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.
Public Significance Statement
This integrative review organizes the traditionally quite separate research areas of dual-task performance and task switching according to three different research perspectives. These perspectives differ in terms of their focus on cognitive structure, flexibility, and plasticity. 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 or task switching) to favor instead a view that emphasizes the fundamental similarity of the underlying cognitive mechanisms across multitasking paradigms.
Existing multifactorial particle swarm optimisation (MFPSO) algorithms only explore a relatively narrow area between the inter-task particles. Meanwhile, these algorithms use a fixed inter-task ...learning probability throughout the evolution process. However, the parameter is problem dependent and can be various at different stages of the evolution. In this work, the authors devise an inter-task learning-based information transferring mechanism to replace the corresponding part in MFPSO. This inter-task learning mechanism transfers the searching step by using a differential term and updates the personal best position by employing an inter-task crossover. By this mean, the particles can explore a broad search space when utilising the additional searching experiences of other tasks. In addition, to enhance the performance on problems with different complementarity, they design a self-adaption strategy to adjust the inter-task learning probability according to the performance feedback. They compared the proposed algorithm with the state-of-the-art algorithms on various benchmark problems. Experimental results demonstrate that the proposed algorithm can transfer inter-task knowledge efficiently and perform well on the problems with different complementarity.
We compared the effects of extended dual-task practice in a task situation of the psychological refractory period (PRP) type with the effects of single-task practice. The experiments tested the ...assumption that performance of Task 2 in the PRP task improves more rapidly with dual-task practice than with single-task practice, which points to a preponed instantiation of Task 2 during dual-task processing in working memory and to the acquisition of dual-task coordination skills. Experiments 1 and 2 showed that such dual-task coordination skills can be acquired under conditions of less-complex tasks with no more than four stimulus-response mappings in Task 2, independently on the compatibility of the mappings. Experiment 3 showed no evidence for the acquisition of dual-task coordination skills under condition of eight stimulus-response mappings in Task 2. This indicates that the working memory load exposed by the number of stimulus-response mappings is a critical parameter limiting the degree to which participants can prepone the conjoint instantiation of two task sets during dual-task processing. The findings specify a model assuming the conjoint and efficient initiation of task sets in working memory as a result of extended dual-task practice.
Public Significance Statement
This study offers a substantial theoretical contribution to the field of executive functions, their optimization, and the characteristics of this optimization under dual-task conditions. This contribution is integrated into an elaborated model (the Efficient Task Instantiation model) on the mechanisms underlying improved dual-task performance after practice.
Task Conflict Biases Decision Making Schuch, Stefanie; Dignath, David
Journal of experimental psychology. General,
05/2021, Volume:
150, Issue:
5
Journal Article
Peer reviewed
The present research explores decision making in multitasking, investigating how people make optimal decisions between tasks. Empirical evidence suggests that difficulties in task performance (i.e., ...response conflict within a task) can bias decision making. Here we investigate whether also conflict between task representations can tune choices away from conflict-associated tasks. Using a combined forced/free-choice task-switching design, we tested whether task conflict that arises because of proactive interference of previously activated tasks biases task choice. We compared free-choice decisions between 3 tasks after forced-choice sequences that instigated either high task conflict (task sequences of type ABA, in which persisting inhibition needs to be overcome because one switches back to a just-abandoned task) or low task conflict (task sequences of type CBA). Results of 2 experiments (N = 16; N = 32, preregistered) showed that participants were more likely to switch away from the previously performed task after high than after low task conflict. Furthermore, participants preferably selected the task that suffered least from task conflict and/or proactive interference. In addition, a third experiment (N = 32) confirmed that this bias in task selection could not be explained in terms of randomness heuristics. These results suggest a close link between decision making and performance in multitasking.
In the present study, we combined the psychological refractory period (PRP) paradigm with a novel task-pair switching logic which enabled us to isolate performance costs occurring at the global level ...of task-pairs. In Experiment 1, in which we used conceptually overlapping responses for Task 1 (T1) and Task 2 (T2), we generated 3 task-pairs by combining 1 of 3 visual tasks (T1) with an auditory task (T2). In addition to worse performance after a short SOA than a long SOA (i.e., PRP effect), we found impaired performance in n − 1 task-pair switches as compared to n − 1 task-pair repetitions (i.e., n − 1 task-pair switch costs), suggesting that task-pairs were activated during dual-task processing. In Experiment 2, we increased the interference between T1 and T2 by using physically overlapping responses and we again observed n − 1 task-pair switch costs. To investigate whether the activation of task-pairs is adjusted by inhibitory control, we looked at the n − 2 task-pair sequence and found performance to be better in n − 2 task-pair repetitions than in n − 2 task-pair switches in both experiments. This n − 2 task-pair repetition benefit was replicated in Experiment 3 in which no immediate task-pair repetitions were included. Hence, the evidence suggests enhanced activation rather than inhibition as a crucial selection mechanism at the global level of dual-task processing.
