Task-switching Paradigm Research Articles

Does a 15-Minute Brief Mindfulness Breathing Exercise Temporarily Enhance Inhibitory Control and Cognitive Flexibility? A Within-Subject Experimental Approach

Intensive mindfulness practices have been shown to improve cognitive abilities such as executive functions. However, most of these mindfulness-based practices require the participants to be involved either an extended immersive experience or repeated daily practice that may span over multiple weeks or months. Extending from the promising effect of intensive mindfulness training, recent studies have also suggested that a single session of brief mindfulness training is sufficient to temporarily enhance cognitive functions. However, the positive effect of brief mindfulness was not always consistent. In view of the inconsistent findings, the current study aims to critically examine the effectiveness of a single-session 15-minute brief mindfulness exercise on both inhibitory control and task-switching using a within-subject experimental design (N = 117). Contrary to our hypothesis, we did not find any evidence that engaging in a brief mindfulness exercise enhanced performance in the flanker task or color-shape task-switching paradigm. These results suggest that a mindfulness intervention of short duration may not be sufficient to immediately enhance higher-order cognitive processes such as inhibitory control and task-switching.

Evidence of task-triggered retrieval of the previous response: a binding perspective on response-repetition benefits in task switching

In task switching, response repetitions (RRs) usually yield performance benefits as compared to response switches, but only when the task also repeats. When the task switches, RR benefits vanish or even turn into costs, yielding an interaction between repeating versus switching the task and the response (the RR effect). Different theoretical accounts for this RR effect exist, but, in the present study, we specifically tested a prediction derived from binding and retrieval accounts. These maintain that repeating the task retrieves the previous-trial response, thus causing RR benefits. Retrieval is possible due to the task-response binding formed in the previous trial. We employed a task-switching paradigm with three response options that allowed us to differentiate error types. Across two experiments (N = 46 and N = 107) we showed that response-repetition errors in response-switch trials were more likely in task repetitions than in task switches, supporting the notion that the previous response is retrieved by the repeating task, despite being wrong. Such a finding is in line with binding and retrieval accounts but cannot be easily accommodated by the competing theoretical accounts. Thus, the present study indicates task-response binding as an important mechanism underlying RR benefits in task repetitions.

Anatomically compliant modes of variations: New tools for brain connectivity.

Anatomical complexity and data dimensionality present major issues when analysing brain connectivity data. The functional and anatomical aspects of the connections taking place in the brain are in fact equally relevant and strongly intertwined. However, due to theoretical challenges and computational issues, their relationship is often overlooked in neuroscience and clinical research. In this work, we propose to tackle this problem through Smooth Functional Principal Component Analysis, which enables to perform dimensional reduction and exploration of the variability in functional connectivity maps, complying with the formidably complicated anatomy of the grey matter volume. In particular, we analyse a population that includes controls and subjects affected by schizophrenia, starting from fMRI data acquired at rest and during a task-switching paradigm. For both sessions, we first identify the common modes of variation in the entire population. We hence explore whether the subjects' expressions along these common modes of variation differ between controls and pathological subjects. In each session, we find principal components that are significantly differently expressed in the healthy vs pathological subjects (with p-values < 0.001), highlighting clearly interpretable differences in the connectivity in the two subpopulations. For instance, the second and third principal components for the rest session capture the imbalance between the Default Mode and Executive Networks characterizing schizophrenia patients.

The impact of food stimuli and fasting on cognitive control in task switching.

Previous research demonstrated motivation-control interactions in task switching. However, motivational effects on switch costs have been mostly examined using monetary rewards. Here, we investigated whether stimulus material linked to food and fasting affect control processes in task switching. We predicted that switching to the task comprising food stimuli would be facilitated, which should result in lower switch costs for this task, and that these effects would be stronger with higher motivational salience of the food stimuli, i.e. in hungry individuals and/or individuals with restrictive eating. Participants switched between categorising food items as sweet or savoury and digits as odd or even in two task-switching paradigms: an alternating runs and a voluntary task switching. Hunger was induced by 14h fasting in the experimental compared to the control group. Results showed lower switch costs for the motivational-affective food task in both task-switching paradigms and in both groups. Switch costs for the neutral digit task were significantly higher in the fasting group compared to the control group in alternating runs task switching only. Individual differences in restrictive eating were related negatively but not significantly to the size of the switch costs. All in all, the results demonstrate an impact of motivational-affective stimuli on cognitive control in task switching and suggest a potential modulatory role of motivational states, though the findings need to be replicated.

