcoming high task set inertia interference and 2) a subcortical-motor network more active during trials with low task set inertia. These networks were distinct from brain regions showing general switching effects (i.e., switch > non-switch) and from other previously-characterized interference effects. Moreover, there were ongoing maturational effects throughout adolescence for the brain regions engaged to overcome high task set inertia not seen for generalized switching effects. These novel findings represent a new avenue of exploration of cognitive set switching neural function. PMID:22584223

Coactivation of cognitive control networks during task switching.

PubMed

Yin, Shouhang; Deák, Gedeon; Chen, Antao

2018-01-01

The ability to flexibly switch between tasks is considered an important component of cognitive control that involves frontal and parietal cortical areas. The present study was designed to characterize network dynamics across multiple brain regions during task switching. Functional magnetic resonance images (fMRI) were captured during a standard rule-switching task to identify switching-related brain regions. Multiregional psychophysiological interaction (PPI) analysis was used to examine effective connectivity between these regions. During switching trials, behavioral performance declined and activation of a generic cognitive control network increased. Concurrently, task-related connectivity increased within and between cingulo-opercular and fronto-parietal cognitive control networks. Notably, the left inferior frontal junction (IFJ) was most consistently coactivated with the 2 cognitive control networks. Furthermore, switching-dependent effective connectivity was negatively correlated with behavioral switch costs. The strength of effective connectivity between left IFJ and other regions in the networks predicted individual differences in switch costs. Task switching was supported by coactivated connections within cognitive control networks, with left IFJ potentially acting as a key hub between the fronto-parietal and cingulo-opercular networks. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Bilingual Control: Sequential Memory in Language Switching

ERIC Educational Resources Information Center

Declerck, Mathieu; Philipp, Andrea M.; Koch, Iring

2013-01-01

To investigate bilingual language control, prior language switching studies presented visual objects, which had to be named in different languages, typically indicated by a visual cue. The present study examined language switching of predictable responses by introducing a novel sequence-based language switching paradigm. In 4 experiments,…

Context Specificity of Post-Error and Post-Conflict Cognitive Control Adjustments

PubMed Central

Forster, Sarah E.; Cho, Raymond Y.

2014-01-01

There has been accumulating evidence that cognitive control can be adaptively regulated by monitoring for processing conflict as an index of online control demands. However, it is not yet known whether top-down control mechanisms respond to processing conflict in a manner specific to the operative task context or confer a more generalized benefit. While previous studies have examined the taskset-specificity of conflict adaptation effects, yielding inconsistent results, control-related performance adjustments following errors have been largely overlooked. This gap in the literature underscores recent debate as to whether post-error performance represents a strategic, control-mediated mechanism or a nonstrategic consequence of attentional orienting. In the present study, evidence of generalized control following both high conflict correct trials and errors was explored in a task-switching paradigm. Conflict adaptation effects were not found to generalize across tasksets, despite a shared response set. In contrast, post-error slowing effects were found to extend to the inactive taskset and were predictive of enhanced post-error accuracy. In addition, post-error performance adjustments were found to persist for several trials and across multiple task switches, a finding inconsistent with attentional orienting accounts of post-error slowing. These findings indicate that error-related control adjustments confer a generalized performance benefit and suggest dissociable mechanisms of post-conflict and post-error control. PMID:24603900

Partially Overlapping Mechanisms of Language and Task Control in Young and Older Bilinguals

PubMed Central

Weissberger, Gali H.; Wierenga, Christina E.; Bondi, Mark W.; Gollan, Tamar H.

2012-01-01

The current study tested the hypothesis that bilinguals rely on domain-general mechanisms of executive control to achieve language control by asking if linguistic and nonlinguistic switching tasks exhibit similar patterns of aging-related decline. Thirty young and 30 aging bilinguals completed a cued language-switching task and a cued color-shape switching task. Both tasks demonstrated significant aging effects, but aging-related slowing and the aging-related increase in errors were significantly larger on the color-shape than on the language task. In the language task, aging increased language-switching costs in both response times and errors, and language-mixing costs only in response times. In contrast, the color-shape task exhibited an aging-related increase in costs only in mixing errors. Additionally, a subset of the older bilinguals could not do the color-shape task, but were able to do the language task, and exhibited significantly larger language-switching costs than matched controls. These differences, and some subtle similarities, in aging effects observed across tasks imply that mechanisms of nonlinguistic task and language control are only partly shared and demonstrate relatively preserved language control in aging. More broadly, these data suggest that age deficits in switching and mixing costs may depend on task expertise, with mixing deficits emerging for less-practiced tasks and switching deficits for highly practiced, possibly “expert” tasks (i.e., language). PMID:22582883

Best core stabilization exercise to facilitate subcortical neuroplasticity: A functional MRI neuroimaging study.

PubMed

Kim, Do Hyun; Lee, Jae Jin; You, Sung Joshua Hyun

2018-03-23

To investigate the effects of conscious (ADIM) and subconscious (DNS) core stabilization exercises on cortical changes in adults with core instability. Five non-symptomatic participants with core instability. A novel core stabilization task switching paradigm was designed to separate cortical or subcortical neural substrates during a series of DNS or ADIM core stabilization tasks. fMRI blood BOLD analysis revealed a distinctive subcortical activation pattern during the performance of the DNS, whereas the cortical motor network was primarily activated during an ADIM. Peak voxel volume values showed significantly greater DNS (11.08 ± 1.51) compared with the ADIM (8.81 ± 0.21) (p= 0.043). The ADIM exercise activated the cortical PMC-SMC-SMA motor network, whereas the DNS exercise activated both these same cortical areas and the subcortical cerebellum-BG-thalamus-cingulate cortex network.

Language Switching across Modalities: Evidence from Bimodal Bilinguals

ERIC Educational Resources Information Center

Dias, Patricia; Villameriel, Saúl; Giezen, Marcel R.; Costello, Brendan; Carreiras, Manuel

2017-01-01

This study investigated whether language control during language production in bilinguals generalizes across modalities, and to what extent the language control system is shaped by competition for the same articulators. Using a cued language-switching paradigm, we investigated whether switch costs are observed when hearing signers switch between a…

Electrophysiological Evidence for Domain-General Processes in Task-Switching

PubMed Central

Capizzi, Mariagrazia; Ambrosini, Ettore; Arbula, Sandra; Mazzonetto, Ilaria; Vallesi, Antonino

2016-01-01

The ability to flexibly switch between tasks is a hallmark of cognitive control. Despite previous studies that have investigated whether different task-switching types would be mediated by distinct or overlapping neural mechanisms, no definitive consensus has been reached on this question yet. Here, we aimed at directly addressing this issue by recording the event-related potentials (ERPs) elicited by two types of task-switching occurring in the context of spatial and verbal cognitive domains. Source analysis was also applied to the ERP data in order to track the spatial dynamics of brain activity underlying task-switching abilities. In separate blocks of trials, participants had to perform either spatial or verbal switching tasks both of which employed the same type of stimuli. The ERP analysis, which was carried out through a channel- and time-uninformed mass univariate approach, showed no significant differences between the spatial and verbal domains in the modulation of switch and repeat trials. Specifically, relative to repeat trials, switch trials in both domains were associated with a first larger positivity developing over left parieto-occipital electrodes and with a subsequent larger negativity distributed over mid-left fronto-central sites. The source analysis reconstruction for the two ERP components complemented these findings by highlighting the involvement of left-lateralized prefrontal areas in task-switching. Overall, our results join and extend recent research confirming the existence of left-lateralized domain-general task-switching processes. PMID:27047366

Choice in multitasking: how delays in the primary task turn a rational into an irrational multitasker.

PubMed

Katidioti, Ioanna; Taatgen, Niels A

2014-06-01

The objective was to establish the nature of choice in cognitive multitasking. Laboratory studies of multitasking suggest people are rational in their switch choices regarding multitasking, whereas observational studies suggest they are not. Threaded cognition theory predicts that switching is opportunistic and depends on availability of cognitive resources. A total of 21 participants answered e-mails by looking up information (similar to customer service employees) while being interrupted by chat messages. They were free to choose when to switch to the chat message. We analyzed the switching behavior and the time they needed to complete the primary mail task. When participants are faced with a delay in the e-mail task, they switch more often to the chat task at high-workload points. Choosing to switch to the secondary task instead of waiting makes them slower. It also makes them forget the information in the e-mail task half of the time, which slows them down even more. When many cognitive resources are available, the probability of switching from one task to another is high. This does not necessarily lead to optimal switching behavior. Potential applications of this research include the minimization of delays in task design and the inability or discouragement of switching in high-workload moments.

Driving and Multitasking: The Good, the Bad, and the Dangerous.

PubMed

Nijboer, Menno; Borst, Jelmer P; van Rijn, Hedderik; Taatgen, Niels A

2016-01-01

Previous research has shown that multitasking can have a positive or a negative influence on driving performance. The aim of this study was to determine how the interaction between driving circumstances and cognitive requirements of secondary tasks affect a driver's ability to control a car. We created a driving simulator paradigm where participants had to perform one of two scenarios: one with no traffic in the driver's lane, and one with substantial traffic in both lanes, some of which had to be overtaken. Four different secondary task conditions were combined with these driving scenarios. In both driving scenarios, using a tablet resulted in the worst, most dangerous, performance, while passively listening to the radio or answering questions for a radio quiz led to the best driving performance. Interestingly, driving as a single task did not produce better performance than driving in combination with one of the radio tasks, and even tended to be slightly worse. These results suggest that drivers switch to internally focused secondary tasks when nothing else is available during monotonous or repetitive driving environments. This mind wandering potentially has a stronger interference effect with driving than non-visual secondary tasks.

Driving and Multitasking: The Good, the Bad, and the Dangerous

PubMed Central

Nijboer, Menno; Borst, Jelmer P.; van Rijn, Hedderik; Taatgen, Niels A.

2016-01-01

Previous research has shown that multitasking can have a positive or a negative influence on driving performance. The aim of this study was to determine how the interaction between driving circumstances and cognitive requirements of secondary tasks affect a driver's ability to control a car. We created a driving simulator paradigm where participants had to perform one of two scenarios: one with no traffic in the driver's lane, and one with substantial traffic in both lanes, some of which had to be overtaken. Four different secondary task conditions were combined with these driving scenarios. In both driving scenarios, using a tablet resulted in the worst, most dangerous, performance, while passively listening to the radio or answering questions for a radio quiz led to the best driving performance. Interestingly, driving as a single task did not produce better performance than driving in combination with one of the radio tasks, and even tended to be slightly worse. These results suggest that drivers switch to internally focused secondary tasks when nothing else is available during monotonous or repetitive driving environments. This mind wandering potentially has a stronger interference effect with driving than non-visual secondary tasks. PMID:27877147

Can You Multitask? Evidence and Limitations of Task Switching and Multitasking in Emergency Medicine.

PubMed

Skaugset, L Melissa; Farrell, Susan; Carney, Michele; Wolff, Margaret; Santen, Sally A; Perry, Marcia; Cico, Stephen John

2016-08-01

Emergency physicians work in a fast-paced environment that is characterized by frequent interruptions and the expectation that they will perform multiple tasks efficiently and without error while maintaining oversight of the entire emergency department. However, there is a lack of definition and understanding of the behaviors that constitute effective task switching and multitasking, as well as how to improve these skills. This article reviews the literature on task switching and multitasking in a variety of disciplines-including cognitive science, human factors engineering, business, and medicine-to define and describe the successful performance of task switching and multitasking in emergency medicine. Multitasking, defined as the performance of two tasks simultaneously, is not possible except when behaviors become completely automatic; instead, physicians rapidly switch between small tasks. This task switching causes disruption in the primary task and may contribute to error. A framework is described to enhance the understanding and practice of these behaviors. Copyright © 2015 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Adult age differences in task switching.

PubMed

Kray, J; Lindenberger, U

2000-03-01

Age differences in 2 components of task-set switching speed were investigated in 118 adults aged 20 to 80 years using task-set homogeneous (e.g., AAAA ...) and task-set heterogeneous (e.g., AABBAABB ... ) blocks. General switch costs were defined as latency differences between heterogeneous and homogeneous blocks. whereas specific switch costs were defined as differences between switch and nonswitch trials within heterogeneous blocks. Both types of costs generalized over verbal, figural, and numeric stimulus materials; were more highly correlated to fluid than to crystallized abilities; and were not eliminated after 6 sessions of practice, indicating that they reflect basic and domain-general aspects of cognitive control. Most important, age-associated increments in costs were significantly greater for general than for specific switch costs, suggesting that the ability to efficiently maintain and coordinate 2 alternating task sets in working memory instead of 1 is more negatively affected by advancing age than the ability to execute the task switch itself.

How to Correct a Task Error: Task-Switch Effects Following Different Types of Error Correction

ERIC Educational Resources Information Center

Steinhauser, Marco

2010-01-01

It has been proposed that switch costs in task switching reflect the strengthening of task-related associations and that strengthening is triggered by response execution. The present study tested the hypothesis that only task-related responses are able to trigger strengthening. Effects of task strengthening caused by error corrections were…

Emotional task management: neural correlates of switching between affective and non-affective task-sets

PubMed Central

Reeck, Crystal

2015-01-01

Although task-switching has been investigated extensively, its interaction with emotionally salient task content remains unclear. Prioritized processing of affective stimulus content may enhance accessibility of affective task-sets and generate increased interference when switching between affective and non-affective task-sets. Previous research has demonstrated that more dominant task-sets experience greater switch costs, as they necessitate active inhibition during performance of less entrenched tasks. Extending this logic to the affective domain, the present experiment examined (a) whether affective task-sets are more dominant than non-affective ones, and (b) what neural mechanisms regulate affective task-sets, so that weaker, non-affective task-sets can be executed. While undergoing functional magnetic resonance imaging, participants categorized face stimuli according to either their gender (non-affective task) or their emotional expression (affective task). Behavioral results were consistent with the affective task dominance hypothesis: participants were slower to switch to the affective task, and cross-task interference was strongest when participants tried to switch from the affective to the non-affective task. These behavioral costs of controlling the affective task-set were mirrored in the activation of a right-lateralized frontostriatal network previously implicated in task-set updating and response inhibition. Connectivity between amygdala and right ventrolateral prefrontal cortex was especially pronounced during cross-task interference from affective features. PMID:25552571

Intentional preparation of auditory attention-switches: Explicit cueing and sequential switch-predictability.

PubMed

Seibold, Julia C; Nolden, Sophie; Oberem, Josefa; Fels, Janina; Koch, Iring

2018-06-01

In an auditory attention-switching paradigm, participants heard two simultaneously spoken number-words, each presented to one ear, and decided whether the target number was smaller or larger than 5 by pressing a left or right key. An instructional cue in each trial indicated which feature had to be used to identify the target number (e.g., female voice). Auditory attention-switch costs were found when this feature changed compared to when it repeated in two consecutive trials. Earlier studies employing this paradigm showed mixed results when they examined whether such cued auditory attention-switches can be prepared actively during the cue-stimulus interval. This study systematically assessed which preconditions are necessary for the advance preparation of auditory attention-switches. Three experiments were conducted that controlled for cue-repetition benefits, modality switches between cue and stimuli, as well as for predictability of the switch-sequence. Only in the third experiment, in which predictability for an attention-switch was maximal due to a pre-instructed switch-sequence and predictable stimulus onsets, active switch-specific preparation was found. These results suggest that the cognitive system can prepare auditory attention-switches, and this preparation seems to be triggered primarily by the memorised switching-sequence and valid expectations about the time of target onset.

Self-Regulatory Capacities Are Depleted in a Domain-Specific Manner

PubMed Central

Zhang, Rui; Stock, Ann-Kathrin; Rzepus, Anneka; Beste, Christian

2017-01-01

Performing an act of self-regulation such as making decisions has been suggested to deplete a common limited resource, which impairs all subsequent self-regulatory actions (ego depletion theory). It has however remained unclear whether self-referred decisions truly impair behavioral control even in seemingly unrelated cognitive domains, and which neurophysiological mechanisms are affected by these potential depletion effects. In the current study, we therefore used an inter-individual design to compare two kinds of depletion, namely a self-referred choice-based depletion and a categorization-based switching depletion, to a non-depleted control group. We used a backward inhibition (BI) paradigm to assess the effects of depletion on task switching and associated inhibition processes. It was combined with EEG and source localization techniques to assess both behavioral and neurophysiological depletion effects. The results challenge the ego depletion theory in its current form: Opposing the theory’s prediction of a general limited resource, which should have yielded comparable effects in both depletion groups, or maybe even a larger depletion in the self-referred choice group, there were stronger performance impairments following a task domain-specific depletion (i.e., the switching-based depletion) than following a depletion based on self-referred choices. This suggests at least partly separate and independent resources for various cognitive control processes rather than just one joint resource for all self-regulation activities. The implications are crucial to consider for people making frequent far-reaching decisions e.g., in law or economy. PMID:29033798

Self-Regulatory Capacities Are Depleted in a Domain-Specific Manner.

PubMed

Zhang, Rui; Stock, Ann-Kathrin; Rzepus, Anneka; Beste, Christian

2017-01-01

Performing an act of self-regulation such as making decisions has been suggested to deplete a common limited resource, which impairs all subsequent self-regulatory actions (ego depletion theory). It has however remained unclear whether self-referred decisions truly impair behavioral control even in seemingly unrelated cognitive domains, and which neurophysiological mechanisms are affected by these potential depletion effects. In the current study, we therefore used an inter-individual design to compare two kinds of depletion, namely a self-referred choice-based depletion and a categorization-based switching depletion, to a non-depleted control group. We used a backward inhibition (BI) paradigm to assess the effects of depletion on task switching and associated inhibition processes. It was combined with EEG and source localization techniques to assess both behavioral and neurophysiological depletion effects. The results challenge the ego depletion theory in its current form: Opposing the theory's prediction of a general limited resource, which should have yielded comparable effects in both depletion groups, or maybe even a larger depletion in the self-referred choice group, there were stronger performance impairments following a task domain-specific depletion (i.e., the switching-based depletion) than following a depletion based on self-referred choices. This suggests at least partly separate and independent resources for various cognitive control processes rather than just one joint resource for all self-regulation activities. The implications are crucial to consider for people making frequent far-reaching decisions e.g., in law or economy.

Did the popsicle melt? Preschoolers' performance in an episodic-like memory task.

PubMed

Martin-Ordas, Gema; Atance, Cristina M; Caza, Julian

2017-10-01

Episodic memory has been tested in non-human animals using depletion paradigms that assess recollection for the "what", "where" and "when" (i.e., how long ago). This paradigm has not been used with human children, yet doing so would provide another means to explore their episodic memory development. Using a depletion paradigm, preschool-aged children were presented in two trials with a preferred food that was only edible after a short interval and a less-preferred food that was edible after the short and long intervals. Younger (mean = 40 months) and older (mean = 65 months) children tended to choose their preferred food after the short intervals, but did not switch to selecting their less-preferred food after the long intervals. Importantly, their choices did not differ with age. Although older children better remembered "what", "where", and "what is where" than did younger children, neither age group successfully estimated "how long ago" an event occurred. Finally, both age groups spontaneously recalled information about Trial 1. We also analysed the relation between the different measures used in the study but no clear patterns emerged. Results are discussed with respect to the cognitive mechanisms necessary to succeed in depletion paradigms and the measurement of episodic memory more broadly.

Task switching costs in preschool children and adults.

PubMed

Peng, Anna; Kirkham, Natasha Z; Mareschal, Denis

2018-08-01

Past research investigating cognitive flexibility has shown that preschool children make many perseverative errors in tasks that require switching between different sets of rules. However, this inflexibility might not necessarily hold with easier tasks. The current study investigated the developmental differences in cognitive flexibility using a task-switching procedure that compared reaction times and accuracy in 4- and 6-year-olds with those in adults. The experiment involved simple target detection tasks and was intentionally designed in a way that the stimulus and response conflicts were minimal together with a long preparation window. Global mixing costs (performance costs when multiple tasks are relevant in a context), and local switch costs (performance costs due to switching to an alternative task) are typically thought to engage endogenous control processes. If this is the case, we should observe developmental differences with both of these costs. Our results show, however, that when the accuracy was good, there were no age differences in cognitive flexibility (i.e., the ability to manage multiple tasks and to switch between tasks) between children and adults. Even though preschool children had slower reaction times and were less accurate, the mixing and switch costs associated with task switching were not reliably larger for preschool children. Preschool children did, however, show more commission errors and greater response repetition effects than adults, which may reflect differences in inhibitory control. Copyright © 2018 Elsevier Inc. All rights reserved.

Alterations in neural systems mediating cognitive flexibility and inhibition in mood disorders.

PubMed

Piguet, Camille; Cojan, Yann; Sterpenich, Virginie; Desseilles, Martin; Bertschy, Gilles; Vuilleumier, Patrik

2016-04-01

Impairment in mental flexibility may be a key component contributing to cardinal cognitive symptoms among mood disorders patients, particularly thought control disorders. Impaired ability to switch from one thought to another might reflect difficulties in either generating new mental states, inhibiting previous states, or both. However, the neural underpinnings of impaired cognitive flexibility in mood disorders remain largely unresolved. We compared a group of mood disorders patients (n = 29) and a group of matched healthy subjects (n = 32) on a novel task-switching paradigm involving happy and sad faces, that allowed us to separate generation of a new mental set (Switch Cost) and inhibition of the previous set during switching (Inhibition Cost), using fMRI. Behavioral data showed a larger Switch Cost in patients relative to controls, but the average Inhibition Cost did not differ between groups. At the neural level, a main effect of group was found with stronger activation of the subgenual cingulate cortex in patients. The larger Switch Cost in patients was reflected by a stronger recruitment of brain regions involved in attention and executive control, including the left intraparietal sulcus, precuneus, left inferior fontal gyrus, and right anterior cingulate. Critically, activity in the subgenual cingulate cortex was not downregulated by inhibition in patients relative to controls. In conclusion, mood disorder patients have exaggerated Switch Cost relative to controls, and this deficit in cognitive flexibility is associated with increased activation of the fronto-parietal attention networks, combined with impaired modulation of the subgenual cingulate cortex when inhibition of previous mental states is needed. © 2016 Wiley Periodicals, Inc.

Stimulus-Category and Response-Repetition Effects in Task Switching: An Evaluation of Four Explanations

ERIC Educational Resources Information Center

Druey, Michel D.

2014-01-01

In many task-switch studies, task sequence and response sequence interact: Response repetitions produce benefits when the task repeats but produce costs when the task switches. Four different theoretical frameworks have been proposed to explain these effects: a reconfiguration-based account, association-learning models, an episodic-retrieval…

Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm.

PubMed

Gagné, Jean-Pierre; Besser, Jana; Lemke, Ulrike

2017-01-01

Published investigations ( n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants' age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified.

Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm

PubMed Central

Besser, Jana; Lemke, Ulrike

2017-01-01

Published investigations (n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants’ age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified. PMID:28091178

The preparation effect in task switching: carryover of SOA.

PubMed

Altmann, Erik M

2004-01-01

A common finding in task-switching studies is switch preparation (commonly known as the preparation effect), in which a longer interval between task cue and trial stimulus (i.e., a longer stimulus onset asynchrony, or SOA) reduces the cost of switching to a different task. Three experiments link switch preparation to within-subjects manipulations of SOA. In Experiment 1, SOA was randomized within subjects, producing switch preparation that was more pronounced when the SOA switched from the previous trial than when the SOA repeated. In Experiment 2, SOA was blocked within subjects, producing switch preparation but not on the first block of trials. In Experiment 3, SOA was manipulated between subjects with sufficient statistical power to detect switch preparation, but the effect was absent. The results favor an encoding view of cognitive control, but show that any putative switching mechanism reacts lazily when exposed to only one SOA.

Component processes in voluntary task switching.

PubMed

Demanet, Jelle; Liefooghe, Baptist

2014-05-01

The present study investigated the involvement of bottom-up and top-down control in task-switching situations in which tasks are selected on a voluntary basis. We tested for indices of both types of control in the reduction in switch cost that is observed when more time is available before executing a task. Participants had to indicate their task choice overtly prior to the actual task execution, and two time intervals were manipulated: the interval between the task-execution response of the previous trial and task-indication response of the current trial and the interval between task-indication response and task-execution response of a particular trial. In Experiment 1, the length of these intervals was manipulated orthogonally, and indices for top-down and bottom-up control were observed. Concerned with the validity of these results, Experiments 2-3 additionally discouraged participants from preparing the upcoming task before their task-indication response. Indices for bottom-up control remained, but not for top-down control. The characteristics of top-down and bottom-up control in voluntary task switching and task switching in general are discussed.

Task Switching Effects in Anticipation Timing

ERIC Educational Resources Information Center

Fairbrother, Jeffrey T.; Brueckner, Sebastian

2008-01-01

To understand how task switching affects human performance, there is a need to investigate how it influences the performance of tasks other than those involving bivalent stimulus categorization. The purpose of this study, therefore, was to investigate the effects of task switching on anticipation timing performance, which typically requires…

Modality and Task Switching Interactions using Bi-Modal and Bivalent Stimuli

ERIC Educational Resources Information Center

Sandhu, Rajwant; Dyson, Benjamin J.

2013-01-01

Investigations of concurrent task and modality switching effects have to date been studied under conditions of uni-modal stimulus presentation. As such, it is difficult to directly compare resultant task and modality switching effects, as the stimuli afford both tasks on each trial, but only one modality. The current study investigated task and…

Emotional task management: neural correlates of switching between affective and non-affective task-sets.

PubMed

Reeck, Crystal; Egner, Tobias

2015-08-01

Although task-switching has been investigated extensively, its interaction with emotionally salient task content remains unclear. Prioritized processing of affective stimulus content may enhance accessibility of affective task-sets and generate increased interference when switching between affective and non-affective task-sets. Previous research has demonstrated that more dominant task-sets experience greater switch costs, as they necessitate active inhibition during performance of less entrenched tasks. Extending this logic to the affective domain, the present experiment examined (a) whether affective task-sets are more dominant than non-affective ones, and (b) what neural mechanisms regulate affective task-sets, so that weaker, non-affective task-sets can be executed. While undergoing functional magnetic resonance imaging, participants categorized face stimuli according to either their gender (non-affective task) or their emotional expression (affective task). Behavioral results were consistent with the affective task dominance hypothesis: participants were slower to switch to the affective task, and cross-task interference was strongest when participants tried to switch from the affective to the non-affective task. These behavioral costs of controlling the affective task-set were mirrored in the activation of a right-lateralized frontostriatal network previously implicated in task-set updating and response inhibition. Connectivity between amygdala and right ventrolateral prefrontal cortex was especially pronounced during cross-task interference from affective features. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

The Failure of Progressive Paradigm Reversal

ERIC Educational Resources Information Center

Guthrie, Gerard

2017-01-01

The student-centred, progressive paradigm has not had sustained success in changing teacher-centred, formalistic practices in "developing" country classrooms. Does "Gestalt-switch" and paradigm reversal demonstrate that progressive theory has realigned with formalistic reality, or has it remained axiomatic in the research and…

Throwing out the rules: anticipatory alpha-band oscillatory attention mechanisms during task-set reconfigurations.

PubMed

Foxe, John J; Murphy, Jeremy W; De Sanctis, Pierfilippo

2014-06-01

We assessed the role of alpha-band oscillatory activity during a task-switching design that required participants to switch between an auditory and a visual task, while task-relevant audiovisual inputs were simultaneously presented. Instructional cues informed participants which task to perform on a given trial and we assessed alpha-band power in the short 1.35-s period intervening between the cue and the task-imperative stimuli, on the premise that attentional biasing mechanisms would be deployed to resolve competition between the auditory and visual inputs. Prior work had shown that alpha-band activity was differentially deployed depending on the modality of the cued task. Here, we asked whether this activity would, in turn, be differentially deployed depending on whether participants had just made a switch of task or were being asked to simply repeat the task. It is well established that performance speed and accuracy are poorer on switch than on repeat trials. Here, however, the use of instructional cues completely mitigated these classic switch-costs. Measures of alpha-band synchronisation and desynchronisation showed that there was indeed greater and earlier differential deployment of alpha-band activity on switch vs. repeat trials. Contrary to our hypothesis, this differential effect was entirely due to changes in the amount of desynchronisation observed during switch and repeat trials of the visual task, with more desynchronisation over both posterior and frontal scalp regions during switch-visual trials. These data imply that particularly vigorous, and essentially fully effective, anticipatory biasing mechanisms resolved the competition between competing auditory and visual inputs when a rapid switch of task was required. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Task switching in video game players: Benefits of selective attention but not resistance to proactive interference.

PubMed

Karle, James W; Watter, Scott; Shedden, Judith M

2010-05-01

Research into the perceptual and cognitive effects of playing video games is an area of increasing interest for many investigators. Over the past decade, expert video game players (VGPs) have been shown to display superior performance compared to non-video game players (nVGPs) on a range of visuospatial and attentional tasks. A benefit of video game expertise has recently been shown for task switching, suggesting that VGPs also have superior cognitive control abilities compared to nVGPs. In two experiments, we examined which aspects of task switching performance this VGP benefit may be localized to. With minimal trial-to-trial interference from minimally overlapping task set rules, VGPs demonstrated a task switching benefit compared to nVGPs. However, this benefit disappeared when proactive interference between tasks was increased, with substantial stimulus and response overlap in task set rules. We suggest that VGPs have no generalized benefit in task switching-related cognitive control processes compared to nVGPs, with switch cost reductions due instead to a specific benefit in controlling selective attention. Copyright 2009 Elsevier B.V. All rights reserved.

Cueing cognitive flexibility: Item-specific learning of switch readiness.

PubMed

Chiu, Yu-Chin; Egner, Tobias

2017-12-01

The rich behavioral repertoire of the human species derives from our ability to flexibly reconfigure processing strategies (task sets) in response to changing requirements. This updating of task sets is effortful, as reflected by longer response times when switching a task than repeating it (switch costs). However, some recent data suggest that switch costs can be reduced by cueing switch readiness bottom-up, by associating particular stimuli with frequent switch requirements. This type of "stimulus-control (S-C) learning" would be highly adaptive, as it combines the speed of automatic (bottom-up) processing with the flexibility and generalizability of controlled (top-down) processing. However, it is unclear whether S-C learning of switch readiness is truly possible, and what the underlying mechanisms are. Here we address these questions by pairing specific stimuli with a need to update task-sets either frequently or rarely. In all 3 experiments, we observe robust item-specific switch probability (ISSP) effects as revealed by smaller switch costs for frequent switch items than for rare switch items. By including a neutral condition, we also show that the ISSP effect is primarily driven by S-C learning reducing switch costs in frequent switch items. Furthermore, by employing 3 tasks in Experiment 3, we establish that the ISSP effect reflects an enhancement of general switch readiness, rather than of the readiness to switch to a specific alternate task. These results firmly establish that switch readiness is malleable by item-specific S-C learning processes, documenting that a generalizable state of cognitive flexibility can be primed by a bottom-up stimulus. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Thought suppression predicts task switching deficits in patients with frontal lobe epilepsy.

PubMed

Gul, Amara; Ahmad, Hira

2015-04-01

To examine the relationship between task switching and thought suppression in connection with frontal lobe epilepsy (FLE). This experimental study included 30 patients with FLE admitted to the Services and Jinnah Hospital, Lahore, Pakistan between February and November 2013, and 30 healthy individuals from the local community. Participants performed a task switching experiment where they switched between emotion and age categorizations among faces. In addition, they completed a thought suppression questionnaire. There were 3 important results: (i) Patients with FLE showed weaker task switching abilities than healthy individuals. This result is attributed toward executive dysfunctions in patients with FLE. (ii) Contrary to the control group, patients with FLE showed larger switch cost for the age than the emotion categorization. This result can be seen in the context of social cognition deficits and poor inhibitory control in patients with FLE. In addition, larger switch costs reflected a binding effect with facial emotion as compared to age. The integration might represent emotion as an intrusive facial dimension that interrupted task switching performance. (iii) Patients with FLE had more recurrent suppression of thoughts than controls. Thought suppression was a significant predictor for switch costs. High scores on thought suppression were correlated with task switching deficits. The results suggest that thought suppression causes significant cognitive decline.

What’s Easier: Doing What You Want, or Being Told What to Do? Cued versus Voluntary Language and Task Switching

PubMed Central

Gollan, Tamar H.; Kleinman, Daniel; Wierenga, Christina E.

2014-01-01

The current study contrasted cued versus voluntary switching to investigate switching efficiency and possible sharing of control mechanisms across linguistic and non-linguistic domains. Bilinguals switched between naming pictures in Spanish versus English or between reading numbers aloud versus adding their digits, either without or with repetition of stimuli, and with fewer requirements as to when and how much they had to switch relative to previous instantiations of voluntary switching. Without repetition (Experiment 1), voluntary responses were faster than cued responses on both stay and switch trials (especially in the non-linguistic switching task), whereas in previous studies the voluntary advantage was restricted to switch-cost reduction. Similarly, when targets were presented repeatedly (Experiment 2), voluntary responses were faster overall for both linguistic and non-linguistic switching, though here the advantage tended to be larger on switch trials. Experiment 3 confirmed the overall voluntary speed advantage for the read-add task in monolinguals, and revealed a reduction in switch costs only for a different non-linguistic task (size-parity judgments). These results reveal greater overall advantages for voluntary over cued switching than previously reported, but also that the precise manifestation of the voluntary advantage can vary with different tasks. In the linguistic domain, lexical inaccessibility introduces some unique control mechanisms, and repetition may magnify cross-domain overlap in control mechanisms. Finally, under some limited conditions, cost-free switches were found in both linguistic and non-linguistic domains; however, suspension of top-down control may be restricted to language or highly automatic tasks. PMID:25313951

Shifting Attention Between Visual Dimensions as a Source of Switch Costs.

PubMed

Elchlepp, Heike; Best, Maisy; Lavric, Aureliu; Monsell, Stephen

2017-04-01

Task-switching experiments have documented a puzzling phenomenon: Advance warning of the switch reduces but does not eliminate the switch cost. Theoretical accounts have posited that the residual switch cost arises when one selects the relevant stimulus-response mapping, leaving earlier perceptual processes unaffected. We put this assumption to the test by seeking electrophysiological markers of encoding a perceptual dimension. Participants categorized a colored letter as a vowel or consonant or its color as "warm" or "cold." Orthogonally to the color manipulation, some colors were eight times more frequent than others, and the letters were in upper- or lowercase. Color frequency modulated the electroencephalogram amplitude at around 150 ms when participants repeated the color-classification task. When participants switched from the letter task to the color task, this effect was significantly delayed. Thus, even when prepared for, a task switch delays or prolongs encoding of the relevant perceptual dimension.

Resolving task rule incongruence during task switching by competitor rule suppression.

PubMed

Meiran, Nachshon; Hsieh, Shulan; Dimov, Eduard

2010-07-01

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

Meta-cognitive processes in executive control development: The case of reactive and proactive control

PubMed Central

Chevalier, Nicolas; Martis, Shaina Bailey; Curran, Tim; Munakata, Yuko

2015-01-01

Young children engage cognitive control reactively in response to events, rather than proactively preparing for events. Such limitations in executive control have been explained in terms of fundamental constraints on children’s cognitive capacities. Alternatively, young children might be capable of proactive control but differ from older children in their meta-cognitive decisions regarding when to engage proactive control. We examined these possibilities in three conditions of a task-switching paradigm, varying in whether task cues were available before or after target onset. Reaction times, ERPs, and pupil dilation showed that 5-year-olds did engage in advance preparation, a critical aspect of proactive control, but only when reactive control was made more difficult, whereas 10-year-olds engaged proactive control whenever possible. These findings highlight meta-cognitive processes in children’s cognitive control, an understudied aspect of executive control development. PMID:25603026

Incorrect predictions reduce switch costs.

PubMed

Kleinsorge, Thomas; Scheil, Juliane

2015-07-01

In three experiments, we combined two sources of conflict within a modified task-switching procedure. The first source of conflict was the one inherent in any task switching situation, namely the conflict between a task set activated by the recent performance of another task and the task set needed to perform the actually relevant task. The second source of conflict was induced by requiring participants to guess aspects of the upcoming task (Exps. 1 & 2: task identity; Exp. 3: position of task precue). In case of an incorrect guess, a conflict accrues between the representation of the guessed task and the actually relevant task. In Experiments 1 and 2, incorrect guesses led to an overall increase of reaction times and error rates, but they reduced task switch costs compared to conditions in which participants predicted the correct task. In Experiment 3, incorrect guesses resulted in faster performance overall and to a selective decrease of reaction times in task switch trials when the cue-target interval was long. We interpret these findings in terms of an enhanced level of controlled processing induced by a combination of two sources of conflict converging upon the same target of cognitive control. Copyright © 2015 Elsevier B.V. All rights reserved.

Out with the Old and in with the New—Is Backward Inhibition a Domain-Specific Process?

PubMed Central

Menghini, Deny; Vicari, Stefano; Petrosini, Laura; Ferlazzo, Fabio

2015-01-01

Effective task switching is supported by the inhibition of the just executed task, so that potential interference from previously executed tasks is adaptively counteracted. This inhibitory mechanism, named Backward Inhibition (BI), has been inferred from the finding that switching back to a recently executed task (A-B-A task sequence) is harder than switching back to a less recently executed task (C-B-A task sequence). Despite the fact that BI effects do impact performance on everyday life activities, up to now it is still not clear whether the BI represents an amodal and material-independent process or whether it interacts with the task material. To address this issue, a group of individuals with Williams syndrome (WS) characterized by specific difficulties in maintaining and processing visuo-spatial, but not verbal, information, and a mental age- and gender-matched group of typically developing (TD) children were subjected to three task-switching experiments requiring verbal or visuo-spatial material to be processed. Results showed that individuals with WS exhibited a normal BI effect during verbal task-switching, but a clear deficit during visuo-spatial task-switching. Overall, our findings demonstrating that the BI is a material-specific process have important implications for theoretical models of cognitive control and its architecture. PMID:26565628

Contextual control over task-set retrieval.

PubMed

Crump, Matthew J C; Logan, Gordon D

2010-11-01

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.

Free Language Selection in the Bilingual Brain: An Event-Related fMRI Study

PubMed Central

Zhang, Yong; Wang, Tao; Huang, Peiyu; Li, Dan; Qiu, Jiang; Shen, Tong; Xie, Peng

2015-01-01

Bilingual speakers may select between two languages either on demand (forced language selection) or on their own volition (free language selection). However, the neural substrates underlying free and forced language selection may differ. While the neural substrates underlying forced language selection have been well-explored with language switching paradigms, those underlying free language selection have remained unclear. Using a modified digit-naming switching paradigm, we addressed the neural substrates underlying free language selection by contrasting free language switching with forced language switching. For a digit-pair trial, Chinese-English bilinguals named each digit in Chinese or English either on demand under forced language selection condition or on their own volition under free language selection condition. The results revealed activation in the frontoparietal regions that mediate volition of language selection. Furthermore, a comparison of free and forced language switching demonstrated differences in the patterns of brain activation. Additionally, free language switching showed reduced switching costs as compared to forced language switching. These findings suggest differences between the mechanism(s) underlying free and forced language switching. As such, the current study suggests interactivity between control of volition and control of language switching in free language selection, providing insights into a model of bilingual language control. PMID:26177885

Neurocognitive systems related to real-world prospective memory.

