Task-switching Costs Research Articles

Supplemental Material for The Task-Switch Cost Is Still Absent After Selectively Stopping a Response in Cued Task Switching

Supplemental Material for The Task-Switch Cost Is Still Absent After Selectively Stopping a Response in Cued Task Switching

The task-switch cost is still absent after selectively stopping a response in cued task switching.

The task-switch cost is one of the most robust phenomena in human task performance, but it can disappear after nogo trials where the actors decide not to respond to the target. According to the response-selection account, it is the occurrence of response selection that generates a task-switch cost on the subsequent trial, and the absence of a switch cost after nogo trials has been attributed to a nonoccurrence of response selection on nogo trials. However, an alternative account is that a task-switch cost is generated but is abolished on nogo trials because of the interference from the nogo signal with the activated task set, suggesting that the absence of a task-switch cost does not necessarily imply the nonoccurrence of response selection. The present study tested these competing accounts by using selective go/nogo procedures for which withholding a response would require selecting a response and inhibiting the selected response. Bayes factors in five experiments provided evidence for the absence of a task-switch cost after selective nogo trials, indicating that the occurrence of response selection does not necessarily result in a task-switch cost on the subsequent trial. The present results are consistent with the task-set interference account that a task-switch cost could be generated on nogo trials but is abolished because a nogo signal interferes with the activated task-set. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Brain activations elicited during task-switching generalize beyond the task: A partial least squares correlation approach to combine fMRI signals and cognition.

An underlying hypothesis for broad transfer from cognitive training is that the regional brain signals engaged during the training task are related to the transfer tasks. However, it is unclear whether the brain activations elicited from a specific cognitive task can generalize to performance of other tasks, esp. in normal aging where cognitive training holds much promise. In this large dual-site functional magnetic resonance imaging (fMRI) study, we aimed to characterize the neurobehavioral correlates of task-switching in normal aging and examine whether the task-switching-related fMRI-blood-oxygen-level-dependent (BOLD) signals, engaged during varieties of cognitive control, generalize to other tasks of executive control and general cognition. We therefore used a hybrid blocked and event-related fMRI task-switching paradigm to investigate brain regions associated with multiple types of cognitive control on 129 non-demented older adults (65-85 years). This large dataset provided a unique opportunity for a data-driven partial least squares-correlation approach to investigate the generalizability of multiple fMRI-BOLD signals associated with task-switching costs to other tasks of executive control, general cognition, and demographic characteristics. While some fMRI signals generalized beyond the scanned task, others did not. Results indicate right middle frontal brain activation as detrimental to task-switching performance, whereas inferior frontal and caudate activations were related to faster processing speed during the fMRI task-switching, but activations of these regions did not predict performance on other tasks of executive control or general cognition. However, BOLD signals from the right lateral occipital cortex engaged during the fMRI task positively predicted performance on a working memory updating task, and BOLD signals from the left post-central gyrus that were disengaged during the fMRI task were related to slower processing speed in the task as well as to lower general cognition. Together, these results suggest generalizability of these BOLD signals beyond the scanned task. The findings also provided evidence for the general slowing hypothesis of aging as most variance in the data were explained by low processing speed and global low BOLD signal in older age. As processing speed shared variance with task-switching and other executive control tasks, it might be a possible basis of generalizability between these tasks. Additional results support the dedifferentiation hypothesis of brain aging, as right middle frontal activations predicted poorer task-switching performance. Overall, we observed that the BOLD signals related to the fMRI task not only generalize to the performance of other executive control tasks, but unique brain predictors of out-of-scanner performance can be identified.

Task switch costs scale with dissimilarity between task rules.