No trait anxiety linked differences in affective and non-affective task-switching

Elevated levels of trait anxiety are argued to interfere with the ability to shift attention between different task sets, yet empirical support for this hypothesis is scarce. Using a task-switching paradigm in two separate studies, we compared high and low trait anxious participants' ability to switch from non-affective, positive, and negative tasks to different non-affective tasks. In Study 1 (N = 59 high and low trait anxious undergraduate students), we found that non-affective-to-non-affective switch costs were smaller than both positive-to-non-affective and negative-to-non-affective switch costs, and positive-to-non-affective switch costs were smaller than negative-to-non-affective switch costs. In Study 2 (N = 97 high and low trait anxious community members), we found that non-affective-to-non-affective switch costs and positive-to-non-affective switch costs were both smaller than negative-to-non-affective switch costs, but positive-to-non-affective and non-affective-to-non-affective switch costs did not differ. Crucially, none of the switch costs in either of the studies or in an analysis of the combined data differed between high and low trait anxious groups. While we cannot exclude the possibility that anxiety linked differences in task-switching do exist when switching from more demanding to less demanding tasks, our studies found no evidence for the general idea that elevated trait anxiety interferes with attentional shifting.

Inhibition during task switching is affected by the number of competing tasks.

Inhibition during task switching is assumed to be indexed by n - 2 repetition costs-that is, performance costs when the task in the current trial equals the task in trial n - 2 (sequences of type ABA) compared with two consecutive switches to another task each (sequences CBA). The present study examined effects of a short-term reduction of the number of candidate tasks on these costs. For this purpose, a variant of the task switching paradigm was used in which in half of the trials, a precue that preceded the task cue allowed for a short-term reduction of the number of candidate tasks. In Experiment 1, one out of three tasks could be excluded. In Experiment 2, one or two out of four tasks could be excluded. Experiment 3 served as control condition using the standard cueing paradigm. Significant n - 2 repetition costs were present with three candidate tasks. In contrast, no costs were visible when the number of candidate tasks was reduced to two. This result is interpreted in terms of a task selection mechanism based on antagonistic constraints among task representations, which operates on a rather superficial level when switching among only two tasks, thereby reducing the need for inhibition.

Multitasking in Complex Environments: An Attempt to Generalize Individual Differences in Multitasking to a Realistic Task Setting

Multitasking is a common feature of many modern work and home environments, and this study investigated the relationship between multitasking performance in two different paradigms: a more controlled task-switching paradigm (TSWP) and a more complex, semi-ecologically valid multitasking paradigm (SynWin). The study also explored whether parallel processors may have performance advantages in a complex dual-task environment. Results showed no significant correlation between individual multitasking efficiency in the TSWP and SynWin paradigms. Additionally, the results indicated that the combination of subtasks was the primary factor affecting performance in dual-task variants of the SynWin, rather than the use of a parallel processing mode. We conclude that there may be constraints with respect to the experimental conditions necessary to generalize findings from controlled multitasking paradigms to semi-ecologically valid tasks scenarios. Future research should prioritize efforts to understand how people multitask in more realistic settings and the underlying cognitive processes involved.

Task Switching and Visual Search: Evidence for a Tradeoff Between Congruent and Incongruent Target Responses

In task switching studies, mapping different responses to the same physical keys creates two response categories: congruent and incongruent. Congruent and incongruent responses are distinguished by whether or not a key press is the same between different task instructions. Task switching studies often report that incongruent responses have higher error rates and RTs than congruent responses. In this study, we investigate this congruency effect by asking: Does the presence of incongruent stimuli detract from performance on congruent stimuli? If true, participants may perform worse on congruent stimuli as more incongruent stimuli are added. To test this hypothesis, we created a visual search and task switching paradigm where participants search for targets while the congruence of a target changes. Results show a tradeoff in accuracy between incongruent and congruent targets—when incongruent stimuli are added, participants are worse at finding congruent stimuli, even though congruent stimuli are targets throughout the task.

Impact of age of onset on bilinguals’ task switching performance in a nonimmigration context

It is not clear whether bilingualism leads to task switching benefits in single-language nonimmigration contexts, as in dual-language and code-switching immigration contexts. Ninety young Persian-speaking monolingual and bilingual adults reported their language proficiency and use, with the early bilinguals indicating a balanced rating for their L1 and L2, and late bilinguals reporting slightly higher ratings for L1, relative to L2. Concerning the onset age of bilingualism, the bilinguals were classified as early and late bilinguals according to whether they initiated active regular use of the two languages before or after the age of eight. A nonverbal alternating-runs task switching paradigm was used to measure global switch cost (GSC) and local switch cost (LSC). The findings revealed a slight nonsignificant GSC but a significantly lower LSC for early bilinguals, compared to monolinguals, suggesting that bilingualism effects on task switching do not transpire uniformly across different contexts.