PubMed

Kalpouzos, Grégoria; Eriksson, Johan; Sjölie, Daniel; Molin, Jonas; Nyberg, Lars

2010-10-08

Prospective memory (PM) denotes the ability to remember to perform actions in the future. It has been argued that standard laboratory paradigms fail to capture core aspects of PM. We combined functional MRI, virtual reality, eye-tracking and verbal reports to explore the dynamic allocation of neurocognitive processes during a naturalistic PM task where individuals performed errands in a realistic model of their residential town. Based on eye movement data and verbal reports, we modeled PM as an iterative loop of five sustained and transient phases: intention maintenance before target detection (TD), TD, intention maintenance after TD, action, and switching, the latter representing the activation of a new intention in mind. The fMRI analyses revealed continuous engagement of a top-down fronto-parietal network throughout the entire task, likely subserving goal maintenance in mind. In addition, a shift was observed from a perceptual (occipital) system while searching for places to go, to a mnemonic (temporo-parietal, fronto-hippocampal) system for remembering what actions to perform after TD. Updating of the top-down fronto-parietal network occurred at both TD and switching, the latter likely also being characterized by frontopolar activity. Taken together, these findings show how brain systems complementary interact during real-world PM, and support a more complete model of PM that can be applied to naturalistic PM tasks and that we named PROspective MEmory DYnamic (PROMEDY) model because of its dynamics on both multi-phase iteration and the interactions of distinct neurocognitive networks.

The Role of Working Memory Capacity and Interference Resolution Mechanisms in Task Switching

PubMed Central

Pettigrew, Corinne; Martin, Randi C.

2015-01-01

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response-distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response-distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching. PMID:26594895

The role of working memory capacity and interference resolution mechanisms in task switching.

PubMed

Pettigrew, Corinne; Martin, Randi C

2016-12-01

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response-distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. A total of 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response-distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores, which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching.

Cognitive assessment of mice strains heterozygous for cell-adhesion genes reveals strain-specific alterations in timing.

PubMed

Gallistel, C R; Tucci, Valter; Nolan, Patrick M; Schachner, Melitta; Jakovcevski, Igor; Kheifets, Aaron; Barboza, Luendro

2014-03-05

We used a fully automated system for the behavioural measurement of physiologically meaningful properties of basic mechanisms of cognition to test two strains of heterozygous mutant mice, Bfc (batface) and L1, and their wild-type littermate controls. Both of the target genes are involved in the establishment and maintenance of synapses. We find that the Bfc heterozygotes show reduced precision in their representation of interval duration, whereas the L1 heterozygotes show increased precision. These effects are functionally specific, because many other measures made on the same mice are unaffected, namely: the accuracy of matching temporal investment ratios to income ratios in a matching protocol, the rate of instrumental and classical conditioning, the latency to initiate a cued instrumental response, the trials on task and the impulsivity in a switch paradigm, the accuracy with which mice adjust timed switches to changes in the temporal constraints, the days to acquisition, and mean onset time and onset variability in the circadian anticipation of food availability.

Cognitive assessment of mice strains heterozygous for cell-adhesion genes reveals strain-specific alterations in timing

PubMed Central

Gallistel, C. R.; Tucci, Valter; Nolan, Patrick M.; Schachner, Melitta; Jakovcevski, Igor; Kheifets, Aaron; Barboza, Luendro

2014-01-01

We used a fully automated system for the behavioural measurement of physiologically meaningful properties of basic mechanisms of cognition to test two strains of heterozygous mutant mice, Bfc (batface) and L1, and their wild-type littermate controls. Both of the target genes are involved in the establishment and maintenance of synapses. We find that the Bfc heterozygotes show reduced precision in their representation of interval duration, whereas the L1 heterozygotes show increased precision. These effects are functionally specific, because many other measures made on the same mice are unaffected, namely: the accuracy of matching temporal investment ratios to income ratios in a matching protocol, the rate of instrumental and classical conditioning, the latency to initiate a cued instrumental response, the trials on task and the impulsivity in a switch paradigm, the accuracy with which mice adjust timed switches to changes in the temporal constraints, the days to acquisition, and mean onset time and onset variability in the circadian anticipation of food availability. PMID:24446498

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

PubMed Central

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

2015-01-01

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

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

PubMed

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

2008-06-01

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

When global rule reversal meets local task switching: The neural mechanisms of coordinated behavioral adaptation to instructed multi-level demand changes.

PubMed

Shi, Yiquan; Wolfensteller, Uta; Schubert, Torsten; Ruge, Hannes

2018-02-01

Cognitive flexibility is essential to cope with changing task demands and often it is necessary to adapt to combined changes in a coordinated manner. The present fMRI study examined how the brain implements such multi-level adaptation processes. Specifically, on a "local," hierarchically lower level, switching between two tasks was required across trials while the rules of each task remained unchanged for blocks of trials. On a "global" level regarding blocks of twelve trials, the task rules could reverse or remain the same. The current task was cued at the start of each trial while the current task rules were instructed before the start of a new block. We found that partly overlapping and partly segregated neural networks play different roles when coping with the combination of global rule reversal and local task switching. The fronto-parietal control network (FPN) supported the encoding of reversed rules at the time of explicit rule instruction. The same regions subsequently supported local task switching processes during actual implementation trials, irrespective of rule reversal condition. By contrast, a cortico-striatal network (CSN) including supplementary motor area and putamen was increasingly engaged across implementation trials and more so for rule reversal than for nonreversal blocks, irrespective of task switching condition. Together, these findings suggest that the brain accomplishes the coordinated adaptation to multi-level demand changes by distributing processing resources either across time (FPN for reversed rule encoding and later for task switching) or across regions (CSN for reversed rule implementation and FPN for concurrent task switching). © 2017 Wiley Periodicals, Inc.

Examining age-related differences in auditory attention control using a task-switching procedure.

PubMed

Lawo, Vera; Koch, Iring

2014-03-01

Using a novel task-switching variant of dichotic selective listening, we examined age-related differences in the ability to intentionally switch auditory attention between 2 speakers defined by their sex. In our task, young (M age = 23.2 years) and older adults (M age = 66.6 years) performed a numerical size categorization on spoken number words. The task-relevant speaker was indicated by a cue prior to auditory stimulus onset. The cuing interval was either short or long and varied randomly trial by trial. We found clear performance costs with instructed attention switches. These auditory attention switch costs decreased with prolonged cue-stimulus interval. Older adults were generally much slower (but not more error prone) than young adults, but switching-related effects did not differ across age groups. These data suggest that the ability to intentionally switch auditory attention in a selective listening task is not compromised in healthy aging. We discuss the role of modality-specific factors in age-related differences.

Direct real-time neural evidence for task-set inertia.

PubMed

Evans, Lisa H; Herron, Jane E; Wilding, Edward L

2015-03-01

One influential explanation for the costs incurred when switching between tasks is that they reflect interference arising from completing the previous task-known as task-set inertia. We report a novel approach for assessing task-set inertia in a memory experiment using event-related potentials (ERPs). After a study phase, participants completed a test block in which they switched between a memory task (retrieving information from the study phase) and a perceptual task. These tasks alternated every two trials. An ERP index of the retrieval of study information was evident in the memory task. It was also present on the first trial of the perceptual task but was markedly attenuated on the second. Moreover, this task-irrelevant ERP activity was positively correlated with a behavioral cost associated with switching between tasks. This real-time measure of neural activity thus provides direct evidence of task-set inertia, its duration, and the functional role it plays in switch costs. © The Author(s) 2015.

Auditory Multi-Stability: Idiosyncratic Perceptual Switching Patterns, Executive Functions and Personality Traits

PubMed Central

Farkas, Dávid; Denham, Susan L.; Bendixen, Alexandra; Tóth, Dénes; Kondo, Hirohito M.; Winkler, István

2016-01-01

Multi-stability refers to the phenomenon of perception stochastically switching between possible interpretations of an unchanging stimulus. Despite considerable variability, individuals show stable idiosyncratic patterns of switching between alternative perceptions in the auditory streaming paradigm. We explored correlates of the individual switching patterns with executive functions, personality traits, and creativity. The main dimensions on which individual switching patterns differed from each other were identified using multidimensional scaling. Individuals with high scores on the dimension explaining the largest portion of the inter-individual variance switched more often between the alternative perceptions than those with low scores. They also perceived the most unusual interpretation more often, and experienced all perceptual alternatives with a shorter delay from stimulus onset. The ego-resiliency personality trait, which reflects a tendency for adaptive flexibility and experience seeking, was significantly positively related to this dimension. Taking these results together we suggest that this dimension may reflect the individual’s tendency for exploring the auditory environment. Executive functions were significantly related to some of the variables describing global properties of the switching patterns, such as the average number of switches. Thus individual patterns of perceptual switching in the auditory streaming paradigm are related to some personality traits and executive functions. PMID:27135945

Alternating between pro- and antisaccades: switch-costs manifest via decoupling the spatial relations between stimulus and response.

PubMed

Heath, Matthew; Gillen, Caitlin; Samani, Ashna

2016-03-01

Antisaccades are a nonstandard task requiring a response mirror-symmetrical to the location of a target. The completion of an antisaccade has been shown to delay the reaction time (RT) of a subsequent prosaccade, whereas the converse switch elicits a null RT cost (i.e., the unidirectional prosaccade switch-cost). The present study sought to determine whether the prosaccade switch-cost arises from low-level interference specific to the sensory features of a target (i.e., modality-dependent) or manifests via the high-level demands of dissociating the spatial relations between stimulus and response (i.e., modality-independent). Participants alternated between pro- and antisaccades wherein the target associated with the response alternated between visual and auditory modalities. Thus, the present design involved task-switch (i.e., switching from a pro- to antisaccade and vice versa) and modality-switch (i.e., switching from a visual to auditory target and vice versa) trials as well as their task- and modality-repetition counterparts. RTs were longer for modality-switch than modality-repetition trials. Notably, however, modality-switch trials did not nullify or lessen the unidirectional prosaccade switch-cost; that is, the magnitude of the RT cost for task-switch prosaccades was equivalent across modality-switch and modality-repetition trials. Thus, competitive interference within a sensory modality does not contribute to the unidirectional prosaccade switch-cost. Instead, the modality-independent findings evince that dissociating the spatial relations between stimulus and response instantiates a high-level and inertially persistent nonstandard task-set that impedes the planning of a subsequent prosaccade.

Exploring adolescent cognitive control in a combined interference switching task.

PubMed

Mennigen, Eva; Rodehacke, Sarah; Müller, Kathrin U; Ripke, Stephan; Goschke, Thomas; Smolka, Michael N

2014-08-01

Cognitive control enables individuals to flexibly adapt to environmental challenges. In the present functional magnetic resonance imaging (fMRI) study, we investigated 185 adolescents at the age of 14 with a combined response interference switching task measuring behavioral responses (reaction time, RT and error rate, ER) and brain activity during the task. This task comprises two types of conflict which are co-occurring, namely, task switching and stimulus-response incongruence. Data indicated that already in adolescents an overlapping cognitive control network comprising the dorsal anterior cingulate cortex (dACC), dorsolateral prefrontal cortex (DLPFC), pre-supplementary motor area (preSMA) and posterior parietal cortex (PPC) is recruited by conflicts arising from task switching and response incongruence. Furthermore our study revealed higher blood oxygenation level dependent (BOLD) responses elicited by incongruent stimuli in participants with a pronounced incongruence effect, calculated as the RT difference between incongruent and congruent trials. No such correlation was observed for switch costs. Furthermore, increased activation of the default mode network (DMN) was only observed in congruent trials compared to incongruent trials, but not in task repetition relative to task switch trials. These findings suggest that even though the two processes of task switching and response incongruence share a common cognitive control network they might be processed differentially within the cognitive control network. Results are discussed in the context of a novel hypothesis concerning antagonistic relations between the DMN and the cognitive control network. Copyright © 2014 Elsevier Ltd. All rights reserved.

Beauty hinders attention switch in change detection: the role of facial attractiveness and distinctiveness.

PubMed

Chen, Wenfeng; Liu, Chang Hong; Nakabayashi, Kazuyo

2012-01-01

Recent research has shown that the presence of a task-irrelevant attractive face can induce a transient diversion of attention from a perceptual task that requires covert deployment of attention to one of the two locations. However, it is not known whether this spontaneous appraisal for facial beauty also modulates attention in change detection among multiple locations, where a slower, and more controlled search process is simultaneously affected by the magnitude of a change and the facial distinctiveness. Using the flicker paradigm, this study examines how spontaneous appraisal for facial beauty affects the detection of identity change among multiple faces. Participants viewed a display consisting of two alternating frames of four faces separated by a blank frame. In half of the trials, one of the faces (target face) changed to a different person. The task of the participant was to indicate whether a change of face identity had occurred. The results showed that (1) observers were less efficient at detecting identity change among multiple attractive faces relative to unattractive faces when the target and distractor faces were not highly distinctive from one another; and (2) it is difficult to detect a change if the new face is similar to the old. The findings suggest that attractive faces may interfere with the attention-switch process in change detection. The results also show that attention in change detection was strongly modulated by physical similarity between the alternating faces. Although facial beauty is a powerful stimulus that has well-demonstrated priority, its influence on change detection is easily superseded by low-level image similarity. The visual system appears to take a different approach to facial beauty when a task requires resource-demanding feature comparisons.

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

PubMed Central

Charles, Lauren M.; Ricketts, Todd A.

2017-01-01

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

Asymmetric Switch Costs in Numeral Naming and Number Word Reading: Implications for Models of Bilingual Language Production.

PubMed

Reynolds, Michael G; Schlöffel, Sophie; Peressotti, Francesca

2015-01-01

One approach used to gain insight into the processes underlying bilingual language comprehension and production examines the costs that arise from switching languages. For unbalanced bilinguals, asymmetric switch costs are reported in speech production, where the switch cost for L1 is larger than the switch cost for L2, whereas, symmetric switch costs are reported in language comprehension tasks, where the cost of switching is the same for L1 and L2. Presently, it is unclear why asymmetric switch costs are observed in speech production, but not in language comprehension. Three experiments are reported that simultaneously examine methodological explanations of task related differences in the switch cost asymmetry and the predictions of three accounts of the switch cost asymmetry in speech production. The results of these experiments suggest that (1) the type of language task (comprehension vs. production) determines whether an asymmetric switch cost is observed and (2) at least some of the switch cost asymmetry arises within the language system.

Asymmetric Switch Costs in Numeral Naming and Number Word Reading: Implications for Models of Bilingual Language Production

PubMed Central

Reynolds, Michael G.; Schlöffel, Sophie; Peressotti, Francesca

2016-01-01

One approach used to gain insight into the processes underlying bilingual language comprehension and production examines the costs that arise from switching languages. For unbalanced bilinguals, asymmetric switch costs are reported in speech production, where the switch cost for L1 is larger than the switch cost for L2, whereas, symmetric switch costs are reported in language comprehension tasks, where the cost of switching is the same for L1 and L2. Presently, it is unclear why asymmetric switch costs are observed in speech production, but not in language comprehension. Three experiments are reported that simultaneously examine methodological explanations of task related differences in the switch cost asymmetry and the predictions of three accounts of the switch cost asymmetry in speech production. The results of these experiments suggest that (1) the type of language task (comprehension vs. production) determines whether an asymmetric switch cost is observed and (2) at least some of the switch cost asymmetry arises within the language system. PMID:26834659

Investigating a method for reducing residual switch costs in cued task switching.

PubMed

Schneider, Darryl W

2016-07-01

Residual switch costs in cued task switching are performance decrements that occur despite a long cue-target interval (CTI) to prepare for a task switch. Verbruggen, Liefooghe, Vandierendonck, and Demanet (Journal of Experimental Psychology: Learning, Memory, and Cognition, 33; 342-356, 2007) showed that briefly presenting the cue during the CTI and leaving it absent after target onset yielded smaller residual switch costs than those obtained when the cue was available for the full CTI and remained present after target onset. The potential effects of cue availability during the CTI (full or partial) and cue status after target onset (present or absent) on residual switch costs were investigated in the present study. In Experiments 1 and 2, cue status was manipulated while holding cue availability constant. In Experiments 3 and 4, cue status and cue availability were manipulated factorially. Residual switch costs were obtained, but they were not modulated consistently by cue status or cue availability across experiments. In Experiment 5, a direct replication of one of Verbruggen and colleagues' experiments yielded divergent results. Implications for understanding task switching are discussed.

Shifting of attentional set is inadequate in severe burnout: Evidence from an event-related potential study.

PubMed

Sokka, Laura; Leinikka, Marianne; Korpela, Jussi; Henelius, Andreas; Lukander, Jani; Pakarinen, Satu; Alho, Kimmo; Huotilainen, Minna

2017-02-01

Individuals with prolonged occupational stress often report difficulties in concentration. Work tasks often require the ability to switch back and forth between different contexts. Here, we studied the association between job burnout and task switching by recording event-related potentials (ERPs) time-locked to stimulus onset during a task with simultaneous cue-target presentation and unpredictable switches in the task. Participants were currently working people with severe, mild, or no burnout symptoms. In all groups, task performance was substantially slower immediately after task switch than during task repetition. However, the error rates were higher in the severe burnout group than in the mild burnout and control groups. Electrophysiological data revealed an increased parietal P3 response for the switch trials relative to repetition trials. Notably, the response was smaller in amplitude in the severe burnout group than in the other groups. The results suggest that severe burnout is associated with inadequate processing when rapid shifting of attention between tasks is required resulting in less accurate performance. Copyright © 2016 Elsevier B.V. All rights reserved.

Still Clever after All These Years: Searching for the Homunculus in Explicitly Cued Task Switching

ERIC Educational Resources Information Center

Logan, Gordon D.; Schneider, Darryl W.; Bundesen, Claus

2007-01-01

Many researchers interpret switch costs in the explicit task-cuing procedure as reflecting endogenous task-set reconfiguration. G. D. Logan and C. Bundesen (2003) challenged this interpretation empirically and theoretically. They argued that many experiments confounded cue encoding benefits with switch costs and they showed that unconfounded…

Task Switching and Shifting between Stopping and Going: Developmental Change in between-Trial Control Adjustments

ERIC Educational Resources Information Center

Huizing, Mariette; van der Molen, Maurits W.

2011-01-01

This study set out to investigate developmental differences in the ability to switch between choice tasks and to shift between Go/NoGo and choice tasks. Three age groups (7-year-olds, 11-year-olds, and young adults) were asked to consider the shape or color of a bivalued target stimulus. The participants performed a switch task in which a cue…

Combining Reaction Time and Accuracy: The Relationship Between Working Memory Capacity and Task Switching as a Case Example.

PubMed

Draheim, Christopher; Hicks, Kenny L; Engle, Randall W

2016-01-01

It is generally agreed upon that the mechanisms underlying task switching heavily depend on working memory, yet numerous studies have failed to show a strong relationship between working memory capacity (WMC) and task-switching ability. We argue that this relationship does indeed exist but that the dependent variable used to measure task switching is problematic. To support our claim, we reanalyzed data from two studies with a new scoring procedure that combines reaction time (RT) and accuracy into a single score. The reanalysis revealed a strong relationship between task switching and WMC that was not present when RT-based switch costs were used as the dependent variable. We discuss the theoretical implications of this finding along with the potential uses and limitations of the scoring procedure we used. More broadly, we emphasize the importance of using measures that incorporate speed and accuracy in other areas of research, particularly in comparisons of subjects differing in cognitive and developmental levels. © The Author(s) 2015.

Neural correlates of task switching in paternal 15q11-q13 deletion Prader-Willi syndrome.

PubMed

Woodcock, Kate A; Humphreys, Glyn W; Oliver, Chris; Hansen, Peter C

2010-12-02

We report a first study of brain activity linked to task switching in individuals with Prader-Willi syndrome (PWS). PWS individuals show a specific cognitive deficit in task switching which may be associated with the display of temper outbursts and repetitive questioning. The performance of participants with PWS and typically developing controls was matched in a cued task switching procedure, and brain activity was contrasted on switching and non-switching blocks using fMRI. Individuals with PWS did not show the typical frontal-parietal pattern of neural activity associated with switching blocks, with significantly reduced activation in regions of the posterior parietal and ventromedial prefrontal cortices. We suggest that this is linked to a difficulty in PWS in setting appropriate attentional weights to enable task-set reconfiguration. In addition to this, PWS individuals did not show the typical pattern of deactivation, with significantly less deactivation in an anterior region of the ventromedial prefrontal cortex. One plausible explanation for this is that individuals with PWS show dysfunction within the default mode network, which has been linked to attentional control. The data point to functional changes in the neural circuitry supporting task switching in PWS even when behavioural performance is matched to controls and thus highlight neural mechanisms that may be involved in a specific pathway between genes, cognition and behaviour. Copyright © 2010 Elsevier B.V. All rights reserved.

A chain-retrieval model for voluntary task switching.

PubMed

Vandierendonck, André; Demanet, Jelle; Liefooghe, Baptist; Verbruggen, Frederick

2012-09-01

To account for the findings obtained in voluntary task switching, this article describes and tests the chain-retrieval model. This model postulates that voluntary task selection involves retrieval of task information from long-term memory, which is then used to guide task selection and task execution. The model assumes that the retrieved information consists of acquired sequences (or chains) of tasks, that selection may be biased towards chains containing more task repetitions and that bottom-up triggered repetitions may overrule the intended task. To test this model, four experiments are reported. In Studies 1 and 2, sequences of task choices and the corresponding transition sequences (task repetitions or switches) were analyzed with the help of dependency statistics. The free parameters of the chain-retrieval model were estimated on the observed task sequences and these estimates were used to predict autocorrelations of tasks and transitions. In Studies 3 and 4, sequences of hand choices and their transitions were analyzed similarly. In all studies, the chain-retrieval model yielded better fits and predictions than statistical models of event choice. In applications to voluntary task switching (Studies 1 and 2), all three parameters of the model were needed to account for the data. When no task switching was required (Studies 3 and 4), the chain-retrieval model could account for the data with one or two parameters clamped to a neutral value. Implications for our understanding of voluntary task selection and broader theoretical implications are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

Updating Sensory "versus" Task Representations during Task-Switching: Insights from Cognitive Brain Potentials in Humans

ERIC Educational Resources Information Center

Perianez, Jose A.; Barcelo, Francisco

2009-01-01

Task-cueing studies suggest that the updating of sensory and task representations both contribute to behavioral task-switch costs [Forstmann, B. U., Brass, M., & Koch, I. (2007). "Methodological and empirical issues when dissociating cue-related from task-related processes in the explicit task-cuing procedure." "Psychological Research, 71"(4),…

A Chain-Retrieval Model for Voluntary Task Switching

ERIC Educational Resources Information Center

Vandierendonck, Andre; Demanet, Jelle; Liefooghe, Baptist; Verbruggen, Frederick

2012-01-01

To account for the findings obtained in voluntary task switching, this article describes and tests the chain-retrieval model. This model postulates that voluntary task selection involves retrieval of task information from long-term memory, which is then used to guide task selection and task execution. The model assumes that the retrieved…

Central Cross-Talk in Task Switching : Evidence from Manipulating Input-Output Modality Compatibility

ERIC Educational Resources Information Center

Stephan, Denise Nadine; Koch, Iring

2010-01-01

Two experiments examined the role of compatibility of input and output (I-O) modality mappings in task switching. We define I-O modality compatibility in terms of similarity of stimulus modality and modality of response-related sensory consequences. Experiment 1 included switching between 2 compatible tasks (auditory-vocal vs. visual-manual) and…

A Neural Network Approach to fMRI Binocular Visual Rivalry Task Analysis

PubMed Central

Bertolino, Nicola; Ferraro, Stefania; Nigri, Anna; Bruzzone, Maria Grazia; Ghielmetti, Francesco; Leonardi, Matilde; Agostino Parati, Eugenio; Grazia Bruzzone, Maria; Franceschetti, Silvana; Caldiroli, Dario; Sattin, Davide; Giovannetti, Ambra; Pagani, Marco; Covelli, Venusia; Ciaraffa, Francesca; Vela Gomez, Jesus; Reggiori, Barbara; Ferraro, Stefania; Nigri, Anna; D'Incerti, Ludovico; Minati, Ludovico; Andronache, Adrian; Rosazza, Cristina; Fazio, Patrik; Rossi, Davide; Varotto, Giulia; Panzica, Ferruccio; Benti, Riccardo; Marotta, Giorgio; Molteni, Franco

2014-01-01

The purpose of this study was to investigate whether artificial neural networks (ANN) are able to decode participants’ conscious experience perception from brain activity alone, using complex and ecological stimuli. To reach the aim we conducted pattern recognition data analysis on fMRI data acquired during the execution of a binocular visual rivalry paradigm (BR). Twelve healthy participants were submitted to fMRI during the execution of a binocular non-rivalry (BNR) and a BR paradigm in which two classes of stimuli (faces and houses) were presented. During the binocular rivalry paradigm, behavioral responses related to the switching between consciously perceived stimuli were also collected. First, we used the BNR paradigm as a functional localizer to identify the brain areas involved the processing of the stimuli. Second, we trained the ANN on the BNR fMRI data restricted to these regions of interest. Third, we applied the trained ANN to the BR data as a ‘brain reading’ tool to discriminate the pattern of neural activity between the two stimuli. Fourth, we verified the consistency of the ANN outputs with the collected behavioral indicators of which stimulus was consciously perceived by the participants. Our main results showed that the trained ANN was able to generalize across the two different tasks (i.e. BNR and BR) and to identify with high accuracy the cognitive state of the participants (i.e. which stimulus was consciously perceived) during the BR condition. The behavioral response, employed as control parameter, was compared with the network output and a statistically significant percentage of correspondences (p-value <0.05) were obtained for all subjects. In conclusion the present study provides a method based on multivariate pattern analysis to investigate the neural basis of visual consciousness during the BR phenomenon when behavioral indicators lack or are inconsistent, like in disorders of consciousness or sedated patients. PMID:25121595

The relationship between emotional intelligence and task-switching in temporal lobe epilepsy.

PubMed

Gul, Amara; Hussain, Imtiaz

2016-01-01

To examine the role of emotional intelligence (EI) in task-switching performance of patients with temporal lobe epilepsy (TLE). An experimental research design conducted at Sheikh Zayed Hospital, Rahim Yar Khan, Mayo and Services Hospital, Lahore, Pakistan from March 2013 to October 2014. Twenty-five patients with TLE and 25 healthy individuals from local community participated in the study. Participants completed measures of intelligence, EI, depression, anxiety, stress, and task-switching experiment. Patients and controls showed an average intelligence quotient, and normal levels of depression, anxiety, and stress. In contrast to controls, patients showed lower EI and impaired task-switching abilities. This result can be seen in the context of disintegrated white matter and cerebral connectivity in patients with TLE. Emotional intelligence was found to be a significant predictor of task-switching performance. Emotional intelligence is a potential marker of higher order cognitive functioning in patients with TLE.

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

PubMed Central

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

2014-01-01

Objectives The dual-task paradigm has been widely used to measure listening effort. The primary objectives of the study were to (1) investigate the effect of hearing aid amplification and a hearing aid directional technology on listening effort measured by a complicated, more real world dual-task paradigm, and (2) compare the results obtained with this paradigm to a simpler laboratory-style dual-task paradigm. Design The listening effort of adults with hearing impairment was measured using two dual-task paradigms, wherein participants performed a speech recognition task simultaneously with either a driving task in a simulator or a visual reaction-time task in a sound-treated booth. The speech materials and road noises for the speech recognition task were recorded in a van traveling on the highway in three hearing aid conditions: unaided, aided with omni directional processing (OMNI), and aided with directional processing (DIR). The change in the driving task or the visual reaction-time task performance across the conditions quantified the change in listening effort. Results Compared to the driving-only condition, driving performance declined significantly with the addition of the speech recognition task. Although the speech recognition score was higher in the OMNI and DIR conditions than in the unaided condition, driving performance was similar across these three conditions, suggesting that listening effort was not affected by amplification and directional processing. Results from the simple dual-task paradigm showed a similar trend: hearing aid technologies improved speech recognition performance, but did not affect performance in the visual reaction-time task (i.e., reduce listening effort). The correlation between listening effort measured using the driving paradigm and the visual reaction-time task paradigm was significant. The finding showing that our older (56 to 85 years old) participants’ better speech recognition performance did not result in reduced listening effort was not consistent with literature that evaluated younger (approximately 20 years old), normal hearing adults. Because of this, a follow-up study was conducted. In the follow-up study, the visual reaction-time dual-task experiment using the same speech materials and road noises was repeated on younger adults with normal hearing. Contrary to findings with older participants, the results indicated that the directional technology significantly improved performance in both speech recognition and visual reaction-time tasks. Conclusions Adding a speech listening task to driving undermined driving performance. Hearing aid technologies significantly improved speech recognition while driving, but did not significantly reduce listening effort. Listening effort measured by dual-task experiments using a simulated real-world driving task and a conventional laboratory-style task was generally consistent. For a given listening environment, the benefit of hearing aid technologies on listening effort measured from younger adults with normal hearing may not be fully translated to older listeners with hearing impairment. PMID:25083599

Anticipatory control through associative learning of subliminal relations: invisible may be better than visible.

PubMed

Farooqui, Ausaf A; Manly, Tom

2015-03-01

We showed that anticipatory cognitive control could be unconsciously instantiated through subliminal cues that predicted enhanced future control needs. In task-switching experiments, one of three subliminal cues preceded each trial. Participants had no conscious experience or knowledge of these cues, but their performance was significantly improved on switch trials after cues that predicted task switches (but not particular tasks). This utilization of subliminal information was flexible and adapted to a change in cues predicting task switches and occurred only when switch trials were difficult and effortful. When cues were consciously visible, participants were unable to discern their relevance and could not use them to enhance switch performance. Our results show that unconscious cognition can implicitly use subliminal information in a goal-directed manner for anticipatory control, and they also suggest that subliminal representations may be more conducive to certain forms of associative learning. © The Author(s) 2015.

Sustained selective attention predicts flexible switching in preschoolers

PubMed Central

Benitez, Viridiana L.; Vales, Catarina; Hanania, Rima; Smith, Linda B.

2016-01-01

Stability and flexibility are fundamental to an intelligent cognitive system. Here, we examine the relationship between stability in selective attention and explicit control of flexible attention. Preschoolers were tested on the Dimension-Preference (DP) task, a task that measures the stability of selective attention to an implicitly primed dimension, and the Dimension-Change Card Sort Task (DCCS), a task that measures flexible attention switching between dimensions. Children who successfully switched on the DCCS task were more likely than those who perseverated to sustain attention to the primed dimension on the DP task across trials. We propose that perseverators have less stable attention and distribute their attention between dimensions, while switchers can successfully stabilize attention to individual dimensions and thus show more enduring priming effects. Flexible attention may emerge, in part, from implicit processes that stabilize attention even in tasks not requiring switching. PMID:28024178

Assessing Top-Down and Bottom-Up Contributions to Auditory Stream Segregation and Integration With Polyphonic Music

PubMed Central

Disbergen, Niels R.; Valente, Giancarlo; Formisano, Elia; Zatorre, Robert J.

2018-01-01

Polyphonic music listening well exemplifies processes typically involved in daily auditory scene analysis situations, relying on an interactive interplay between bottom-up and top-down processes. Most studies investigating scene analysis have used elementary auditory scenes, however real-world scene analysis is far more complex. In particular, music, contrary to most other natural auditory scenes, can be perceived by either integrating or, under attentive control, segregating sound streams, often carried by different instruments. One of the prominent bottom-up cues contributing to multi-instrument music perception is their timbre difference. In this work, we introduce and validate a novel paradigm designed to investigate, within naturalistic musical auditory scenes, attentive modulation as well as its interaction with bottom-up processes. Two psychophysical experiments are described, employing custom-composed two-voice polyphonic music pieces within a framework implementing a behavioral performance metric to validate listener instructions requiring either integration or segregation of scene elements. In Experiment 1, the listeners' locus of attention was switched between individual instruments or the aggregate (i.e., both instruments together), via a task requiring the detection of temporal modulations (i.e., triplets) incorporated within or across instruments. Subjects responded post-stimulus whether triplets were present in the to-be-attended instrument(s). Experiment 2 introduced the bottom-up manipulation by adding a three-level morphing of instrument timbre distance to the attentional framework. The task was designed to be used within neuroimaging paradigms; Experiment 2 was additionally validated behaviorally in the functional Magnetic Resonance Imaging (fMRI) environment. Experiment 1 subjects (N = 29, non-musicians) completed the task at high levels of accuracy, showing no group differences between any experimental conditions. Nineteen listeners also participated in Experiment 2, showing a main effect of instrument timbre distance, even though within attention-condition timbre-distance contrasts did not demonstrate any timbre effect. Correlation of overall scores with morph-distance effects, computed by subtracting the largest from the smallest timbre distance scores, showed an influence of general task difficulty on the timbre distance effect. Comparison of laboratory and fMRI data showed scanner noise had no adverse effect on task performance. These Experimental paradigms enable to study both bottom-up and top-down contributions to auditory stream segregation and integration within psychophysical and neuroimaging experiments. PMID:29563861

Measurement and Evidence of Computer-Based Task Switching and Multitasking by "Net Generation" Students

ERIC Educational Resources Information Center

Judd, Terry; Kennedy, Gregor

2011-01-01

Logs of on-campus computer and Internet usage were used to conduct a study of computer-based task switching and multitasking by undergraduate medical students. A detailed analysis of over 6000 individual sessions revealed that while a majority of students engaged in both task switching and multitasking behaviours, they did so less frequently than…

Improving Running Times for the Determination of Fractional Snow-Covered Area from Landsat TM/ETM+ via Utilization of the CUDA® Programming Paradigm

NASA Astrophysics Data System (ADS)

McGibbney, L. J.; Rittger, K.; Painter, T. H.; Selkowitz, D.; Mattmann, C. A.; Ramirez, P.

2014-12-01

As part of a JPL-USGS collaboration to expand distribution of essential climate variables (ECV) to include on-demand fractional snow cover we describe our experience and implementation of a shift towards the use of NVIDIA's CUDA® parallel computing platform and programming model. In particular the on-demand aspect of this work involves the improvement (via faster processing and a reduction in overall running times) for determination of fractional snow-covered area (fSCA) from Landsat TM/ETM+. Our observations indicate that processing tasks associated with remote sensing including the Snow Covered Area and Grain Size Model (SCAG) when applied to MODIS or LANDSAT TM/ETM+ are computationally intensive processes. We believe the shift to the CUDA programming paradigm represents a significant improvement in the ability to more quickly assert the outcomes of such activities. We use the TMSCAG model as our subject to highlight this argument. We do this by describing how we can ingest a LANDSAT surface reflectance image (typically provided in HDF format), perform spectral mixture analysis to produce land cover fractions including snow, vegetation and rock/soil whilst greatly reducing running time for such tasks. Within the scope of this work we first document the original workflow used to assert fSCA for Landsat TM and it's primary shortcomings. We then introduce the logic and justification behind the switch to the CUDA paradigm for running single as well as batch jobs on the GPU in order to achieve parallel processing. Finally we share lessons learned from the implementation of myriad of existing algorithms to a single set of code in a single target language as well as benefits this ultimately provides scientists at the USGS.

Time Sharing Between Robotics and Process Control: Validating a Model of Attention Switching.

PubMed

Wickens, Christopher Dow; Gutzwiller, Robert S; Vieane, Alex; Clegg, Benjamin A; Sebok, Angelia; Janes, Jess

2016-03-01

The aim of this study was to validate the strategic task overload management (STOM) model that predicts task switching when concurrence is impossible. The STOM model predicts that in overload, tasks will be switched to, to the extent that they are attractive on task attributes of high priority, interest, and salience and low difficulty. But more-difficult tasks are less likely to be switched away from once they are being performed. In Experiment 1, participants performed four tasks of the Multi-Attribute Task Battery and provided task-switching data to inform the role of difficulty and priority. In Experiment 2, participants concurrently performed an environmental control task and a robotic arm simulation. Workload was varied by automation of arm movement and both the phases of environmental control and existence of decision support for fault management. Attention to the two tasks was measured using a head tracker. Experiment 1 revealed the lack of influence of task priority and confirmed the differing roles of task difficulty. In Experiment 2, the percentage attention allocation across the eight conditions was predicted by the STOM model when participants rated the four attributes. Model predictions were compared against empirical data and accounted for over 95% of variance in task allocation. More-difficult tasks were performed longer than easier tasks. Task priority does not influence allocation. The multiattribute decision model provided a good fit to the data. The STOM model is useful for predicting cognitive tunneling given that human-in-the-loop simulation is time-consuming and expensive. © 2016, Human Factors and Ergonomics Society.

Self-paced preparation for a task switch eliminates attentional inertia but not the performance switch cost.

PubMed

Longman, Cai S; Lavric, Aureliu; Monsell, Stephen

2017-06-01

The performance overhead associated with changing tasks (the "switch cost") usually diminishes when the task is specified in advance but is rarely eliminated by preparation. A popular account of the "residual" (asymptotic) switch cost is that it reflects "task-set inertia": carry-over of task-set parameters from the preceding trial(s). New evidence for a component of "task-set inertia" comes from eye-tracking, where the location associated with the previously (but no longer) relevant task is fixated preferentially over other irrelevant locations, even when preparation intervals are generous. Might such limits in overcoming task-set inertia in general, and "attentional inertia" in particular, result from suboptimal scheduling of preparation when the time available is outside one's control? In the present study, the stimulus comprised 3 digits located at the points of an invisible triangle, preceded by a central verbal cue specifying which of 3 classification tasks to perform, each consistently applied to just 1 digit location. The digits were presented only when fixation moved away from the cue, thus giving the participant control over preparation time. In contrast to our previous research with experimenter-determined preparation intervals, we found no sign of attentional inertia for the long preparation intervals. Self-paced preparation reduced but did not eliminate the performance switch cost-leaving a clear residual component in both reaction time and error rates. That the scheduling of preparation accounts for some, but not all, components of the residual switch cost, challenges existing accounts of the switch cost, even those which distinguish between preparatory and poststimulus reconfiguration processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Effect of N-3 on N-2 Repetition Costs in Task Switching

ERIC Educational Resources Information Center

Schuch, Stefanie; Grange, James A.

2015-01-01

N-2 task repetition cost is a response time and error cost returning to a task recently performed after one intervening trial (i.e., an ABA task sequence) compared with returning to a task not recently performed (i.e., a CBA task sequence). This cost is considered a robust measure of inhibitory control during task switching. The present article…

Investigating the Effect of Voltage-Switching on Low-Energy Task Scheduling in Hard Real-Time Systems

DTIC Science & Technology

2005-01-01

We investigate the effect of voltage-switching on task execution times and energy consumption for dual-speed hard real - time systems , and present a...scheduling algorithm and apply it to two real-life task sets. Our results show that energy can be conserved in embedded real - time systems using energy...aware task scheduling. We also show that switching times have a significant effect on the energy consumed in hard real - time systems .