Public Significance Statement
Our actions often consist of several subtasks that have to be, at least partly, performed simultaneously. For example, when we want to start a car, we have to perform the two partially overlapping subtasks of releasing the clutch and pressing the gas pedal. The present study provides evidence that in dual-task situations, simultaneously performed subtasks are grouped together to a single hierarchical higher-order task, representing a higher-level connection between the task sets of both subtasks. Moreover, the findings suggest that persisting activation, which results in residual positive priming of the previously relevant higher-order task, seems to be the crucial selection mechanism at the level of higher-order tasks. Hence, in addition to cognitive control mechanisms coordinating overlapping task processing at the level of subtasks, human actions in dual-task situations are enabled by cognitive control mechanisms acting at the global level of higher-order mental representations covering the task sets of both subtasks.
Prior research suggests that visual features of the classroom environment (e.g., charts and posters) are potential sources of distraction hindering children's ability to maintain attention to ...instructional activities and reducing learning gains in a laboratory classroom. However, prior research only examined short‐term exposure to elements of classroom décor, and it remains unknown whether children habituate to the visual environment with repeated exposure. In study 1, we explored experimentally the possibility that children may habituate to the visual environment if the visual displays are static. We measured kindergarten children's patterns of attention allocation in a decorated classroom environment over a 2‐week period and compared the percentage of time children spent off‐task to a baseline condition in which the classroom environment was streamlined (i.e., charts, posters, and manipulatives were removed). The findings indicate that with more prolonged exposure to a static visual environment, partial habitation effects were observed: Attention to the environment declined at the end of the exposure period compared to the beginning of the study; however, the environment remained a significant source of off‐task behavior even after 2 weeks of exposure. In study 2, we extend this work by conducting a longitudinal observation of six primary classrooms in which we measured children's patterns of attention allocation in real classrooms for 15 weeks to investigate whether increasing familiarity with the classroom décor would influence attention toward the visual environment. No evidence of habituation was observed in genuine classrooms in study 2. Potential implications for classroom design and future directions are discussed.
According to the strength model, self-control is a finite resource that determines capacity for effortful control over dominant responses and, once expended, leads to impaired self-control task ...performance, known as
ego depletion
. A meta-analysis of 83 studies tested the effect of ego depletion on task performance and related outcomes, alternative explanations and moderators of the effect, and additional strength model hypotheses. Results revealed a significant effect of ego depletion on self-control task performance. Significant effect sizes were found for ego depletion on effort, perceived difficulty, negative affect, subjective fatigue, and blood glucose levels. Small, nonsignificant effects were found for positive affect and self-efficacy. Moderator analyses indicated minimal variation in the effect across sphere of depleting and dependent task, frequently used depleting and dependent tasks, presentation of tasks as single or separate experiments, type of dependent measure and control condition task, and source laboratory. The effect size was moderated by depleting task duration, task presentation by the same or different experimenters, intertask interim period, dependent task complexity, and use of dependent tasks in the choice and volition and cognitive spheres. Motivational incentives, training on self-control tasks, and glucose supplementation promoted better self-control in ego-depleted samples. Expecting further acts of self-control exacerbated the effect. Findings provide preliminary support for the ego-depletion effect and strength model hypotheses. Support for motivation and fatigue as alternative explanations for ego depletion indicate a need to integrate the strength model with other theories. Findings provide impetus for future investigation testing additional hypotheses and mechanisms of the ego-depletion effect.
The task-switching paradigm offers enormous possibilities to study cognitive control as well as task interference. The current review provides an overview of recent research on both topics. First, we ...review different experimental approaches to task switching, such as comparing mixed-task blocks with single-task blocks, predictable task-switching and task-cuing paradigms, intermittent instructions, and voluntary task selection. In the 2nd part, we discuss findings on preparatory control mechanisms in task switching and theoretical accounts of task preparation. We consider preparation processes in two-stage models, consider preparation as an all-or-none process, address the question of whether preparation is switch-specific, reflect on preparation as interaction of cue encoding and memory retrieval, and discuss the impact of verbal mediation on preparation. In the 3rd part, we turn to interference phenomena in task switching. We consider proactive interference of tasks and inhibition of recently performed tasks indicated by asymmetrical switch costs and n-2 task-repetition costs. We discuss stimulus-based interference as a result of stimulus-based response activation and stimulus-based task activation, and response-based interference because of applying bivalent rather than univalent responses, response repetition effects, and carryover of response selection and execution. In the 4th and final part, we mention possible future research fields.
The task-switching paradigm is being increasingly used as a tool for studying cognitive control and task coordination. Different procedural variations have been developed. They have in common that a ...comparison is made between transitions in which the previous task is repeated and transitions that involve a change toward another task. In general, a performance switch cost is observed such that switching to a new task results in a slower and more error-prone execution of the task. The present article reviews the theoretical explanations of the switch cost and the findings collected in support of those explanations. Resolution and protection from interference by previous events explain part of the switching cost, but processes related to task setting and task preparation also play a prominent role, as testified by faster execution and lower switch costs when the preparation time is longer. The authors discuss the evidence in favor of each of these sets of accounts and raise a number of questions that situate task switching in a broader context of cognitive control processes. The role of several aspects of the task set, including task variations, task-set overlap, and task-set structure, is addressed, as is the role of knowledge about probability of task changes and about the structure of task sequences.
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