Control dilemma: Evidence of the stability–flexibility trade-off

Cognitive control can be applied flexibly when task goals or environments change (i.e., cognitive flexibility), or stably to pursue a goal in the face of distraction (i.e., cognitive stability). Whether these seemingly contradictory characteristics have an inverse relationship has been controversial, as some studies have suggested a trade-off mechanism between cognitive flexibility and cognitive stability, while others have not found such reciprocal associations. This study investigated the possible antagonistic correlation between cognitive flexibility and stability using a novel version of the flexibility–stability paradigm and the classic cued task switching paradigm. In Experiment 1, we showed that cognitive flexibility was inversely correlated with cognitive stability, as increased distractor proportions were associated with decreased cognitive flexibility and greater cognitive stability. Moreover, cognitive flexibility and stability were regulated by a single control system instead of two independent control mechanisms, as the model selection results indicated that the reciprocally regulated model with one integration parameter outperformed all other models, and the model parameter was inversely linked to cognitive flexibility and stability. We found similar results using the classic cued task switching paradigm in Experiment 2. Therefore, a trade-off between cognitive flexibility and stability was observed from the paradigms used in this study.

Measuring cognitive flexibility in anorexia nervosa: Wisconsin Card Sorting Test versus cued task-switching

PurposeThe Wisconsin Card Sorting Test (WCST) is the most common measure of cognitive flexibility in anorexia nervosa (AN), but task-switching paradigms are beginning to be utilized. The current study directly compared performance on a cued task-switching measure and the WCST to evaluate their association in participants with a lifetime diagnosis of AN, and to assess which measure is more strongly associated with clinical symptoms.MethodsForty-five women with a lifetime diagnosis of AN completed the WCST, cued color-shape task-switching paradigm, Anti-saccade Keyboard Task, Running Memory Span, Eating Disorder Examination Questionnaire, Depression Anxiety Stress Scales short form and Eating Disorder Flexibility Index.ResultsThere was no evidence of a significant association between WCST perseverative errors and cued task-switching switch costs. Results suggest lower working memory capacity is a determinant of higher perseverative error rate. When controlling for mood variables, neither cognitive flexibility measure was a significant independent predictor of symptom severity.ConclusionsResults provide support for previous suggestions that WCST perseverative errors could occur due to difficulties with working memory, sensitivity to feedback, and issues with concept formation. Cued task-switching paradigms may provide a useful measure of cognitive flexibility for future eating disorders research by reducing task-specific confounds.Level of evidenceLevel III Case–control analytic study.

Acute stress imparts a transient benefit to task-switching that is not modulated following a single bout of exercise.

Cognitive flexibility represents a core component of executive function that promotes the ability to efficiently alternate-or "switch"-between different tasks. Literature suggests that acute stress negatively impacts cognitive flexibility, whereas a single bout of aerobic exercise supports a postexercise improvement in cognitive flexibility. Here, we examined whether a single bout of aerobic exercise attenuates a stress-induced decrement in task-switching. Forty participants (age range = 19-30) completed the Trier Social Stress Test (TSST) and were randomized into separate Exercise or Rest groups entailing 20-min sessions of heavy intensity exercise (80% of heart rate maximum via cycle ergometer) or rest, respectively. Stress induction was confirmed via state anxiety and heart rate. Task-switching was assessed prior to the TSST (i.e., pre-TSST), following the TSST (i.e., post-TSST), and following Exercise and Rest interventions (i.e., post-intervention) via pro- (i.e., saccade to veridical target location) and antisaccades (i.e., saccade mirror-symmetrical to target location) arranged in an AABB task-switching paradigm. The underlying principle of the AABB paradigm suggests that when prosaccades are preceded by antisaccades (i.e., task-switch trials), the reaction times are longer compared to their task-repeat counterparts (i.e., unidirectional prosaccade switch-cost). As expected, the pre-TSST assessment yielded a prosaccade switch cost. Notably, post-TSST physiological measures indicated a reliable stress response and at this assessment a null prosaccade switch-cost was observed. In turn, post-intervention assessments revealed a switch-cost independent of Exercise and Rest groups. Accordingly, the immediate effects of acute stress supported improved task-switching in young adults; however, these benefits were not modulated by a single bout of aerobic exercise.