More Attention to Attention? An Eye-Tracking Investigation of Selection of Perceptual Attributes during a Task Switch

ERIC Educational Resources Information Center

Longman, Cai S.; Lavric, Aureliu; Monsell, Stephen

2013-01-01

Switching tasks prolongs response times, an effect reduced but not eliminated by active preparation. To explore the role of attentional selection of the relevant stimulus attribute in these task-switch costs, we measured eye fixations in participants cued to identify either a face or a letter displayed on its forehead. With only 200 ms between cue…

Dynamic Trial-by-Trial Recoding of Task-Set Representations in the Frontoparietal Cortex Mediates Behavioral Flexibility

PubMed Central

Qiao, Lei; Zhang, Lijie

2017-01-01

Cognitive flexibility forms the core of the extraordinary ability of humans to adapt, but the precise neural mechanisms underlying our ability to nimbly shift between task sets remain poorly understood. Recent functional magnetic resonance imaging (fMRI) studies employing multivoxel pattern analysis (MVPA) have shown that a currently relevant task set can be decoded from activity patterns in the frontoparietal cortex, but whether these regions support the dynamic transformation of task sets from trial to trial is not clear. Here, we combined a cued task-switching protocol with human (both sexes) fMRI, and harnessed representational similarity analysis (RSA) to facilitate a novel assessment of trial-by-trial changes in neural task-set representations. We first used MVPA to define task-sensitive frontoparietal and visual regions and found that neural task-set representations on switch trials are less stably encoded than on repeat trials. We then exploited RSA to show that the neural representational pattern dissimilarity across consecutive trials is greater for switch trials than for repeat trials, and that the degree of this pattern dissimilarity predicts behavior. Moreover, the overall neural pattern of representational dissimilarities followed from the assumption that repeating sets, compared with switching sets, results in stronger neural task representations. Finally, when moving from cue to target phase within a trial, pattern dissimilarities tracked the transformation from previous-trial task representations to the currently relevant set. These results provide neural evidence for the longstanding assumptions of an effortful task-set reconfiguration process hampered by task-set inertia, and they demonstrate that frontoparietal and stimulus processing regions support “dynamic adaptive coding,” flexibly representing changing task sets in a trial-by-trial fashion. SIGNIFICANCE STATEMENT Humans can fluently switch between different tasks, reflecting an ability to dynamically configure “task sets,” rule representations that link stimuli to appropriate responses. Recent studies show that neural signals in frontal and parietal brain regions can tell us which of two tasks a person is currently performing. However, it is not known whether these regions are also involved in dynamically reconfiguring task-set representations when switching between tasks. Here we measured human brain activity during task switching and tracked the similarity of neural task-set representations from trial to trial. We show that frontal and parietal brain regions flexibly recode changing task sets in a trial-by-trial fashion, and that task-set similarity over consecutive trials predicts behavior. PMID:28972126

Long-Term Effects of Attentional Performance on Functional Brain Network Topology

PubMed Central

Breckel, Thomas P. K.; Thiel, Christiane M.; Bullmore, Edward T.; Zalesky, Andrew; Patel, Ameera X.; Giessing, Carsten

2013-01-01

Individuals differ in their cognitive resilience. Less resilient people demonstrate a greater tendency to vigilance decrements within sustained attention tasks. We hypothesized that a period of sustained attention is followed by prolonged changes in the organization of “resting state” brain networks and that individual differences in cognitive resilience are related to differences in post-task network reorganization. We compared the topological and spatial properties of brain networks as derived from functional MRI data (N = 20) recorded for 6 mins before and 12 mins after the performance of an attentional task. Furthermore we analysed changes in brain topology during task performance and during the switches between rest and task conditions. The cognitive resilience of each individual was quantified as the rate of increase in response latencies over the 32-minute time course of the attentional paradigm. On average, functional networks measured immediately post-task demonstrated significant and prolonged changes in network organization compared to pre-task networks with higher connectivity strength, more clustering, less efficiency, and shorter distance connections. Individual differences in cognitive resilience were significantly correlated with differences in the degree of recovery of some network parameters. Changes in network measures were still present in less resilient individuals in the second half of the post-task period (i.e. 6–12 mins after task completion), while resilient individuals already demonstrated significant reductions of functional connectivity and clustering towards pre-task levels. During task performance brain topology became more integrated with less clustering and higher global efficiency, but linearly decreased with ongoing time-on-task. We conclude that sustained attentional task performance has prolonged, “hang-over” effects on the organization of post-task resting-state brain networks; and that more cognitively resilient individuals demonstrate faster rates of network recovery following a period of attentional effort. PMID:24040185

An Integrated Model of Cognitive Control in Task Switching

ERIC Educational Resources Information Center

Altmann, Erik M.; Gray, Wayne D.

2008-01-01

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…

Response Selection Difficulty and Asymmetrical Costs of Switching Between Tasks and Stimuli: No Evidence for an Exogenous Component of Task-Set Reconfiguration

ERIC Educational Resources Information Center

Hubner, Mike; Kluwe, Rainer H.; Luna-Rodriguez, Aquiles; Peters, Alexandra

2004-01-01

Four task-switching experiments examined the notion of an exogenous component of task-set reconfiguration (i.e., a process needed to shift task set that is not initiated in the absence of a task-associated figuration stimulus). The authors varied the complexity and familiarity of stimulus-response (SR) mapping rules to produce differentially…

The effect of action video game experience on task-switching

PubMed Central

Green, C.Shawn; Sugarman, Michael A.; Medford, Katherine; Klobusicky, Elizabeth; Daphne Bavelier

2012-01-01

There is now a substantial body of work demonstrating that action video game experience results in enhancements in a wide variety of perceptual skills. More recently, several groups have also demonstrated improvements in abilities that are more cognitive in nature, in particular, the ability to efficiently switch between tasks. In a series of four experiments, we add to this body of work, demonstrating that the action video game player advantage is not exclusively due to an ability to map manual responses onto arbitrary buttons, but rather generalizes to vocal responses, is not restricted to tasks that are perceptual in nature (e.g. respond to a physical dimension of the stimulus such as its color), but generalizes to more cognitive tasks (e.g. is a number odd or even), and is present whether the switch requires a goal-switch or only a motor switch. Finally, a training study establishes that the relationship between the reduction in switch cost and action game playing is causal. PMID:22393270

Further evidence for a deficit in switching attention in schizophrenia.

PubMed

Smith, G L; Large, M M; Kavanagh, D J; Karayanidis, F; Barrett, N A; Michie, P T; O'Sullivan, B T

1998-08-01

In this study, sustained, selective, divided, and switching attention, and reloading of working memory were investigated in schizophrenia by using a newly developed Visual Attention Battery (VAB). Twenty-four outpatients with schizophrenia and 24 control participants were studied using the VAB. Performance on VAB components was correlated with performance of standard tests. Patients with schizophrenia were significantly impaired on VAB tasks that required switching of attention and reloading of working memory but had normal performance on tasks involving sustained attention or attention to multiple stimulus features. Switching attention and reloading of working memory were highly correlated with Trails (B-A) score for patients. The decline in performance on the switching-attention task in patients with schizophrenia met criteria for a differential deficit in switching attention. Future research should examine the neurophysiological basis of the switching deficit and its sensitivity and specificity to schizophrenia.

Application of a Curriculum Hierarchy Evaluation (CHE) Model to Sequentially Arranged Tasks.

ERIC Educational Resources Information Center

O'Malley, J. Michael

A curriculum hierarchy evaluation (CHE) model was developed by combining a transfer paradigm with an aptitude-treatment-task interaction (ATTI) paradigm. Positive transfer was predicted between sequentially arranged tasks, and a programed or nonprogramed treatment was predicted to interact with aptitude and with tasks. Eighteen four and five…

Optimized Motor Imagery Paradigm Based on Imagining Chinese Characters Writing Movement.

PubMed

Qiu, Zhaoyang; Allison, Brendan Z; Jin, Jing; Zhang, Yu; Wang, Xingyu; Li, Wei; Cichocki, Andrzej

2017-07-01

motor imagery (MI) is a mental representation of motor behavior. The MI-based brain computer interfaces (BCIs) can provide communication for the physically impaired. The performance of MI-based BCI mainly depends on the subject's ability to self-modulate electroencephalogram signals. Proper training can help naive subjects learn to modulate brain activity proficiently. However, training subjects typically involve abstract motor tasks and are time-consuming. to improve the performance of naive subjects during motor imagery, a novel paradigm was presented that would guide naive subjects to modulate brain activity effectively. In this new paradigm, pictures of the left or right hand were used as cues for subjects to finish the motor imagery task. Fourteen healthy subjects (11 male, aged 22-25 years, and mean 23.6±1.16) participated in this study. The task was to imagine writing a Chinese character. Specifically, subjects could imagine hand movements corresponding to the sequence of writing strokes in the Chinese character. This paradigm was meant to find an effective and familiar action for most Chinese people, to provide them with a specific, extensively practiced task and help them modulate brain activity. results showed that the writing task paradigm yielded significantly better performance than the traditional arrow paradigm (p < 0.001). Questionnaire replies indicated that most subjects thought that the new paradigm was easier. the proposed new motor imagery paradigm could guide subjects to help them modulate brain activity effectively. Results showed that there were significant improvements using new paradigm, both in classification accuracy and usability.

Video game use and cognitive performance: does it vary with the presence of problematic video game use?

PubMed

Collins, Emily; Freeman, Jonathan

2014-03-01

Action video game players have been found to outperform nonplayers on a variety of cognitive tasks. However, several failures to replicate these video game player advantages have indicated that this relationship may not be straightforward. Moreover, despite the discovery that problematic video game players do not appear to demonstrate the same superior performance as nonproblematic video game players in relation to multiple object tracking paradigms, this has not been investigated for other tasks. Consequently, this study compared gamers and nongamers in task switching ability, visual short-term memory, mental rotation, enumeration, and flanker interference, as well as investigated the influence of self-reported problematic video game use. A total of 66 participants completed the experiment, 26 of whom played action video games, including 20 problematic players. The results revealed no significant effect of playing action video games, nor any influence of problematic video game play. This indicates that the previously reported cognitive advantages in video game players may be restricted to specific task features or samples. Furthermore, problematic video game play may not have a detrimental effect on cognitive performance, although this is difficult to ascertain considering the lack of video game player advantage. More research is therefore sorely needed.

Perceptual and Conceptual Priming of Cue Encoding in Task Switching

ERIC Educational Resources Information Center

Schneider, Darryl W.

2016-01-01

Transition effects in task-cuing experiments can be partitioned into task switching and cue repetition effects by using multiple cues per task. In the present study, the author shows that cue repetition effects can be partitioned into perceptual and conceptual priming effects. In 2 experiments, letters or numbers in their uppercase/lowercase or…

Anodal tDCS applied during multitasking training leads to transferable performance gains.

PubMed

Filmer, Hannah L; Lyons, Maxwell; Mattingley, Jason B; Dux, Paul E

2017-10-11

Cognitive training can lead to performance improvements that are specific to the tasks trained. Recent research has suggested that transcranial direct current stimulation (tDCS) applied during training of a simple response-selection paradigm can broaden performance benefits to an untrained task. Here we assessed the impact of combined tDCS and training on multitasking, stimulus-response mapping specificity, response-inhibition, and spatial attention performance in a cohort of healthy adults. Participants trained over four days with concurrent tDCS - anodal, cathodal, or sham - applied to the left prefrontal cortex. Immediately prior to, 1 day after, and 2 weeks after training, performance was assessed on the trained multitasking paradigm, an untrained multitasking paradigm, a go/no-go inhibition task, and a visual search task. Training combined with anodal tDCS, compared with training plus cathodal or sham stimulation, enhanced performance for the untrained multitasking paradigm and visual search tasks. By contrast, there were no training benefits for the go/no-go task. Our findings demonstrate that anodal tDCS combined with multitasking training can extend to untrained multitasking paradigms as well as spatial attention, but with no extension to the domain of response inhibition.

Dynamics of Driver Distraction: The process of engaging and disengaging

PubMed Central

Lee, John D.

2014-01-01

Driver distraction research has a long history, spanning nearly 50 years, but intensifying over the last decade. The dominant paradigm guiding this research defines distraction in terms of excessive workload and limited attentional resources. This approach largely ignores how drivers come to engage in these tasks and under what conditions they engage and disengage from driving—the dynamics of distraction. The dynamics of distraction identifies breakdowns of interruption management as an important contributor to distraction, leading to describe distraction in terms of failures of task timing, switching, and prioritization. The dynamics of distraction also identifies disengagement in driving (e.g., mind wandering) as a substantial challenge that secondary tasks might exacerbate or mitigate. Increasing vehicle automation accentuates the need to consider these dynamics of distraction. Automation offers drivers more opportunity to engage in distractions and disengage from driving, and can surprise drivers by unexpectedly requiring drivers to quickly re-engage in driving—placing greater importance of interruption management expertise. This review describes distraction in terms of breakdowns in interruption management and problems of engagement, and summarizes how contingency, conditioning, and consequence traps lead to problems of engaging and disengaging in driving and distractions. PMID:24776224

Effects of deep brain stimulation of the peduncolopontine area on working memory tasks in patients with Parkinson's disease.

PubMed

Costa, Alberto; Carlesimo, Giovanni Augusto; Caltagirone, Carlo; Mazzone, Paolo; Pierantozzi, Mariangela; Stefani, Alessandro; Peppe, Antonella

2010-01-01

The present paper was aimed at investigating the effect of low-frequency electrical stimulation (25 Hz) of the peduncolopontine (PPN) area on working memory (WM) functioning in patients with Parkinson's disease (PD). Five PD patients who underwent simultaneous PPN area- and subthalamic nucleus-deep brain stimulation (DBS) implantation participated in the study. PD patients were evaluated in the morning at least 12 h after antiparkinsonian therapy withdrawal in two conditions: i) after continuous PPN area stimulation (Off Therapy/On PPN: "On" condition); ii) at least 120 min after PPN area had been switched "Off" (Off Ther/Off PPN: "Off" condition). The experimental WM task consisted of an n-back paradigm with verbal and visual-object stimuli. PD patients showed a consistent response time decrease on both the verbal and the visual-object tasks passing from the "Off" to the "On" condition (p < 0.05). However, the accuracy score did not significantly differ between the two experimental conditions. The present findings, although preliminary, suggest that PPN area stimulation facilitates the speed processing of information in the content of WM, possibly through the modulation of the attentional resources.

Task-relevant information is prioritized in spatiotemporal contextual cueing.

PubMed

Higuchi, Yoko; Ueda, Yoshiyuki; Ogawa, Hirokazu; Saiki, Jun

2016-11-01

Implicit learning of visual contexts facilitates search performance-a phenomenon known as contextual cueing; however, little is known about contextual cueing under situations in which multidimensional regularities exist simultaneously. In everyday vision, different information, such as object identity and location, appears simultaneously and interacts with each other. We tested the hypothesis that, in contextual cueing, when multiple regularities are present, the regularities that are most relevant to our behavioral goals would be prioritized. Previous studies of contextual cueing have commonly used the visual search paradigm. However, this paradigm is not suitable for directing participants' attention to a particular regularity. Therefore, we developed a new paradigm, the "spatiotemporal contextual cueing paradigm," and manipulated task-relevant and task-irrelevant regularities. In four experiments, we demonstrated that task-relevant regularities were more responsible for search facilitation than task-irrelevant regularities. This finding suggests our visual behavior is focused on regularities that are relevant to our current goal.

White matter integrity between left basal ganglia and left prefrontal cortex is compromised in gambling disorder.

PubMed

van Timmeren, Tim; Jansen, Jochem M; Caan, Matthan W A; Goudriaan, Anna E; van Holst, Ruth J

2017-11-01

Pathological gambling (PG) is a behavioral addiction characterized by an inability to stop gambling despite the negative consequences, which may be mediated by cognitive flexibility deficits. Indeed, impaired cognitive flexibility has previously been linked to PG and also to reduced integrity of white matter connections between the basal ganglia and the prefrontal cortex. It remains unclear, however, how white matter integrity problems relate to cognitive inflexibility seen in PG. We used a cognitive switch paradigm during functional magnetic resonance imaging in pathological gamblers (PGs; n = 26) and healthy controls (HCs; n = 26). Cognitive flexibility performance was measured behaviorally by accuracy and reaction time on the switch task, while brain activity was measured in terms of blood oxygen level-dependent responses. We also used diffusion tensor imaging on a subset of data (PGs = 21; HCs = 21) in combination with tract-based spatial statistics and probabilistic fiber tracking to assess white matter integrity between the basal ganglia and the dorsolateral prefrontal cortex. Although there were no significant group differences in either task performance, related neural activity or tract-based spatial statistics, PGs did show decreased white matter integrity between the left basal ganglia and prefrontal cortex. Our results complement and expand similar findings from a previous study in alcohol-dependent patients. Although we found no association between white matter integrity and task performance here, decreased white matter connections may contribute to a diminished ability to recruit prefrontal networks needed for regulating behavior in PG. Hence, our findings could resonate an underlying risk factor for PG, and we speculate that these findings may extend to addiction in general. © 2016 Society for the Study of Addiction.

A Developmental Window into Trade-offs in Executive Function: The Case of Task Switching versus Response Inhibition in 6-year-olds

PubMed Central

Chatham, Christopher H.; Wiseheart, Melody; Munakata, Yuko

2014-01-01

Good executive function has been linked to many positive outcomes in academic performance, health, and social competence. However, some aspects of executive function may interfere with other cognitive processes. Childhood provides a unique test case for investigating such cognitive trade-offs, given the dramatic failures and developments observed during this period. For example, most children categorically switch or perseverate when asked to switch between rules on a card-sorting task. To test potential trade-offs with the development of task switching abilities, we compared 6-year-olds who switched versus perseverated in a card-sorting task on two aspects of inhibitory control: response inhibition (via a stop signal task) and interference control (via a Simon task). Across two studies, switchers showed worse response inhibition than perseverators, consistent with the idea of cognitive trade-offs; however, switchers showed better interference control than perseverators, consistent with prior work documenting benefits associated with the development of executive function. This pattern of positive and negative associations may reflect aspects of working memory (active maintenance of current goals, and clearing of prior goals) that help children focused on a single task-goal but hurt in situations with conflicting goals. Implications for understanding components of executive function and their relationships across development are discussed. PMID:24791710

Common and Distinct Neural Mechanisms of Attentional Switching and Response Conflict

PubMed Central

Kim, Chobok; Johnson, Nathan F.; Gold, Brian T.

2012-01-01

The human capacities for overcoming prepotent actions and flexibly switching between tasks represent cornerstones of cognitive control. Functional neuroimaging has implicated a diverse set of brain regions contributing to each of these cognitive control processes. However, the extent to which attentional switching and response conflict draw on shared or distinct neural mechanisms remains unclear. The current study examined the neural correlates of response conflict and attentional switching using event-related functional magnetic resonance imaging (fMRI) and a fully randomized 2×2 design. We manipulated an arrow-word version of the Stroop task to measure conflict and switching in the context of a single task decision, in response to a common set of stimuli. Under these common conditions, both behavioral and imaging data showed significant main effects of conflict and switching but no interaction. However, conjunction analyses identified frontal regions involved in both switching and response conflict, including the dorsal anterior cingulate cortex (dACC) and left inferior frontal junction. In addition, connectivity analyses demonstrated task-dependent functional connectivity patterns between dACC and inferior temporal cortex for attentional switching and between dACC and posterior parietal cortex for response conflict. These results suggest that the brain makes use of shared frontal regions, but can dynamically modulate the connectivity patterns of some of those regions, to deal with attentional switching and response conflict. PMID:22750124

Common and distinct neural mechanisms of attentional switching and response conflict.

PubMed

Kim, Chobok; Johnson, Nathan F; Gold, Brian T

2012-08-21

The human capacities for overcoming prepotent actions and flexibly switching between tasks represent cornerstones of cognitive control. Functional neuroimaging has implicated a diverse set of brain regions contributing to each of these cognitive control processes. However, the extent to which attentional switching and response conflict draw on shared or distinct neural mechanisms remains unclear. The current study examined the neural correlates of response conflict and attentional switching using event-related functional magnetic resonance imaging (fMRI) and a fully randomized 2×2 design. We manipulated an arrow-word version of the Stroop task to measure conflict and switching in the context of a single task decision, in response to a common set of stimuli. Under these common conditions, both behavioral and imaging data showed significant main effects of conflict and switching but no interaction. However, conjunction analyses identified frontal regions involved in both switching and response conflict, including the dorsal anterior cingulate cortex (dACC) and left inferior frontal junction. In addition, connectivity analyses demonstrated task-dependent functional connectivity patterns between dACC and inferior temporal cortex for attentional switching and between dACC and posterior parietal cortex for response conflict. These results suggest that the brain makes use of shared frontal regions, but can dynamically modulate the connectivity patterns of some of those regions, to deal with attentional switching and response conflict. Copyright © 2012 Elsevier B.V. All rights reserved.

Sustained selective attention predicts flexible switching in preschoolers.

PubMed

Benitez, Viridiana L; Vales, Catarina; Hanania, Rima; Smith, Linda B

2017-04-01

Stability and flexibility are fundamental to an intelligent cognitive system. Here, we examined the relationship between stability in selective attention and explicit control of flexible attention. Preschoolers were tested on the Dimension Preference (DP) task, which measures the stability of selective attention to an implicitly primed dimension, and the Dimension Change Card Sort (DCCS) task, which measures flexible attention switching between dimensions. Children who successfully switched on the DCCS task were more likely than those who perseverated to sustain attention to the primed dimension on the DP task across trials. We propose that perseverators have less stable attention and distribute their attention between dimensions, whereas switchers can successfully stabilize attention to individual dimensions and, thus, show more enduring priming effects. Flexible attention may emerge, in part, from implicit processes that stabilize attention even in tasks not requiring switching. Copyright © 2016 Elsevier Inc. All rights reserved.

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

ERIC Educational Resources Information Center

Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

2015-01-01

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

Abacus Training Affects Math and Task Switching Abilities and Modulates Their Relationships in Chinese Children

PubMed Central

Yao, Yuan; Weng, Jian; Hu, Yuzheng; Chen, Feiyan

2015-01-01

Our previous work demonstrated that abacus-based mental calculation (AMC), a traditional Chinese calculation method, could help children improve their math abilities (e.g. basic arithmetical ability) and executive function (e.g. working memory). This study further examined the effects of long-term AMC training on math ability in visual-spatial domain and the task switching component of executive function. More importantly, this study investigated whether AMC training modulated the relationship between math abilities and task switching. The participants were seventy 7-year-old children who were randomly assigned into AMC and control groups at primary school entry. Children in AMC group received 2-hour AMC training every week since primary school entry. On the contrary, children in the control group had never received any AMC training. Math and task switching abilities were measured one year and three years respectively after AMC training began. The results showed that AMC children performed better than their peers on math abilities in arithmetical and visual-spatial domains. In addition, AMC group responded faster than control group in the switching task, while no group difference was found in switch cost. Most interestingly, group difference was present in the relationships between math abilities and switch cost. These results implied the effect of AMC training on math abilities as well as its relationship with executive function. PMID:26444689

Abacus Training Affects Math and Task Switching Abilities and Modulates Their Relationships in Chinese Children.

PubMed

Wang, Chunjie; Geng, Fengji; Yao, Yuan; Weng, Jian; Hu, Yuzheng; Chen, Feiyan

2015-01-01

Our previous work demonstrated that abacus-based mental calculation (AMC), a traditional Chinese calculation method, could help children improve their math abilities (e.g. basic arithmetical ability) and executive function (e.g. working memory). This study further examined the effects of long-term AMC training on math ability in visual-spatial domain and the task switching component of executive function. More importantly, this study investigated whether AMC training modulated the relationship between math abilities and task switching. The participants were seventy 7-year-old children who were randomly assigned into AMC and control groups at primary school entry. Children in AMC group received 2-hour AMC training every week since primary school entry. On the contrary, children in the control group had never received any AMC training. Math and task switching abilities were measured one year and three years respectively after AMC training began. The results showed that AMC children performed better than their peers on math abilities in arithmetical and visual-spatial domains. In addition, AMC group responded faster than control group in the switching task, while no group difference was found in switch cost. Most interestingly, group difference was present in the relationships between math abilities and switch cost. These results implied the effect of AMC training on math abilities as well as its relationship with executive function.

Detailed analysis of the supermarket task included on the Japanese version of the Rapid Dementia Screening Test.

PubMed

Moriyama, Yasushi; Yoshino, Aihide; Muramatsu, Taro; Mimura, Masaru

2017-05-01

The supermarket task, which is included in the Japanese version of the Rapid Dementia Screening Test, requires the quick (1 min) generation of words for things that can be bought in a supermarket. Cluster size and switches are investigated during this task. We investigated how the severity of dementia related to cluster size and switches on the supermarket task in patients with Alzheimer's disease. We administered the Japanese version of the Rapid Dementia Screening Test to 250 patients with very mild to severe Alzheimer's disease and to 49 healthy volunteers. Patients had Mini-Mental State Examination scores from 12 to 26 and Clinical Dementia Rating scale scores from 0.5 to 3. Patients were divided into four groups based on their Clinical Dementia Rating score (0.5, 1, 2, 3). We performed statistical analyses between the four groups and control subjects based on cluster size and switch scores on the supermarket task. The score for cluster size and switches deteriorated according to the severity of dementia. Moreover, for subjects with a Clinical Dementia Rating score of 0.5, cluster size was impaired, but switches were intact. Our findings indicate that the scores for cluster size and switches on the supermarket task may be useful for detecting the severity of symptoms of dementia in patients with Alzheimer's disease. © 2016 The Authors. Psychogeriatrics © 2016 Japanese Psychogeriatric Society.

Loss restlessness and gain calmness: durable effects of losses and gains on choice switching.

PubMed

Yechiam, Eldad; Zahavi, Gal; Arditi, Eli

2015-08-01

While the traditional conceptualization of the effect of losses focuses on bias in the subjective weight of losses compared with respective gains, some accounts suggest more global task-related effects of losses. Based on a recent attentional theory, we predicted a positive after-effect of losses on choice switching in later tasks. In two experimental studies, we found increased choice switching rates in tasks with losses compared to tasks with no losses. Additionally, this heightened shifting behavior was maintained in subsequent tasks that do not include losses, a phenomenon we refer to as "loss restlessness." Conversely, gains were found to have an opposite "calming" effect on choice switching. Surprisingly, the loss restlessness phenomenon was observed following an all-losses payoff regime but not after a task with symmetric mixed gains and losses. This suggests that the unresolved mental account following an all-losses regime increases search behavior. Potential implications to macro level phenomena, such as the leverage effect, are discussed.

Cognitive Flexibility in ASD; Task Switching with Emotional Faces

ERIC Educational Resources Information Center

de Vries, Marieke; Geurts, Hilde M.

2012-01-01

Children with autism spectrum disorders (ASDs) show daily cognitive flexibility deficits, but laboratory data are unconvincing. The current study aimed to bridge this gap. Thirty-one children with ASD (8-12 years) and 31 age- and IQ-matched typically developing children performed a gender emotion switch task. Unannounced switches and complex…

Cognitive effort is modulated outside of the explicit awareness of conflict frequency: Evidence from pupillometry.

PubMed

Diede, Nathaniel T; Bugg, Julie M

2017-05-01

Classic theories of cognitive control conceptualized controlled processes as slow, strategic, and willful, with automatic processes being fast and effortless. The context-specific proportion compatibility (CSPC) effect, the reduction in the compatibility effect in a context (e.g., location) associated with a high relative to low likelihood of conflict, challenged classic theories by demonstrating fast and flexible control that appears to operate outside of conscious awareness. Two theoretical questions yet to be addressed are whether the CSPC effect is accompanied by context-dependent variation in effort, and whether the exertion of effort depends on explicit awareness of context-specific task demands. To address these questions, pupil diameter was measured during a CSPC paradigm. Stimuli were randomly presented in either a mostly compatible location or a mostly incompatible location. Replicating prior research, the CSPC effect was found. The novel finding was that pupil diameter was greater in the mostly incompatible location compared to the mostly compatible location, despite participants' lack of awareness of context-specific task demands. Additionally, this difference occurred regardless of trial type or a preceding switch in location. These patterns support the view that context (location) dictates selection of optimal attentional settings in the CSPC paradigm, and varying levels of effort and performance accompany these settings. Theoretically, these patterns imply that cognitive control may operate fast, flexibly, and outside of awareness, but not effortlessly. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Degrading emotional memories induced by a virtual reality paradigm.

PubMed

Cuperus, Anne A; Laken, Maarten; van den Hout, Marcel A; Engelhard, Iris M

2016-09-01

In Eye Movement and Desensitization and Reprocessing (EMDR) therapy, a dual-task approach is used: patients make horizontal eye movements while they recall aversive memories. Studies showed that this reduces memory vividness and/or emotionality. A strong explanation is provided by working memory theory, which suggests that other taxing dual-tasks are also effective. Experiment 1 tested whether a visuospatial task which was carried out while participants were blindfolded taxes working memory. Experiment 2 tested whether this task degrades negative memories induced by a virtual reality (VR) paradigm. In experiment 1, participants responded to auditory cues with or without simultaneously carrying out the visuospatial task. In experiment 2, participants recalled negative memories induced by a VR paradigm. The experimental group simultaneously carried out the visuospatial task, and a control group merely recalled the memories. Changes in self-rated memory vividness and emotionality were measured. The slowing down of reaction times due to the visuospatial task indicated that its cognitive load was greater than the load of the eye movements task in previous studies. The task also led to reductions in emotionality (but not vividness) of memories induced by the VR paradigm. Weaknesses are that only males were tested in experiment 1, and the effectiveness of the VR fear/trauma induction was not assessed with ratings of mood or intrusions in experiment 2. The results suggest that the visuospatial task may be applicable in clinical settings, and the VR paradigm may provide a useful method of inducing negative memories. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cognitive Training Sustainably Improves Executive Functioning in Middle-Aged Industry Workers Assessed by Task Switching: A Randomized Controlled ERP Study

PubMed Central

Gajewski, Patrick D.; Freude, Gabriele; Falkenstein, Michael

2017-01-01

Recently, we reported results of a cross-sectional study investigating executive functions in dependence of aging and type of work. That study showed deficits in performance and electrophysiological activity in middle-aged workers with long-term repetitive and unchallenging work. Based on these findings, we conducted a longitudinal study that aimed at ameliorating these cognitive deficits by means of a trainer-guided cognitive training (CT) in 57 further middle-aged workers with repetitive type of work from the same factory. This study was designed as a randomized controlled trail with pre- (t1), post- (t2), and a 3-month follow-up (t3) measure. The waiting control group was trained between t2 and t3. The training lasted 3 months (20 sessions) and was evaluated with the same task switching paradigm used in the previous cross-sectional study. The CT improved performance in accuracy at the behavioral level and affected the electrophysiological correlates of retrieval of stimulus-response sets (P2), response selection (N2), and error detection (Ne), thus unveiling the neuronal background of the behavioral effects. The same training effects were observed in the waiting control group after CT at t3. Moreover, at t3, most of the behavioral and electrophysiological training-induced changes were found stable. Hence, CT appears to be an important intervention for compensating cognitive deficits in executive functions in middle-aged employees with cognitively unchallenging work. PMID:28275347

Toward a functional analysis of the basal ganglia.

PubMed

Hayes, A E; Davidson, M C; Keele, S W; Rafal, R D

1998-03-01

Parkinson patients were tested in two paradigms to test the hypothesis that the basal ganglia are involved in the shifting of attentional set. Set shifting means a respecification of the conditions that regulate responding, a process sometimes referred to as an executive process. In one paradigm, upon the appearance of each stimulus, subjects were instructed to respond either to its color or to its shape. In a second paradigm, subjects learned to produce short sequences of three keypresses in response to two arbitrary stimuli. Reaction times were compared for the cases where set either remained the same or changed for two successive stimuli. Parkinson patients were slow to change set compared to controls. Parkinson patients were also less able to filter the competing but irrelevant set than were control subjects. The switching deficit appears to be dopamine based; the magnitude of the shifting deficit was related to the degree to which 1-dopa-based medication ameliorated patients' motor symptoms. Moreover, temporary withholding of medication, a so-called off manipulation, increased the time to switch. Using the framework of equilibrium point theory of movement, we discuss how a set switching deficit may also underlie clinical motor disturbances seen in Parkinson's disease.

Switch-Task Performance in Rats Is Disturbed by 12 h of Sleep Deprivation But Not by 12 h of Sleep Fragmentation

PubMed Central

Leenaars, Cathalijn H.C.; Joosten, Ruud N.J.M.A.; Zwart, Allard; Sandberg, Hans; Ruimschotel, Emma; Hanegraaf, Maaike A.J.; Dematteis, Maurice; Feenstra, Matthijs G.P.; van Someren, Eus J.W.

2012-01-01

Study Objectives: Task-switching is an executive function involving the prefrontal cortex. Switching temporarily attenuates the speed and/or accuracy of performance, phenomena referred to as switch costs. In accordance with the idea that prefrontal function is particularly sensitive to sleep loss, switch-costs increase during prolonged waking in humans. It has been difficult to investigate the underlying neurobiological mechanisms because of the lack of a suitable animal model. Here, we introduce the first switch-task for rats and report the effects of sleep deprivation and inactivation of the medial prefrontal cortex. Design: Rats were trained to repeatedly switch between 2 stimulus-response associations, indicated by the presentation of a visual or an auditory stimulus. These stimulus-response associations were offered in blocks, and performance was compared for the first and fifth trials of each block. Performance was tested after exposure to 12 h of total sleep deprivation, sleep fragmentation, and their respective movement control conditions. Finally, it was tested after pharmacological inactivation of the medial prefrontal cortex. Settings: Controlled laboratory settings. Participants: 15 male Wistar rats. Measurements & Results: Both accuracy and latency showed switch-costs at baseline. Twelve hours of total sleep deprivation, but not sleep fragmentation, impaired accuracy selectively on the switch-trials. Inactivation of the medial prefrontal cortex by local neuronal inactivation resulted in an overall decrease in accuracy. Conclusions: We developed and validated a switch-task that is sensitive to sleep deprivation. This introduces the possibility for in-depth investigations on the neurobiological mechanisms underlying executive impairments after sleep disturbance in a rat model. Citation: Leenaars CHC; Joosten RNJMA; Zwart A; Sandberg H; Ruimschotel E; Hanegraaf MAJ; Dematteis M; Feenstra MGP; van Someren EJW. Switch-task performance in rats is disturbed by 12 h of sleep deprivation but not by 12 h of sleep fragmentation. SLEEP 2012;35(2):211-221. PMID:22294811

The Effects of Level of Autonomy on Human-Agent Teaming for Multi-Robot Control and Local Security Maintenance

DTIC Science & Technology

2013-11-01

different types of tasks, the associated costs of task switching also increase (Squire et al., 2006). Task switching costs may be increased with higher...switching costs as well, particularly when managing robot teams of increasing size (Squire et al., 2006). 1.3 Individual Differences The effects of...Research: Ready to Deliver the Promises. Mind 2003, 2 (3), 4. Jian, J.; Bisantz, A. M.; Drury , C. G. Foundations for an Empirically Determined Scale

Outsourcing cognitive control to the environment: adult age differences in the use of task cues.

PubMed

Spieler, Daniel H; Mayr, Ulrich; LaGrone, Susan

2006-10-01

When an initial phase of cued task switching is followed by a phase of single-task trials, older adults show difficulties changing to the more efficient single-task mode of processing (Mayr & Liebscher, 2001). In Experiment 1, we show that these costs follow older adults' continued tendency to inspect task cues even though these provide no new information. In Experiment 2, we included a condition in which task cues were eliminated from the display after the task-switching phase. In this condition, older adults behaved the same as younger adults, suggesting that the presence of the task cue is critical for observing age differences while switching from a "high-control" to a "low-control" mode of processing. We discuss our results in terms of a life-span shift with regard to the reliance on internal versus external sources of information under conditions of high-control demands.

Visual Attention Allocation Between Robotic Arm and Environmental Process Control: Validating the STOM Task Switching Model

NASA Technical Reports Server (NTRS)

Wickens, Christopher; Vieanne, Alex; Clegg, Benjamin; Sebok, Angelia; Janes, Jessica

2015-01-01

Fifty six participants time shared a spacecraft environmental control system task with a realistic space robotic arm control task in either a manual or highly automated version. The former could suffer minor failures, whose diagnosis and repair were supported by a decision aid. At the end of the experiment this decision aid unexpectedly failed. We measured visual attention allocation and switching between the two tasks, in each of the eight conditions formed by manual-automated arm X expected-unexpected failure X monitoring- failure management. We also used our multi-attribute task switching model, based on task attributes of priority interest, difficulty and salience that were self-rated by participants, to predict allocation. An un-weighted model based on attributes of difficulty, interest and salience accounted for 96 percent of the task allocation variance across the 8 different conditions. Task difficulty served as an attractor, with more difficult tasks increasing the tendency to stay on task.

Differential Effects of Aging on Processes Underlying Task Switching

ERIC Educational Resources Information Center

West, Robert; Travers, Stephanie

2008-01-01

In this study, we used event-related brain potentials (ERPs) to examine the effects of aging on processes underlying task switching. The response time data revealed an age-related increase in mixing costs before controlling for general slowing and no effect of aging on switching costs. In the cue-locked epoch, the ERP data revealed little effect…

Automation of learning-set testing - The video-task paradigm

NASA Technical Reports Server (NTRS)

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

1989-01-01

Researchers interested in studying discrimination learning in primates have typically utilized variations in the Wisconsin General Test Apparatus (WGTA). In the present experiment, a new testing apparatus for the study of primate learning is proposed. In the video-task paradigm, rhesus monkeys (Macaca mulatta) respond to computer-generated stimuli by manipulating a joystick. Using this apparatus, discrimination learning-set data for 2 monkeys were obtained. Performance on Trial 2 exceeded 80 percent within 200 discrimination learning problems. These data illustrate the utility of the video-task paradigm in comparative research. Additionally, the efficient learning and rich data that were characteristic of this study suggest several advantages of the present testing paradigm over traditional WGTA testing.

Modality Switching Cost during Property Verification by 7 Years of Age

ERIC Educational Resources Information Center

Ambrosi, Solene; Kalenine, Solene; Blaye, Agnes; Bonthoux, Francoise

2011-01-01

Recent studies in neuroimagery and cognitive psychology support the view of sensory-motor based knowledge: when processing an object concept, neural systems would re-enact previous experiences with this object. In this experiment, a conceptual switching cost paradigm derived from Pecher, Zeelenberg, and Barsalou (2003, 2004) was used to…

Rethinking volitional control over task choice in multitask environments: use of a stimulus set selection strategy in voluntary task switching.

PubMed

Arrington, Catherine M; Weaver, Starla M

2015-01-01

Under conditions of volitional control in multitask environments, subjects may engage in a variety of strategies to guide task selection. The current research examines whether subjects may sometimes use a top-down control strategy of selecting a task-irrelevant stimulus dimension, such as location, to guide task selection. We term this approach a stimulus set selection strategy. Using a voluntary task switching procedure, subjects voluntarily switched between categorizing letter and number stimuli that appeared in two, four, or eight possible target locations. Effects of stimulus availability, manipulated by varying the stimulus onset asynchrony between the two target stimuli, and location repetition were analysed to assess the use of a stimulus set selection strategy. Considered across position condition, Experiment 1 showed effects of both stimulus availability and location repetition on task choice suggesting that only in the 2-position condition, where selection based on location always results in a target at the selected location, subjects may have been using a stimulus set selection strategy on some trials. Experiment 2 replicated and extended these findings in a visually more cluttered environment. These results indicate that, contrary to current models of task selection in voluntary task switching, the top-down control of task selection may occur in the absence of the formation of an intention to perform a particular task.

Switch-task performance in rats is disturbed by 12 h of sleep deprivation but not by 12 h of sleep fragmentation.

PubMed

Leenaars, Cathalijn H C; Joosten, Ruud N J M A; Zwart, Allard; Sandberg, Hans; Ruimschotel, Emma; Hanegraaf, Maaike A J; Dematteis, Maurice; Feenstra, Matthijs G P; van Someren, Eus J W

2012-02-01

Task-switching is an executive function involving the prefrontal cortex. Switching temporarily attenuates the speed and/or accuracy of performance, phenomena referred to as switch costs. In accordance with the idea that prefrontal function is particularly sensitive to sleep loss, switch-costs increase during prolonged waking in humans. It has been difficult to investigate the underlying neurobiological mechanisms because of the lack of a suitable animal model. Here, we introduce the first switch-task for rats and report the effects of sleep deprivation and inactivation of the medial prefrontal cortex. Rats were trained to repeatedly switch between 2 stimulus-response associations, indicated by the presentation of a visual or an auditory stimulus. These stimulus-response associations were offered in blocks, and performance was compared for the first and fifth trials of each block. Performance was tested after exposure to 12 h of total sleep deprivation, sleep fragmentation, and their respective movement control conditions. Finally, it was tested after pharmacological inactivation of the medial prefrontal cortex. Controlled laboratory settings. 15 male Wistar rats. Both accuracy and latency showed switch-costs at baseline. Twelve hours of total sleep deprivation, but not sleep fragmentation, impaired accuracy selectively on the switch-trials. Inactivation of the medial prefrontal cortex by local neuronal inactivation resulted in an overall decrease in accuracy. We developed and validated a switch-task that is sensitive to sleep deprivation. This introduces the possibility for in-depth investigations on the neurobiological mechanisms underlying executive impairments after sleep disturbance in a rat model.