Cognitive flexibility enables humans to voluntarily switch tasks. Task switching requires replacing the previously active task representation with a new one, an operation that typically results in a switch cost. Thus, understanding cognitive flexibility requires understanding how tasks are represented in the brain. We hypothesize that task representations are cognitive map-like, such that the magnitude of the difference between task representations reflects their conceptual differences: The greater the distinction between the two task representations, the more updating is required. This hypothesis predicts that switch costs should increase with between task dissimilarity. To test this hypothesis, we use an experimental design that parametrically manipulates the similarity between task rules. We observe that response time scales with the dissimilarity between the task rules. The findings shed light on the organizational principles of task representations and extend the conventional binary task-switch effect (task repeat vs. switch) to a theoretical framework with parametric task switches. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Effects of healthy ageing and bilingualism on attention networks

Abstract Both ageing and bilingualism can have positive as well as adverse cognitive effects. We investigated their combined impact on subcomponents of attention. We used the Attention Network Task to examine alerting, orienting, executive control and task-switching costs. Group comparisons revealed age-related declines for alerting alongside benefits for executive control, for mono- and bilinguals alike. For orienting, age-related decline was more pronounced for bilinguals than monolinguals. Task-switching was unaffected by age or language group. Within bilinguals, we found limited impact of individual differences in L2 proficiency, language switching or mixing: proficiency improves orienting and decreases switch costs, for young and older bilinguals alike; but no other individual differences effects were found. Thus, attention is a multi-faceted network, with clear adverse (alerting) and protective (executive control) ageing effects. We found these to be largely similar for mono- and bilinguals, with variability within bilinguals having only limited impact.

Binding of response-independent task rules

Binding theories claim that features of an episode are bound to each other and can be retrieved once these features are re-encountered. Binding effects have been shown in task-switching studies with a strong focus on bindings of observable features such as responses. In this study, we aimed to investigate whether task rules, translating stimulus information into motor output can be bound and subsequently retrieved even if they act independently from specific response codes. To address this question, we utilized a task-switching paradigm with varying visual context features. Unlike previous studies, tasks in the present study did not differ in their response options, and sequential response repetitions were eliminated by design. In three experiments, we observed larger task-switch costs on trials repeating the context of the previous trial than on context-change trials. According to binding accounts, this suggests that response-independent task rules adopted in the previous trial became bound to the context feature and were retrieved upon re-encountering the context feature in the current trial. The results of this study generalize previous findings indicating that binding processes can include response-independent control to task-switching situations.

Double task switching: An investigation into the effects of similarity and task-rule congruency on cognitive flexibility.

Similarity between tasks is an understudied factor in research on cognitive flexibility. This behavioural experiment had 31 participants perform a task switch paradigm in which participants were required to switch between 4 tasks of varying similarity. The experiment was constructed in a way that simultaneously allows for investigating the impact of mental fatigue and task-rule congruency on the participants. The results indicate that similarity between tasks substantially impacts performance with different effects on RT and accuracy. While learning effects may have negated the impact of mental fatigue across the 5 experimental blocks, a significant decrease in performance was observed within blocks. Furthermore, the exploratory analysis proposes a novel interaction between task-rule incongruent trials and the task of the previous trial. These results support the notion that neither the interference view of cognitive flexibility nor the reconfiguration view are fully adequate at explaining task switch costs if similarity is added as a factor. The presented study presents strong evidence that fundamental findings in the domain of cognitive flexibility may not map linearly to more ecological settings where tasks are often more dissimilar.

Driving Frequency Modulates Correlations Between Executive Functions and Driving Performance: A Driving Simulator Study.

Driving a car requires a complex combination of various cognitive functions (e.g., visual perception, motor control, decision making, and others), and deficits in any of these processes may compromise driving safety. Amongst these, executive functions such as inhibitory control, task switching, and decision-making are important, as they enable drivers to process information from their surroundings and respond appropriately to changing road conditions. Although previous research has focused on laboratory measures of individual executive functions, it remains unclear whether performance on such laboratory tests readily translates to actual on-the-road driving performance, especially since drivers' skill levels can vary widely, based on their driving frequency. To this end, we divided 30 participants into two categories based on their driving frequency (i.e., daily commuter vs. weekend only drivers), and we used three well-known executive functioning tasks (the stop signal task, Iowa gambling task or IGT, and a task-switching test) to see whether scores on these tasks predicted such driving performances and behaviors such as braking time, lane-keeping, speed limit violations, and inter-vehicle distance (e.g., in a driving simulator). Participants went through a follow-lead-car scenario in the driving simulator for 20minutes and then completed the three executive tasks. We found that stop signal reaction time (SSRT) best predicted driving performance, and remained predictive against driver distraction, as well as variabilities in driving frequency. The IGT predicted speed limit violations in high-frequency drivers, whereas task-switching cost predicted lane keeping performance in low-frequency drivers. Together, these results highlight the importance of driving frequency when considering correlates between executive functions and driving performance and behavior. They also imply that executive tasks better predict driving performance in low-frequency (or inexperienced) drivers, while driver temperament (i.e., impulsiveness as indicated by IGT) better predicted driving performance in high-frequency (or experienced) drivers.