Evidence for an Asymmetric Switch Cost in State Creativity

ABSTRACT The role of top-down control in divergent creativity remains heavily debated. An outstanding question about the state dynamics of creativity concerns acute shifts between heightened and lowered creative states. Particularly, do transitions between creative states incur a “switch cost” as observed in other domains of cognition? Prior research showed that asymmetric switch costs are often incurred such that reaction time is asymmetrically slower when participants switch from a task involving more top-down control to a task involving less top-down control. We tested the hypothesis that frequent acute transitions from creativity-cued responding (associated with heightened creative state) to uncued responding (associated with lowered creative state) would incur an asymmetric switch cost such that uncued responding would be disproportionately impacted by state changes. We utilized the “thin slices” verb generation task in a task-switching paradigm. Consistent with the hypothesis of asymmetric switch costs in shifts between creative states, we observed a substantial switch cost when switching from creativity-cued trials to uncued trials, but no switch cost when switching from uncued trials to creativity-cued trials. These findings provide indirect evidence that heightened creative states may require substantially more top-down control than lowered creative states, supporting the theory that divergent creativity requires increased top-down control.

Commonalities between mind wandering and task-set switching: An event-related potential study

Previous research has established that mind wandering does not necessarily disrupt one's task-switching performance. Here we investigated the effects of mind wandering on electrophysiological signatures, measured using event-related potentials (ERPs), during a switching task. In the current study, a final sample of 22 young adults performed a task-switching paradigm while electroencephalography was continuously recorded; mind wandering was assessed via thought probes at the end of each block. Consistent with previous research, we found no significant disruptive effects of mind wandering on task-switching performance. The ERP results showed that at the posterior electrode sites (P3, Pz, and P4), P3 amplitude was higher for mind-wandering switch trials than on-task switch trials, thus opposing the typical pattern of P3 attenuation during periods of mind wandering relative to on-task episodes. Considering that increased P3 amplitude during higher-order switch trials (e.g., response rule switching) may reflect the implementation of new higher-order task sets/rules, the current findings seem to indicate similar executive control processes underlie mind wandering and task-set switching, providing further evidence in favor of a role for switching in mind wandering.

Response-repetition costs in task switching do not index a simple response-switch bias: Evidence from manipulating the number of response alternatives

Response repetitions aid performance when a task repeats but impair performance when a task switches. Although this interaction is robust, theoretical accounts remain controversial. Here, we used an un-cued, predictable task-switching paradigm with univalent targets to explore whether a simple bias to switch the response when the task switches can explain the interaction. In Experiment 1A (n = 40), we replicated the basic interaction in a two-choice task. In Experiment 1B (n = 60), we observed the same interaction in a three-choice task, wherein a bias to switch the response when the task switches cannot prime a specific alternative response because both remaining response alternatives are equally likely. Exploratory comparisons revealed a larger interaction between task repetition and response repetition in the three-choice task than in the two-choice task for mean response time (RT) and the opposite pattern for mean error rate (ER). Critically, in the three-choice task, response-repetition costs in task switches were significant in both RT and ER. Since a bias to switch the response cannot prime a specific response alternative in a three-choice task, we conclude that such a bias cannot account for response-repetition costs in task-switch trials.

Electrophysiological Correlates of Proactive Control and Binding Processes during Task Switching in Tourette Syndrome.

The occurrence of tics in Tourette syndrome (TS) has often been linked to impaired cognitive control, but empirical findings are still inconclusive. A recent view proposes that tics may be the result of an abnormally strong interrelation between perceptual processes and motor actions, commonly referred to as perception-action binding. The general aim of the present study was to examine proactive control and binding effects in the context of task switching in adult human patients with TS and matched healthy controls. A cued task switching paradigm was employed in 24 patients (18 male, 6 female) and 25 controls while recording electroencephalography (EEG). Residue iteration decomposition (RIDE) was applied to analyze cue-locked proactive cognitive control and target-locked binding processes. Behavioral task switching performance was unaltered in patients with TS. A cue-locked parietal switch positivity, reflecting proactive control processes involved in the reconfiguration of the new task did not differ between groups. Importantly, target-locked fronto-central (N2) and parietal (P3) modulations, reflecting binding processes between perception and action, differed between groups. Underlying neurophysiological processes were best depicted after temporal decomposition of the EEG signal. The present results argue for unaltered proactive control but altered perception-action binding processes in the context of task switching, supporting the view that the integration of perception and action is processed differently in patients TS. Future studies should further investigate the specific conditions under which binding may be altered in TS and the influence of top-down processes, such as proactive control, on bindings.

Task Switching: On the Relation of Cognitive Flexibility with Cognitive Capacity.