Psychophysical spectro-temporal receptive fields in an auditory task.

PubMed

Shub, Daniel E; Richards, Virginia M

2009-05-01

Psychophysical relative weighting functions, which provide information about the importance of different regions of a stimulus in forming decisions, are traditionally estimated using trial-based procedures, where a single stimulus is presented and a single response is recorded. Everyday listening is much more "free-running" in that we often must detect randomly occurring signals in the presence of a continuous background. Psychophysical relative weighting functions have not been measured with free-running paradigms. Here, we combine a free-running paradigm with the reverse correlation technique used to estimate physiological spectro-temporal receptive fields (STRFs) to generate psychophysical relative weighting functions that are analogous to physiological STRFs. The psychophysical task required the detection of a fixed target signal (a sequence of spectro-temporally coherent tone pips with a known frequency) in the presence of a continuously presented informational masker (spectro-temporally random tone pips). A comparison of psychophysical relative weighting functions estimated with the current free-running paradigm and trial-based paradigms, suggests that in informational-masking tasks subjects' decision strategies are similar in both free-running and trial-based paradigms. For more cognitively challenging tasks there may be differences in the decision strategies with free-running and trial-based paradigms.

Cognitive Control Signals in Posterior Cingulate Cortex

PubMed Central

Hayden, Benjamin Y.; Smith, David V.; Platt, Michael L.

2010-01-01

Efficiently shifting between tasks is a central function of cognitive control. The role of the default network – a constellation of areas with high baseline activity that declines during task performance – in cognitive control remains poorly understood. We hypothesized that task switching demands cognitive control to shift the balance of processing toward the external world, and therefore predicted that switching between the two tasks would require suppression of activity of neurons within the posterior cingulate cortex (CGp). To test this idea, we recorded the activity of single neurons in CGp, a central node in the default network, in monkeys performing two interleaved tasks. As predicted, we found that basal levels of neuronal activity were reduced following a switch from one task to another and gradually returned to pre-switch baseline on subsequent trials. We failed to observe these effects in lateral intraparietal cortex, part of the dorsal fronto-parietal cortical attention network directly connected to CGp. These findings indicate that suppression of neuronal activity in CGp facilitates cognitive control, and suggest that activity in the default network reflects processes that directly compete with control processes elsewhere in the brain. PMID:21160560

Electrophysiological correlates of preparation and implementation for different types of task shifts.

PubMed

Hsieh, Shulan; Wu, Mengyao

2011-11-14

The ability to flexibly shift between tasks is central to cognitive control, but whether the same brain mechanisms mediate shifting across different tasks is unknown. In this study, we investigated whether variations in stimulus-dimensions or response-mapping might influence task switching in terms of its preparatory processes, as reflected in cue-locked event-related potentials (ERPs), and its implementation processes, as reflected in stimulus-locked ERPs. Participants judged pairs of digits as same or different in one of two conditions. In one condition, the task-relevant stimulus-dimension was either repeated or switched across trials while the response-mapping rule was kept constant. In the other condition, the task-relevant stimulus-dimension was kept constant while the response-mapping rule was repeated or switched across trials. The length of the preparatory interval was manipulated. Data revealed switch-related preparatory ERP components (including N2 and a late slow positivity) that were associated with both types of task shifting and an N400-like negativity that distinguished between the two types. Several switch-related implementation ERP components associated with both types of task shifting were found at posterior sites. Distinct frontal modulations of the N1, P2, and N2 were found to associate with the implementation of the response-mapping shift, whereas a slow positivity was associated with the implementation of the stimulus-dimension shift. Therefore, this study demonstrates that there are shared and distinct processes across different types of task shifting. Finally, because the same transition-cue was used for different task shifts, the distinct processes cannot be explained simply by differences in cue processing. Copyright © 2011 Elsevier B.V. All rights reserved.

Exploring individual differences in task switching: Persistence and other personality traits related to anterior cingulate cortex function.

PubMed

Umemoto, A; Holroyd, C B

2016-01-01

Anterior cingulate cortex (ACC) is involved in cognitive control and decision-making but its precise function is still highly debated. Based on evidence from lesion, neurophysiological, and neuroimaging studies, we have recently proposed a critical role for ACC in motivating extended behaviors according to learned task values (Holroyd and Yeung, 2012). Computational simulations based on this theory suggest a hierarchical mechanism in which a caudal division of ACC selects and applies control over task execution, and a rostral division of ACC facilitates switches between tasks according to a higher task strategy (Holroyd and McClure, 2015). This theoretical framework suggests that ACC may contribute to personality traits related to persistence and reward sensitivity (Holroyd and Umemoto, 2016). To explore this possibility, we carried out a voluntary task switching experiment in which on each trial participants freely chose one of two tasks to perform, under the condition that they try to select the tasks "at random" and equally often. The participants also completed several questionnaires that assessed personality trait related to persistence, apathy, anhedonia, and rumination, in addition to the Big 5 personality inventory. Among other findings, we observed greater compliance with task instructions by persistent individuals, as manifested by a greater facility with switching between tasks, which is suggestive of increased engagement of rostral ACC. © 2016 Elsevier B.V. All rights reserved.

Cognitive capacity limitations and Need for Cognition differentially predict reward-induced cognitive effort expenditure.

PubMed

Sandra, Dasha A; Otto, A Ross

2018-03-01

While psychological, economic, and neuroscientific accounts of behavior broadly maintain that people minimize expenditure of cognitive effort, empirical work reveals how reward incentives can mobilize increased cognitive effort expenditure. Recent theories posit that the decision to expend effort is governed, in part, by a cost-benefit tradeoff whereby the potential benefits of mental effort can offset the perceived costs of effort exertion. Taking an individual differences approach, the present study examined whether one's executive function capacity, as measured by Stroop interference, predicts the extent to which reward incentives reduce switch costs in a task-switching paradigm, which indexes additional expenditure of cognitive effort. In accordance with the predictions of a cost-benefit account of effort, we found that a low executive function capacity-and, relatedly, a low intrinsic motivation to expend effort (measured by Need for Cognition)-predicted larger increase in cognitive effort expenditure in response to monetary reward incentives, while individuals with greater executive function capacity-and greater intrinsic motivation to expend effort-were less responsive to reward incentives. These findings suggest that an individual's cost-benefit tradeoff is constrained by the perceived costs of exerting cognitive effort. Copyright © 2017 Elsevier B.V. All rights reserved.

The juggling paradigm: a novel social neuroscience approach to identify neuropsychophysiological markers of team mental models.

PubMed

Filho, Edson; Bertollo, Maurizio; Robazza, Claudio; Comani, Silvia

2015-01-01

Since the discovery of the mirror neuron system in the 1980s, little, if any, research has been devoted to the study of interactive motor tasks (Goldman, 2012). Scientists interested in the neuropsychophysiological markers of joint motor action have relied on observation paradigms and passive tasks rather than dynamic paradigms and interactive tasks (Konvalinka and Roepstorff, 2012). Within this research scenario, we introduce a novel research paradigm that uses cooperative juggling as a platform to capture peripheral (e.g., skin conductance, breathing and heart rates, electromyographic signals) and central neuropsychophysiological (e.g., functional connectivity within and between brains) markers underlying the notion of team mental models (TMM). We discuss the epistemological and theoretical grounds of a cooperative juggling paradigm, and propose testable hypotheses on neuropsychophysiological markers underlying TMM. Furthermore, we present key methodological concerns that may influence peripheral responses as well as single and hyperbrain network configurations during joint motor action. Preliminary findings of the paradigm are highlighted. We conclude by delineating avenues for future research.

Durability of classification and action learning: differences revealed using ex-Gaussian distribution analysis.

PubMed

Moutsopoulou, Karolina; Waszak, Florian

2013-05-01

It has been shown that in associative learning it is possible to disentangle the effects caused on behaviour by the associations between a stimulus and a classification (S-C) and the associations between a stimulus and the action performed towards it (S-A). Such evidence has been provided using ex-Gaussian distribution analysis to show that different parameters of the reaction time distribution reflect the different processes. Here, using this method, we investigate another difference between these two types of associations: What is the relative durability of these associations across time? Using a task-switching paradigm and by manipulating the lag between the point of the creation of the associations and the test phase, we show that S-A associations have stronger effects on behaviour when the lag between the two repetitions of a stimulus is short. However, classification learning affects behaviour not only in short-term lags but also (and equally so) when the lag between prime and probe is long and the same stimuli are repeatedly presented within a different classification task, demonstrating a remarkable durability of S-C associations.

Stable Scalp EEG Spatiospectral Patterns Across Paradigms Estimated by Group ICA.

PubMed

Labounek, René; Bridwell, David A; Mareček, Radek; Lamoš, Martin; Mikl, Michal; Slavíček, Tomáš; Bednařík, Petr; Baštinec, Jaromír; Hluštík, Petr; Brázdil, Milan; Jan, Jiří

2018-01-01

Electroencephalography (EEG) oscillations reflect the superposition of different cortical sources with potentially different frequencies. Various blind source separation (BSS) approaches have been developed and implemented in order to decompose these oscillations, and a subset of approaches have been developed for decomposition of multi-subject data. Group independent component analysis (Group ICA) is one such approach, revealing spatiospectral maps at the group level with distinct frequency and spatial characteristics. The reproducibility of these distinct maps across subjects and paradigms is relatively unexplored domain, and the topic of the present study. To address this, we conducted separate group ICA decompositions of EEG spatiospectral patterns on data collected during three different paradigms or tasks (resting-state, semantic decision task and visual oddball task). K-means clustering analysis of back-reconstructed individual subject maps demonstrates that fourteen different independent spatiospectral maps are present across the different paradigms/tasks, i.e. they are generally stable.

Intended actions and unexpected outcomes: automatic and controlled processing in a rapid motor task

PubMed Central

Cheyne, Douglas O.; Ferrari, Paul; Cheyne, James A.

2012-01-01

Human action involves a combination of controlled and automatic behavior. These processes may interact in tasks requiring rapid response selection or inhibition, where temporal constraints preclude timely intervention by conscious, controlled processes over automatized prepotent responses. Such contexts tend to produce frequent errors, but also rapidly executed correct responses, both of which may sometimes be perceived as surprising, unintended, or “automatic”. In order to identify neural processes underlying these two aspects of cognitive control, we measured neuromagnetic brain activity in 12 right-handed subjects during manual responses to rapidly presented digits, with an infrequent target digit that required switching response hand (bimanual task) or response finger (unimanual task). Automaticity of responding was evidenced by response speeding (shorter response times) prior to both failed and fast correct switches. Consistent with this automaticity interpretation of fast correct switches, we observed bilateral motor preparation, as indexed by suppression of beta band (15–30 Hz) oscillations in motor cortex, prior to processing of the switch cue in the bimanual task. In contrast, right frontal theta activity (4–8 Hz) accompanying correct switch responses began after cue onset, suggesting that it reflected controlled inhibition of the default response. Further, this activity was reduced on fast correct switch trials suggesting a more automatic mode of inhibitory control. We also observed post-movement (event-related negativity) ERN-like responses and theta band increases in medial and anterior frontal regions that were significantly larger on error trials, and may reflect a combination of error and delayed inhibitory signals. We conclude that both automatic and controlled processes are engaged in parallel during rapid motor tasks, and that the relative strength and timing of these processes may underlie both optimal task performance and subjective experiences of automaticity or control. PMID:22912612

Incidental Learning of S-R Contingencies in the Masked Prime Task

ERIC Educational Resources Information Center

Schlaghecken, Friederike; Blagrove, Elisabeth; Maylor, Elizabeth A.

2007-01-01

Subliminal motor priming effects in the masked prime paradigm can only be obtained when primes are part of the task set. In 2 experiments, the authors investigated whether the relevant task set feature needs to be explicitly instructed or could be extracted automatically in an incidental learning paradigm. Primes and targets were symmetrical…

Proactive Adjustments of Response Strategies in the Stop-Signal Paradigm

ERIC Educational Resources Information Center

Verbruggen, Frederick; Logan, Gordon D.

2009-01-01

In the stop-signal paradigm, fast responses are harder to inhibit than slow responses, so subjects must balance speed is the go task with successful stopping in the stop task. In theory, subjects achieve this balance by adjusting response thresholds for the go task, making proactive adjustments in response to instructions that indicate that…

Humans Integrate Monetary and Liquid Incentives to Motivate Cognitive Task Performance

PubMed Central

Yee, Debbie M.; Krug, Marie K.; Allen, Ariel Z.; Braver, Todd S.

2016-01-01

It is unequivocal that a wide variety of incentives can motivate behavior. However, few studies have explicitly examined whether and how different incentives are integrated in terms of their motivational influence. The current study examines the combined effects of monetary and liquid incentives on cognitive processing, and whether appetitive and aversive incentives have distinct influences. We introduce a novel task paradigm, in which participants perform cued task-switching for monetary rewards that vary parametrically across trials, with liquid incentives serving as post-trial performance feedback. Critically, the symbolic meaning of the liquid was held constant (indicating successful reward attainment), while liquid valence was blocked. In the first experiment, monetary rewards combined additively with appetitive liquid feedback to improve subject task performance. Aversive liquid feedback counteracted monetary reward effects in low monetary reward trials, particularly in a subset of participants who tended to avoid responding under these conditions. Self-report motivation ratings predicted behavioral performance above and beyond experimental effects. A follow-up experiment replicated the predictive power of motivation ratings even when only appetitive liquids were used, suggesting that ratings reflect idiosyncratic subjective values of, rather than categorical differences between, the liquid incentives. Together, the findings indicate an integrative relationship between primary and secondary incentives and potentially dissociable influences in modulating motivational value, while informing hypotheses regarding candidate neural mechanisms. PMID:26834668

How Positive Affect Modulates Cognitive Control: Reduced Perseveration at the Cost of Increased Distractibility

ERIC Educational Resources Information Center

Dreisbach, Gesine; Goschke, Thomas

2004-01-01

A fundamental problem that organisms face in a changing environment is how to regulate dynamically the balance between stable maintenance and flexible switching of goals and cognitive sets. The authors show that positive affect plays an important role in the regulation of this stability-flexibility balance. In a cognitive set-switching paradigm,…

Bottom-Up Influences on Voluntary Task Switching: The Elusive Homunculus Escapes

ERIC Educational Resources Information Center

Yeung, Nick

2010-01-01

Voluntary action can be studied by giving participants free choice over which task to perform in response to each presented stimulus. In such experiments, performance costs are observed when participants choose to switch tasks from the previous trial. It has been proposed that these costs primarily index the time-consuming operation of top-down…

Inhibition, interference, and conflict in task switching.

PubMed

Costa, Russell E; Friedrich, Frances J

2012-12-01

The role of inhibition in the task-switching process has received increased empirical and theoretical attention in the literature on cognitive control. Many accounts have suggested that inhibition occurs when a conflict must be resolved-for example, when a target stimulus contains features of more than one task. In the two experiments reported here, we used variants of backward inhibition, or N - 2 repetition, designs to examine (1) whether inhibition occurs in the absence of conflict at the stimulus or response level, (2) when in the task-switching process such inhibition may occur, and (3) the potential consequences of inhibition. In Experiment 1, we demonstrate that neither stimulus- nor response-level conflict is necessary for inhibition to occur, while the results of Experiment 2 suggest that inhibition may be associated with a reduction of proactive interference (PI) from a previously performed task. Evidence of inhibition and the reduction of PI both occurred at the task-set level. However, inhibition of specific stimulus values can also occur, but this is clearly separable from task-set inhibition. Both experiments also provided evidence that task-set inhibition can be applied at the time of the new task cue, as opposed to at the onset of the target or at the response stage of the trial. Taken together, the results from these experiments provide insight into when and where in the task-switching process inhibition may occur, as well as into the potential functional benefits that inhibition of task sets may provide.

An Object-Oriented Approach to Writing Computational Electromagnetics Codes

NASA Technical Reports Server (NTRS)

Zimmerman, Martin; Mallasch, Paul G.

1996-01-01

Presently, most computer software development in the Computational Electromagnetics (CEM) community employs the structured programming paradigm, particularly using the Fortran language. Other segments of the software community began switching to an Object-Oriented Programming (OOP) paradigm in recent years to help ease design and development of highly complex codes. This paper examines design of a time-domain numerical analysis CEM code using the OOP paradigm, comparing OOP code and structured programming code in terms of software maintenance, portability, flexibility, and speed.

Task-switching costs promote the evolution of division of labor and shifts in individuality

PubMed Central

Goldsby, Heather J.; Dornhaus, Anna; Kerr, Benjamin; Ofria, Charles

2012-01-01

From microbes to humans, the success of many organisms is achieved by dividing tasks among specialized group members. The evolution of such division of labor strategies is an important aspect of the major transitions in evolution. As such, identifying specific evolutionary pressures that give rise to group-level division of labor has become a topic of major interest among biologists. To overcome the challenges associated with studying this topic in natural systems, we use actively evolving populations of digital organisms, which provide a unique perspective on the de novo evolution of division of labor in an open-ended system. We provide experimental results that address a fundamental question regarding these selective pressures: Does the ability to improve group efficiency through the reduction of task-switching costs promote the evolution of division of labor? Our results demonstrate that as task-switching costs rise, groups increasingly evolve division of labor strategies. We analyze the mechanisms by which organisms coordinate their roles and discover strategies with striking biological parallels, including communication, spatial patterning, and task-partitioning behaviors. In many cases, under high task-switching costs, individuals cease to be able to perform tasks in isolation, instead requiring the context of other group members. The simultaneous loss of functionality at a lower level and emergence of new functionality at a higher level indicates that task-switching costs may drive both the evolution of division of labor and also the loss of lower-level autonomy, which are both key components of major transitions in evolution. PMID:22872867

Exploring the cognitive load of negative thinking: a novel dual-task experiment.

PubMed

Takano, Keisuke; Iijima, Yudai; Sakamoto, Shinji; Tanno, Yoshihiko

2014-12-01

Females are more likely to engage in the preoccupation of past negative experiences than males, which might contribute to their greater tendency toward depression. However, there is limited understanding regarding the cognitive basis for the negative autobiographical information processing of females. In the present study, we assessed the cognitive resources required for negative thinking, by using a novel dual-task paradigm that combined think-aloud and time-estimation tasks. Fifty-three Japanese undergraduate students were asked to think aloud about personal past or future emotional episodes for a particular duration. In addition, they were asked to estimate the duration of their speech. Their estimates were compared to the actual time taken, and the errors were used as indices of cognitive burden during the speech task. As compared to males, females exhibited greater judgment errors, particularly when thinking about their past negative experiences. This suggests that females allocate more attentional resources toward thinking about the past. Participants could rehearse the task during the time reproduction phase, and the quality of the rehearsal and their memory capacity might have influenced the accuracy of their duration judgment. Females tend to allocate more attentional resources than males to thinking about past negative episodes, which in turn might be associated with reduced availability of resources for central cognitive control processes such as inhibition of and switching away from processing of negative autobiographical information. Copyright © 2014 Elsevier Ltd. All rights reserved.

Face matching in a long task: enforced rest and desk-switching cannot maintain identification accuracy

PubMed Central

Alenezi, Hamood M.; Fysh, Matthew C.; Johnston, Robert A.

2015-01-01

In face matching, observers have to decide whether two photographs depict the same person or different people. This task is not only remarkably difficult but accuracy declines further during prolonged testing. The current study investigated whether this decline in long tasks can be eliminated with regular rest-breaks (Experiment 1) or room-switching (Experiment 2). Both experiments replicated the accuracy decline for long face-matching tasks and showed that this could not be eliminated with rest or room-switching. These findings suggest that person identification in applied settings, such as passport control, might be particularly error-prone due to the long and repetitive nature of the task. The experiments also show that it is difficult to counteract these problems. PMID:26312179

The influence of cueing on attentional focus in perceptual decision making.

PubMed

Yang, Cheng-Ta; Little, Daniel R; Hsu, Ching-Chun

2014-11-01

Selective attention has been known to play an important role in decision making. In the present study, we combined a cueing paradigm with a redundant-target detection task to examine how attention affects the decision process when detecting the redundant targets. Cue validity was manipulated in two experiments. The results showed that when the cue was 50 % valid in one experiment, the participants adopted a parallel self-terminating processing strategy, indicative of a diffuse attentional focus on both target locations. When the cue was 100 % valid in the second experiment, all of the participants switched to a serial self-terminating processing strategy, which in our study indicated focused attention to a single target location. This study demonstrates the flexibility of the decision mechanism and highlights the importance of top-down control in selecting a decision strategy.

Neuro-Oscillatory Mechanisms of Intersensory Selective Attention and Task Switching in School-Aged Children, Adolescents and Young Adults

ERIC Educational Resources Information Center

Murphy, Jeremy W.; Foxe, John J.; Molholm, Sophie

2016-01-01

The ability to attend to one among multiple sources of information is central to everyday functioning. Just as central is the ability to switch attention among competing inputs as the task at hand changes. Such processes develop surprisingly slowly, such that even into adolescence, we remain slower and more error prone at switching among tasks…

Memory Influences on Hippocampal and Striatal Neural Codes: Effects of a Shift Between Task Rules

PubMed Central

Yeshenko, Oxana; Mizumori, Sheri J.Y.

2007-01-01

Interactions with neocortical memory systems may facilitate flexible information processing by hippocampus. We sought direct evidence for such memory influences by recording hippocampal neural responses to a change in cognitive strategy. Well trained rats switched (within a single recording session) between the use of place and response strategies to solve a plus maze task. Maze and extramaze environments were constant throughout testing. Place fields demonstrated (in-field) firing rate and location based reorganization (Leutgeb, Leutgeb, Barnes, Moser, McNaughton, & Moser, 2005) after a task switch, suggesting that hippocampus encoded each phase of testing as a different context, or episode. The task switch also resulted in qualitative and quantitative changes to discharge that were correlated with an animal's velocity or acceleration of movement. Thus, the effects of a strategy switch extended beyond the spatial domain, and the movement correlates were not passive reflections of the current behavioral state. To determine whether hippocampal neural responses were unique, striatal place and movement-correlated neurons were simultaneously recorded with hippocampal neurons. Striatal place and movement cells exhibited a response profile that was similar, but not identical, to that observed for hippocampus after a strategy switch. Thus, retrieval of a different memory led both neural systems to represent a different context. However, hippocampus may play a special (though not exclusive) role in flexible spatial processing since correlated firing amongst cell pairs was highest when rats successfully switched between two spatial tasks. Correlated firing by striatal cell pairs increased following any strategy switch, supporting the view that striatum codes changes in reinforcement contingencies. PMID:17240173

Analogous selection processes in declarative and procedural working memory: N-2 list-repetition and task-repetition costs.

PubMed

Gade, Miriam; Souza, Alessandra S; Druey, Michel D; Oberauer, Klaus

2017-01-01

Working memory (WM) holds and manipulates representations for ongoing cognition. Oberauer (Psychology of Learning and Motivation, 51, 45-100, 2009) distinguishes between two analogous WM sub-systems: a declarative WM which handles the objects of thought, and a procedural WM which handles the representations of (cognitive) actions. Here, we assessed whether analogous effects are observed when participants switch between memory sets (declarative representations) and when they switch between task sets (procedural representations). One mechanism assumed to facilitate switching in procedural WM is the inhibition of previously used, but currently irrelevant task sets, as indexed by n-2 task-repetition costs (Mayr & Keele, Journal of Experimental Psychology: General, 129(1), 4-26, 2000). In this study we tested for an analogous effect in declarative WM. We assessed the evidence for n-2 list-repetition costs across eight experiments in which participants switched between memory lists to perform speeded classifications, mental arithmetic, or a local recognition test. N-2 list-repetition costs were obtained consistently in conditions assumed to increase interference between memory lists, and when lists formed chunks in long-term memory. Further analyses across experiments revealed a substantial contribution of episodic memory to n-2 list-repetition costs, thereby questioning the interpretation of n-2 repetition costs as reflecting inhibition. We reanalyzed the data of eight task-switching experiments, and observed that episodic memory also contributes to n-2 task-repetition costs. Taken together, these results show analogous processing principles in declarative and procedural WM, and question the relevance of inhibitory processes for efficient switching between mental sets.

Time limits during visual foraging reveal flexible working memory templates.

PubMed

Kristjánsson, Tómas; Thornton, Ian M; Kristjánsson, Árni

2018-06-01

During difficult foraging tasks, humans rarely switch between target categories, but switch frequently during easier foraging. Does this reflect fundamental limits on visual working memory (VWM) capacity or simply strategic choice due to effort? Our participants performed time-limited or unlimited foraging tasks where they tapped stimuli from 2 target categories while avoiding items from 2 distractor categories. These time limits should have no effect if capacity imposes limits on VWM representations but more flexible VWM could allow observers to use VWM according to task demands in each case. We found that with time limits, participants switched more frequently and switch-costs became much smaller than during unlimited foraging. Observers can therefore switch between complex (conjunction) target categories when needed. We propose that while maintaining many complex templates in working memory is effortful and observers avoid this, they can do so if this fits task demands, showing the flexibility of working memory representations used for visual exploration. This is in contrast with recent proposals, and we discuss the implications of these findings for theoretical accounts of working memory. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Cognitive switching processes in young people with attention-deficit/hyperactivity disorder.

PubMed

Oades, Robert D; Christiansen, Hanna

2008-01-01

Patients with attention-deficit/hyperactivity disorder (ADHD) can be slow at switching between stimuli, or between sets of stimuli to control behaviour appropriate to changing situations. We examined clinical and experimental parameters that may influence the speed of such processes measured in the trail-making (TMT) and switch-tasks in cases with ADHD combined type, their non-affected siblings and unrelated healthy controls. The latency for completion of the trail-making task controlling for psychomotor processing (TMT-B-A) was longer for ADHD cases, and correlated with Conners' ratings of symptom severity across all subjects. The effect decreased with age. Switch-task responses to questions of "Which number?" and "How many?" between sets of 1/111 or 3/333 elicited differential increases in latency with condition that affected all groups. But there was evidence for increased symptom-related intra-individual variability among the ADHD cases, and across all subjects. Young siblings showed familiality for some measures of TMT and switch-task performance but these were modest. The potential influences of moderator variables on the efficiency of processing stimulus change rather than the speed of processing are discussed.

The Complex Nature of Bilinguals' Language Usage Modulates Task-Switching Outcomes

PubMed Central

Yang, Hwajin; Hartanto, Andree; Yang, Sujin

2016-01-01

In view of inconsistent findings regarding bilingual advantages in executive functions (EF), we reviewed the literature to determine whether bilinguals' different language usage causes measureable changes in the shifting aspects of EF. By drawing on the theoretical framework of the adaptive control hypothesis—which postulates a critical link between bilinguals' varying demands on language control and adaptive cognitive control (Green and Abutalebi, 2013), we examined three factors that characterize bilinguals' language-switching experience: (a) the interactional context of conversational exchanges, (b) frequency of language switching, and (c) typology of code-switching. We also examined whether methodological variations in previous task-switching studies modulate task-specific demands on control processing and lead to inconsistencies in the literature. Our review demonstrates that not only methodological rigor but also a more finely grained, theory-based approach will be required to understand the cognitive consequences of bilinguals' varied linguistic practices in shifting EF. PMID:27199800

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

PubMed

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

2017-06-01

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

Symbiotic Sensing for Energy-Intensive Tasks in Large-Scale Mobile Sensing Applications.

PubMed

Le, Duc V; Nguyen, Thuong; Scholten, Hans; Havinga, Paul J M

2017-11-29

Energy consumption is a critical performance and user experience metric when developing mobile sensing applications, especially with the significantly growing number of sensing applications in recent years. As proposed a decade ago when mobile applications were still not popular and most mobile operating systems were single-tasking, conventional sensing paradigms such as opportunistic sensing and participatory sensing do not explore the relationship among concurrent applications for energy-intensive tasks. In this paper, inspired by social relationships among living creatures in nature, we propose a symbiotic sensing paradigm that can conserve energy, while maintaining equivalent performance to existing paradigms. The key idea is that sensing applications should cooperatively perform common tasks to avoid acquiring the same resources multiple times. By doing so, this sensing paradigm executes sensing tasks with very little extra resource consumption and, consequently, extends battery life. To evaluate and compare the symbiotic sensing paradigm with the existing ones, we develop mathematical models in terms of the completion probability and estimated energy consumption. The quantitative evaluation results using various parameters obtained from real datasets indicate that symbiotic sensing performs better than opportunistic sensing and participatory sensing in large-scale sensing applications, such as road condition monitoring, air pollution monitoring, and city noise monitoring.

Symbiotic Sensing for Energy-Intensive Tasks in Large-Scale Mobile Sensing Applications

PubMed Central

Scholten, Hans; Havinga, Paul J. M.

2017-01-01

Energy consumption is a critical performance and user experience metric when developing mobile sensing applications, especially with the significantly growing number of sensing applications in recent years. As proposed a decade ago when mobile applications were still not popular and most mobile operating systems were single-tasking, conventional sensing paradigms such as opportunistic sensing and participatory sensing do not explore the relationship among concurrent applications for energy-intensive tasks. In this paper, inspired by social relationships among living creatures in nature, we propose a symbiotic sensing paradigm that can conserve energy, while maintaining equivalent performance to existing paradigms. The key idea is that sensing applications should cooperatively perform common tasks to avoid acquiring the same resources multiple times. By doing so, this sensing paradigm executes sensing tasks with very little extra resource consumption and, consequently, extends battery life. To evaluate and compare the symbiotic sensing paradigm with the existing ones, we develop mathematical models in terms of the completion probability and estimated energy consumption. The quantitative evaluation results using various parameters obtained from real datasets indicate that symbiotic sensing performs better than opportunistic sensing and participatory sensing in large-scale sensing applications, such as road condition monitoring, air pollution monitoring, and city noise monitoring. PMID:29186037

Influence of task switching costs on colony homeostasis

NASA Astrophysics Data System (ADS)

Jeanson, Raphaël; Lachaud, Jean-Paul

2015-06-01

In social insects, division of labour allows colonies to optimise the allocation of workers across all available tasks to satisfy colony requirements. The maintenance of stable conditions within colonies (homeostasis) requires that some individuals move inside the nest to monitor colony needs and execute unattended tasks. We developed a simple theoretical model to explore how worker mobility inside the nest and task switching costs influence the maintenance of stable levels of task-associated stimuli. Our results indicate that worker mobility in large colonies generates important task switching costs and is detrimental to colony homeostasis. Our study suggests that the balance between benefits and costs associated with the mobility of workers patrolling inside the nest depends on colony size. We propose that several species of ants with diverse life-history traits should be appropriate to test the prediction that the proportion of mobile workers should vary during colony ontogeny.

Attentional Modulation of Word Recognition by Children in a Dual-Task Paradigm

ERIC Educational Resources Information Center

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

2008-01-01

Purpose: This study investigated an account of limited short-term memory capacity for children's speech perception in noise using a dual-task paradigm. Method: Sixty-four normal-hearing children (7-14 years of age) participated in this study. Dual tasks were repeating monosyllabic words presented in noise at 8 dB signal-to-noise ratio and…

Effects of Bright Light Therapy of Sleep, Cognition, Brain Function, and Neurochemistry in Mild Traumatic Brain Injury

DTIC Science & Technology

2012-01-01

computerized stimulation paradigms for use during functional neuroimaging (i.e., MSIT). Accomplishments: • The following computer tasks were...and Stability Test. • Programming of all computerized functional MRI stimulation paradigms and assessment tasks using E-prime software was completed...Computer stimulation paradigms were tested in the scanner environment to ensure that they could be presented and seen by subjects in the scanner

Managing competing demands through task-switching and multitasking: a multi-setting observational study of 200 clinicians over 1000 hours.

PubMed

Walter, Scott R; Li, Ling; Dunsmuir, William T M; Westbrook, Johanna I

2014-03-01

To provide a detailed characterisation of clinicians' work management strategies. 1002.3 h of observational data were derived from three previous studies conducted in a teaching hospital in Sydney, Australia, among emergency department (ED) doctors (n=40), ward doctors (n=57) and ward nurses (n=104). The rates of task-switching (pausing a task to handle an incoming task) and multitasking (adding a task in parallel to an existing task) were compared in each group. Random intercepts logistic regression was used to determine factors significantly associated with clinicians' use of task-switching over multitasking and to quantify variation between individual clinicians. Task-switching rates were higher among ED doctors (6.0 per hour) than ward staff (2.2 and 1.8 per hour for doctors and nurses, respectively) and vice versa for multitasking rates (9.2 vs 17.3 and 14.1 per hour). Clinicians' strategy use was significantly related to the nature and complexity of work and to the person they were working with. In some settings, time of day, day of the week or previous chosen strategy affected a clinician's strategy. Independent of these factors, there was significant variation between individual clinicians in their use of strategies in a given situation (ED doctors p=0.04, ward staff p=0.03). Despite differences in factors associated with work management strategy use among ED doctors, ward doctors and ward nurses, clinicians in all settings appeared to prioritise certain types of tasks over others. Documentation was generally given low priority in all groups, while the arrival of direct care tasks tended to be treated with high priority. These findings suggest that considerations of safety may be implicit in task-switching and multitasking decisions. Although these strategies have been cast in a negative light, future research should consider their role in optimising competing quality and efficiency demands.

Heightened Conflict in Cue-Target Translation Increases Backward Inhibition in Set Switching

ERIC Educational Resources Information Center

Grange, James A.; Houghton, George

2010-01-01

Backward inhibition (BI) is a performance cost that occurs when an individual returns to a task after 1 (vs. more than 1) intervening trial, and it may reflect the inhibition of task-set components during switching. In 3 experiments, we support the theory that inhibition can target cue-based preparatory stages of a task. Participants performed a…

Characterizing neurocognitive late effects in childhood leukemia survivors using a combination of neuropsychological and cognitive neuroscience measures.

PubMed

Van Der Plas, Ellen; Erdman, Lauren; Nieman, Brian J; Weksberg, Rosanna; Butcher, Darci T; O'connor, Deborah L; Aufreiter, Susanne; Hitzler, Johann; Guger, Sharon L; Schachar, Russell J; Ito, Shinya; Spiegler, Brenda J

2017-10-10

Knowledge about cognitive late effects in survivors of childhood acute lymphoblastic leukemia (ALL) is largely based on standardized neuropsychological measures and parent reports. To examine whether cognitive neuroscience paradigms provided additional insights into neurocognitive and behavioral late effects in ALL survivors, we assessed cognition and behavior using a selection of cognitive neuroscience tasks and standardized measures probing domains previously demonstrated to be affected by chemotherapy. 130 ALL survivors and 158 control subjects, between 8 and 18 years old at time of testing, completed the n-back (working memory) and stop-signal (response inhibition) tasks. ALL survivors also completed standardized measures of intelligence (Wechsler Intelligence Scales [WISC-IV]), motor skills (Grooved Pegboard), math abilities (WIAT-III), and executive functions (Delis-Kaplan Executive Function System). Parents completed behavioral measures of executive functions (Behavior Rating Inventory of Executive Function [BRIEF]) and attention (Conners-3). ALL survivors exhibited deficiencies in working memory and response inhibition compared with controls. ALL survivors also exhibited deficits on WISC-IV working memory and processing speed, Grooved Pegboard, WIAT-III addition and subtraction fluency, and numerical operations, as well as DKEFS number-letter switching. Parent reports suggested more attention deficits (Conners-3) and behavioral difficulties (BRIEF) in ALL survivors compared with referenced norms. Low correspondence between standardized and experimental measures of working memory and response inhibition was noted. The use of cognitive neuroscience paradigms complements our understanding of the cognitive deficits evident after treatment of ALL. These measures could further delineate cognitive processes involved in neurocognitive late effects, providing opportunities to explore their underlying mechanisms.

Study of optoelectronic switch for satellite-switched time-division multiple access

NASA Technical Reports Server (NTRS)

Su, Shing-Fong; Jou, Liz; Lenart, Joe

1987-01-01

The use of optoelectronic switching for satellite switched time division multiple access will improve the isolation and reduce the crosstalk of an IF switch matrix. The results are presented of a study on optoelectronic switching. Tasks include literature search, system requirements study, candidate switching architecture analysis, and switch model optimization. The results show that the power divided and crossbar switching architectures are good candidates for an IF switch matrix.

Implementations of clinical functional magnetic resonance imaging using character-based paradigms for the prediction of Chinese language dominance.

PubMed

Liu, Ho-Ling; Wu, Chien-Te; Chen, Jian-Chuan; Hsu, Yuan-Yu; Wai, Yau-Yau; Wan, Yung-Liang

2003-01-01

Recently, functional MRI (fMRI) using word generation (WG) tasks has been shown to be effective for mapping the Chinese language-related brain areas. In clinical applications, however, patients' performance cannot be easily monitored during WG tasks. In this study, we evaluated the feasibility of a word choice (WC) paradigm in the clinical setting and compared the results with those from WG tasks. Intrasubject comparisons of fMRI with both WG and WC paradigms were performed on six normal human subjects and two tumor patients. Subject responses in the WC paradigm, based on semantic judgments, were recorded. Activation strength, extent, and laterality were evaluated and compared. Our results showed that fMRI with the WC paradigm evoked weaker neuronal activation than that with the WG paradigm in Chinese language-related brain areas. It was sufficient to reveal language laterality for clinical use, however. In addition, it resulted in less nonlanguage-specific brain activation. Results from the patient data demonstrated strong evidence for the necessity of incorporating response monitoring during fMRI studies, which suggested that fMRI with the WC paradigm is more appropriate to be implemented for the prediction of Chinese language dominance in clinical environments.

Barriers to critical thinking: workflow interruptions and task switching among nurses.

PubMed

Cornell, Paul; Riordan, Monica; Townsend-Gervis, Mary; Mobley, Robin

2011-10-01

Nurses are increasingly called upon to engage in critical thinking. However, current workflow inhibits this goal with frequent task switching and unpredictable demands. To assess workflow's cognitive impact, nurses were observed at 2 hospitals with different patient loads and acuity levels. Workflow on a medical/surgical and pediatric oncology unit was observed, recording tasks, tools, collaborators, and locations. Nineteen nurses were observed for a total of 85.2 hours. Tasks were short with a mean duration of 62.4 and 81.6 seconds on the 2 units. More than 50% of the recorded tasks were less than 30 seconds in length. An analysis of task sequence revealed few patterns and little pairwise repetition. Performance on specific tasks differed between the 2 units, but the character of the workflow was highly similar. The nonrepetitive flow and high amount of switching indicate nurses experience a heavy cognitive load with little uninterrupted time. This implies that nurses rarely have the conditions necessary for critical thinking.