Differential Switch Costs in Typically Achieving Children and Children With Mathematical Difficulties

Children with mathematical difficulties need to spend more time than typically achieving children on solving even simple equations. Since these tasks already require a larger share of their cognitive resources, additional demands imposed by the need to switch between tasks may lead to a greater decline of performance in children with mathematical difficulties. We explored differential task switch costs with respect to switching between addition versus subtraction with a tablet-based arithmetic verification task and additional standardized tests in German elementary school children in Grades 1 to 4. Two independent studies were conducted. In Study 1, we assessed the validity of a newly constructed tablet-based arithmetic verification task in a controlled classroom-setting (n = 165). Then, effects of switching between different types of arithmetic operations on accuracy and response latency were analyzed through generalized linear mixed models in an online-based testing (Study 2; n = 3,409). Children with mathematical difficulties needed more time and worked less accurately overall. They also exhibited a stronger performance decline when working in a task-switching condition, when working on subtraction (vs. addition) items and in operations with two-digit (vs. one-digit) operations. These results underline the value of process data in the context of assessing mathematical difficulties.

Investigating Ecological Momentary Assessed Physical Activity and Core Executive Functions in 18- to 24-Year-Old Undergraduate Students.

Although evidence for young children (<10) and older adults (>64) highlights an association between physical activity (PA) and executive functions (EFs), there is a paucity of research on adolescents aged 18-24 years. Thus, this study examined the associations between PA and EF and the difference in EF between individuals who achieve the moderate-to-vigorous (MVPA) guidelines and those who do not. Forty-seven participants engaged in a Stroop task, a reverse Corsi-block test, and a task-switching test, to measure inhibition, working memory, and cognitive flexibility, respectively. An ecological momentary assessment (EMA) was used to determine the participant's MVPA and step count, through the "Pathverse" app. Multiple regressions were run to predict the task-switch cost, the Stroop effect, and the backward Corsi span from time spent in MVPA. A two-way ANCOVA examined the effects of achieving the MVPA guidelines on EF. MVPA and step count did not significantly predict EF. There were no significant differences in EF between participants achieving the MVPA guidelines and those that did not. Time spent in MVPA and step count were not significantly associated with working memory, cognitive flexibility, or inhibition in adolescents. Further research is warranted to understand other factors that may significantly affect EF, within and outside an individual's control.

Preparing a task is sufficient to generate a subsequent task-switch cost affecting task performance.

This study investigated the nature of switch costs after trials on which the cued task had been either only prepared (cue-only trials) or both prepared and performed (completed trials). Previous studies have found that task-switch costs occur following cue-only trials, demonstrating that preparing-without performing-a task is sufficient to produce a subsequent switch cost. However, it is not clear whether switch costs after these different types of trial reflect an impact of task-switching upon task preparation or task performance on the current trial. The present study examined this question using a double-registration procedure with both cue-only and completed trials. Participants responded to both task-cue and target stimuli. In cue responses, a cost of switching task cues (cue-switch cost) but not of switching tasks (task-switch cost) followed both cue-only and completed trials. In target responses, a task-switch cost but no cue-switch cost followed both cue-only trials and completed trials, and this task-switch cost was larger following completed than cue-only trials. The presence of the task-switch cost in target responses following cue-only trials indicates a specific impact of previous preparation upon task performance, and the increased size of this cost following completed trials indicates an additional impact of previous performance. Together, these results suggest that both task preparation and task performance contribute to the subsequent task-switch cost affecting task performance. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Functional Connectivity Alterations of Cognitive Flexibility in Aging: Different Patterns of Global and Local Switch Costs.