The task-switching paradigm is deemed a measure of cognitive flexibility. Previous research has demonstrated that individual differences in task-switch costs are moderately inversely related to cognitive ability. However, current theories emphasize multiple component processes of task switching, such as task-set preparation and task-set inertia. The relations of task-switching processes with cognitive ability were investigated in the current study. Participants completed a task-switching paradigm with geometric forms and a visuospatial working memory capacity (WMC) task. The task-switch effect was decomposed with the diffusion model. Effects of task-switching and response congruency were estimated as latent differences using structural equation modeling. Their magnitudes and relations with visuospatial WMC were investigated. Effects in the means of parameter estimates replicated previous findings, namely increased non-decision time in task-switch trials. Further, task switches and response incongruency had independent effects on drift rates, reflecting their differential effects on task readiness. Findings obtained with the figural tasks employed in this study revealed that WMC was inversely related to the task-switch effect in non-decision time. Relations with drift rates were inconsistent. Finally, WMC was moderately inversely related to response caution. These findings suggest that more able participants either needed less time for task-set preparation or that they invested less time for task-set preparation.

How attention and knowledge modulate memory: The differential impact of cognitive conflicts on subsequent memory—A review of a decade of research

In order to cope with cognitive conflicts, attention and knowledge are required. In some conditions, cognitive conflicts can boost subsequent memory and in other conditions, they can attenuate subsequent memory. The goal of the present study is to provide a narrative review of studies from the last decade in which Stroop or flanker conflicts, task switching, perceptual disfluency or semantic incongruence were manipulated at study. We propose an integrative framework considering attentional mechanisms and knowledge structures. Attentional mechanisms can refer to conflict resolution, which is required to explain the memory benefit for incongruent stimuli in Stroop and Flanker paradigms. Attentional mechanisms can also refer to attention allocation, which is required to explain the memory cost for targets and the memory benefit for task-irrelevant distractors in task-switching paradigms. Moreover, attention allocation policies can also account for the inconsistent results for perceptual disfluency manipulations. Prior knowledge is required to explain effects of semantic congruency and incongruency: Information that is expected, or congruent with prior knowledge, is better remembered, namely by pre-existing schemata. Moreover, information that is unexpected or incongruent with prior knowledge attracts attention and is better remembered. The impact of prior knowledge on memory performance thus results in a U-shape function. We integrate the findings according to this framework and suggest directions for future research.

Influences of cognitive control on number processing: New evidence from switching between two numerical tasks.

A growing body of research suggests that basic numerical abilities such as number magnitude and number parity processing are influenced by cognitive control. So far, however, evidence for number processing being influenced by cognitive control came primarily from observed adaptations to stimulus set characteristics (e.g., ratio or order of specific stimulus types) and switches between a numerical and non-numerical task. Complementing this previous research, the present study employed a task switching paradigm exclusively involving numerical tasks (i.e., magnitude comparisons and parity judgements) to examine how cognitive control processes influence number processing. Participants were presented with a single-digit number and had to either judge its parity or compare its magnitude with a standard of 5, depending on a preceding cue. Based on previous results, we expected the numerical distance effect and the spatial-numerical association of response codes (SNARC) effect to be modulated in switch trials requiring the exertion of cognitive control. Partly in line with our expectations, the numerical distance effect was reduced in switch trials. However, no modulation of the SNARC effect was observed. The results pattern suggests that number processing is influenced by cognitive control, depending on task requirements and the type of numerical information (i.e., numerical magnitude vs spatial association of numbers) that is processed. To reconcile the present and previous results, we propose an information prioritisation account, suggesting that cognitive control primarily influences the processing of the information type that requires the most explicit processing.

Assessing Flexibility of Solution Strategy: Strategy Shifting as a Measure of Cognitive Reserve.

This series of experiments explores whether flexibility in strategy shifting might function as an expression of cognitive reserve (CR). A reasoning task was designed using matrix reasoning stimuli that each required 1 of 2 specific solution strategies: logicoanalytic and visuospatial. It was formatted as a task-switching paradigm, assessing the ability to switch between solution strategies as measured by switch costs. Study 1 was done on Amazon Mechanical Turk and included an assessment of CR proxies. Study 2 used participants who had been studied extensively with neuropsychological assessments and structural neuroimaging. Study 1 found that switch costs increased with aging. In addition, a relationship between switch costs and CR proxies was noted, suggesting a relationship between the flexibility of strategy shifting and CR. The results of Study 2 again indicated that age negatively affected strategy-shifting flexibility, but that individuals with higher CR as measured with standard proxies performed better. The flexibility measure accounted for additional variance in cognitive performance over that explained by cortical thickness, suggesting that it may contribute to CR. Overall, the results are consistent with the idea that flexibility in strategy shifting might be 1 cognitive process that underlies cognitive reserve.