Asymmetrical Switch Costs in Bilingual Language Production Induced by Reading Words

ERIC Educational Resources Information Center

Peeters, David; Runnqvist, Elin; Bertrand, Daisy; Grainger, Jonathan

2014-01-01

We examined language-switching effects in French-English bilinguals using a paradigm where pictures are always named in the same language (either French or English) within a block of trials, and on each trial, the picture is preceded by a printed word from the same language or from the other language. Participants had to either make a language…

Switching Attention Within Working Memory is Reflected in the P3a Component of the Human Event-Related Brain Potential

PubMed Central

Berti, Stefan

2016-01-01

The flexible access to information in working memory is crucial for adaptive behavior. It is assumed that this is realized by switching the focus of attention within working memory. Switching of attention is mirrored in the P3a component of the human event-related brain potential (ERP) and it has been argued that the processes reflected by the P3a are also relevant for selecting information within working memory. The aim of the present study was to further evaluate whether the P3a mirrors genuine switching of attention within working memory by applying an object switching task: Participants updated a memory list of four digits either by replacing one item with another digit or by processing the stored digit. ERPs were computed separately for two types of trials: (1) trials in which an object was repeated and (2) trials in which a switch to a new object was required in order to perform the task. Object-switch trials showed increased response times compared with repetition trials in both task conditions. In addition, switching costs were increased in the processing compared with the replacement condition. Pronounced P3a’s were obtained in switching trials but there were no difference between the two updating tasks (replacement or processing). These results were qualified by the finding that the magnitude of the visual location shift also affects the ERPs in the P3a time window. Taken together, the present pattern of results suggest that the P3a reflects an initial process of selecting information in working memory but not the memory updating itself. PMID:26779009

Afternoon nap and bright light exposure improve cognitive flexibility post lunch.

PubMed

Slama, Hichem; Deliens, Gaétane; Schmitz, Rémy; Peigneux, Philippe; Leproult, Rachel

2015-01-01

Beneficial effects of napping or bright light exposure on cognitive performance have been reported in participants exposed to sleep loss. Nonetheless, few studies investigated the effect of these potential countermeasures against the temporary drop in performance observed in mid-afternoon, and even less so on cognitive flexibility, a crucial component of executive functions. This study investigated the impact of either an afternoon nap or bright light exposure on post-prandial alterations in task switching performance in well-rested participants. Twenty-five healthy adults participated in two randomized experimental conditions, either wake versus nap (n=15), or bright light versus placebo (n=10). Participants were tested on a switching task three times (morning, post-lunch and late afternoon sessions). The interventions occurred prior to the post-lunch session. In the nap/wake condition, participants either stayed awake watching a 30-minute documentary or had the opportunity to take a nap for 30 minutes. In the bright light/placebo condition, participants watched a documentary under either bright blue light or dim orange light (placebo) for 30 minutes. The switch cost estimates cognitive flexibility and measures task-switching efficiency. Increased switch cost scores indicate higher difficulties to switch between tasks. In both control conditions (wake or placebo), accuracy switch-cost score increased post lunch. Both interventions (nap or bright light) elicited a decrease in accuracy switch-cost score post lunch, which was associated with diminished fatigue and decreased variability in vigilance. Additionally, there was a trend for a post-lunch benefit of bright light with a decreased latency switch-cost score. In the nap group, improvements in accuracy switch-cost score were associated with more NREM sleep stage N1. Thus, exposure to bright light during the post-lunch dip, a countermeasure easily applicable in daily life, results in similar beneficial effects as a short nap on performance in the cognitive flexibility domain with possible additional benefits on latency switch-cost scores.

Afternoon Nap and Bright Light Exposure Improve Cognitive Flexibility Post Lunch

PubMed Central

Schmitz, Rémy; Peigneux, Philippe; Leproult, Rachel

2015-01-01

Beneficial effects of napping or bright light exposure on cognitive performance have been reported in participants exposed to sleep loss. Nonetheless, few studies investigated the effect of these potential countermeasures against the temporary drop in performance observed in mid-afternoon, and even less so on cognitive flexibility, a crucial component of executive functions. This study investigated the impact of either an afternoon nap or bright light exposure on post-prandial alterations in task switching performance in well-rested participants. Twenty-five healthy adults participated in two randomized experimental conditions, either wake versus nap (n=15), or bright light versus placebo (n=10). Participants were tested on a switching task three times (morning, post-lunch and late afternoon sessions). The interventions occurred prior to the post-lunch session. In the nap/wake condition, participants either stayed awake watching a 30-minute documentary or had the opportunity to take a nap for 30 minutes. In the bright light/placebo condition, participants watched a documentary under either bright blue light or dim orange light (placebo) for 30 minutes. The switch cost estimates cognitive flexibility and measures task-switching efficiency. Increased switch cost scores indicate higher difficulties to switch between tasks. In both control conditions (wake or placebo), accuracy switch-cost score increased post lunch. Both interventions (nap or bright light) elicited a decrease in accuracy switch-cost score post lunch, which was associated with diminished fatigue and decreased variability in vigilance. Additionally, there was a trend for a post-lunch benefit of bright light with a decreased latency switch-cost score. In the nap group, improvements in accuracy switch-cost score were associated with more NREM sleep stage N1. Thus, exposure to bright light during the post-lunch dip, a countermeasure easily applicable in daily life, results in similar beneficial effects as a short nap on performance in the cognitive flexibility domain with possible additional benefits on latency switch-cost scores. PMID:26016658

Intelligent single switch wheelchair navigation.

PubMed

Ka, Hyun W; Simpson, Richard; Chung, Younghyun

2012-11-01

We have developed an intelligent single switch scanning interface and wheelchair navigation assistance system, called intelligent single switch wheelchair navigation (ISSWN), to improve driving safety, comfort and efficiency for individuals who rely on single switch scanning as a control method. ISSWN combines a standard powered wheelchair with a laser rangefinder, a single switch scanning interface and a computer. It provides the user with context sensitive and task specific scanning options that reduce driving effort based on an interpretation of sensor data together with user input. Trials performed by 9 able-bodied participants showed that the system significantly improved driving safety and efficiency in a navigation task by significantly reducing the number of switch presses to 43.5% of traditional single switch wheelchair navigation (p < 0.001). All participants made a significant improvement (39.1%; p < 0.001) in completion time after only two trials.

Selecting Paradigms From Cognitive Neuroscience for Translation into Use in Clinical Trials: Proceedings of the Third CNTRICS Meeting

PubMed Central

Barch, Deanna M.; Carter, Cameron S.; Arnsten, Amy; Buchanan, Robert W.; Cohen, Jonathan D.; Geyer, Mark; Green, Michael F.; Krystal, John H.; Nuechterlein, Keith; Robbins, Trevor; Silverstein, Steven; Smith, Edward E.; Strauss, Milton; Wykes, Til; Heinssen, Robert

2009-01-01

This overview describes the goals and objectives of the third conference conducted as part of the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) initiative. This third conference was focused on selecting specific paradigms from cognitive neuroscience that measured the constructs identified in the first CNTRICS meeting, with the goal of facilitating the translation of these paradigms into use in clinical trials contexts. To identify such paradigms, we had an open nomination process in which the field was asked to nominate potentially relevant paradigms and to provide information on several domains relevant to selecting the most promising tasks for each construct (eg, construct validity, neural bases, psychometrics, availability of animal models). Our goal was to identify 1–2 promising tasks for each of the 11 constructs identified at the first CNTRICS meeting. In this overview article, we describe the on-line survey used to generate nominations for promising tasks, the criteria that were used to select the tasks, the rationale behind the criteria, and the ways in which breakout groups worked together to identify the most promising tasks from among those nominated. This article serves as an introduction to the set of 6 articles included in this special issue that provide information about the specific tasks discussed and selected for the constructs from each of 6 broad domains (working memory, executive control, attention, long-term memory, perception, and social cognition). PMID:19023126

From gaze cueing to perspective taking: Revisiting the claim that we automatically compute where or what other people are looking at

PubMed Central

Bukowski, Henryk; Hietanen, Jari K.; Samson, Dana

2015-01-01

ABSTRACT Two paradigms have shown that people automatically compute what or where another person is looking at. In the visual perspective-taking paradigm, participants judge how many objects they see; whereas, in the gaze cueing paradigm, participants identify a target. Unlike in the former task, in the latter task, the influence of what or where the other person is looking at is only observed when the other person is presented alone before the task-relevant objects. We show that this discrepancy across the two paradigms is not due to differences in visual settings (Experiment 1) or available time to extract the directional information (Experiment 2), but that it is caused by how attention is deployed in response to task instructions (Experiment 3). Thus, the mere presence of another person in the field of view is not sufficient to compute where/what that person is looking at, which qualifies the claimed automaticity of such computations. PMID:26924936

From gaze cueing to perspective taking: Revisiting the claim that we automatically compute where or what other people are looking at.

PubMed

Bukowski, Henryk; Hietanen, Jari K; Samson, Dana

2015-09-14

Two paradigms have shown that people automatically compute what or where another person is looking at. In the visual perspective-taking paradigm, participants judge how many objects they see; whereas, in the gaze cueing paradigm, participants identify a target. Unlike in the former task, in the latter task, the influence of what or where the other person is looking at is only observed when the other person is presented alone before the task-relevant objects. We show that this discrepancy across the two paradigms is not due to differences in visual settings (Experiment 1) or available time to extract the directional information (Experiment 2), but that it is caused by how attention is deployed in response to task instructions (Experiment 3). Thus, the mere presence of another person in the field of view is not sufficient to compute where/what that person is looking at, which qualifies the claimed automaticity of such computations.

Selecting a Response in Task Switching: Testing a Model of Compound Cue Retrieval

ERIC Educational Resources Information Center

Schneider, Darryl W.; Logan, Gordon D.

2009-01-01

How can a task-appropriate response be selected for an ambiguous target stimulus in task-switching situations? One answer is to use compound cue retrieval, whereby stimuli serve as joint retrieval cues to select a response from long-term memory. In the present study, the authors tested how well a model of compound cue retrieval could account for a…

Adaptive Control of Response Preparedness in Task Switching

ERIC Educational Resources Information Center

Steinhauser, Marco; Hubner, Ronald; Druey, Michel

2009-01-01

When rapidly switching between two tasks, bivalent stimuli can accidentally trigger the previously executed and therefore still activated response. Recently, it has been suggested that behavioral response-repetition effects reflect response inhibition that reduces the risk of such erroneous response repetitions. The present study investigated…

Advance Preparation in Task-Switching: Converging Evidence from Behavioral, Brain Activation, and Model-Based Approaches

PubMed Central

Karayanidis, Frini; Jamadar, Sharna; Ruge, Hannes; Phillips, Natalie; Heathcote, Andrew; Forstmann, Birte U.

2010-01-01

Recent research has taken advantage of the temporal and spatial resolution of event-related brain potentials (ERPs) and functional magnetic resonance imaging (fMRI) to identify the time course and neural circuitry of preparatory processes required to switch between different tasks. Here we overview some key findings contributing to understanding strategic processes in advance preparation. Findings from these methodologies are compatible with advance preparation conceptualized as a set of processes activated for both switch and repeat trials, but with substantial variability as a function of individual differences and task requirements. We then highlight new approaches that attempt to capitalize on this variability to link behavior and brain activation patterns. One approach examines correlations among behavioral, ERP and fMRI measures. A second “model-based” approach accounts for differences in preparatory processes by estimating quantitative model parameters that reflect latent psychological processes. We argue that integration of behavioral and neuroscientific methodologies is key to understanding the complex nature of advance preparation in task-switching. PMID:21833196

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

NASA Technical Reports Server (NTRS)

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

1989-01-01

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

B-1 Systems Approach to Training. Task Analysis Listings

DTIC Science & Technology

1975-07-01

OFF FUEL VALVES AND PUMPS PHR-OFF FUEL VALVES AND PUMPS = AUTO ^FT TFR MODE LAND SELECTOR SWITCHES TQ *QFF...TFR MODE SWITCH-RIGHT «JFT L TFR MODE SELECT SWITCH TQ * TF1 CHECKLIST TFR MODE SWITCH-LEFT TFR MODE SWITCH-LEFT...DOOR HANDLE ENTRY LADDER CONTROL SWITCH ENTRY LADDER CONTROL SWITCH = DN* 16.1.1.001.OC* SET TANK FILL VALVE SWS ON

Development and Pilot Testing of the Dual Task Screen in Healthy Adolescents.

PubMed

Stephens, Jaclyn; Nicholson, Rachel; Slomine, Beth; Suskauer, Stacy

Athletes with mild traumatic brain injury (mTBI) should refrain from high-risk activities until recovered (symptom free and cognitive and physical exam findings normalize). Studies have suggested that this examination may not be sufficiently sensitive because dual-task paradigms, which typically assess motor performance while a person simultaneously completes a distractor task, can detect residual deficits in athletes who otherwise appear recovered from mTBI. Paradigms used to date are time-intensive procedures conducted in laboratory settings. Here, we report findings from a pilot study of the Dual Task Screen (DTS), which is a brief evaluation with two dual-task paradigms. In 32 healthy female adolescents, the DTS was administered in a mean of 5.63 min in the community, and every participant had poorer dual-condition performance on at least one of the motor tasks. The DTS is a clinically feasible measure and merits additional study regarding utility in adolescents with mTBIs. Copyright © 2018 by the American Occupational Therapy Association, Inc.

Age matters: The effect of onset age of video game play on task-switching abilities.

PubMed

Hartanto, Andree; Toh, Wei Xing; Yang, Hwajin

2016-05-01

Although prior research suggests that playing video games can improve cognitive abilities, recent empirical studies cast doubt on such findings (Unsworth et al., 2015). To reconcile these inconsistent findings, we focused on the link between video games and task switching. Furthermore, we conceptualized video-game expertise as the onset age of active video-game play rather than the frequency of recent gameplay, as it captures both how long a person has played video games and whether the individual began playing during periods of high cognitive plasticity. We found that the age of active onset better predicted switch and mixing costs than did frequency of recent gameplay; specifically, players who commenced playing video games at an earlier age reaped greater benefits in terms of task switching than did those who started at a later age. Moreover, improving switch costs required a more extensive period of video-game experience than did mixing costs; this finding suggests that certain cognitive abilities benefit from different amounts of video game experience.

Computational Prosodic Markers for Autism

ERIC Educational Resources Information Center

Van Santen, Jan P.H.; Prud'hommeaux, Emily T.; Black, Lois M.; Mitchell, Margaret

2010-01-01

We present results obtained with new instrumental methods for the acoustic analysis of prosody to evaluate prosody production by children with Autism Spectrum Disorder (ASD) and Typical Development (TD). Two tasks elicit focal stress--one in a vocal imitation paradigm, the other in a picture-description paradigm; a third task also uses a vocal…

Decision Making and Learning while Taking Sequential Risks

ERIC Educational Resources Information Center

Pleskac, Timothy J.

2008-01-01

A sequential risk-taking paradigm used to identify real-world risk takers invokes both learning and decision processes. This article expands the paradigm to a larger class of tasks with different stochastic environments and different learning requirements. Generalizing a Bayesian sequential risk-taking model to the larger set of tasks clarifies…

Emergency Physician Task Switching Increases With the Introduction of a Commercial Electronic Health Record.

PubMed

Benda, Natalie C; Meadors, Margaret L; Hettinger, A Zachary; Ratwani, Raj M

2016-06-01

We evaluate how the transition from a homegrown electronic health record to a commercial one affects emergency physician work activities from initial introduction to long-term use. We completed a quasi-experimental study across 3 periods during the transition from a homegrown system to a commercially available electronic health record with computerized provider order entry. Observation periods consisted of pre-implementation, 1 month before the implementation of the commercial electronic health record; "go-live" 1 week after implementation; and post-implementation, 3 to 4 months after use began. Fourteen physicians were observed in each period (N=42) with a minute-by-minute observation template to record emergency physician time allocation across 5 task-based categories (computer, verbal communication, patient room, paper [chart/laboratory results], and other). The average number of tasks physicians engaged in per minute was also analyzed as an indicator of task switching. From pre- to post-implementation, there were no significant differences in the amount of time spent on the various task categories. There were changes in time allocation from pre-implementation to go-live and go-live to pre-implementation, characterized by a significant increase in time spent on computer tasks during go-live relative to the other periods. Critically, the number of tasks physicians engaged in per minute increased from 1.7 during pre-implementation to 1.9 during post-implementation (difference 0.19 tasks per minute; 95% confidence interval 0.039 to 0.35). The increase in the number of tasks physicians engaged in per minute post-implementation indicates that physicians switched tasks more frequently. Frequent task switching behavior raises patient safety concerns. Copyright © 2015 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Mix and Switch Effects in Bilingual Language Processing

ERIC Educational Resources Information Center

Koeth, Joel T.

2012-01-01

This study utilized a novel task design in an effort to identify the source of the second language processing advantage commonly reported in mixed language conditions, investigate switch cost asymmetry in non-balanced bilinguals, and identify task-related variables that potentially contribute to inconsistent results across studies with similar…

Mechanisms underlying transfer of task-defined rules across feature dimensions.

PubMed

Baroni, Giulia; Yamaguchi, Motonori; Chen, Jing; Proctor, Robert W

2013-01-01

The Simon effect can be reversed, favoring spatially noncorresponding responses, when people respond to stimulus colors (e.g., green) by pressing a key labeled with the alternative color (i.e., red). This Hedge and Marsh reversal is most often attributed to transfer of logical recoding rules from the color dimension to the location dimension. A recent study showed that this transfer of logical recoding rules can occur not only within a single task but also across two separate tasks that are intermixed. The present study investigated the conditions that determine the transfer of logical recoding rules across tasks. Experiment 1 examined whether it occurs in a transfer paradigm, that is when the two tasks are performed separately, but provided little support for this possibility. Experiment 2 investigated the role of task-set readiness, using a mixed-task paradigm with a predictable trials sequence, which indicated that there is no transfer of task-defined rules across tasks even when they are highly active during the Simon task. Finally, Experiments 3 and 4 used a mixed-task paradigm, where trials of the two tasks were mixed randomly and unpredictably, and manipulated the amount of feature overlap between tasks. Results indicated that task similarity is a determining factor for transfer of task-defined rules to occur. Overall, the study provides evidence that transfer of logical recoding rules tends to occur across two tasks when tasks are unpredictably intermixed and use stimuli that are highly similar and confusable.

Inflexible Minds: Impaired Attention Switching in Recent-Onset Schizophrenia

PubMed Central

Smid, Henderikus G. O. M.; Martens, Sander; de Witte, Marc R.; Bruggeman, Richard

2013-01-01

Impairment of sustained attention is assumed to be a core cognitive abnormality in schizophrenia. However, this seems inconsistent with a recent hypothesis that in schizophrenia the implementation of selection (i.e., sustained attention) is intact but the control of selection (i.e., switching the focus of attention) is impaired. Mounting evidence supports this hypothesis, indicating that switching of attention is a bigger problem in schizophrenia than maintaining the focus of attention. To shed more light on this hypothesis, we tested whether schizophrenia patients are impaired relative to controls in sustaining attention, switching attention, or both. Fifteen patients with recent-onset schizophrenia and fifteen healthy volunteers, matched on age and intelligence, performed sustained attention and attention switching tasks, while performance and brain potential measures of selective attention were recorded. In the sustained attention task, patients did not differ from the controls on these measures. In the attention switching task, however, patients showed worse performance than the controls, and early selective attention related brain potentials were absent in the patients while clearly present in the controls. These findings support the hypothesis that schizophrenia is associated with an impairment of the mechanisms that control the direction of attention (attention switching), while the mechanisms that implement a direction of attention (sustained attention) are intact. PMID:24155980

Lost time: Bindings do not represent temporal order information.

PubMed

Moeller, Birte; Frings, Christian

2018-06-04

Many accounts of human action control assume bindings between features of stimuli and responses of individual events. One widely accepted assumption about these bindings is that they do not contain temporal-order representations regarding the integrated elements. Even though several theories either explicitly or implicitly include it, this assumption has never been tested directly. One reason for this lack of evidence is likely that typical stimulus-response binding paradigms are inapt for such a test. Adapting a new paradigm of response-response binding to include order switches between response integration and retrieval, we were able to analyze possible representation of order information in bindings for the first time. Binding effects were identical for intact and switched response orders, indicating that bindings indeed include no temporal-order information.

The self in conflict: actors and agency in the mediated sequential Simon task.

PubMed

Spapé, Michiel M; Ahmed, Imtiaj; Jacucci, Giulio; Ravaja, Niklas

2015-01-01

Executive control refers to the ability to withstand interference in order to achieve task goals. The effect of conflict adaptation describes that after experiencing interference, subsequent conflict effects are weaker. However, changes in the source of conflict have been found to disrupt conflict adaptation. Previous studies indicated that this specificity is determined by the degree to which one source causes episodic retrieval of a previous source. A virtual reality version of the Simon task was employed to investigate whether changes in a visual representation of the self would similarly affect conflict adaptation. Participants engaged in a mediated Simon task via 3D "avatar" models that either mirrored the participants' movements, or were presented statically. A retrieval cue was implemented as the identity of the avatar: switching it from a male to a female avatar was expected to disrupt the conflict adaptation effect (CAE). The results show that only in static conditions did the CAE depend on the avatar identity, while in dynamic conditions, changes did not cause disruption. We also explored the effect of conflict and adaptation on the degree of movement made with the task-irrelevant hand and replicated the reaction time pattern. The findings add to earlier studies of source-specific conflict adaptation by showing that a visual representation of the self in action can provide a cue that determines episodic retrieval. Furthermore, the novel paradigm is made openly available to the scientific community and is described in its significance for studies of social cognition, cognitive psychology, and human-computer interaction.

Assessing selective sustained attention in 3- to 5-year-old children: Evidence from a new paradigm

PubMed Central

Fisher, Anna; Thiessen, Erik; Godwin, Karrie; Kloos, Heidi; Dickerson, John

2012-01-01

Selective sustained attention (SSA) is crucial for higher-order cognition. Factors promoting SSA are described as exogenous or endogenous. However, there is little research specifying how these factors interact during development – due, largely, to the paucity of developmentally-appropriate paradigms. We report findings from a novel paradigm designed to investigate SSA in preschoolers. The findings indicate that this task (1) has good psychometric and parametric properties, and (2) allows investigation of exogenous and endogenous factors within the same task, making it possible to attribute changes in performance to different mechanisms of attentional control rather than to differences in engagement in different tasks. PMID:23022318

Assessing selective sustained attention in 3- to 5-year-old children: evidence from a new paradigm.

PubMed

Fisher, Anna; Thiessen, Erik; Godwin, Karrie; Kloos, Heidi; Dickerson, John

2013-02-01

Selective sustained attention (SSA) is crucial for higher order cognition. Factors promoting SSA are described as exogenous or endogenous. However, there is little research specifying how these factors interact during development, due largely to the paucity of developmentally appropriate paradigms. We report findings from a novel paradigm designed to investigate SSA in preschoolers. The findings indicate that this task (a) has good psychometric and parametric properties and (b) allows investigation of exogenous and endogenous factors within the same task, making it possible to attribute changes in performance to different mechanisms of attentional control rather than to differences in engagement in different tasks. Copyright © 2012 Elsevier Inc. All rights reserved.

Diet/Energy Balance Affect Sleep and Wakefulness Independent of Body Weight.

PubMed

Perron, Isaac J; Pack, Allan I; Veasey, Sigrid

2015-12-01

Excessive daytime sleepiness commonly affects obese people, even in those without sleep apnea, yet its causes remain uncertain. We sought to determine whether acute dietary changes could induce or rescue wake impairments independent of body weight. We implemented a novel feeding paradigm that generates two groups of mice with equal body weight but opposing energetic balance. Two subsets of mice consuming either regular chow (RC) or high-fat diet (HFD) for 8 w were switched to the opposite diet for 1 w. Sleep recordings were conducted at Week 0 (baseline), Week 8 (pre-diet switch), and Week 9 (post-diet switch) for all groups. Sleep homeostasis was measured at Week 8 and Week 9. Young adult, male C57BL/6J mice. Differences in total wake, nonrapid eye movement (NREM), and rapid eye movement (REM) time were quantified, in addition to changes in bout fragmentation/consolidation. At Week 9, the two diet switch groups had similar body weight. However, animals switched to HFD (and thus gaining weight) had decreased wake time, increased NREM sleep time, and worsened sleep/wake fragmentation compared to mice switched to RC (which were in weight loss). These effects were driven by significant sleep/wake changes induced by acute dietary manipulations (Week 8 → Week 9). Sleep homeostasis, as measured by delta power increase following sleep deprivation, was unaffected by our feeding paradigm. Acute dietary manipulations are sufficient to alter sleep and wakefulness independent of body weight and without effects on sleep homeostasis. © 2015 Associated Professional Sleep Societies, LLC.

Characterizing Information Processing With a Mobile Device: Measurement of Simple and Choice Reaction Time.

PubMed

Burke, Daniel; Linder, Susan; Hirsch, Joshua; Dey, Tanujit; Kana, Daniel; Ringenbach, Shannon; Schindler, David; Alberts, Jay

2017-10-01

Information processing is typically evaluated using simple reaction time (SRT) and choice reaction time (CRT) paradigms in which a specific response is initiated following a given stimulus. The measurement of reaction time (RT) has evolved from monitoring the timing of mechanical switches to computerized paradigms. The proliferation of mobile devices with touch screens makes them a natural next technological approach to assess information processing. The aims of this study were to determine the validity and reliability of using of a mobile device (Apple iPad or iTouch) to accurately measure RT. Sixty healthy young adults completed SRT and CRT tasks using a traditional test platform and mobile platforms on two occasions. The SRT was similar across test modality: 300, 287, and 280 milliseconds (ms) for the traditional, iPad, and iTouch, respectively. The CRT was similar within mobile devices, though slightly faster on the traditional: 359, 408, and 384 ms for traditional, iPad, and iTouch, respectively. Intraclass correlation coefficients ranged from 0.79 to 0.85 for SRT and from 0.75 to 0.83 for CRT. The similarity and reliability of SRT across platforms and consistency of SRT and CRT across test conditions indicate that mobile devices provide the next generation of assessment platforms for information processing.

Visual Foraging With Fingers and Eye Gaze

PubMed Central

Thornton, Ian M.; Smith, Irene J.; Chetverikov, Andrey; Kristjánsson, Árni

2016-01-01

A popular model of the function of selective visual attention involves search where a single target is to be found among distractors. For many scenarios, a more realistic model involves search for multiple targets of various types, since natural tasks typically do not involve a single target. Here we present results from a novel multiple-target foraging paradigm. We compare finger foraging where observers cancel a set of predesignated targets by tapping them, to gaze foraging where observers cancel items by fixating them for 100 ms. During finger foraging, for most observers, there was a large difference between foraging based on a single feature, where observers switch easily between target types, and foraging based on a conjunction of features where observers tended to stick to one target type. The pattern was notably different during gaze foraging where these condition differences were smaller. Two conclusions follow: (a) The fact that a sizeable number of observers (in particular during gaze foraging) had little trouble switching between different target types raises challenges for many prominent theoretical accounts of visual attention and working memory. (b) While caveats must be noted for the comparison of gaze and finger foraging, the results suggest that selection mechanisms for gaze and pointing have different operational constraints. PMID:27433323

Is refreshing in working memory impaired in older age? Evidence from the retro-cue paradigm.

PubMed

Loaiza, Vanessa M; Souza, Alessandra S

2018-04-10

Impairments in refreshing have been suggested as one source of working memory (WM) deficits in older age. Retro-cues provide an important method of investigating this question: a retro-cue guides attention to one WM item, thereby arguably refreshing it and increasing its accessibility compared with a no-cue baseline. In contrast to the refreshing deficit hypothesis, intact retro-cue benefits have been found in older adults. Refreshing, however, is assumed to boost not one but several WM representations when sequentially applied to them. Hence, intact refreshing requires the flexible switching of attention among WM items. So far, it remains an open question whether older adults show this flexibility. Here, we investigated whether older adults can use multiple cues to sequentially refresh WM representations. Younger and older adults completed a continuous-color delayed-estimation task, in which the number of retro-cues (0, 1, or 2) presented during the retention interval was manipulated. The results showed a similar retro-cue benefit for younger and older adults, even in the two-cue condition in which participants had to switch attention between items to refresh representations in WM. These findings suggest that the capacity to use cues to refresh information in visual WM may be preserved with age. © 2018 New York Academy of Sciences.

Cue response dissociates inhibitory processes: task identity information is related to backward inhibition but not to competitor rule suppression.

PubMed

Regev, Shirley; Meiran, Nachshon

2017-01-01

In task switching, a conflict between competing task-sets is resolved by inhibiting the interfering task-set. Recent models have proposed a framework of the task-set as composed of two hierarchical components: abstract task identity (e.g., respond to quantity) and more concrete task rules (e.g., category-response rules mapping the categories "one" and "three" to the left and right keys, respectively). The present study explored whether task-set inhibition is the outcome of a general control process or whether it reflects multiple inhibitory processes, each targeting a different component of the competing task-set. To this end, two effects of task-set inhibition were examined: backward inhibition (BI), reflecting the suppression of a just-performed task-set that is no longer relevant; and, competitor rule suppression (CRS), reflecting the suppression of an irrelevant task-set that generates a response conflict. In two task switching experiments, each involving three tasks, we asked participants to make two responses: a cue response, indicating the identity of the relevant task (e.g., "Color"), and a target response requiring the implementation of the task rule (e.g., "Red"). The results demonstrate that BI, but not CRS, appears in cue responses, and thus, suggests that BI reflects inhibition that influences representations related to abstract task identity, rather than (just) competing responses or response rules. These results support a dissociation between inhibitory processes in task switching. The current findings also provide further evidence for a multi-component conceptualization of task-set and task-set inhibition.

The default mode network and the working memory network are not anti-correlated during all phases of a working memory task.

PubMed

Piccoli, Tommaso; Valente, Giancarlo; Linden, David E J; Re, Marta; Esposito, Fabrizio; Sack, Alexander T; Di Salle, Francesco

2015-01-01

The default mode network and the working memory network are known to be anti-correlated during sustained cognitive processing, in a load-dependent manner. We hypothesized that functional connectivity among nodes of the two networks could be dynamically modulated by task phases across time. To address the dynamic links between default mode network and the working memory network, we used a delayed visuo-spatial working memory paradigm, which allowed us to separate three different phases of working memory (encoding, maintenance, and retrieval), and analyzed the functional connectivity during each phase within and between the default mode network and the working memory network networks. We found that the two networks are anti-correlated only during the maintenance phase of working memory, i.e. when attention is focused on a memorized stimulus in the absence of external input. Conversely, during the encoding and retrieval phases, when the external stimulation is present, the default mode network is positively coupled with the working memory network, suggesting the existence of a dynamically switching of functional connectivity between "task-positive" and "task-negative" brain networks. Our results demonstrate that the well-established dichotomy of the human brain (anti-correlated networks during rest and balanced activation-deactivation during cognition) has a more nuanced organization than previously thought and engages in different patterns of correlation and anti-correlation during specific sub-phases of a cognitive task. This nuanced organization reinforces the hypothesis of a direct involvement of the default mode network in cognitive functions, as represented by a dynamic rather than static interaction with specific task-positive networks, such as the working memory network.

The Default Mode Network and the Working Memory Network Are Not Anti-Correlated during All Phases of a Working Memory Task

PubMed Central

Piccoli, Tommaso; Valente, Giancarlo; Linden, David E. J.; Re, Marta; Esposito, Fabrizio; Sack, Alexander T.; Salle, Francesco Di

2015-01-01

Introduction The default mode network and the working memory network are known to be anti-correlated during sustained cognitive processing, in a load-dependent manner. We hypothesized that functional connectivity among nodes of the two networks could be dynamically modulated by task phases across time. Methods To address the dynamic links between default mode network and the working memory network, we used a delayed visuo-spatial working memory paradigm, which allowed us to separate three different phases of working memory (encoding, maintenance, and retrieval), and analyzed the functional connectivity during each phase within and between the default mode network and the working memory network networks. Results We found that the two networks are anti-correlated only during the maintenance phase of working memory, i.e. when attention is focused on a memorized stimulus in the absence of external input. Conversely, during the encoding and retrieval phases, when the external stimulation is present, the default mode network is positively coupled with the working memory network, suggesting the existence of a dynamically switching of functional connectivity between “task-positive” and “task-negative” brain networks. Conclusions Our results demonstrate that the well-established dichotomy of the human brain (anti-correlated networks during rest and balanced activation-deactivation during cognition) has a more nuanced organization than previously thought and engages in different patterns of correlation and anti-correlation during specific sub-phases of a cognitive task. This nuanced organization reinforces the hypothesis of a direct involvement of the default mode network in cognitive functions, as represented by a dynamic rather than static interaction with specific task-positive networks, such as the working memory network. PMID:25848951

Response-cue interval effects in extended-runs task switching: memory, or monitoring?

PubMed

Altmann, Erik M

2017-09-26

This study investigated effects of manipulating the response-cue interval (RCI) in the extended-runs task-switching procedure. In this procedure, a task cue is presented at the start of a run of trials and then withdrawn, such that the task has to be stored in memory to guide performance until the next task cue is presented. The effects of the RCI manipulation were not as predicted by an existing model of memory processes in task switching (Altmann and Gray, Psychol Rev 115:602-639, 2008), suggesting that either the model is incorrect or the RCI manipulation did not have the intended effect. The manipulation did produce a theoretically meaningful pattern, in the form of a main effect on response time that was not accompanied by a similar effect on the error rate. This pattern, which replicated across two experiments, is interpreted here in terms of a process that monitors for the next task cue, with a longer RCI acting as a stronger signal that a cue is about to appear. The results have implications for the human factors of dynamic task environments in which critical events occur unpredictably.

Task-switching deficits and repetitive behaviour in genetic neurodevelopmental disorders: data from children with Prader-Willi syndrome chromosome 15 q11-q13 deletion and boys with Fragile X syndrome.

PubMed

Woodcock, Kate A; Oliver, Chris; Humphreys, Glyn W

2009-03-01

Prader-Willi syndrome (PWS) and Fragile X syndrome (FraX) are associated with distinctive cognitive and behavioural profiles. We examined whether repetitive behaviours in the two syndromes were associated with deficits in specific executive functions. PWS, FraX, and typically developing (TD) children were assessed for executive functioning using the Test of Everyday Attention for Children and an adapted Simon spatial interference task. Relative to the TD children, children with PWS and FraX showed greater costs of attention switching on the Simon task, but after controlling for intellectual ability, these switching deficits were only significant in the PWS group. Children with PWS and FraX also showed significantly increased preference for routine and differing profiles of other specific types of repetitive behaviours. A measure of switch cost from the Simon task was positively correlated to scores on preference for routine questionnaire items and was strongly associated with scores on other items relating to a preference for predictability. It is proposed that a deficit in attention switching is a component of the endophenotypes of both PWS and FraX and is associated with specific behaviours. This proposal is discussed in the context of neurocognitive pathways between genes and behaviour.

Autism: Hard to Switch from Details to the Whole.

PubMed

Soriano, María Felipa; Ibáñez-Molina, Antonio J; Paredes, Natalia; Macizo, Pedro

2017-12-18

It has long been proposed that individuals with autism exhibit a superior processing of details at the expense of an impaired global processing. This theory has received some empirical support, but results are mixed. In this research we have studied local and global processing in ASD and Typically Developing children, with an adaptation of the Navon task, designed to measure congruency effects between local and global stimuli and switching cost between local and global tasks. ASD children showed preserved global processing; however, compared to Typically Developing children, they exhibited more facilitation from congruent local stimuli when they performed the global task. In addition, children with ASD had more switching cost than Typically Developing children only when they switched from the local to the global task, reflecting a specific difficulty to disengage from local stimuli. Together, results suggest that ASD is characterized by a tendency to process local details, they benefit from the processing of local stimuli at the expense of increasing cost to disengage from local stimuli when global processing is needed. Thus, this work demonstrates experimentally the advantages and disadvantages of the increased local processing in children with ASD.

Interval timing in genetically modified mice: a simple paradigm

PubMed Central

Balci, F.; Papachristos, E. B.; Gallistel, C. R.; Brunner, D.; Gibson, J.; Shumyatsky, G. P.

2009-01-01

We describe a behavioral screen for the quantitative study of interval timing and interval memory in mice. Mice learn to switch from a short-latency feeding station to a long-latency station when the short latency has passed without a feeding. The psychometric function is the cumulative distribution of switch latencies. Its median measures timing accuracy and its interquartile interval measures timing precision. Next, using this behavioral paradigm, we have examined mice with a gene knockout of the receptor for gastrin-releasing peptide that show enhanced (i.e. prolonged) freezing in fear conditioning. We have tested the hypothesis that the mutants freeze longer because they are more uncertain than wild types about when to expect the electric shock. The knockouts however show normal accuracy and precision in timing, so we have rejected this alternative hypothesis. Last, we conduct the pharmacological validation of our behavioral screen using D-amphetamine and methamphetamine. We suggest including the analysis of interval timing and temporal memory in tests of genetically modified mice for learning and memory and argue that our paradigm allows this to be done simply and efficiently. PMID:17696995

Interval timing in genetically modified mice: a simple paradigm.

PubMed

Balci, F; Papachristos, E B; Gallistel, C R; Brunner, D; Gibson, J; Shumyatsky, G P

2008-04-01

We describe a behavioral screen for the quantitative study of interval timing and interval memory in mice. Mice learn to switch from a short-latency feeding station to a long-latency station when the short latency has passed without a feeding. The psychometric function is the cumulative distribution of switch latencies. Its median measures timing accuracy and its interquartile interval measures timing precision. Next, using this behavioral paradigm, we have examined mice with a gene knockout of the receptor for gastrin-releasing peptide that show enhanced (i.e. prolonged) freezing in fear conditioning. We have tested the hypothesis that the mutants freeze longer because they are more uncertain than wild types about when to expect the electric shock. The knockouts however show normal accuracy and precision in timing, so we have rejected this alternative hypothesis. Last, we conduct the pharmacological validation of our behavioral screen using d-amphetamine and methamphetamine. We suggest including the analysis of interval timing and temporal memory in tests of genetically modified mice for learning and memory and argue that our paradigm allows this to be done simply and efficiently.

Episodic, generalized, and semantic memory tests: switching and strength effects.

PubMed

Humphreys, Michael S; Murray, Krista L

2011-09-01

We continue the process of investigating the probabilistic paired associate paradigm in an effort to understand the memory access control processes involved and to determine whether the memory structure produced is in transition between episodic and semantic memory. In this paradigm two targets are probabilistically paired with a cue across a large number of short lists. Participants can recall the target paired with the cue in the most recent list (list specific test), produce the first of the two targets that have been paired with that cue to come to mind (generalised test), and produce a free association response (semantic test). Switching between a generalised test and a list specific test did not produce a switching cost indicating a general similarity in the control processes involved. In addition, there was evidence for a dissociation between two different strength manipulations (amount of study time and number of cue-target pairings) such that number of pairings influenced the list specific, generalised and the semantic test but amount of study time only influenced the list specific and generalised test. © 2011 Canadian Psychological Association

Identification and location tasks rely on different mental processes: a diffusion model account of validity effects in spatial cueing paradigms with emotional stimuli.

PubMed

Imhoff, Roland; Lange, Jens; Germar, Markus

2018-02-22

Spatial cueing paradigms are popular tools to assess human attention to emotional stimuli, but different variants of these paradigms differ in what participants' primary task is. In one variant, participants indicate the location of the target (location task), whereas in the other they indicate the shape of the target (identification task). In the present paper we test the idea that although these two variants produce seemingly comparable cue validity effects on response times, they rest on different underlying processes. Across four studies (total N = 397; two in the supplement) using both variants and manipulating the motivational relevance of cue content, diffusion model analyses revealed that cue validity effects in location tasks are primarily driven by response biases, whereas the same effect rests on delay due to attention to the cue in identification tasks. Based on this, we predict and empirically support that a symmetrical distribution of valid and invalid cues would reduce cue validity effects in location tasks to a greater extent than in identification tasks. Across all variants of the task, we fail to replicate the effect of greater cue validity effects for arousing (vs. neutral) stimuli. We discuss the implications of these findings for best practice in spatial cueing research.