Cognitive flexibility declines with aging and is usually indicated by task switch costs including global and local switch costs. Cognitive flexibility in aging is associated with alterations in functional connectivity. However, whether different task-modulated connectivity mechanisms underlying global and local switch costs remain unclear. Here we use the support vector machine to identify age-related functional connectivity in global and local switch costs between older (n = 32) and young adults (n = 33). Participants completed a cued task-switching task during the functional magnetic resonance imaging scan. Results show an age-related decline behaviorally in global but not in local switch costs. Moreover, distinct patterns of age-related alterations of connectivity were observed for each cost. Specifically, only multivariate changes in connectivity patterns were observed for local switch cost, whereas specific age-related connections were revealed for global switch cost. In older adults, the task-modulated left dorsal premotor cortex-left precuneus connectivity decreased, and the left inferior frontal junction-left inferior parietal sulcus connectivity correlated with decreased global switch cost. This study provides novel evidence for different neural patterns in global and local switch costs by illuminating connectivity mechanisms underlying cognitive flexibility in aging.

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.

Risk-Aware Contextual Learning for Edge-Assisted Crowdsourced Live Streaming

This paper proposes an edge-assisted crowdsourced live video transcoding approach where the transcoding capabilities of the edge transcoders are unknown and dynamic. The resilience and trustworthiness of highly unstable transcoders in decision making are characterized with mean-variance-based measures to avoid making highly risky decisions. The risk level of each device’s situation is assessed and two upper confidence bounds of the variance of transcoding performance are presented. Based on the derived bounds and by leveraging the contextual information of devices, two risk-aware contextual learning schemes are developed to efficiently estimate the transcoding capabilities of the edge devices. Combining context awareness and risk sensitivity, a novel transcoding task assignment and viewer association algorithm is proposed. Simulation results demonstrate that the proposed algorithm achieves robust task offloading with superior network utility performance as compared to the linear upper confidence bound and the risk-aware mean-variance upper confidence bound-based algorithms. In particular, an epoch-based task assignment strategy is designed to reduce the task switching costs incurred in assigning the same transcoding task to different transcoders over time. This strategy also reduces the computational time needed. Numerical results confirm that this strategy achieves up to 86.8% switching costs reduction and 92.3% computational time reduction.

The double task-switching protocol: An investigation into the effects of similarity and conflict on cognitive flexibility in the context of mental fatigue.

Considerable fundamental studies have focused on the mechanisms governing cognitive flexibility and the associated costs of switching between tasks. Task-switching costs refer to the phenomenon that reaction times and accuracy decrease briefly following the switch from one task to another. However, cognitive flexibility also impacts day-to-day life in many complex work environments where operators have to perform several different tasks. One major difference between typical tasks examined in fundamental studies and real-world applications is that fundamental studies often rely on much more similar tasks, which is not the case for real-world applications. In the latter, operators may switch between vastly dissimilar tasks. Therefore, this behavioural study aims to test if task-switching costs are different for switches between similar and dissimilar tasks. The proposed protocol has participants switch between 2 pairs of two tasks each. Between pairs, there is more dissimilarity, while the two tasks within each pair are more similar. In addition, this study examines the impact of mental fatigue and interference in form of confounding information on cognitive flexibility. To induce mental fatigue the participants' breaks between blocks will be limited. We expect that dissimilarity between tasks will result in greater task-switching costs.

Modelling human behaviour in cognitive tasks with latent dynamical systems.

Response time data collected from cognitive tasks are a cornerstone of psychology and neuroscience research, yet existing models of these data either make strong assumptions about the data-generating process or are limited to modelling single trials. We introduce task-DyVA, a deep learning framework in which expressive dynamical systems are trained to reproduce sequences of response times observed in data from individual human subjects. Models fitted to a large task-switching dataset captured subject-specific behavioural differences with high temporal precision, including task-switching costs. Through perturbation experiments and analyses of the models' latent dynamics, we find support for a rational account of switch costs in terms of a stability-flexibility trade-off. Thus, our framework can be used to discover interpretable cognitive theories that explain how the brain dynamically gives rise to behaviour.

Neural correlates of affective task switching and asymmetric affective task switching costs.