Relationship disruption stress in human infants: a validation study with experimental and control groups.

PubMed

Haley, David W

2011-09-01

The current study examined whether the psychological stress of the still-face (SF) task (i.e. stress resulting from a parent's unresponsiveness) is a valid laboratory stress paradigm for evaluating infant cortisol reactivity. Given that factors external to the experimental paradigm, such as arriving at a new place, may cause an elevation in cortisol secretion; we tested the hypothesis that infants would show a cortisol response to the SF task but not to a normal FF task (control). Saliva was collected for cortisol measurement from 6-month-old infants (n = 31) randomly assigned to either a repeated SF task or to a continuous FF task. Parent-infant dyads were videotaped. Salivary cortisol concentration was measured at baseline, 20, and 30 min after the start of the procedure. Infant salivary cortisol concentrations showed a significant increase over time for the SF task but not for the FF task. The results provide new evidence that the repeated SF task provides a psychological challenge that is due to the SF condition rather than to some non-task related factor; these results provide internal validity for the paradigm. The study offers new insight into the role of parent-infant interactions in the activation of the infant stress response system.

Attentional blink in adults with attention-deficit hyperactivity disorder. Influence of eye movements.

PubMed

Armstrong, I T; Munoz, D P

2003-09-01

The attentional blink paradigm tests attention by overloading it: a list of stimuli is presented very rapidly one after another at the same location on a computer screen, each item overwriting the last, and participants monitor the list using two criteria [e.g. detect the target (red letter) and identify the probe (letter p)]. If the interval between the target and the probe is greater than about 500 ms, both are usually reported correctly, but, when the interval between the target and the probe is within 200-500 ms, report of the probe declines. This decline is the attentional blink, an interval of time when attention is supposedly switching from the first criterion to the second. The attentional blink paradigm should be difficult to perform correctly without vigilantly attending to the rapidly presented list. Vigilance tasks are often used to assess attention-deficit hyperactivity disorder (ADHD). Symptoms of the disorder include hyperactivity and attentional dysfunction; however, some people with ADHD also have difficulty maintaining gaze at a fixed location. We tested 15 adults with ADHD and their age- and sex-matched controls, measuring accuracy and gaze stability during the attentional blink task. ADHD participants reported fewer targets and probes, took longer to recover from the attentional blink, made more eye movements, and made identification errors consistent with non-perception of the letter list. In contrast, errors made by control participants were consistent with guessing (i.e., report of a letter immediately preceding or succeeding the correct letter). Excessive eye movements result in poorer performance for all participants; however, error patterns confirm that the weak performance of ADHD participants may be related to gaze instability as well as to attentional dysfunction.

Effects of aging and job demands on cognitive flexibility assessed by task switching.

PubMed

Gajewski, Patrick D; Wild-Wall, Nele; Schapkin, Sergei A; Erdmann, Udo; Freude, Gabriele; Falkenstein, Michael

2010-10-01

In a cross-sectional, electrophysiological study 91 workers of a big car factory performed a series of switch tasks to assess their cognitive control functions. Four groups of workers participated in the study: 23 young and 23 middle aged assembly line employees and 22 young and 23 middle aged employees with flexible job demands like service and maintenance. Participants performed three digit categorisation tasks. In addition to single task blocks, a cue-based (externally guided) and a memory-based (internally guided) task switch block was administered. Compared to young participants, older ones showed the typical RT-decline. No differences between younger and older participants regarding the local switch costs could be detected despite the source of the current task information. In contrast, whereas the groups did not differ in mixing costs in the cued condition, clear performance decrements in the memory-based mixing block were observed in the group of older employees with repetitive work demands. These findings were corroborated by a number of electrophysiological results showing a reduced CNV suggesting an impairment of task specific preparation, an attenuated P3b suggesting reduced working memory capacity and a decreased Ne suggesting deficits in error monitoring in older participants with repetitive job demands. The results are compatible with the assumption that long lasting, unchallenging job demands may induce several neurocognitive impairments which are already evident in the early fifties. Longitudinal studies are needed to confirm this assumption. Copyright © 2010 Elsevier B.V. All rights reserved.

The hierarchy of task decision and response selection: a task-switching event related potentials study.

PubMed

Braverman, Ami; Berger, Andrea; Meiran, Nachshon

2014-07-01

According to "hierarchical" multi-step theories, response selection is preceded by a decision regarding which task rule should be executed. Other theories assume a "flat" single-step architecture in which task information and stimulus information are simultaneously considered. Using task switching, the authors independently manipulated two kinds of conflict: task conflict (with information that potentially triggers the relevant or the competing task rule/identity) and response conflict (with information that potentially triggers the relevant or the competing response code/motor response). Event related potentials indicated that the task conflict effect began before the response conflict effect and carried on in parallel with it. These results are more in line with the hierarchical view. Copyright © 2014 Elsevier Inc. All rights reserved.

Circuit-Host Coupling Induces Multifaceted Behavioral Modulations of a Gene Switch.

PubMed

Blanchard, Andrew E; Liao, Chen; Lu, Ting

2018-02-06

Quantitative modeling of gene circuits is fundamentally important to synthetic biology, as it offers the potential to transform circuit engineering from trial-and-error construction to rational design and, hence, facilitates the advance of the field. Currently, typical models regard gene circuits as isolated entities and focus only on the biochemical processes within the circuits. However, such a standard paradigm is getting challenged by increasing experimental evidence suggesting that circuits and their host are intimately connected, and their interactions can potentially impact circuit behaviors. Here we systematically examined the roles of circuit-host coupling in shaping circuit dynamics by using a self-activating gene switch as a model circuit. Through a combination of deterministic modeling, stochastic simulation, and Fokker-Planck equation formalism, we found that circuit-host coupling alters switch behaviors across multiple scales. At the single-cell level, it slows the switch dynamics in the high protein production regime and enlarges the difference between stable steady-state values. At the population level, it favors cells with low protein production through differential growth amplification. Together, the two-level coupling effects induce both quantitative and qualitative modulations of the switch, with the primary component of the effects determined by the circuit's architectural parameters. This study illustrates the complexity and importance of circuit-host coupling in modulating circuit behaviors, demonstrating the need for a new paradigm-integrated modeling of the circuit-host system-for quantitative understanding of engineered gene networks. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Adult age differences in information foraging in an interactive reading environment.

PubMed

Liu, Xiaomei; Chin, Jessie; Payne, Brennan R; Fu, Wai-Tat; Morrow, Daniel G; Stine-Morrow, Elizabeth A L

2016-05-01

When learning about a single topic in natural reading environments, readers are confronted with multiple sources varying in the type and amount of information. In this situation, readers are free to adaptively respond to the constraints of the environment (e.g., through selection of resources and time allocation for study), but there may be costs of exploring and switching between sources (e.g., disruption of attention, opportunity costs for study). From an ecological perspective, such properties of the environment are expected to influence learning strategies. In the current study, we used a novel reading paradigm to investigate age differences in the effects of information richness (i.e., sentence elaboration) and costs of switching between texts (i.e., time delay) on selection of sources and study time allocation. Consistent with the ecological view, participants progressed from less informative to more informative texts. Furthermore, increased switch cost led to a tendency to allocate more effort to easier materials and to greater persistence in reading, which in turn, led to better memory in both immediate and delayed recall. Older adults showed larger effects of switch cost, such that the age difference in delayed recall was eliminated in the high switch cost condition. Based on an ecological paradigm of reading that affords choice and self-regulation, our study provided evidence for preservation with age in the ability to adapt to changing learning environments so as to improve performance. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Limited Impact of Exposure Duration on Holistic Word Processing.

PubMed

Chen, Changming; Abbasi, Najam Ul Hasan; Song, Shuang; Chen, Jie; Li, Hong

2016-01-01

The current study explored the impact of stimuli exposure duration on holistic word processing measured by the complete composite paradigm (CPc paradigm). The participants were asked to match the cued target parts of two characters which were presented for either a long (600 ms) or a short duration (170 ms). They were also tested by two popular versions of the CPc paradigm: the "early-fixed" task where the attention cue was visible from the beginning of each trial at a fixed position, and the "delayed-random" task where the cue showed up after the study character at random locations. The holistic word effect, as indexed by the alignment × congruency interaction, was identified in both tasks and was unaffected by the stimuli duration in both tasks. Meanwhile, the "delayed-random" task did not bring about larger holistic word effect than the "early-fixed" task. These results suggest the exposure duration (from around 150 to 600 ms) has a limited impact on the holistic word effect, and have methodological implications for experiment designs in this field.

Age differences in working memory updating: the role of interference, focus switching and substituting information.

PubMed

Lendínez, Cristina; Pelegrina, Santiago; Lechuga, M Teresa

2015-05-01

Working memory updating (WMU) tasks require different elements in working memory (WM) to be maintained simultaneously, accessing one of these elements, and substituting its content. This study examined possible developmental changes from childhood to adulthood both in focus switching and substituting information in WM. In addition, possible age-related changes in interference due to representational overlap between the different elements simultaneously held in these tasks were examined. Children (8- and 11-year-olds), adolescents (14-year-olds) and younger adults (mean age=22 years) were administered a numerical updating memory task, in which updating and focus switching were manipulated. As expected, response times decreased and recall performance increased with age. More importantly, the time needed for focus switching was longer in children than in adolescents and younger adults. On the other hand, substitution of information and interference due to representational overlap were not affected by age. These results suggest that age-related changes in focus switching might mediate developmental changes in WMU performance. Copyright © 2015 Elsevier B.V. All rights reserved.

Noise-constrained switching times for heteroclinic computing

NASA Astrophysics Data System (ADS)

Neves, Fabio Schittler; Voit, Maximilian; Timme, Marc

2017-03-01

Heteroclinic computing offers a novel paradigm for universal computation by collective system dynamics. In such a paradigm, input signals are encoded as complex periodic orbits approaching specific sequences of saddle states. Without inputs, the relevant states together with the heteroclinic connections between them form a network of states—the heteroclinic network. Systems of pulse-coupled oscillators or spiking neurons naturally exhibit such heteroclinic networks of saddles, thereby providing a substrate for general analog computations. Several challenges need to be resolved before it becomes possible to effectively realize heteroclinic computing in hardware. The time scales on which computations are performed crucially depend on the switching times between saddles, which in turn are jointly controlled by the system's intrinsic dynamics and the level of external and measurement noise. The nonlinear dynamics of pulse-coupled systems often strongly deviate from that of time-continuously coupled (e.g., phase-coupled) systems. The factors impacting switching times in pulse-coupled systems are still not well understood. Here we systematically investigate switching times in dependence of the levels of noise and intrinsic dissipation in the system. We specifically reveal how local responses to pulses coact with external noise. Our findings confirm that, like in time-continuous phase-coupled systems, piecewise-continuous pulse-coupled systems exhibit switching times that transiently increase exponentially with the number of switches up to some order of magnitude set by the noise level. Complementarily, we show that switching times may constitute a good predictor for the computation reliability, indicating how often an input signal must be reiterated. By characterizing switching times between two saddles in conjunction with the reliability of a computation, our results provide a first step beyond the coding of input signal identities toward a complementary coding for the intensity of those signals. The results offer insights on how future heteroclinic computing systems may operate under natural, and thus noisy, conditions.

The neuronal dynamics underlying cognitive flexibility in set shifting tasks.

PubMed

Stemme, Anja; Deco, Gustavo; Busch, Astrid

2007-12-01

The ability to switch attention from one aspect of an object to another or in other words to switch the "attentional set" as investigated in tasks like the "Wisconsin Card Sorting Test" is commonly referred to as cognitive flexibility. In this work we present a biophysically detailed neurodynamical model which illustrates the neuronal base of the processes related to this cognitive flexibility. For this purpose we conducted behavioral experiments which allow the combined evaluation of different aspects of set shifting tasks: uninstructed set shifts as investigated in Wisconsin-like tasks, effects of stimulus congruency as investigated in Stroop-like tasks and the contribution of working memory as investigated in "Delayed-Match-to-Sample" tasks. The work describes how general experimental findings are usable to design the architecture of a biophysical detailed though minimalistic model with a high orientation on neurobiological findings and how, in turn, the simulations support experimental investigations. The resulting model is able to account for experimental and individual response times and error rates and enables the switch of attention as a system inherent model feature: The switching process suggested by the model is based on the memorization of the visual stimuli and does not require any synaptic learning. The operation of the model thus demonstrates with at least a high probability the neuronal dynamics underlying a key component of human behavior: the ability to adapt behavior according to context requirements--cognitive flexibility.

Dynamics of task sets: evidence from dense-array event-related potentials.

PubMed

Poulsen, Catherine; Luu, Phan; Davey, Colin; Tucker, Don M

2005-06-01

Prior research suggests that task sets facilitate coherent, goal-directed behavior by providing an internal, contextual frame that biases selection toward context-relevant stimulus attributes and responses. Questions about how task sets are engaged, maintained, and shifted have recently become a major focus of research on executive control processes. We employed dense-array (128-channel) event-related potential (ERP) methodology to examine the dynamics of brain systems engaged during the preparation and implementation of task switching. The EEG was recorded while participants performed letter and digit judgments to pseudorandomly-ordered, univalent (#3, A%) and bivalent (G5) stimulus trials, with the appropriate task cued by a colored rectangle presented 450 ms before target onset. Results revealed spatial and temporal variations in brain activity that could be related to preparatory processes common to both switch and repeat trials, switch-specific control processes engaged to reconfigure and maintain task set under conflict, and visual priming benefits of task repetition. Despite extensive practice and improvement, both behavioral and ERP results indicated that subjects maintained high levels of executive control processing with extended task engagement. The patterns of ERP activity obtained in the present study fit well with functional neuroanatomical models of self-regulation of action. The frontopolar and right-lateralized frontal switch effects obtained in the present study are consistent with the role of these regions in adapting to changing contextual contingencies. In contrast, the centroparietal P3b and N384 effects related to the contextual ambiguity of bivalent trials are consistent with the context monitoring and updating functions associated with the posterior cingulate learning circuit.

A behavioral task for investigating action discovery, selection and switching: comparison between types of reinforcer

PubMed Central

Fisher, Simon D.; Gray, Jason P.; Black, Melony J.; Davies, Jennifer R.; Bednark, Jeffery G.; Redgrave, Peter; Franz, Elizabeth A.; Abraham, Wickliffe C.; Reynolds, John N. J.

2014-01-01

Action discovery and selection are critical cognitive processes that are understudied at the cellular and systems neuroscience levels. Presented here is a new rodent joystick task suitable to test these processes due to the range of action possibilities that can be learnt while performing the task. Rats learned to manipulate a joystick while progressing through task milestones that required increasing degrees of movement accuracy. In a switching phase designed to measure action discovery, rats were repeatedly required to discover new target positions to meet changing task demands. Behavior was compared using both food and electrical brain stimulation reward (BSR) of the substantia nigra as reinforcement. Rats reinforced with food and those with BSR performed similarly overall, although BSR-treated rats exhibited greater vigor in responding. In the switching phase, rats learnt new actions to adapt to changing task demands, reflecting action discovery processes. Because subjects are required to learn different goal-directed actions, this task could be employed in further investigations of the cellular mechanisms of action discovery and selection. Additionally, this task could be used to assess the behavioral flexibility impairments seen in conditions such as Parkinson's disease and obsessive-compulsive disorder. The versatility of the task will enable cross-species investigations of these impairments. PMID:25477795

Are stimulus-response rules represented phonologically for task-set preparation and maintenance?

PubMed

van 't Wout, Félice; Lavric, Aureliu; Monsell, Stephen

2013-09-01

Accounts of task-set control generally assume that the current task's stimulus-response (S-R) rules must be elevated to a privileged state of activation. How are they represented in this state? In 3 task-cuing experiments, we tested the hypothesis that phonological working memory is used to represent S-R rules for task-set control by getting participants to switch between 2 sets of arbitrary S-R rules and manipulating the articulatory duration (Experiment 1) or phonological similarity (Experiments 2 and 3) of the names of the stimulus terms. The task cue specified which of 2 objects (Experiment 1) or consonants (Experiment 2) in a display to identify with a key press. In Experiment 3, participants switched between identifying an object/consonant and its color/visual texture. After practice, neither the duration nor the similarity of the stimulus terms had detectable effects on overall performance, task-switch cost, or its reduction with preparation. Only in the initial single-task training blocks was phonological similarity a significant handicap. Hence, beyond a very transient role, there is no evidence that (declarative) phonological working memory makes a functional contribution to representing S-R rules for task-set control, arguably because once learned, they are represented in nonlinguistic procedural working memory. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Comparing Electric Shock and a Fearful Screaming Face as Unconditioned Stimuli for Fear Learning

PubMed Central

Glenn, Catherine R.; Lieberman, Lynne; Hajcak, Greg

2012-01-01

The potency of an unconditioned stimulus (UCS) can impact the degree of fear learning. One of the most common and effective UCSs is an electric shock, which is inappropriate for certain populations (e.g., children). To address this need, a novel fear learning paradigm was recently developed that uses a fearful female face and scream as the UCS. The present study directly compared the efficacy of the screaming female UCS and a traditional shock UCS in two fear learning paradigms. Thirty-six young adults completed two fear learning tasks and a measure of trait anxiety; fear learning was indexed with fear-potentiated startle (FPS) and self-reported fear ratings. Results indicated comparable FPS across the two tasks. However, larger overall startle responses were exhibited in the shock task, and participants rated the shock UCS and overall task as more aversive than the screaming female. In addition, trait anxiety was only related to FPS in the fear learning task that employed a shock as the UCS. Taken together, results indicate that, although both UCS paradigms can be used for fear conditioning (i.e., to produce differences between CS+ and CS−), the shock UCS paradigm is more aversive and potentially more sensitive to individual differences in anxiety. PMID:23007035

Is Rest Really Rest? Resting State Functional Connectivity during Rest and Motor Task Paradigms.

PubMed

Jurkiewicz, Michael T; Crawley, Adrian P; Mikulis, David J

2018-04-18

Numerous studies have identified the default mode network (DMN) within the brain of healthy individuals, which has been attributed to the ongoing mental activity of the brain during the wakeful resting-state. While engaged during specific resting-state fMRI paradigms, it remains unclear as to whether traditional block-design simple movement fMRI experiments significantly influence the default mode network or other areas. Using blood-oxygen level dependent (BOLD) fMRI we characterized the pattern of functional connectivity in healthy subjects during a resting-state paradigm and compared this to the same resting-state analysis performed on motor task data residual time courses after regressing out the task paradigm. Using seed-voxel analysis to define the DMN, the executive control network (ECN), and sensorimotor, auditory and visual networks, the resting-state analysis of the residual time courses demonstrated reduced functional connectivity in the motor network and reduced connectivity between the insula and the ECN compared to the standard resting-state datasets. Overall, performance of simple self-directed motor tasks does little to change the resting-state functional connectivity across the brain, especially in non-motor areas. This would suggest that previously acquired fMRI studies incorporating simple block-design motor tasks could be mined retrospectively for assessment of the resting-state connectivity.

Social strain and executive function across the lifespan: The dark (and light) sides of social engagement

PubMed Central

Tun, Patricia A.; Miller-Martinez, Dana; Lachman, Margie E.; Seeman, Teresa

2012-01-01

We investigated how the association between social strain and cognitive efficiency varies with task demands across adulthood, from latencies on simpler speeded tasks to tests involving executive function. Participants (N= 3280) were drawn from the MIDUS survey, a large, diverse national sample of adults who completed cognitive tests including speeded task-switching (Tun & Lachman, 2008). After controlling for demographic and health variables, we found that higher levels of reported social strain were associated with slower processing speed, particularly for the complex task-switching test relative to simpler speeded tests. Effects of strain were greatest for those with the lowest general cognitive ability. Moreover, those with very high levels of social strain but low levels of social support gave the poorest task-switching performance. These findings provide further evidence for the complex relationship between the social environment and cognition across adulthood, particularly the association between efficiency of executive functions and negative social interactions. PMID:22873285

Automaticity of Cognitive Control: Goal Priming in Response-Inhibition Paradigms

ERIC Educational Resources Information Center

Verbruggen, Frederick; Logan, Gordon D.

2009-01-01

Response inhibition is a hallmark of cognitive control. An executive system inhibits responses by activating a stop goal when a stop signal is presented. The authors asked whether the stop goal could be primed by task-irrelevant information in stop-signal and go/no-go paradigms. In Experiment 1, the task-irrelevant primes "GO," ###, or "STOP" were…

Do Causal and Concessive Connectives Guide Emotional Expectancies in Comprehension? A Double-Task Paradigm Using Emotional Icons

ERIC Educational Resources Information Center

Morera, Yurena; León, José A.; Escudero, Inmaculada; de Vega, Manuel

2017-01-01

Continuity and discontinuity are sometimes marked in discourse by means of connectives. This study tested for the first time whether causal and concessive connectives induce expectations of emotional continuity and discontinuity, respectively. Using a novel double-task paradigm, participants first listened to an antecedent clause with a causal or…

The Development of Visual and Auditory Selective Attention Using the Central-Incidental Paradigm.

ERIC Educational Resources Information Center

Conroy, Robert L.; Weener, Paul

Analogous auditory and visual central-incidental learning tasks were administered to 24 students from each of the second, fourth, and sixth grades. The visual tasks served as another modification of Hagen's central-incidental learning paradigm, with the interpretation that focal attention processes continue to develop until the age of 12 or 13…

The Failure of Deactivating Intentions: Aftereffects of Completed Intentions in the Repeated Prospective Memory Cue Paradigm

ERIC Educational Resources Information Center

Walser, Moritz; Fischer, Rico; Goschke, Thomas

2012-01-01

We used a newly developed experimental paradigm to investigate aftereffects of completed intentions on subsequent performance that required the maintenance and execution of new intentions. Participants performed an ongoing number categorization task and an additional prospective memory (PM) task, which required them to respond to PM cues that…

The role of subjective frequency in language switching: An ERP investigation using masked priming

PubMed Central

Chauncey, Krysta; Grainger, Jonathan; Holcomb, Phillip J.

2012-01-01

Two experiments examined the nature of language-switching effects in a priming paradigm with event-related brain potential (ERP) recordings. primes and targets were always unrelated words but could be either from the same or different languages (Experiment 1) or from the same or a different frequency range (Experiment 2). Effects of switching language across prime and target differed as a function of the direction of the switch and prime duration in Experiment 1. Effects tended to be stronger with 100-ms prime durations than with 50-ms durations, and the expected pattern of greater negativity in the switch condition appeared earlier when primes were in L1 and targets in L2 than vice versa. Experiment 2 examined whether these language-switching effects could be due to differences in the subjective frequency of words in a bilingual’s two languages, by testing a frequency-switching manipulation within the L1. Effects of frequency switching were evident in the ERP waveforms, but the pattern did not resemble the language-switching effects, therefore suggesting that different mechanisms are at play. PMID:21264577

Estimating the executive demands of a one-back choice reaction time task by means of the selective interference paradigm.

PubMed

Szmalec, Arnaud; Vandierendonck, André

2007-08-01

The present study proposes a new executive task, the one-back choice reaction time (RT) task, and implements the selective interference paradigm to estimate the executive demands of the processing components involved in this task. Based on the similarities between a one-back choice RT task and the n-back updating task, it was hypothesized that one-back delaying of a choice reaction involves executive control. In three experiments, framed within Baddeley's (1986) working-memory model, a one-back choice RT task, a choice RT task, articulatory suppression, and matrix tapping were performed concurrently with primary tasks involving verbal, visuospatial, and executive processing. The results demonstrate that one-back delaying of a choice reaction interferes with tasks requiring executive control, while the potential interference at the level of the verbal or visuospatial working memory slave systems remains minimal.

Event-related potential indices of workload in a single task paradigm

NASA Technical Reports Server (NTRS)

Horst, R. L.; Munson, R. C.; Ruchkin, D. S.

1984-01-01

Many previous studies of both behavioral and physiological correlates of cognitive workload have burdened subjects with a contrived secondary task in order to assess the workload of a primary task. The present study investigated event-related potential (ERP) indices of workload in a single task paradigm. Subjects monitored changing digital readouts for values that went 'out-of-bounds'. The amplitude of a long-latency positivity in the ERPs elicited by readout changes increased with the number of readouts being monitored. This effect of workload on ERPs is reported, along with plans for additional analyses to address theoretical implications.

Children's Task-Switching Efficiency: Missing Our Cue?

ERIC Educational Resources Information Center

Holt, Anna E.; Deák, Gedeon

2015-01-01

In simple rule-switching tests, 3- and 4-year-olds can follow each of two sorting rules but sometimes make perseverative errors when switching. Older children make few errors but respond slowly when switching. These age-related changes might reflect the maturation of executive functions (e.g., inhibition). However, they might also reflect…

Differential Neural Correlates of Set-Shifting in the Bingeing-Purging and Restrictive Subtypes of Anorexia Nervosa: An fMRI Study.

PubMed

Van Autreve, Sara; De Baene, Wouter; Baeken, Chris; van Heeringen, Kees; Vancayseele, Nikita; Vervaet, Myriam

2016-07-01

In this study, possible differences in the neural correlates of set-shifting abilities between the restrictive (AN-R) and bingeing/purging (AN-BP) subtypes of anorexia nervosa have been explored. Three groups of participants performed a set-shifting task during functional magnetic resonance imaging: patients with AN-R (N = 16), AN-BP (N = 13) and healthy control participants (N = 15). As in a typical set-shifting experiment, participants had to switch between two easy tasks (i.e. 'Is the presented number odd/even' or 'Is the presented number smaller/larger than 5'). The trials in which the task was repeated (repeat trials) were compared with trials in which the task was switched (switch trials). With regards to the level of task performance, no significant group differences could be established. However, when comparing switch specific brain activity across study groups, a stronger activation was found in the insula and the precuneus in AN-R when compared to AN-BP and HC. These results suggest that the both subtypes of AN might have different neurobiological correlates, and thus, might benefit from different treatment approaches. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

Energy and Power Aware Computing Through Management of Computational Entropy

DTIC Science & Technology

2008-01-01

18 2.4.1 ACIP living framework forum task...This research focused on two sub- tasks: (1) Assessing the need and planning for a potential “Living Framework Forum ” (LFF) software architecture...probabilistic switching with plausible device realizations to save energy in our patent application [35]. In [35], we showed an introverted switch in

Relations as Rules: The Role of Attention in the Dimensional Change Card Sort Task

ERIC Educational Resources Information Center

Honomichl, Ryan D.; Chen, Zhe

2011-01-01

Preschoolers are typically unable to switch sorting rules during the Dimensional Change Card Sort task. One explanation for this phenomenon is attentional inflexibility (Kirkham, Cruess, & Diamond, 2003). In 4 experiments with 3- to 4-year-olds, we tested this hypothesis by examining the influence of dimensional salience on switching performance.…

Attention Difficulties and Mood-Related Ruminative Response Style in Adolescents with Unipolar Depression

ERIC Educational Resources Information Center

Wilkinson, Paul O.; Goodyer, Ian M.

2006-01-01

Background: Depressed adults may show impairment in switching attention from one task to another. Rumination on negative thoughts is associated with the onset and persistence of depressive episodes. It is unclear if such mood-related ruminations are specifically associated with slowed ability in switching attention from one task to another.…

The combined effects of L-theanine and caffeine on cognitive performance and mood.

PubMed

Owen, Gail N; Parnell, Holly; De Bruin, Eveline A; Rycroft, Jane A

2008-08-01

The aim of this study was to compare 50 mg caffeine, with and without 100 mg L-theanine, on cognition and mood in healthy volunteers. The effects of these treatments on word recognition, rapid visual information processing, critical flicker fusion threshold, attention switching and mood were compared to placebo in 27 participants. Performance was measured at baseline and again 60 min and 90 min after each treatment (separated by a 7-day washout). Caffeine improved subjective alertness at 60 min and accuracy on the attention-switching task at 90 min. The L-theanine and caffeine combination improved both speed and accuracy of performance of the attention-switching task at 60 min, and reduced susceptibility to distracting information in the memory task at both 60 min and 90 min. These results replicate previous evidence which suggests that L-theanine and caffeine in combination are beneficial for improving performance on cognitively demanding tasks.

A model for combined targeting and tracking tasks in computer applications.

PubMed

Senanayake, Ransalu; Hoffmann, Errol R; Goonetilleke, Ravindra S

2013-11-01

Current models for targeted-tracking are discussed and shown to be inadequate as a means of understanding the combined task of tracking, as in the Drury's paradigm, and having a final target to be aimed at, as in the Fitts' paradigm. It is shown that the task has to be split into components that are, in general, performed sequentially and have a movement time component dependent on the difficulty of the individual component of the task. In some cases, the task time may be controlled by the Fitts' task difficulty, and in others, it may be dominated by the Drury's task difficulty. Based on an experiment carried out that captured movement time in combinations of visually controlled and ballistic movements, a model for movement time in targeted-tracking was developed.

Impaired preparatory re-mapping of stimulus-response associations and rule-implementation in schizophrenic patients--the role for differences in early processing.

PubMed

Finke, Mareike; Barceló, Francisco; Garolera, Maite; Cortiñas, Miriam; Garrido, Gemma; Pajares, Marta; Escera, Carles

2011-07-01

An accurate representation of task-set information is needed for successful goal directed behavior. Recent studies point to disturbances in the early processing stages as plausible causes for task-switching deficits in schizophrenia. A task-cueing protocol was administered to a group of schizophrenic patients and compared with a sample of age-matched healthy controls. Patients responded slower and less accurate compared with controls in all conditions. The concurrent recording of event-related brain potentials to contextual cues and target events revealed abnormalities in the early processing of both cue-locked and target-locked N1 potentials. Abnormally enhanced target-locked P2 amplitudes were observed in schizophrenic patients for task-switch trials only, suggesting disrupted stimulus evaluation and memory retrieval processes. The endogenous P3 potentials discriminated between task conditions but without further differences between groups. These results suggest that the observed impairments in task-switching behavior were not specifically related to anticipatory set-shifting, but derived from a deficit in the implementation of task-set representations at target onset in the presence of irrelevant and conflicting information. Copyright © 2011 Elsevier B.V. All rights reserved.

Cobra communications switch integration program

NASA Technical Reports Server (NTRS)

Shively, Robert J.; Haworth, Loran A.; Szoboszlay, Zoltan; Murray, F. Gerald

1989-01-01

The paper describes a design modification to reduce the visual and manual workload associated with the radio selection and communications tasks in the U.S. Army AH-1 Cobra helicopter. The modification involves the integration of the radio selection and microphone actuating tasks into a single operation controlled by the transmit-intercom switch. Ground-based and flight tests were conducted to evaluate the modified configuration during twelve flight tasks. The results show that the proposed configuration performs twice as fast as the original configuration.

Performance of Brazilian children on phonemic and semantic verbal fluency tasks

PubMed Central

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

2011-01-01

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

Diet/Energy Balance Affect Sleep and Wakefulness Independent of Body Weight

PubMed Central

Perron, Isaac J.; Pack, Allan I.; Veasey, Sigrid

2015-01-01

Study Objectives: Excessive daytime sleepiness commonly affects obese people, even in those without sleep apnea, yet its causes remain uncertain. We sought to determine whether acute dietary changes could induce or rescue wake impairments independent of body weight. Design: We implemented a novel feeding paradigm that generates two groups of mice with equal body weight but opposing energetic balance. Two subsets of mice consuming either regular chow (RC) or high-fat diet (HFD) for 8 w were switched to the opposite diet for 1 w. Sleep recordings were conducted at Week 0 (baseline), Week 8 (pre-diet switch), and Week 9 (post-diet switch) for all groups. Sleep homeostasis was measured at Week 8 and Week 9. Participants: Young adult, male C57BL/6J mice. Measurements and Results: Differences in total wake, nonrapid eye movement (NREM), and rapid eye movement (REM) time were quantified, in addition to changes in bout fragmentation/consolidation. At Week 9, the two diet switch groups had similar body weight. However, animals switched to HFD (and thus gaining weight) had decreased wake time, increased NREM sleep time, and worsened sleep/wake fragmentation compared to mice switched to RC (which were in weight loss). These effects were driven by significant sleep/wake changes induced by acute dietary manipulations (Week 8 → Week 9). Sleep homeostasis, as measured by delta power increase following sleep deprivation, was unaffected by our feeding paradigm. Conclusions: Acute dietary manipulations are sufficient to alter sleep and wakefulness independent of body weight and without effects on sleep homeostasis. Citation: Perron IJ, Pack AI, Veasey S. Diet/energy balance affect sleep and wakefulness independent of body weight. SLEEP 2015;38(12):1893–1903. PMID:26158893

Task Differences and Prosociality; Investigating Pet Dogs' Prosocial Preferences in a Token Choice Paradigm.

PubMed

Dale, Rachel; Quervel-Chaumette, Mylène; Huber, Ludwig; Range, Friederike; Marshall-Pescini, Sarah

2016-01-01

Prosociality has received increasing interest by non-human animal researchers since the initial discoveries that suggested it is not a uniquely human trait. However, thus far studies, even within the same species, have not garnered conclusive results. A prominent suggestion for this disparity is the effect methodology can have on prosocial responses in animals. We recently found evidence of prosociality in domestic dogs towards familiar conspecifics using a bar-pulling paradigm, in which a subject could pull a rope to deliver food to its partner. Therefore, the current study aimed to assess whether dogs would show a similar response in a different paradigm, based on the token exchange task paradigm frequently used with primates. In this task, dogs had the option to touch a token with their nose that delivered a reward to an adjacent receiver enclosure, which contained a familiar conspecific, a stranger or no dog at all. Crucially, we also included a social facilitation control condition, whereby the partner (stranger/familiar) was present but unable to access the food. We found that the familiarity effect remained consistent across tasks, with dogs of both the bar-pulling and token choice experiments providing more food to familiar partners than in a non-social control and providing less food to stranger partners than this same control. However, in contrast to our previous bar-pulling experiment, we could not exclude social facilitation as an underlying motive in the current task. We propose this difference in results between tasks may be related to increased task complexity in the token choice paradigm, making it harder for dogs to discriminate between the test and social facilitation conditions. Overall our findings suggest that subtle methodological changes can have an impact on prosocial behaviours in dogs and highlights the importance of controlling for social facilitation effects in such experiments.

The Face-to-Face Light Detection Paradigm: A New Methodology for Investigating Visuospatial Attention Across Different Face Regions in Live Face-to-Face Communication Settings.

PubMed

Thompson, Laura A; Malloy, Daniel M; Cone, John M; Hendrickson, David L

2010-01-01

We introduce a novel paradigm for studying the cognitive processes used by listeners within interactive settings. This paradigm places the talker and the listener in the same physical space, creating opportunities for investigations of attention and comprehension processes taking place during interactive discourse situations. An experiment was conducted to compare results from previous research using videotaped stimuli to those obtained within the live face-to-face task paradigm. A headworn apparatus is used to briefly display LEDs on the talker's face in four locations as the talker communicates with the participant. In addition to the primary task of comprehending speeches, participants make a secondary task light detection response. In the present experiment, the talker gave non-emotionally-expressive speeches that were used in past research with videotaped stimuli. Signal detection analysis was employed to determine which areas of the face received the greatest focus of attention. Results replicate previous findings using videotaped methods.

The Face-to-Face Light Detection Paradigm: A New Methodology for Investigating Visuospatial Attention Across Different Face Regions in Live Face-to-Face Communication Settings

PubMed Central

Thompson, Laura A.; Malloy, Daniel M.; Cone, John M.; Hendrickson, David L.

2009-01-01

We introduce a novel paradigm for studying the cognitive processes used by listeners within interactive settings. This paradigm places the talker and the listener in the same physical space, creating opportunities for investigations of attention and comprehension processes taking place during interactive discourse situations. An experiment was conducted to compare results from previous research using videotaped stimuli to those obtained within the live face-to-face task paradigm. A headworn apparatus is used to briefly display LEDs on the talker’s face in four locations as the talker communicates with the participant. In addition to the primary task of comprehending speeches, participants make a secondary task light detection response. In the present experiment, the talker gave non-emotionally-expressive speeches that were used in past research with videotaped stimuli. Signal detection analysis was employed to determine which areas of the face received the greatest focus of attention. Results replicate previous findings using videotaped methods. PMID:21113354

E-learning, dual-task, and cognitive load: The anatomy of a failed experiment.

PubMed

Van Nuland, Sonya E; Rogers, Kem A

2016-01-01

The rising popularity of commercial anatomy e-learning tools has been sustained, in part, due to increased annual enrollment and a reduction in laboratory hours across educational institutions. While e-learning tools continue to gain popularity, the research methodologies used to investigate their impact on learning remain imprecise. As new user interfaces are introduced, it is critical to understand how functionality can influence the load placed on a student's memory resources, also known as cognitive load. To study cognitive load, a dual-task paradigm wherein a learner performs two tasks simultaneously is often used, however, its application within educational research remains uncommon. Using previous paradigms as a guide, a dual-task methodology was developed to assess the cognitive load imposed by two commercial anatomical e-learning tools. Results indicate that the standard dual-task paradigm, as described in the literature, is insensitive to the cognitive load disparities across e-learning tool interfaces. Confounding variables included automation of responses, task performance tradeoff, and poor understanding of primary task cognitive load requirements, leading to unreliable quantitative results. By modifying the secondary task from a basic visual response to a more cognitively demanding task, such as a modified Stroop test, the automation of secondary task responses can be reduced. Furthermore, by recording baseline measures for the primary task as well as the secondary task, it is possible for task performance tradeoff to be detected. Lastly, it is imperative that the cognitive load of the primary task be designed such that it does not overwhelm the individual's ability to learn new material. © 2015 American Association of Anatomists.

A Pattern of Perseveration in Cocaine Addiction May Reveal Neurocognitive Processes Implicit in the Wisconsin Card Sorting Test

PubMed Central

Woicik, Patricia A.; Urban, Catherine; Alia-Klein, Nelly; Henry, Ashley; Maloney, Thomas; Telang, Frank; Wang, Gene-Jack; Volkow, Nora D.; Goldstein, Rita Z.

2011-01-01

The ability to adapt behavior in a changing environment is necessary for humans to achieve their goals and can be measured in the lab with tests of rule-based switching. Disease models, such as cocaine addiction, have revealed that alterations in dopamine interfere with adaptive set switching, culminating in perseveration. We explore perseverative behavior in individuals with cocaine use disorders (CUD) and healthy controls (CON) during performance of the Wisconsin Card Sorting Test (WCST) (N = 107 in each group). By examining perseverative errors within each of the 6 blocks of the WCST, we uniquely test two forms of set switching that are differentiated by either the presence (extradimensional set shifting (EDS) – first 3 blocks) or absence (task-set switching – last 3 blocks) of contingency learning. We also explore relationships between perseveration and select cognitive and drug use factors including verbal learning and memory, trait inhibitory control, motivational state, and urine status for cocaine (in CUD). Results indicate greater impairment for CUD than CON on the WCST, even in higher performing CUD who completed all 6 blocks of the WCST. Block by block analysis conducted on completers’ scores indicate a tendency for greater perseveration in CUD than CON but only during the first task-set switch; no such deficits were observed during EDS. This task-set switching impairment was modestly associated with two indices of immediate recall (r = −.32, −.29) and urine status for cocaine [t (134) = 2.3, p <.03]. By distinguishing these two forms of switching on the WCST, the current study reveals a neurocognitive context (i.e. initial stage of task-set switching) implicit in the WCST that possibly relies upon intact dopaminergic function, but that is impaired in CUD, as associated with worse recall and possibly withdrawal from cocaine. Future studies should investigate whether dopaminergically innervated pathways alone, or in combination with other monoamines, underlie this implicit neurocognitive processes in the WCST. PMID:21392517

Application of real-time machine learning to myoelectric prosthesis control: A case series in adaptive switching.

PubMed

Edwards, Ann L; Dawson, Michael R; Hebert, Jacqueline S; Sherstan, Craig; Sutton, Richard S; Chan, K Ming; Pilarski, Patrick M

2016-10-01

Myoelectric prostheses currently used by amputees can be difficult to control. Machine learning, and in particular learned predictions about user intent, could help to reduce the time and cognitive load required by amputees while operating their prosthetic device. The goal of this study was to compare two switching-based methods of controlling a myoelectric arm: non-adaptive (or conventional) control and adaptive control (involving real-time prediction learning). Case series study. We compared non-adaptive and adaptive control in two different experiments. In the first, one amputee and one non-amputee subject controlled a robotic arm to perform a simple task; in the second, three able-bodied subjects controlled a robotic arm to perform a more complex task. For both tasks, we calculated the mean time and total number of switches between robotic arm functions over three trials. Adaptive control significantly decreased the number of switches and total switching time for both tasks compared with the conventional control method. Real-time prediction learning was successfully used to improve the control interface of a myoelectric robotic arm during uninterrupted use by an amputee subject and able-bodied subjects. Adaptive control using real-time prediction learning has the potential to help decrease both the time and the cognitive load required by amputees in real-world functional situations when using myoelectric prostheses. © The International Society for Prosthetics and Orthotics 2015.

Multitasking During Degraded Speech Recognition in School-Age Children

PubMed Central

Ward, Kristina M.; Brehm, Laurel

2017-01-01

Multitasking requires individuals to allocate their cognitive resources across different tasks. The purpose of the current study was to assess school-age children’s multitasking abilities during degraded speech recognition. Children (8 to 12 years old) completed a dual-task paradigm including a sentence recognition (primary) task containing speech that was either unprocessed or noise-band vocoded with 8, 6, or 4 spectral channels and a visual monitoring (secondary) task. Children’s accuracy and reaction time on the visual monitoring task was quantified during the dual-task paradigm in each condition of the primary task and compared with single-task performance. Children experienced dual-task costs in the 6- and 4-channel conditions of the primary speech recognition task with decreased accuracy on the visual monitoring task relative to baseline performance. In all conditions, children’s dual-task performance on the visual monitoring task was strongly predicted by their single-task (baseline) performance on the task. Results suggest that children’s proficiency with the secondary task contributes to the magnitude of dual-task costs while multitasking during degraded speech recognition. PMID:28105890

Multitasking During Degraded Speech Recognition in School-Age Children.

PubMed

Grieco-Calub, Tina M; Ward, Kristina M; Brehm, Laurel

2017-01-01

Multitasking requires individuals to allocate their cognitive resources across different tasks. The purpose of the current study was to assess school-age children's multitasking abilities during degraded speech recognition. Children (8 to 12 years old) completed a dual-task paradigm including a sentence recognition (primary) task containing speech that was either unprocessed or noise-band vocoded with 8, 6, or 4 spectral channels and a visual monitoring (secondary) task. Children's accuracy and reaction time on the visual monitoring task was quantified during the dual-task paradigm in each condition of the primary task and compared with single-task performance. Children experienced dual-task costs in the 6- and 4-channel conditions of the primary speech recognition task with decreased accuracy on the visual monitoring task relative to baseline performance. In all conditions, children's dual-task performance on the visual monitoring task was strongly predicted by their single-task (baseline) performance on the task. Results suggest that children's proficiency with the secondary task contributes to the magnitude of dual-task costs while multitasking during degraded speech recognition.

When underadditivity of factor effects in the Psychological Refractory Period paradigm implies a bottleneck: evidence from psycholinguistics.

PubMed

Besner, Derek; Reynolds, Mike; O'Malley, Shannon

2009-11-01

The Psychological Refractory Period (PRP) paradigm is a dual-task procedure that can be used to examine the resource demands of specific cognitive processes. Inferences about the underlying processes are typically based on performance in the second of two speeded tasks. If the effect of a factor manipulated in Task 2 decreases as the stimulus onset asynchrony (SOA) between tasks decreases (underadditivity), the normative inference is that the effect of this factor occurs prior to a limited-capacity central processing mechanism. In contrast, if the effect of a factor is additive with SOA then the inference is that this indexes a process that either uses a limited-capacity central processing mechanism or occurs after some process that uses this mechanism. A heretofore unidentified exception to this logic arises when Task 2 involves two separate processes that operate in parallel, but compete. Interference with one process in Task 2 because of work on Task 1 will eliminate or reduce competition within Task 2 and is hence manifest as an underadditive interaction with decreasing SOA. This is illustrated here by reference to a PRP experiment in which the ubiquitous effect of spelling-to-sound regularity on reading aloud time is eliminated at a short SOA and by consideration of three converging lines of investigation in the PRP paradigm when Task 2 involves reading aloud.

Mechanism to support generic collective communication across a variety of programming models

DOEpatents

Almasi, Gheorghe [Ardsley, NY; Dozsa, Gabor [Ardsley, NY; Kumar, Sameer [White Plains, NY

2011-07-19

A system and method for supporting collective communications on a plurality of processors that use different parallel programming paradigms, in one aspect, may comprise a schedule defining one or more tasks in a collective operation, an executor that executes the task, a multisend module to perform one or more data transfer functions associated with the tasks, and a connection manager that controls one or more connections and identifies an available connection. The multisend module uses the available connection in performing the one or more data transfer functions. A plurality of processors that use different parallel programming paradigms can use a common implementation of the schedule module, the executor module, the connection manager and the multisend module via a language adaptor specific to a parallel programming paradigm implemented on a processor.

Distinguishing response conflict and task conflict in the Stroop task: evidence from ex-Gaussian distribution analysis.

PubMed

Steinhauser, Marco; Hübner, Ronald

2009-10-01

It has been suggested that performance in the Stroop task is influenced by response conflict as well as task conflict. The present study investigated the idea that both conflict types can be isolated by applying ex-Gaussian distribution analysis which decomposes response time into a Gaussian and an exponential component. Two experiments were conducted in which manual versions of a standard Stroop task (Experiment 1) and a separated Stroop task (Experiment 2) were performed under task-switching conditions. Effects of response congruency and stimulus bivalency were used to measure response conflict and task conflict, respectively. Ex-Gaussian analysis revealed that response conflict was mainly observed in the Gaussian component, whereas task conflict was stronger in the exponential component. Moreover, task conflict in the exponential component was selectively enhanced under task-switching conditions. The results suggest that ex-Gaussian analysis can be used as a tool to isolate different conflict types in the Stroop task. PsycINFO Database Record (c) 2009 APA, all rights reserved.

A novel channel selection method for optimal classification in different motor imagery BCI paradigms.

PubMed

Shan, Haijun; Xu, Haojie; Zhu, Shanan; He, Bin

2015-10-21

For sensorimotor rhythms based brain-computer interface (BCI) systems, classification of different motor imageries (MIs) remains a crucial problem. An important aspect is how many scalp electrodes (channels) should be used in order to reach optimal performance classifying motor imaginations. While the previous researches on channel selection mainly focus on MI tasks paradigms without feedback, the present work aims to investigate the optimal channel selection in MI tasks paradigms with real-time feedback (two-class control and four-class control paradigms). In the present study, three datasets respectively recorded from MI tasks experiment, two-class control and four-class control experiments were analyzed offline. Multiple frequency-spatial synthesized features were comprehensively extracted from every channel, and a new enhanced method IterRelCen was proposed to perform channel selection. IterRelCen was constructed based on Relief algorithm, but was enhanced from two aspects: change of target sample selection strategy and adoption of the idea of iterative computation, and thus performed more robust in feature selection. Finally, a multiclass support vector machine was applied as the classifier. The least number of channels that yield the best classification accuracy were considered as the optimal channels. One-way ANOVA was employed to test the significance of performance improvement among using optimal channels, all the channels and three typical MI channels (C3, C4, Cz). The results show that the proposed method outperformed other channel selection methods by achieving average classification accuracies of 85.2, 94.1, and 83.2 % for the three datasets, respectively. Moreover, the channel selection results reveal that the average numbers of optimal channels were significantly different among the three MI paradigms. It is demonstrated that IterRelCen has a strong ability for feature selection. In addition, the results have shown that the numbers of optimal channels in the three different motor imagery BCI paradigms are distinct. From a MI task paradigm, to a two-class control paradigm, and to a four-class control paradigm, the number of required channels for optimizing the classification accuracy increased. These findings may provide useful information to optimize EEG based BCI systems, and further improve the performance of noninvasive BCI.

An investigation of the neural substrates of mind wandering induced by viewing traditional Chinese landscape paintings.

PubMed

Wang, Tingting; Mo, Lei; Vartanian, Oshin; Cant, Jonathan S; Cupchik, Gerald

2014-01-01

The present study was conducted to investigate whether the calming effect induced by viewing traditional Chinese landscape paintings would make disengagement from that mental state more difficult, as measured by performance on a cognitive control task. In Experiment 1 we examined the subjective experience of viewing traditional Chinese landscape paintings vs. realistic oil landscape paintings in a behavioral study. Our results confirmed that, as predicted, traditional Chinese landscape paintings induce greater levels of relaxation and mind wandering and lower levels of object-oriented absorption and recognition, compared to realistic oil landscape paintings. In Experiment 2 we used functional Magnetic Resonance Imaging to explore the behavioral and neural effects of viewing traditional Chinese landscape paintings on a task requiring cognitive control (i.e., the flanker task)-administered immediately following exposure to paintings. Contrary to our prediction, the behavioral data demonstrated that compared to realistic oil landscape paintings, exposure to traditional Chinese landscape paintings had no effect on performance on the flanker task. However, the neural data demonstrated an interaction effect such that there was greater activation in the inferior parietal cortex and the superior frontal gyrus on incongruent compared with congruent flanker trials when participants switched from viewing traditional Chinese landscape paintings to the flanker task than when they switched from realistic oil landscape paintings. These results suggest that switching from traditional Chinese landscape paintings placed greater demands on the brain's attention and working memory networks during the flanker task than did switching from realistic oil landscape paintings.

The benefits of endurance exercise and Tai Chi Chuan for the task-switching aspect of executive function in older adults: an ERP study.

PubMed

Fong, Dong-Yang; Chi, Li-Kang; Li, Fuzhong; Chang, Yu-Kai

2014-01-01

This study was designed to determine the relationship between physical activity and the task-switching aspect of executive function by investigating the modulating roles of age, modality of physical activity, and type of cognitive function using behavioral and event-related potential (ERP) assessments. Sixty-four participants were assigned to one of four groups based on age and history of physical activity: older adults performing endurance exercise (OEE), older adults practicing Tai Chi Chuan (OTC), older adults with a sedentary lifestyle (OSL), and young adults (YA). Study participants completed a task-switching task under homogeneous and heterogeneous conditions while ERPs were recorded. The results revealed that YA had shortest reaction times compared with the three older adults groups, with OSL exhibiting the longest reaction time. YA also exhibited shorter P3 latency than OSL. No differences were observed in P3 amplitude between YA, OEE, and OTC; however, all three groups had significantly larger P3 amplitude compared with OSL in both task conditions. In conclusion, age and participation in physical activity influence the relationship between physical activity and task-switching, and a positive relationship was observed regardless of the modality of physical activity and type of cognitive function. Our ERP findings support the model of the scaffolding theory of aging and cognition (STAC) and suggest that regular participation in endurance exercise and Tai Chi Chuan may have equivalent beneficial effects on cognition at the behavioral and neuroelectric levels.

The benefits of endurance exercise and Tai Chi Chuan for the task-switching aspect of executive function in older adults: an ERP study

PubMed Central

Fong, Dong-Yang; Chi, Li-Kang; Li, Fuzhong; Chang, Yu-Kai

2014-01-01

This study was designed to determine the relationship between physical activity and the task-switching aspect of executive function by investigating the modulating roles of age, modality of physical activity, and type of cognitive function using behavioral and event-related potential (ERP) assessments. Sixty-four participants were assigned to one of four groups based on age and history of physical activity: older adults performing endurance exercise (OEE), older adults practicing Tai Chi Chuan (OTC), older adults with a sedentary lifestyle (OSL), and young adults (YA). Study participants completed a task-switching task under homogeneous and heterogeneous conditions while ERPs were recorded. The results revealed that YA had shortest reaction times compared with the three older adults groups, with OSL exhibiting the longest reaction time. YA also exhibited shorter P3 latency than OSL. No differences were observed in P3 amplitude between YA, OEE, and OTC; however, all three groups had significantly larger P3 amplitude compared with OSL in both task conditions. In conclusion, age and participation in physical activity influence the relationship between physical activity and task-switching, and a positive relationship was observed regardless of the modality of physical activity and type of cognitive function. Our ERP findings support the model of the scaffolding theory of aging and cognition (STAC) and suggest that regular participation in endurance exercise and Tai Chi Chuan may have equivalent beneficial effects on cognition at the behavioral and neuroelectric levels. PMID:25389403

The modulation of auditory novelty processing by working memory load in school age children and adults: a combined behavioral and event-related potential study

PubMed Central

2010-01-01

Background We investigated the processing of task-irrelevant and unexpected novel sounds and its modulation by working-memory load in children aged 9-10 and in adults. Environmental sounds (novels) were embedded amongst frequently presented standard sounds in an auditory-visual distraction paradigm. Each sound was followed by a visual target. In two conditions, participants evaluated the position of a visual stimulus (0-back, low load) or compared the position of the current stimulus with the one two trials before (2-back, high load). Processing of novel sounds were measured with reaction times, hit rates and the auditory event-related brain potentials (ERPs) Mismatch Negativity (MMN), P3a, Reorienting Negativity (RON) and visual P3b. Results In both memory load conditions novels impaired task performance in adults whereas they improved performance in children. Auditory ERPs reflect age-related differences in the time-window of the MMN as children showed a positive ERP deflection to novels whereas adults lack an MMN. The attention switch towards the task irrelevant novel (reflected by P3a) was comparable between the age groups. Adults showed more efficient reallocation of attention (reflected by RON) under load condition than children. Finally, the P3b elicited by the visual target stimuli was reduced in both age groups when the preceding sound was a novel. Conclusion Our results give new insights in the development of novelty processing as they (1) reveal that task-irrelevant novel sounds can result in contrary effects on the performance in a visual primary task in children and adults, (2) show a positive ERP deflection to novels rather than an MMN in children, and (3) reveal effects of auditory novels on visual target processing. PMID:20929535

Affective Modulation of Cognitive Control is Determined by Performance-Contingency and Mediated by Ventromedial Prefrontal and Cingulate Cortex

PubMed Central

King, Joseph A.; Korb, Franziska M.; Krebs, Ruth M.; Notebaert, Wim; Egner, Tobias

2013-01-01

Cognitive control requires a fine balance between stability, the protection of an on-going task-set, and flexibility, the ability to update a task-set in line with changing contingencies. It is thought that emotional processing modulates this balance, but results have been equivocal regarding the direction of this modulation. Here, we tested the hypothesis that a crucial determinant of this modulation is whether affective stimuli represent performance-contingent or task-irrelevant signals. Combining functional magnetic resonance imaging with a conflict task-switching paradigm, we contrasted the effects of presenting negative- and positive-valence pictures on the stability/flexibility trade-off in humans, depending on whether picture presentation was contingent on behavioral performance. Both the behavioral and neural expressions of cognitive control were modulated by stimulus valence and performance contingency: in the performance-contingent condition, cognitive flexibility was enhanced following positive pictures, whereas in the nonperformance-contingent condition, positive stimuli promoted cognitive stability. The imaging data showed that, as anticipated, the stability/flexibility trade-off per se was reflected in differential recruitment of dorsolateral frontoparietal and striatal regions. In contrast, the affective modulation of stability/flexibility shifts was mirrored, unexpectedly, by neural responses in ventromedial prefrontal and posterior cingulate cortices, core nodes of the “default mode” network. Our results demonstrate that the affective modulation of cognitive control depends on the performance contingency of the affect-inducing stimuli, and they document medial default mode regions to mediate the flexibility-promoting effects of performance-contingent positive affect, thus extending recent work that recasts these regions as serving a key role in on-task control processes. PMID:24155301

Development of a novel visuomotor integration paradigm by integrating a virtual environment with mobile eye-tracking and motion-capture systems

PubMed Central

Miller, Haylie L.; Bugnariu, Nicoleta; Patterson, Rita M.; Wijayasinghe, Indika; Popa, Dan O.

2018-01-01

Visuomotor integration (VMI), the use of visual information to guide motor planning, execution, and modification, is necessary for a wide range of functional tasks. To comprehensively, quantitatively assess VMI, we developed a paradigm integrating virtual environments, motion-capture, and mobile eye-tracking. Virtual environments enable tasks to be repeatable, naturalistic, and varied in complexity. Mobile eye-tracking and minimally-restricted movement enable observation of natural strategies for interacting with the environment. This paradigm yields a rich dataset that may inform our understanding of VMI in typical and atypical development. PMID:29876370

Vigilance on the move: video game-based measurement of sustained attention.

PubMed

Szalma, J L; Schmidt, T N; Teo, G W L; Hancock, P A

2014-01-01

Vigilance represents the capacity to sustain attention to any environmental source of information over prolonged periods on watch. Most stimuli used in vigilance research over the previous six decades have been relatively simple and often purport to represent important aspects of detection and discrimination tasks in real-world settings. Such displays are most frequently composed of single stimulus presentations in discrete trials against a uniform, often uncluttered background. The present experiment establishes a dynamic, first-person perspective vigilance task in motion using a video-game environment. 'Vigilance on the move' is thus a new paradigm for the study of sustained attention. We conclude that the stress of vigilance extends to the new paradigm, but whether the performance decrement emerges depends upon specific task parameters. The development of the task, the issues to be resolved and the pattern of performance, perceived workload and stress associated with performing such dynamic vigilance are reported. The present experiment establishes a dynamic, first-person perspective movement-based vigilance task using a video-game environment. 'Vigilance on the move' is thus a new paradigm for the evaluation of sustained attention in operational environments in which individuals move as they monitor their environment. Issues addressed in task development are described.

Effort-Based Decision-Making Paradigms for Clinical Trials in Schizophrenia: Part 1—Psychometric Characteristics of 5 Paradigms

PubMed Central

Reddy, L. Felice; Horan, William P.; Barch, Deanna M.; Buchanan, Robert W.; Dunayevich, Eduardo; Gold, James M.; Lyons, Naomi; Marder, Stephen R.; Treadway, Michael T.; Wynn, Jonathan K.; Young, Jared W.; Green, Michael F.

2015-01-01

Impairments in willingness to exert effort contribute to the motivational deficits characteristic of the negative symptoms of schizophrenia. The current study evaluated the psychometric properties of 5 new or adapted paradigms to determine their suitability for use in clinical trials of schizophrenia. This study included 94 clinically stable participants with schizophrenia and 40 healthy controls. The effort-based decision-making battery was administered twice to the schizophrenia group (baseline, 4-week retest) and once to the control group. The 5 paradigms included 1 that assesses cognitive effort, 1 perceptual effort, and 3 that assess physical effort. Each paradigm was evaluated on (1) patient vs healthy control group differences, (2) test-retest reliability, (3) utility as a repeated measure (ie, practice effects), and (4) tolerability. The 5 paradigms showed varying psychometric strengths and weaknesses. The Effort Expenditure for Rewards Task showed the best reliability and utility as a repeated measure, while the Grip Effort Task had significant patient-control group differences, and superior tolerability and administration duration. The other paradigms showed weaker psychometric characteristics in their current forms. These findings highlight challenges in adapting effort and motivation paradigms for use in clinical trials. PMID:26142081

When Stroop helps Piaget: An inter-task positive priming paradigm in 9-year-old children.

PubMed

Linzarini, A; Houdé, O; Borst, G

2015-11-01

To determine whether inhibitory control is domain general or domain specific in school children, we asked 40 9-year-old children to perform an inter-task priming paradigm in which they responded to Stroop items on the primes and to Piaget number conservation items on the probes. The children were more efficient in the inhibition of a misleading "length-equals-number" heuristic in the number conservation task if they had successfully inhibited a previous prepotent reading response in the Stroop task. This study provides evidence that the inhibitory control ability of school children generalizes to distinct cognitive domains, that is, verbal for the Stroop task and logico-mathematical for Piaget's number conservation task. Copyright © 2015 Elsevier Inc. All rights reserved.

Flexible and inflexible task sets: asymmetric interference when switching between emotional expression, sex, and age classification of perceived faces.

PubMed

Schuch, Stefanie; Werheid, Katja; Koch, Iring

2012-01-01

The present study investigated whether the processing characteristics of categorizing emotional facial expressions are different from those of categorizing facial age and sex information. Given that emotions change rapidly, it was hypothesized that processing facial expressions involves a more flexible task set that causes less between-task interference than the task sets involved in processing age or sex of a face. Participants switched between three tasks: categorizing a face as looking happy or angry (emotion task), young or old (age task), and male or female (sex task). Interference between tasks was measured by global interference and response interference. Both measures revealed patterns of asymmetric interference. Global between-task interference was reduced when a task was mixed with the emotion task. Response interference, as measured by congruency effects, was larger for the emotion task than for the nonemotional tasks. The results support the idea that processing emotional facial expression constitutes a more flexible task set that causes less interference (i.e., task-set "inertia") than processing the age or sex of a face.

Executive function processes predict mobility outcomes in older adults.

PubMed

Gothe, Neha P; Fanning, Jason; Awick, Elizabeth; Chung, David; Wójcicki, Thomas R; Olson, Erin A; Mullen, Sean P; Voss, Michelle; Erickson, Kirk I; Kramer, Arthur F; McAuley, Edward

2014-02-01

To examine the relationship between performance on executive function measures and subsequent mobility outcomes in community-dwelling older adults. Randomized controlled clinical trial. Champaign-Urbana, Illinois. Community-dwelling older adults (N = 179; mean age 66.4). A 12-month exercise trial with two arms: an aerobic exercise group and a stretching and strengthening group. Established cognitive tests of executive function (flanker task, task switching, and a dual-task paradigm) and the Wisconsin card sort test. Mobility was assessed using the timed 8-foot up and go test and times to climb up and down a flight of stairs. Participants completed the cognitive tests at baseline and the mobility measures at baseline and after 12 months of the intervention. Multiple regression analyses were conducted to determine whether baseline executive function predicted postintervention functional performance after controlling for age, sex, education, cardiorespiratory fitness, and baseline mobility levels. Selective baseline executive function measurements, particularly performance on the flanker task (β = 0.15-0.17) and the Wisconsin card sort test (β = 0.11-0.16) consistently predicted mobility outcomes at 12 months. The estimates were in the expected direction, such that better baseline performance on the executive function measures predicted better performance on the timed mobility tests independent of intervention. Executive functions of inhibitory control, mental set shifting, and attentional flexibility were predictive of functional mobility. Given the literature associating mobility limitations with disability, morbidity, and mortality, these results are important for understanding the antecedents to poor mobility function that well-designed interventions to improve cognitive performance can attenuate. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

The Fate of the Method of 'Paradigms' in Paleobiology.

PubMed

Rudwick, Martin J S

2017-11-02

An earlier article described the mid-twentieth century origins of the method of "paradigms" in paleobiology, as a way of making testable hypotheses about the functional morphology of extinct organisms. The present article describes the use of "paradigms" through the 1970s and, briefly, to the end of the century. After I had proposed the paradigm method to help interpret the ecological history of brachiopods, my students developed it in relation to that and other invertebrate phyla, notably in Euan Clarkson's analysis of vision in trilobites. David Raup's computer-aided "theoretical morphology" was then combined with my functional or adaptive emphasis, in Adolf Seilacher's tripartite "constructional morphology." Stephen Jay Gould, who had strongly endorsed the method, later switched to criticizing the "adaptationist program" he claimed it embodied. Although the explicit use of paradigms in paleobiology had declined by the end of the century, the method was tacitly subsumed into functional morphology as "biomechanics."

[New Paradigms? Current Trends within National and International Psychotherapy Research].

PubMed

Strauß, Bernhard

2015-09-01

This article is devoted to the question which paradigms currently determine psychotherapy and psychotherapy research, and if there are indicators of paradigm changes in this field. The question of the efficacy and effectiveness (including the effectiveness of a transfer of psychotherapeutic knowledge to service) is specifically focussed as well as the question of the central therapeutic factors and the significance of the person of the therapist. It is argued that there are really some signals of a paradigm switch, with a turn away from controlled outcome research, representing only a minor part of patients in need of psychotherapy, towards a more specific process oriented research, also considering differential effects of the therapist. The most prominent indicator of a paradigm change is reflected by an increasing influence of patient oriented psychotherapy research which - consequently - should also be supported by the insurances as well as the funding organisations. © Georg Thieme Verlag KG Stuttgart · New York.

Evaluating the Effort Expended to Understand Speech in Noise Using a Dual-Task Paradigm: The Effects of Providing Visual Speech Cues

ERIC Educational Resources Information Center

Fraser, Sarah; Gagne, Jean-Pierre; Alepins, Majolaine; Dubois, Pascale

2010-01-01

Purpose: Using a dual-task paradigm, 2 experiments (Experiments 1 and 2) were conducted to assess differences in the amount of listening effort expended to understand speech in noise in audiovisual (AV) and audio-only (A-only) modalities. Experiment 1 had equivalent noise levels in both modalities, and Experiment 2 equated speech recognition…

Verbal Fluency Performance in Amnestic MCI and Older Adults with Cognitive Complaints

PubMed Central

Nutter-Upham, Katherine E.; Saykin, Andrew J.; Rabin, Laura A.; Roth, Robert M.; Wishart, Heather A.; Pare, Nadia; Flashman, Laura A.

2009-01-01

Verbal fluency tests are employed regularly during neuropsychological assessments of older adults, and deficits are a common finding in patients with Alzheimer’s disease (AD). Little extant research, however, has investigated verbal fluency ability and subtypes in preclinical stages of neurodegenerative disease. We examined verbal fluency performance in 107 older adults with amnestic mild cognitive impairment (MCI, n = 37), cognitive complaints (CC, n = 37) despite intact neuropsychological functioning, and demographically-matched healthy controls (HC, n = 33). Participants completed fluency tasks with letter, semantic category, and semantic switching constraints. Both phonemic and semantic fluency were statistically (but not clinically) reduced in amnestic MCI relative to cognitively intact older adults, indicating subtle changes in both the quality of the semantic store and retrieval slowing. Investigation of the underlying constructs of verbal fluency yielded two factors: Switching (including switching and shifting tasks) and Production (including letter, category, and action naming tasks), and both factors discriminated MCI from HC albeit to different degrees. Correlational findings further suggested that all fluency tasks involved executive control to some degree, while those with an added executive component (i.e., switching and shifting) were less dependent on semantic knowledge. Overall, our findings highlight the importance of including multiple verbal fluency tests in assessment batteries targeting preclinical dementia populations and suggest that individual fluency tasks may tap specific cognitive processes. PMID:18339515

If You Stay, It Might Be Easier: Switch Costs from Comprehension to Production in a Joint Switching Task

ERIC Educational Resources Information Center

Gambi, Chiara; Hartsuiker, Robert J.

2016-01-01

Switching language is costly for bilingual speakers and listeners, suggesting that language control is effortful in both modalities. But are the mechanisms underlying language control similar across modalities? In this study, we attempted to answer this question by testing whether bilingual speakers incur a cost when switching to a different…

Opposing influences on conflict-driven adaptation in the Eriksen flanker task

PubMed Central

Bugg, Julie M.

2009-01-01

Compatibility effects in conflict paradigms are reduced following incompatible trials, and this effect is referred to as conflict adaptation. A perplexing pattern exists, however, with conflict-driven adaptation emerging in several paradigms (e.g., Stroop, Simon) but not consistently in the Eriksen and Eriksen (1974) flanker task. The present experiments address the seemingly elusive presence of conflict adaptation in this task. Experiment 1 shows that a negative-priming-like slowing may be masking conflict adaptation in the flanker task. In Experiment 2, conflict adaptation was revealed when a larger stimulus set designed to reduce negative priming was implemented. Taken together, the findings indicate that a consideration of processes opposing conflict adaptation in the flanker task may help reconcile prior findings. PMID:18927038

When deception becomes easy: the effects of task switching and goal neglect on the truth proportion effect

PubMed Central

Van Bockstaele, Bram; Wilhelm, Christine; Meijer, Ewout; Debey, Evelyne; Verschuere, Bruno

2015-01-01

Lying is typically more cognitively demanding than truth telling. Yet, recent cognitive models of lying propose that lying can be just as easy as truth telling, depending on contextual factors. In line with this idea, research has shown that the cognitive cost of deception decreases when people frequently respond deceptively, while it increases when people rarely respond deceptively (i.e., the truth proportion effect). In the present study, we investigated two possible underlying mechanisms of the truth proportion effect. In Experiment 1 (N = 121), we controlled for the impact of switch costs by keeping the number of switches between deceptive and truthful responses constant. We found that people who often responded deceptively made fewer errors when responding deceptively than people who only occasionally responded deceptively, replicating the truth proportion effect. Thus, while the truth proportion effect in earlier studies may be partially driven by the cost of switching between truthful and deceptive responses, we still found evidence for the truth proportion effect while controlling for switch costs. In Experiment 2 (N = 68), we assessed whether the truth proportion effect is influenced by goal neglect. According to this view, the truth proportion effect should be reduced if participants are cued to maintain the task goals, while it should be larger when participants are allowed to neglect the task goals. In line with this hypothesis, we found a smaller truth proportion effect when participants were cued with the task goals compared to when they were not cued. This study shows that the truth proportion effect is influenced by goal neglect, implying that frequent deceptive responding strengthens the goal of responding deceptively. Our findings imply that the accuracy of lie detection tests could be increased by using a majority of truth-items (i.e., induce the truth proportion effect), and that the truth proportion effect should be maximized by (1) increasing the number of truth-lie task switches and (2) inducing goal neglect. PMID:26579047

Roles of context in acquisition of human instrumental learning: Implications for the understanding of the mechanisms underlying context-switch effects.

PubMed

Gámez, A Matías; León, Samuel P; Rosas, Juan M

2017-09-01

Four experiments in human instrumental learning explored the associations involving the context that develop after three trials of training on simple discriminations. Experiments 1 and 4 found a deleterious effect of switching the learning context that cannot be explained by the context-outcome binary associations commonly used to explain context-switch effects after short training in human predictive learning and in animal Pavlovian conditioning. Evidence for context-outcome (Experiment 2), context-discriminative stimulus (Experiment 3), and context-instrumental response (Experiment 4) binary associations was found within the same training paradigm, suggesting that contexts became associated with all the elements of the situation, regardless of whether those associations played a role in a specific context-switch effect detected on performance.

Inhibition in motor imagery: a novel action mode switching paradigm.

PubMed

Rieger, Martina; Dahm, Stephan F; Koch, Iring

2017-04-01

Motor imagery requires that actual movements are prevented (i.e., inhibited) from execution. To investigate at what level inhibition takes place in motor imagery, we developed a novel action mode switching paradigm. Participants imagined (indicating only start and end) and executed movements from start buttons to target buttons, and we analyzed trial sequence effects. Trial sequences depended on current action mode (imagination or execution), previous action mode (pure blocks/same mode, mixed blocks/same mode, or mixed blocks/other mode), and movement sequence (action repetition, hand repetition, or hand alternation). Results provided evidence for global inhibition (indicated by switch benefits in execution-imagination (E-I)-sequences in comparison to I-I-sequences), effector-specific inhibition (indicated by hand repetition costs after an imagination trial), and target inhibition (indicated by target repetition benefits in I-I-sequences). No evidence for subthreshold motor activation or action-specific inhibition (inhibition of the movement of an effector to a specific target) was obtained. Two (global inhibition and effector-specific inhibition) of the three observed mechanisms are active inhibition mechanisms. In conclusion, motor imagery is not simply a weaker form of execution, which often is implied in views focusing on similarities between imagination and execution.

Effort in Multitasking: Local and Global Assessment of Effort.

PubMed

Kiesel, Andrea; Dignath, David

2017-01-01

When performing multiple tasks in succession, self-organization of task order might be superior compared to external-controlled task schedules, because self-organization allows optimizing processing modes and thus reduces switch costs, and it increases commitment to task goals. However, self-organization is an additional executive control process that is not required if task order is externally specified and as such it is considered as time-consuming and effortful. To compare self-organized and externally controlled task scheduling, we suggest assessing global subjective and objectives measures of effort in addition to local performance measures. In our new experimental approach, we combined characteristics of dual tasking settings and task switching settings and compared local and global measures of effort in a condition with free choice of task sequence and a condition with cued task sequence. In a multi-tasking environment, participants chose the task order while the task requirement of the not-yet-performed task remained the same. This task preview allowed participants to work on the previously non-chosen items in parallel and resulted in faster responses and fewer errors in task switch trials than in task repetition trials. The free-choice group profited more from this task preview than the cued group when considering local performance measures. Nevertheless, the free-choice group invested more effort than the cued group when considering global measures. Thus, self-organization in task scheduling seems to be effortful even in conditions in which it is beneficiary for task processing. In a second experiment, we reduced the possibility of task preview for the not-yet-performed tasks in order to hinder efficient self-organization. Here neither local nor global measures revealed substantial differences between the free-choice and a cued task sequence condition. Based on the results of both experiments, we suggest that global assessment of effort in addition to local performance measures might be a useful tool for multitasking research.

Microworlds for Learning Object-Oriented Programming: Considerations from Research to Practice

ERIC Educational Resources Information Center

Djelil, Fahima; Albouy-Kissi, Adelaide; Albouy-Kissi, Benjamin; Sanchez, Eric; Lavest, Jean-Marc

2016-01-01

Object-Oriented paradigm is a common paradigm for introductory programming courses. However, many teachers find that transitioning to teaching this paradigm is a difficult task. To overcome this complexity, many experienced teachers use microworlds to give beginner students an intuitive and rapid understanding of fundamental abstract concepts of…

Age-Related Differences in Listening Effort During Degraded Speech Recognition.

PubMed

Ward, Kristina M; Shen, Jing; Souza, Pamela E; Grieco-Calub, Tina M

The purpose of the present study was to quantify age-related differences in executive control as it relates to dual-task performance, which is thought to represent listening effort, during degraded speech recognition. Twenty-five younger adults (YA; 18-24 years) and 21 older adults (OA; 56-82 years) completed a dual-task paradigm that consisted of a primary speech recognition task and a secondary visual monitoring task. Sentence material in the primary task was either unprocessed or spectrally degraded into 8, 6, or 4 spectral channels using noise-band vocoding. Performance on the visual monitoring task was assessed by the accuracy and reaction time of participants' responses. Performance on the primary and secondary task was quantified in isolation (i.e., single task) and during the dual-task paradigm. Participants also completed a standardized psychometric measure of executive control, including attention and inhibition. Statistical analyses were implemented to evaluate changes in listeners' performance on the primary and secondary tasks (1) per condition (unprocessed vs. vocoded conditions); (2) per task (single task vs. dual task); and (3) per group (YA vs. OA). Speech recognition declined with increasing spectral degradation for both YA and OA when they performed the task in isolation or concurrently with the visual monitoring task. OA were slower and less accurate than YA on the visual monitoring task when performed in isolation, which paralleled age-related differences in standardized scores of executive control. When compared with single-task performance, OA experienced greater declines in secondary-task accuracy, but not reaction time, than YA. Furthermore, results revealed that age-related differences in executive control significantly contributed to age-related differences on the visual monitoring task during the dual-task paradigm. OA experienced significantly greater declines in secondary-task accuracy during degraded speech recognition than YA. These findings are interpreted as suggesting that OA expended greater listening effort than YA, which may be partially attributed to age-related differences in executive control.

"Smart inhibition": electrophysiological evidence for the suppression of conflict-generating task rules during task switching.

PubMed

Meiran, Nachshon; Hsieh, Shulan; Chang, Chi-Chih

2011-09-01

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.

Investigation on the improvement and transfer of dual-task coordination skills.

PubMed

Strobach, Tilo; Frensch, Peter A; Soutschek, Alexander; Schubert, Torsten

2012-11-01

Recent research has demonstrated that dual-task performance in situations with two simultaneously presented tasks can be substantially improved with extensive practice. This improvement was related to the acquisition of task coordination skills. Earlier studies provided evidence that these skills result from hybrid practice, including dual and single tasks, but not from single-task practice. It is an open question, however, whether task coordination skills are independent from the specific practice situation and are transferable to new situations or whether they are non-transferable and task-specific. The present study, therefore, tested skill transfer in (1) a dual-task situation with identical tasks in practice and transfer, (2) a dual-task situation with two tasks changed from practice to transfer, and (3) a task switching situation with two sequentially presented tasks. Our findings are largely consistent with the assumption that task coordination skills are non-transferable and task-specific. We cannot, however, definitively reject the assumption of transferable skills when measuring error rates in the dual-task situation with two changed tasks after practice. In the task switching situation, single-task and hybrid practice both led to a transfer effect on mixing costs.

Behavioral plasticity through the modulation of switch neurons.

PubMed

Vassiliades, Vassilis; Christodoulou, Chris

2016-02-01

A central question in artificial intelligence is how to design agents capable of switching between different behaviors in response to environmental changes. Taking inspiration from neuroscience, we address this problem by utilizing artificial neural networks (NNs) as agent controllers, and mechanisms such as neuromodulation and synaptic gating. The novel aspect of this work is the introduction of a type of artificial neuron we call "switch neuron". A switch neuron regulates the flow of information in NNs by selectively gating all but one of its incoming synaptic connections, effectively allowing only one signal to propagate forward. The allowed connection is determined by the switch neuron's level of modulatory activation which is affected by modulatory signals, such as signals that encode some information about the reward received by the agent. An important aspect of the switch neuron is that it can be used in appropriate "switch modules" in order to modulate other switch neurons. As we show, the introduction of the switch modules enables the creation of sequences of gating events. This is achieved through the design of a modulatory pathway capable of exploring in a principled manner all permutations of the connections arriving on the switch neurons. We test the model by presenting appropriate architectures in nonstationary binary association problems and T-maze tasks. The results show that for all tasks, the switch neuron architectures generate optimal adaptive behaviors, providing evidence that the switch neuron model could be a valuable tool in simulations where behavioral plasticity is required. Copyright © 2015 Elsevier Ltd. All rights reserved.

Discounting the value of safety: effects of perceived risk and effort.

PubMed

Sigurdsson, Sigurdur O; Taylor, Matthew A; Wirth, Oliver

2013-09-01

Although falls from heights remain the most prevalent cause of fatalities in the construction industry, factors impacting safety-related choices associated with work at heights are not completely understood. Better tools are needed to identify and study the factors influencing safety-related choices and decision making. Using a computer-based task within a behavioral economics paradigm, college students were presented a choice between two hypothetical scenarios that differed in working height and effort associated with retrieving and donning a safety harness. Participants were instructed to choose the scenario in which they were more likely to wear the safety harness. Based on choice patterns, switch points were identified, indicating when the perceived risk in both scenarios was equivalent. Switch points were a systematic function of working height and effort, and the quantified relation between perceived risk and effort was described well by a hyperbolic equation. Choice patterns revealed that the perceived risk of working at heights decreased as the effort to retrieve and don a safety harness increased. Results contribute to the development of computer-based procedure for assessing risk discounting within a behavioral economics framework. Such a procedure can be used as a research tool to study factors that influence safety-related decision making with a goal of informing more effective prevention and intervention strategies. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.