The control of emotions is of potentially great clinical relevance. Accordingly, there has been increasing interest in understanding the cognitive mechanisms underlying the ability to switch efficiently between the processing of affective and non-affective information. Reports of asymmetrically increased switch costs when switching toward the more salient emotion task indicate specific demands in the flexible control of emotion. The neural mechanisms underlying affective task switching, however, are so far not fully understood. Using functional Magnetic Resonance Imaging (MRI) (N = 57), we observed that affective task switching was accompanied by increased activity in domain-general fronto-parietal control systems. Blood-oxygen-level-dependent (BOLD) activity in the posterior medial frontal and anterolateral prefrontal cortex was directly related to affective switch costs, indicating that these regions play a particular role in individual differences in (affective) task-switching ability. Asymmetric switch costs were associated with increased activity in the right inferior frontal and dorsal anterior medial prefrontal cortex, two brain regions critical for response inhibition. This suggests that asymmetric switch costs might-to a great extent-reflect higher demands on inhibitory control of the dominant emotion task. These results contribute to a refined understanding of brain systems for the flexible control of emotions and thereby identify valuable target systems for future clinical research.

A task segment framework to study keylogged translation processes

The Task Segment Framework (TSF) is a tool to analyze full typing flows of translation tasks as keylogged with timestamps recorded for keydown, keyup, mouse clicks and moves, and actions performed in other applications. The TSF assumes that intentional pauses flag stretches where subjects concentrate on unrecorded cognitive processes such as planning and assessment. The interspersed typing stretches are task segments, with or without text, where basic subtasks may be observed, mainly adding new text, changing existing text, and searching for information. Accumulated experience and planning allow translators to lump strategically similar activities together, in order to spare efforts and task switching costs while maximizing efficiency. Hence, task segments may contain activities of just one such subtask or many. Translation fluency is a key notion of the TSF, operationalized through many indicators such as typing speed, prior pause length, TS (task segment) length in events, text length as full words, number of typos and respites (=mid inter-keystroke intervals), subtask(s), and the like. The approach seems particularly sensitive to translation expertise levels and may be applied with variations to other multilectal mediated communication tasks. This article lays down the conceptual basis of the TSF and summarizes its basic notions and constructs.

Differential impact of glycemic control and comorbid conditions on the neurophysiology underlying task switching in older adults with type 2 diabetes.

Type 2 diabetes is known to negatively affect higher order cognition and the brain, but the underlying mechanisms are not fully understood. In particular, glycemic control and common comorbidities are both thought to contribute to alterations in cortical neurophysiology in type 2 diabetes, but their specific impact remains unknown. The current study probed the dynamics underlying cognitive control in older participants with type 2 diabetes, with and without additional comorbid conditions (i.e., cardiovascular disease, nephropathy, peripheral neuropathy, retinopathy), using a task switching paradigm and a dynamic functional brain mapping method based on magnetoencephalography (MEG). We hypothesized that neural dynamics would be differentially impacted by the level of glycemic control (i.e., diabetes itself) and the burden of additional comorbid conditions. Supporting this hypothesis, our findings indicated separable, but widespread alterations across frontal, parietal, temporal and cerebellum regions in neural task-switch costs in type 2 diabetes that were differentially attributable to glycemic control and the presence of comorbid conditions. These effects were spatially non-overlapping and the effects were not statistically related to one another. Further, several of the effects that were related to the presence of comorbidities were associated with behavioral performance, indicating progressive deficits in brain function with extended disease. These findings provide insight on the underlying neuropathology and may inform future treatment plans to curtail the neural impact of type 2 diabetes.

Timing of internal processes: Investigating introspection about the costs of task switching and memory search

During the last two decades, there has been new interest in introspection about multitasking performance. In this field, subjective timing of one’s own reaction times (introspective RTs) has proven a useful measure to assess introspection. However, whether timing our own cognitive processing makes use of the same timing mechanisms as timing external intervals has been called into question. Here we take a novel approach to this question and build on the previously observed dissociation between the interference of task switching and memory search with a concurrent time production task whereby temporal productions increased with increasing memory set size but were not affected by switch costs. We tested whether a similar dissociation could be observed in this paradigm when participants provide introspective RTs instead of concurrent temporal productions. The results showed no such dissociation as switch costs and the effect of memory set size on RTs were both reflected in introspective RTs. These findings indicate that the underlying timing mechanisms differ between temporal productions and introspective RTs in this multitasking context, and that introspective RTs are still strikingly accurate estimates of objective RTs.