Speech-in-speech perception and executive function involvement

PubMed Central

Perrone-Bertolotti, Marcela; Tassin, Maxime

2017-01-01

This present study investigated the link between speech-in-speech perception capacities and four executive function components: response suppression, inhibitory control, switching and working memory. We constructed a cross-modal semantic priming paradigm using a written target word and a spoken prime word, implemented in one of two concurrent auditory sentences (cocktail party situation). The prime and target were semantically related or unrelated. Participants had to perform a lexical decision task on visual target words and simultaneously listen to only one of two pronounced sentences. The attention of the participant was manipulated: The prime was in the pronounced sentence listened to by the participant or in the ignored one. In addition, we evaluate the executive function abilities of participants (switching cost, inhibitory-control cost and response-suppression cost) and their working memory span. Correlation analyses were performed between the executive and priming measurements. Our results showed a significant interaction effect between attention and semantic priming. We observed a significant priming effect in the attended but not in the ignored condition. Only priming effects obtained in the ignored condition were significantly correlated with some of the executive measurements. However, no correlation between priming effects and working memory capacity was found. Overall, these results confirm, first, the role of attention for semantic priming effect and, second, the implication of executive functions in speech-in-noise understanding capacities. PMID:28708830

Preschool Children's Performance in Task Switching on the Dimensional Change Card Sort Task: Separating the Dimensions Aids the Ability to Switch

PubMed Central

Diamond, Adele; Carlson, Stephanie M.; Beck, Danielle M.

2006-01-01

Fifty-seven children (53% female) at 3 ages (2½, 3, and 3½ years) were tested on the standard Dimensional Change Card Sort (DCCS) task with integrated stimuli (e.g., a red truck) and on a separated-dimensions version where colorless shapes were presented on a colored background (e.g., a black truck on a red background). Roughly twice as many children successfully switched sorting dimensions when color was a property of the background than when color was a property of the shape itself. Children succeeded 6 months earlier in switching sorting criteria when the dimensions were separated. When evidence of both indecision and accuracy was taken into account, a clear and rich developmental progression emerged. These results support an inhibitory control interpretation of preschoolers' problems on the DCCS task. Diamond theorized that young children can have difficulty integrating features not part of a single object and separating features of a single object so that the object can be categorized first by one attribute and then by another. Preschoolers remain stuck in thinking about objects according to the objects' initially relevant attribute (attentional inertia; Kirkham, Cruess, & Diamond, 2003). To switch perspectives, the old way of thinking about the objects must be inhibited. Separating color and shape reduced the need for such inhibition; a truck was always a truck, and the background was always red. PMID:16144433

Long-lasting effects of performance-contingent unconscious and conscious reward incentives during cued task-switching.

PubMed

Capa, Rémi L; Bouquet, Cédric A; Dreher, Jean-Claude; Dufour, André

2013-01-01

Motivation is often thought to interact consciously with executive control, although recent studies have indicated that motivation can also be unconscious. To date, however, the effects of unconscious motivation on high-order executive control functions have not been explored. Only a few studies using subliminal stimuli (i.e., those not related to motivation, such as an arrow to prime a response) have reported short-lived effects on high-order executive control functions. Here, building on research on unconscious motivation, in which a behavior of perseverance is induced to attain a goal, we hypothesized that subliminal motivation can have long-lasting effects on executive control processes. We investigated the impact of unconscious/conscious monetary reward incentives on evoked potentials and neural activity dynamics during cued task-switching performance. Participants performed long runs of task-switching. At the beginning of each run, a reward (50 cents or 1 cent) was displayed, either subliminally or supraliminally. Participants earned the reward contingent upon their correct responses to each trial of the run. A higher percentage of runs was achieved with higher (conscious and unconscious) than lower rewards, indicating that unconscious high rewards have long-lasting behavioral effects. Event-related potential (ERP) results indicated that unconscious and conscious rewards influenced preparatory effort in task preparation, as suggested by a greater fronto-central contingent negative variation (CNV) starting at cue-onset. However, a greater parietal P3 associated with better reaction times (RTs) was observed only under conditions of conscious high reward, suggesting a larger amount of working memory invested during task performance. Together, these results indicate that unconscious and conscious motivations are similar at early stages of task-switching preparation but differ during task performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Selective Attention and Attention Switching: Towards a Unified Developmental Approach

ERIC Educational Resources Information Center

Hanania, Rima; Smith, Linda B.

2010-01-01

We review and relate two literatures on the development of attention in children: one concerning flexible attention switching and the other concerning selective attention. The first is a growing literature on preschool children's performances in an attention-switching task indicating that children become more flexible in their attentional control…

Language Switching in the Production of Phrases

ERIC Educational Resources Information Center

Tarlowski, Andrzej; Wodniecka, Zofia; Marzecova, Anna

2013-01-01

The language switching task has provided a useful insight into how bilinguals produce language. So far, however, the studies using this method have been limited to lexical access. The present study provides empirical evidence on language switching in the production of simple grammar structures. In the reported experiment, Polish-English unbalanced…

Congenital blindness limits allocentric to egocentric switching ability.

PubMed

Ruggiero, Gennaro; Ruotolo, Francesco; Iachini, Tina

2018-03-01

Many everyday spatial activities require the cooperation or switching between egocentric (subject-to-object) and allocentric (object-to-object) spatial representations. The literature on blind people has reported that the lack of vision (congenital blindness) may limit the capacity to represent allocentric spatial information. However, research has mainly focused on the selective involvement of egocentric or allocentric representations, not the switching between them. Here we investigated the effect of visual deprivation on the ability to switch between spatial frames of reference. To this aim, congenitally blind (long-term visual deprivation), blindfolded sighted (temporary visual deprivation) and sighted (full visual availability) participants were compared on the Ego-Allo switching task. This task assessed the capacity to verbally judge the relative distances between memorized stimuli in switching (from egocentric-to-allocentric: Ego-Allo; from allocentric-to-egocentric: Allo-Ego) and non-switching (only-egocentric: Ego-Ego; only-allocentric: Allo-Allo) conditions. Results showed a difficulty in congenitally blind participants when switching from allocentric to egocentric representations, not when the first anchor point was egocentric. In line with previous results, a deficit in processing allocentric representations in non-switching conditions also emerged. These findings suggest that the allocentric deficit in congenital blindness may determine a difficulty in simultaneously maintaining and combining different spatial representations. This deficit alters the capacity to switch between reference frames specifically when the first anchor point is external and not body-centered.

Transferring cognitive tasks between brain imaging modalities: implications for task design and results interpretation in FMRI studies.

PubMed

Warbrick, Tracy; Reske, Martina; Shah, N Jon

2014-09-22

As cognitive neuroscience methods develop, established experimental tasks are used with emerging brain imaging modalities. Here transferring a paradigm (the visual oddball task) with a long history of behavioral and electroencephalography (EEG) experiments to a functional magnetic resonance imaging (fMRI) experiment is considered. The aims of this paper are to briefly describe fMRI and when its use is appropriate in cognitive neuroscience; illustrate how task design can influence the results of an fMRI experiment, particularly when that task is borrowed from another imaging modality; explain the practical aspects of performing an fMRI experiment. It is demonstrated that manipulating the task demands in the visual oddball task results in different patterns of blood oxygen level dependent (BOLD) activation. The nature of the fMRI BOLD measure means that many brain regions are found to be active in a particular task. Determining the functions of these areas of activation is very much dependent on task design and analysis. The complex nature of many fMRI tasks means that the details of the task and its requirements need careful consideration when interpreting data. The data show that this is particularly important in those tasks relying on a motor response as well as cognitive elements and that covert and overt responses should be considered where possible. Furthermore, the data show that transferring an EEG paradigm to an fMRI experiment needs careful consideration and it cannot be assumed that the same paradigm will work equally well across imaging modalities. It is therefore recommended that the design of an fMRI study is pilot tested behaviorally to establish the effects of interest and then pilot tested in the fMRI environment to ensure appropriate design, implementation and analysis for the effects of interest.

Characterising switching behaviour in perceptual multi-stability.

PubMed

Denham, Susan; Bendixen, Alexandra; Mill, Robert; Tóth, Dénes; Wennekers, Thomas; Coath, Martin; Bőhm, Tamás; Szalardy, Orsolya; Winkler, István

2012-09-15

When people experience an unchanging sensory input for a long period of time, their perception tends to switch stochastically and unavoidably between alternative interpretations of the sensation; a phenomenon known as perceptual bi-stability or multi-stability. The huge variability in the experimental data obtained in such paradigms makes it difficult to distinguish typical patterns of behaviour, or to identify differences between switching patterns. Here we propose a new approach to characterising switching behaviour based upon the extraction of transition matrices from the data, which provide a compact representation that is well-understood mathematically. On the basis of this representation we can characterise patterns of perceptual switching, visualise and simulate typical switching patterns, and calculate the likelihood of observing a particular switching pattern. The proposed method can support comparisons between different observers, experimental conditions and even experiments. We demonstrate the insights offered by this approach using examples from our experiments investigating multi-stability in auditory streaming. However, the methodology is generic and thus widely applicable in studies of multi-stability in any domain. Copyright © 2012 Elsevier B.V. All rights reserved.

Does children's moral compass waver under social pressure? Using the conformity paradigm to test preschoolers' moral and social-conventional judgments.

PubMed

Kim, Elizabeth B; Chen, Chuansheng; Smetana, Judith G; Greenberger, Ellen

2016-10-01

The current study tested whether preschoolers' moral and social-conventional judgments change under social pressure using Asch's conformity paradigm. A sample of 132 preschoolers (Mage=3.83years, SD=0.85) rated the acceptability of moral and social-conventional events and also completed a visual judgment task (i.e., comparing line length) both independently and after having viewed two peers who consistently made immoral, unconventional, or visually inaccurate judgments. Results showed evidence of conformity on all three tasks, but conformity was stronger on the social-conventional task than on the moral and visual tasks. Older children were less susceptible to pressure for social conformity for the moral and visual tasks but not for the conventional task. Copyright © 2016 Elsevier Inc. All rights reserved.

The fluid events model: Predicting continuous task action change.

PubMed

Radvansky, Gabriel A; D'Mello, Sidney; Abbott, Robert G; Morgan, Brent; Fike, Karl; Tamplin, Andrea K

2015-01-01

The fluid events model is a behavioural model aimed at predicting the likelihood that people will change their actions in ongoing, interactive events. From this view, not only are people responding to aspects of the environment, but they are also basing responses on prior experiences. The fluid events model is an attempt to predict the likelihood that people will shift the type of actions taken within an event on a trial-by-trial basis, taking into account both event structure and experience-based factors. The event-structure factors are: (a) changes in event structure, (b) suitability of the current action to the event, and (c) time on task. The experience-based factors are: (a) whether a person has recently shifted actions, (b) how often a person has shifted actions, (c) whether there has been a dip in performance, and (d) a person's propensity to switch actions within the current task. The model was assessed using data from a series of tasks in which a person was producing responses to events. These were two stimulus-driven figure-drawing studies, a conceptually driven decision-making study, and a probability matching study using a standard laboratory task. This analysis predicted trial-by-trial action switching in a person-independent manner with an average accuracy of 70%, which reflects a 34% improvement above chance. In addition, correlations between overall switch rates and actual switch rates were remarkably high (mean r = .98). The experience-based factors played a more major role than the event-structure factors, but this might be attributable to the nature of the tasks.

An investigation of the neural substrates of mind wandering induced by viewing traditional Chinese landscape paintings

PubMed Central

Wang, Tingting; Mo, Lei; Vartanian, Oshin; Cant, Jonathan S.; Cupchik, Gerald

2015-01-01

The present study was conducted to investigate whether the calming effect induced by viewing traditional Chinese landscape paintings would make disengagement from that mental state more difficult, as measured by performance on a cognitive control task. In Experiment 1 we examined the subjective experience of viewing traditional Chinese landscape paintings vs. realistic oil landscape paintings in a behavioral study. Our results confirmed that, as predicted, traditional Chinese landscape paintings induce greater levels of relaxation and mind wandering and lower levels of object-oriented absorption and recognition, compared to realistic oil landscape paintings. In Experiment 2 we used functional Magnetic Resonance Imaging to explore the behavioral and neural effects of viewing traditional Chinese landscape paintings on a task requiring cognitive control (i.e., the flanker task)—administered immediately following exposure to paintings. Contrary to our prediction, the behavioral data demonstrated that compared to realistic oil landscape paintings, exposure to traditional Chinese landscape paintings had no effect on performance on the flanker task. However, the neural data demonstrated an interaction effect such that there was greater activation in the inferior parietal cortex and the superior frontal gyrus on incongruent compared with congruent flanker trials when participants switched from viewing traditional Chinese landscape paintings to the flanker task than when they switched from realistic oil landscape paintings. These results suggest that switching from traditional Chinese landscape paintings placed greater demands on the brain’s attention and working memory networks during the flanker task than did switching from realistic oil landscape paintings. PMID:25610386

Ocular dynamics and visual tracking performance after Q-switched laser exposure

NASA Astrophysics Data System (ADS)

Zwick, Harry; Stuck, Bruce E.; Lund, David J.; Nawim, Maqsood

2001-05-01

In previous investigations of q-switched laser retinal exposure in awake task oriented non-human primates (NHPs), the threshold for retinal damage occurred well below that of the threshold for permanent visual function loss. Visual function measures used in these studies involved measures of visual acuity and contrast sensitivity. In the present study, we examine the same relationship for q-switched laser exposure using a visual performance task, where task dependency involves more parafoveal than foveal retina. NHPs were trained on a visual pursuit motor tracking performance task that required maintaining a small HeNe laser spot (0.3 degrees) centered in a slowly moving (0.5deg/sec) annulus. When NHPs reliably produced visual target tracking efficiencies > 80%, single q-switched laser exposures (7 nsec) were made coaxially with the line of sight of the moving target. An infrared camera imaged the pupil during exposure to obtain the pupillary response to the laser flash. Retinal images were obtained with a scanning laser ophthalmoscope 3 days post exposure under ketamine and nembutol anesthesia. Q-switched visible laser exposures at twice the damage threshold produced small (about 50mm) retinal lesions temporal to the fovea; deficits in NHP visual pursuit tracking were transient, demonstrating full recovery to baseline within a single tracking session. Post exposure analysis of the pupillary response demonstrated that the exposure flash entered the pupil, followed by 90 msec refractory period and than a 12 % pupillary contraction within 1.5 sec from the onset of laser exposure. At 6 times the morphological threshold damage level for 532 nm q-switched exposure, longer term losses in NHP pursuit tracking performance were observed. In summary, q-switched laser exposure appears to have a higher threshold for permanent visual performance loss than the corresponding threshold to produce retinal threshold injury. Mechanisms of neural plasticity within the retina and at higher visual brain centers may mediat

Perceptuo-motor interactions in the perceptual organization of speech: evidence from the verbal transformation effect

PubMed Central

Basirat, Anahita; Schwartz, Jean-Luc; Sato, Marc

2012-01-01

The verbal transformation effect (VTE) refers to perceptual switches while listening to a speech sound repeated rapidly and continuously. It is a specific case of perceptual multistability providing a rich paradigm for studying the processes underlying the perceptual organization of speech. While the VTE has been mainly considered as a purely auditory effect, this paper presents a review of recent behavioural and neuroimaging studies investigating the role of perceptuo-motor interactions in the effect. Behavioural data show that articulatory constraints and visual information from the speaker's articulatory gestures can influence verbal transformations. In line with these data, functional magnetic resonance imaging and intracranial electroencephalography studies demonstrate that articulatory-based representations play a key role in the emergence and the stabilization of speech percepts during a verbal transformation task. Overall, these results suggest that perceptuo (multisensory)-motor processes are involved in the perceptual organization of speech and the formation of speech perceptual objects. PMID:22371618

Stability of the Positive Mood Effect on Creativity When Task Switching, Practice Effect, and Test Item Differences Are Taken into Consideration

ERIC Educational Resources Information Center

Tan, Chee-Seng; Qu, Li

2015-01-01

Although experimentally induced positive mood can generally last for 20 min and the induced mood is conducive to creative performance, it is still unclear whether the facilitation effect is stable during these 20 min. Two studies were conducted to examine this issue while controlling for the impacts of task switching, practice effect, and test…

Automatic Digital Switching Specialist Career Ladder: United States Air Force Job Inventory. AFSCs 29530, 29570, and 29590.

ERIC Educational Resources Information Center

Air Force Personnel and Training Research Center, Lackland AFB, TX.

The U. S. Air Force job inventory for the automatic digital switching specialist career ladder is divided into 12 categories, each of which is broken down into a duty-task list. Space is provided for Air Force personnel filling out the inventory to check whether each task is at present part of their duties. The 12 categories are: organizing and…

Bias to negative emotions: a depression state-dependent marker in adolescent major depressive disorder.

PubMed

Maalouf, Fadi T; Clark, Luke; Tavitian, Lucy; Sahakian, Barbara J; Brent, David; Phillips, Mary L

2012-06-30

The aim of the current research was to examine for the first time the extent to which bias to negative emotions in an inhibitory control paradigm is a state or trait marker in major depressive disorder (MDD) in adolescents. We administered the affective go/no go task which measures the ability to switch attention to or away from positive or negative emotional stimuli to 40 adolescents with MDD (20 in acute episode (MDDa) and 20 in remission (MDDr)) and 17 healthy controls (HC). MDDa were significantly faster on the shift to negative target blocks as compared to shift to positive target blocks while HC and MDDr displayed the opposite pattern as measured by an "emotional bias index" (EBI=latency (shift to negative targets)-latency (shift to positive targets)). There was also a trend for an effect of group on commission errors, suggesting more impulsive responding by MDDa than both MDDr and HC independently of stimulus valence throughout the task. Negative bias was not associated with depression severity or medication status. In conclusion, bias to negative emotional stimuli appears to be present in the acute stage of MDD and absent in remission suggesting that it is a depression state-specific marker of MDD in adolescents. Latency emerges as a better proxy of negative bias than commission errors and accuracy on this inhibitory control task in adolescents with MDD. Copyright © 2012 Elsevier Ltd. All rights reserved.

Voluntary task switching under load: contribution of top-down and bottom-up factors in goal-directed behavior.

PubMed

Demanet, Jelle; Verbruggen, Frederick; Liefooghe, Baptist; Vandierendonck, André

2010-06-01

The present study investigated the relative contribution of bottom-up and top-down control to task selection in the voluntary task-switching (VTS) procedure. In order to manipulate the efficiency of top-down control, a concurrent working memory load was imposed during VTS. In three experiments, bottom-up factors, such as stimulus repetitions, repetition of irrelevant information, and stimulus-task associations, were introduced in order to investigate their influence on task selection. We observed that the tendency to repeat tasks was stronger under load, suggesting that top-down control counteracts the automatic tendency to repeat tasks. The results also indicated that task selection can be guided by several elements in the environment, but that only the influence of stimulus repetitions depends on the efficiency of top-down control. The theoretical implications of these findings are discussed within the interplay between top-down and bottom-up control that underlies the voluntary selection of tasks.

Attentional Flexibility During Approach and Avoidance Motivational States: The Role of Context in Shifts of Attentional Breadth

PubMed Central

Calcott, Rebecca D.; Berkman, Elliot T.

2014-01-01

In the present studies, we aimed to understand how approach and avoidance states affect attentional flexibility by examining attentional shifts on a trial-by-trial basis. We also examined how a novel construct in this area, task context, might interact with motivation to influence attentional flexibility. Participants completed a modified composite letter task in which the ratio of global to local targets was varied by block, making different levels of attentional focus beneficial to performance on different blocks. Study 1 demonstrated that, in the absence of a motivation manipulation, switch costs were lowest on blocks with an even ratio of global and local trials and were higher on blocks with an uneven ratio. Other participants completed the task while viewing pictures (Studies 2 and 3) and assuming arm positions (Studies 2 and 4) to induce approach, avoidance, and neutral motivational states. Avoidance motivation reduced switch costs in evenly proportioned contexts, whereas approach motivation reduced switch costs in mostly global contexts. Additionally, approach motivation imparted a similar switch cost magnitude across different contexts, whereas avoidance and neutral states led to variable switch costs depending on the context. Subsequent analyses revealed that these effects were driven largely by faster switching to local targets on mostly global blocks in the approach condition. These findings suggest that avoidance facilitates attentional shifts when switches are frequent, whereas approach facilitates responding to rare or unexpected local stimuli. The main implication of these results is that motivation has different effects on attentional shifts depending on the context. PMID:24294866

Prediction of User Preference over Shared Control Paradigms for a Robotic Wheelchair

DTIC Science & Technology

2017-07-20

the experimentally -observed changes between subject groups and sessions, while providing unique insight into the relative contribution of task metrics...WHEELCHAIR, including the four tested shared- control paradigms. The correlation model and experimental results are provided in Sections IV and V. Section VI...paradigm-specific models. Moreover, we also observe differences between sub- ject groups —meaning that subjects’ evaluations of a control paradigm are

Effort-Based Decision-Making Paradigms for Clinical Trials in Schizophrenia: Part 1—Psychometric Characteristics of 5 Paradigms.

PubMed

Reddy, L Felice; Horan, William P; Barch, Deanna M; Buchanan, Robert W; Dunayevich, Eduardo; Gold, James M; Lyons, Naomi; Marder, Stephen R; Treadway, Michael T; Wynn, Jonathan K; Young, Jared W; Green, Michael F

2015-09-01

Impairments in willingness to exert effort contribute to the motivational deficits characteristic of the negative symptoms of schizophrenia. The current study evaluated the psychometric properties of 5 new or adapted paradigms to determine their suitability for use in clinical trials of schizophrenia. This study included 94 clinically stable participants with schizophrenia and 40 healthy controls. The effort-based decision-making battery was administered twice to the schizophrenia group (baseline, 4-week retest) and once to the control group. The 5 paradigms included 1 that assesses cognitive effort, 1 perceptual effort, and 3 that assess physical effort. Each paradigm was evaluated on (1) patient vs healthy control group differences, (2) test-retest reliability, (3) utility as a repeated measure (ie, practice effects), and (4) tolerability. The 5 paradigms showed varying psychometric strengths and weaknesses. The Effort Expenditure for Rewards Task showed the best reliability and utility as a repeated measure, while the Grip Effort Task had significant patient-control group differences, and superior tolerability and administration duration. The other paradigms showed weaker psychometric characteristics in their current forms. These findings highlight challenges in adapting effort and motivation paradigms for use in clinical trials. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center 2015.

Efficient Ada multitasking on a RISC register window architecture

NASA Technical Reports Server (NTRS)

Kearns, J. P.; Quammen, D.

1987-01-01

This work addresses the problem of reducing context switch overhead on a processor which supports a large register file - a register file much like that which is part of the Berkeley RISC processors and several other emerging architectures (which are not necessarily reduced instruction set machines in the purest sense). Such a reduction in overhead is particularly desirable in a real-time embedded application, in which task-to-task context switch overhead may result in failure to meet crucial deadlines. A storage management technique by which a context switch may be implemented as cheaply as a procedure call is presented. The essence of this technique is the avoidance of the save/restore of registers on the context switch. This is achieved through analysis of the static source text of an Ada tasking program. Information gained during that analysis directs the optimized storage management strategy for that program at run time. A formal verification of the technique in terms of an operational control model and an evaluation of the technique's performance via simulations driven by synthetic Ada program traces are presented.

A network of molecular switches controls the activation of the two-component response regulator NtrC

NASA Astrophysics Data System (ADS)

Vanatta, Dan K.; Shukla, Diwakar; Lawrenz, Morgan; Pande, Vijay S.

2015-06-01

Recent successes in simulating protein structure and folding dynamics have demonstrated the power of molecular dynamics to predict the long timescale behaviour of proteins. Here, we extend and improve these methods to predict molecular switches that characterize conformational change pathways between the active and inactive state of nitrogen regulatory protein C (NtrC). By employing unbiased Markov state model-based molecular dynamics simulations, we construct a dynamic picture of the activation pathways of this key bacterial signalling protein that is consistent with experimental observations and predicts new mutants that could be used for validation of the mechanism. Moreover, these results suggest a novel mechanistic paradigm for conformational switching.

Comparison of fMRI data from passive listening and active-response story processing tasks in children

PubMed Central

Vannest, Jennifer J.; Karunanayaka, Prasanna R.; Altaye, Mekibib; Schmithorst, Vincent J.; Plante, Elena M.; Eaton, Kenneth J.; Rasmussen, Jerod M.; Holland, Scott K.

2009-01-01

Purpose To use functional MRI methods to visualize a network of auditory and language-processing brain regions associated with processing an aurally-presented story. We compare a passive listening (PL) story paradigm to an active-response (AR) version including on-line performance monitoring and a sparse acquisition technique. Materials/Methods Twenty children (ages 11−13) completed PL and AR story processing tasks. The PL version presented alternating 30-second blocks of stories and tones; the AR version presented story segments, comprehension questions, and 5s tone sequences, with fMRI acquisitions between stimuli. fMRI data was analyzed using a general linear model approach and paired t-test identifying significant group activation. Results Both tasks activated in primary auditory cortex, superior temporal gyrus bilaterally, left inferior frontal gyrus. The AR task demonstrated more extensive activation, including dorsolateral prefrontal cortex and anterior/posterior cingulate cortex. Comparison of effect size in each paradigm showed a larger effect for the AR paradigm in a left inferior frontal ROI. Conclusion Activation patterns for story processing in children are similar in passive listening and active-response tasks. Increases in extent and magnitude of activation in the AR task are likely associated with memory and attention resources engaged across acquisition intervals. PMID:19306445

Comparison of fMRI data from passive listening and active-response story processing tasks in children.

PubMed

Vannest, Jennifer J; Karunanayaka, Prasanna R; Altaye, Mekibib; Schmithorst, Vincent J; Plante, Elena M; Eaton, Kenneth J; Rasmussen, Jerod M; Holland, Scott K

2009-04-01

To use functional MRI (fMRI) methods to visualize a network of auditory and language-processing brain regions associated with processing an aurally-presented story. We compare a passive listening (PL) story paradigm to an active-response (AR) version including online performance monitoring and a sparse acquisition technique. Twenty children (ages 11-13 years) completed PL and AR story processing tasks. The PL version presented alternating 30-second blocks of stories and tones; the AR version presented story segments, comprehension questions, and 5-second tone sequences, with fMRI acquisitions between stimuli. fMRI data was analyzed using a general linear model approach and paired t-test identifying significant group activation. Both tasks showed activation in the primary auditory cortex, superior temporal gyrus bilaterally, and left inferior frontal gyrus (IFG). The AR task demonstrated more extensive activation, including the dorsolateral prefrontal cortex and anterior/posterior cingulate cortex. Comparison of effect size in each paradigm showed a larger effect for the AR paradigm in a left inferior frontal region-of-interest (ROI). Activation patterns for story processing in children are similar in PL and AR tasks. Increases in extent and magnitude of activation in the AR task are likely associated with memory and attention resources engaged across acquisition intervals.

Testing the social dog hypothesis: are dogs also more skilled than chimpanzees in non-communicative social tasks?

PubMed

Wobber, Victoria; Hare, Brian

2009-07-01

Relative to non-human primates, domestic dogs possess a number of social skills that seem exceptional-particularly in solving problems involving cooperation and communication with humans. However, the degree to which dogs' unusual skills are contextually specialized is still unclear. Here, we presented dogs with a social problem that did not require them to use cooperative-communicative cues and compared their performance to that of chimpanzees to assess the extent of dogs' capabilities relative to those of non-human primates. We tested the abilities of dogs and chimpanzees to inhibit previously learned responses by using a social and a non-social version of a reversal learning task. In contrast to previous findings in cooperative-communicative social tasks, dogs were not more skilled on the social task than the non-social task, while chimpanzees were significantly better in the social paradigm. Chimpanzees were able to inhibit their prior learning better and more quickly in the social paradigm than they were in the non-social paradigm, while dogs took more time to inhibit what they had learned in both versions of the task. These results suggest that the dogs' sophisticated social skills in using human social cues may be relatively specialized as a result of domestication.

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

PubMed

Tschentscher, Nadja; Hauk, Olaf

2015-01-01

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

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

PubMed Central

Tschentscher, Nadja; Hauk, Olaf

2015-01-01

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

Perceptual switch rates with ambiguous structure-from-motion figures in bipolar disorder.

PubMed

Krug, Kristine; Brunskill, Emma; Scarna, Antonina; Goodwin, Guy M; Parker, Andrew J

2008-08-22

Slowing of the rate at which a rivalrous percept switches from one configuration to another has been suggested as a potential trait marker for bipolar disorder. We measured perceptual alternations for a bistable, rotating, structure-from-motion cylinder in bipolar and control participants. In a control task, binocular depth rendered the direction of cylinder rotation unambiguous to monitor participants' performance and attention during the experimental task. A particular direction of rotation was perceptually stable, on average, for 33.5s in participants without psychiatric diagnosis. Euthymic, bipolar participants showed a slightly slower rate of switching between the two percepts (percept duration 42.3s). Under a parametric analysis of the best-fitting model for individual participants, this difference was statistically significant. However, the variability within groups was high, so this difference in average switch rates was not big enough to serve as a trait marker for bipolar disorder. We also found that low-level visual capacities, such as stereo threshold, influence perceptual switch rates. We suggest that there is no single brain location responsible for perceptual switching in all different ambiguous figures and that perceptual switching is generated by the actions of local cortical circuitry.

Characterizing switching and congruency effects in the Implicit Association Test as reactive and proactive cognitive control.

PubMed

Hilgard, Joseph; Bartholow, Bruce D; Dickter, Cheryl L; Blanton, Hart

2015-03-01

Recent research has identified an important role for task switching, a cognitive control process often associated with executive functioning, in the Implicit Association Test (IAT). However, switching does not fully account for IAT effects, particularly when performance is scored using more recent d-score formulations. The current study sought to characterize multiple control processes involved in IAT performance through the use of event-related brain potentials (ERPs). Participants performed a race-evaluative IAT while ERPs were recorded. Behaviorally, participants experienced superadditive reaction time costs of incongruency and task switching, consistent with previous studies. The ERP showed a marked medial frontal negativity (MFN) 250-450 ms post-stimulus at midline fronto-central locations that were more negative for incongruent than congruent trials but more positive for switch than for no-switch trials, suggesting separable control processes are engaged by these two factors. Greater behavioral IAT bias was associated with both greater switch-related and congruency-related ERP activity. Findings are discussed in terms of the Dual Mechanisms of Control model of reactive and proactive cognitive control. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Perceptual Measurement in Schizophrenia: Promising Electrophysiology and Neuroimaging Paradigms From CNTRICS

PubMed Central

Butler, Pamela D.; Chen, Yue; Ford, Judith M.; Geyer, Mark A.; Silverstein, Steven M.; Green, Michael F.

2012-01-01

The sixth meeting of the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) focused on selecting promising imaging paradigms for each of the cognitive constructs selected in the first CNTRICS meeting. In the domain of perception, the 2 constructs of interest were “gain control” and “visual integration.” CNTRICS received 6 task nominations for imaging paradigms for gain control and 3 task nominations for integration. The breakout group for perception evaluated the degree to which each of these tasks met prespecified criteria. For gain control, the breakout group believed that one task (mismatch negativity) was already mature and was being incorporated into multisite clinical trials. The breakout group recommended that 1 visual task (steady-state visual evoked potentials to magnocellular- vs parvocellular-biased stimuli) and 2 auditory measures (an event-related potential (ERP) measure of corollary discharge and a functional magnetic resonance imaging (fMRI) version of prepulse inhibition of startle) be adapted for use in clinical trials in schizophrenia research. For visual integration, the breakout group recommended that fMRI and ERP versions of a contour integration test and an fMRI version of a coherent motion test be adapted for use in clinical trials. This manuscript describes the ways in which each of these tasks met the criteria used in the breakout group to evaluate and recommend tasks for further development. PMID:21890745

Cross-Modal Attention-Switching Is Impaired in Autism Spectrum Disorders

ERIC Educational Resources Information Center

Reed, Phil; McCarthy, Julia

2012-01-01

This investigation aimed to determine if children with ASD are impaired in their ability to switch attention between different tasks, and whether performance is further impaired when required to switch across two separate modalities (visual and auditory). Eighteen children with ASD (9-13 years old) were compared with 18 typically-developing…

How do highly proficient bilinguals control their lexicalization process? Inhibitory and language-specific selection mechanisms are both functional.

PubMed

Costa, Albert; Santesteban, Mikel; Ivanova, Iva

2006-09-01

The authors report 4 experiments exploring the language-switching performance of highly proficient bilinguals in a picture-naming task. In Experiment 1, they tested the impact of language similarity and age of 2nd language acquisition on the language-switching performance of highly proficient bilinguals. Experiments 2, 3, and 4 assessed the performance of highly proficient bilinguals in language-switching contexts involving (a) the 2nd language (L2) and the L3 of the bilinguals, (b) the L3 and the L4, and (c) the L1 and a recently learned new language. Highly proficient bilinguals showed symmetrical switching costs regardless of the age at which the L2 was learned and of the similarities of the 2 languages and asymmetrical switching costs when 1 of the languages involved in the switching task was very weak (an L4 or a recently learned language). The theoretical implications of these results for the attentional mechanisms used by highly proficient bilinguals to control their lexicalization process are discussed. Copyright 2006 APA

Breaking a habit: a further role of the phonological loop in action control.

PubMed

Saeki, Erina; Baddeley, Alan D; Hitch, Graham J; Saito, Satoru

2013-10-01

Recent research has suggested that keeping track of a task goal in rapid task switching may depend on the phonological loop component of working memory. In this study, we investigated whether the phonological loop plays a similar role when a single switch extending over several trials is required after many trials on which one has performed a competing task. Participants were shown pairs of digits varying in numerical and physical size, and they were required to decide which digit was numerically or physically larger. An experimental cycle consisted of four blocks of 24 trials. In Experiment 1, participants in the task change groups performed the numerical-size judgment task during the first three blocks, and then changed to the physical-size judgment task in the fourth. Participants in the continuation groups performed only the physical-size judgment task throughout all four blocks. We found negative effects of articulatory suppression on the fourth block, but only in the task change groups. Experiment 2 was a replication, with the modification that both groups received identical instructions and practice. Experiment 3 was a further replication using numerical-size judgment as the target task. The results showed a pattern similar to that from Experiment 1, with negative effects of articulatory suppression found only in the task change group. The congruity of numerical and physical size had a reliable effect on performance in all three experiments, but unlike the task change, it did not reliably interact with articulatory suppression. The results suggest that in addition to its well-established role in rapid task switching, the phonological loop also contributes to active goal maintenance in longer-term action control.

Modafinil improves rapid shifts of attention.

PubMed

Marchant, Natalie L; Kamel, Faddy; Echlin, Kezia; Grice, John; Lewis, Mark; Rusted, Jennifer M

2009-01-01

The majority of studies investigating the cognitive effects of modafinil, a wake-promoting compound, demonstrate some improvements in attention. The potential of the drug to selectively benefit distinct components of attention has yet to be fully explored in healthy adults. The present study was conducted to investigate modafinil's effect on specific cognitive tasks that tax components of attention switching. One required the rapid switching of attention between stimuli, and another contained an embedded working memory component on top of the attentional shift requirements. Additionally, prospective memory was examined, which requires the interruption of an ongoing activity to retrieve and act upon a previously formed intention. Healthy non-smoking volunteers, matched on age, intelligence, and baseline cognitive ability, received either a capsule that contained 200 mg modafinil or placebo. Subjective measures of mood and physiological response were taken throughout the experimental session, and the tasks were completed between 2 and 3 h post-dosing. Two hundred milligrams modafinil improved accuracy without a reaction time trade-off, in both conditions of the attention-shifting task, but only when resources were most challenged. In contrast, the drug afforded no improvement in prospective remembering or in the ongoing task that was interrupted. Modafinil appears to promote rapid switching of attention in conditions that are most demanding, whilst it offers no benefits in a task that requires unpredictable and infrequent disengagement of attention from an ongoing task in order to act upon an alternative task.

Neural networks supporting switching, hypothesis testing, and rule application

PubMed Central

Liu, Zhiya; Braunlich, Kurt; Wehe, Hillary S.; Seger, Carol A.

2015-01-01

We identified dynamic changes in recruitment of neural connectivity networks across three phases of a flexible rule learning and set-shifting task similar to the Wisconsin Card Sort Task: switching, rule learning via hypothesis testing, and rule application. During fMRI scanning, subjects viewed pairs of stimuli that differed across four dimensions (letter, color, size, screen location), chose one stimulus, and received feedback. Subjects were informed that the correct choice was determined by a simple unidimensional rule, for example “choose the blue letter.” Once each rule had been learned and correctly applied for 4-7 trials, subjects were cued via either negative feedback or visual cues to switch to learning a new rule. Task performance was divided into three phases: Switching (first trial after receiving the switch cue), hypothesis testing (subsequent trials through the last error trial), and rule application (correct responding after the rule was learned). We used both univariate analysis to characterize activity occurring within specific regions of the brain, and a multivariate method, constrained principal component analysis for fMRI (fMRI-CPCA), to investigate how distributed regions coordinate to subserve different processes. As hypothesized, switching was subserved by a limbic network including the ventral striatum, thalamus, and parahippocampal gyrus, in conjunction with cortical salience network regions including the anterior cingulate and frontoinsular cortex. Activity in the ventral striatum was associated with switching regardless of how switching was cued; visually cued shifts were associated with additional visual cortical activity. After switching, as subjects moved into the hypothesis testing phase, a broad fronto-parietal-striatal network (associated with the cognitive control, dorsal attention, and salience networks) increased in activity. This network was sensitive to rule learning speed, with greater extended activity for the slowest learning speed late in the time course of learning. As subjects shifted from hypothesis testing to rule application, activity in this network decreased and activity in the somatomotor and default mode networks increased. PMID:26197092

Neural networks supporting switching, hypothesis testing, and rule application.

PubMed

Liu, Zhiya; Braunlich, Kurt; Wehe, Hillary S; Seger, Carol A

2015-10-01

We identified dynamic changes in recruitment of neural connectivity networks across three phases of a flexible rule learning and set-shifting task similar to the Wisconsin Card Sort Task: switching, rule learning via hypothesis testing, and rule application. During fMRI scanning, subjects viewed pairs of stimuli that differed across four dimensions (letter, color, size, screen location), chose one stimulus, and received feedback. Subjects were informed that the correct choice was determined by a simple unidimensional rule, for example "choose the blue letter". Once each rule had been learned and correctly applied for 4-7 trials, subjects were cued via either negative feedback or visual cues to switch to learning a new rule. Task performance was divided into three phases: Switching (first trial after receiving the switch cue), hypothesis testing (subsequent trials through the last error trial), and rule application (correct responding after the rule was learned). We used both univariate analysis to characterize activity occurring within specific regions of the brain, and a multivariate method, constrained principal component analysis for fMRI (fMRI-CPCA), to investigate how distributed regions coordinate to subserve different processes. As hypothesized, switching was subserved by a limbic network including the ventral striatum, thalamus, and parahippocampal gyrus, in conjunction with cortical salience network regions including the anterior cingulate and frontoinsular cortex. Activity in the ventral striatum was associated with switching regardless of how switching was cued; visually cued shifts were associated with additional visual cortical activity. After switching, as subjects moved into the hypothesis testing phase, a broad fronto-parietal-striatal network (associated with the cognitive control, dorsal attention, and salience networks) increased in activity. This network was sensitive to rule learning speed, with greater extended activity for the slowest learning speed late in the time course of learning. As subjects shifted from hypothesis testing to rule application, activity in this network decreased and activity in the somatomotor and default mode networks increased. Copyright © 2015 Elsevier Ltd. All rights reserved.