Task-order representations in dual tasks: Separate or integrated with component task sets?

2021 ◽  
pp. 174702182110184
Author(s):  
Lynn Huestegge ◽  
Mareike A Hoffmann ◽  
Tilo Strobach
Keyword(s):  
Temporal Order ◽  
Spatial Task ◽  
Task Characteristics ◽  
Switch Costs ◽  
Task Order ◽  
Order Task ◽  
Component Task ◽  
Specific Manner ◽  
Oculomotor Responses ◽  
Task Sets

In situations requiring the execution of two tasks at around the same time, we need to decide which of the tasks should be executed first. Previous research has revealed several factors that affect the outcome of such response order control processes, including bottom-up factors (e.g., the temporal order of the stimuli associated with the two tasks) and top-down factors (e.g., instructions). In addition, it has been shown that tasks associated with certain response modalities are preferably executed first (e.g., temporal prioritisation of tasks involving oculomotor responses). In this study, we focused on a situation in which task order has to be unpredictably switched from trial to trial and asked whether task-order representations are coded separately or integrated with the component task sets (i.e., in a task-specific manner). Across three experiments, we combined two tasks known to differ in prioritisation, namely an oculomotor and a manual (or pedal) task. The results indicated robust task-order switch costs (i.e., longer RTs when task order was switched vs. repeated). Importantly, the data demonstrate that it is possible to show an asymmetry of task-order switch costs: While these costs were of similar size for both task orders in one particular experimental setting with specific spatial task characteristics, two experiments consistently indicated that it was easier for participants to switch to their prioritised task order (i.e., to execute the dominant oculomotor task first). This suggests that in a situation requiring frequent task-order switches (indicated by unpredictable changes in stimulus order), task order is represented in an integrated, task-specific manner, bound to characteristics (here, associated effector systems) of the component tasks.

scholarly journals EXPRESS: When Two Actors Perform Different Tasks: Still No Evidence for Shared Task-Sets in Joint Task Switching

2021 ◽  
pp. 174702182110315
Author(s):  
Motonori Yamaguchi ◽  
Husnain H. Shah ◽  
Bernhard Hommel
Keyword(s):  
Task Switching ◽  
The Other ◽  
Shared Task ◽  
Joint Condition ◽  
Task Instructions ◽  
Switch Costs ◽  
Joint Task ◽  
Task Sets ◽  
Rule Out

Two different variations of joint task switching led to different conclusions as to whether co-acting individuals share the same task-sets. The present study aimed at bridging this gap by replicating the version in which two actors performed two different tasks. Experiment 1 showed switch costs across two actors in a joint condition, which agreed with previous studies, but also yielded even larger switch costs in a solo condition, which contradicted the claim that actors represent an alternative task as their own when it is carried out by the co-actor but not when no one carries it out. Experiments 2 and 3 further examined switch costs in the solo condition with the aim to rule out possible influences of task instructions for and experiences with the other task that was not assigned to the actor. Before participants were instructed on the second of the two tasks, switch costs were still obtained without a co-actor when explicit task names (“COLOUR” and “SHAPE”) served as go/nogo signals (Experiment 2), but not when arbitrary symbols (“XXXX” and “​​​​”) served as go/nogo signals (Experiment 3). The results thus imply that switch costs depend on participants’ knowledge of task cues being assigned to two different tasks, but not on whether the other task is performed by a co-actor. These findings undermine the assumption that switch costs in the joint conditions reflect shared task-sets between co-actors in this procedure.

scholarly journals Contextual Adaptation of Cognitive Flexibility is driven by Task- and Item-Level Learning

2019 ◽  
Author(s):  
Audrey Siqi-Liu ◽  
Tobias Egner
Keyword(s):  
Cognitive Flexibility ◽  
Stimulus Item ◽  
Transfer Task ◽  
Learning Mechanisms ◽  
Behavioral Experiments ◽  
Task Set ◽  
Switch Costs ◽  
Cognitive Stability ◽  
Current Task ◽  
Task Sets

Adaptive behavior requires finding, and adjusting, an optimal tradeoff between focusing on a current task-set (cognitive stability) and updating that task-set when the environment changes (cognitive flexibility). Such dynamic adjustments of cognitive flexibility are observed in cued task-switching paradigms, where switch costs tend to decrease as the proportion of switch trials over blocks increases. However, the learning mechanisms underlying this phenomenon, here referred to as the list-wide proportion switch effect (LWPSE), are currently unknown.We addressed this question across four behavioral experiments. Experiment 1 replicated the basic LWPSE reported in previous studies. Having participants switch between three instead of two tasks, Experiment 2 demonstrated that the LWPSE is preserved even when the specific alternate task to switch to cannot be anticipated. Experiments 3a and 3b tested for the generalization of list-wide switch-readiness to an unbiased “transfer task,” presented equally often as switch and repeat trials, by intermixing the transfertask with biased tasks. Despite the list-wide bias, the LWPSE was only found for biased tasks, suggesting that the modulations of switch costs are task set and/or task stimulus (item)-specific. To evaluate these two possibilities, Experiment 4 employed biased versus unbiased stimuli within biased task sets and found switch-cost modulations for both stimuli sets. These results establish how people adapt their stability-flexibility tradeoff to different contexts. Specifically, our findings show that people learn to associate context appropriate levels of switch readiness with switch-predictive cues, provided by task sets as well as specific task stimuli.

scholarly journals Click Trains do not Alter Auditory Temporal Order Judgements

2020 ◽  
Vol 8 (3-4) ◽  
pp. 239-253
Author(s):  
Daniel Poole ◽  
Kyle J. Lees ◽  
Luke A. Jones
Keyword(s):  
Diffusion Model ◽  
Temporal Order ◽  
Decision Time ◽  
Model Parameters ◽  
Cognitive Mechanisms ◽  
Time Data ◽  
Previous Suggestion ◽  
Order Task ◽  
Click Train ◽  
Temporal Order Judgement

Brief periods of repetitive stimulation (click trains) presented either contiguous or simultaneous to an interval have been previously shown to impact on its perceived duration. In the current investigation we asked whether the perception of temporal order can be altered in a similar way. Participants completed a dichotic spectral temporal order judgement task with the stimuli titrated to their individual thresholds. Immediately prior to the judgement, participants were presented with five seconds of click trains, white noise or silence. We extended previous work on this topic by using each participant’s accuracy and response time data to estimate diffusion model parameters so that the cognitive mechanisms underlying any effect of click trains on the response could be disentangled. There was no effect of stimulation condition on participant’s accuracy, or diffusion model parameters (drift rate, boundary separation or non-decision time). The present findings therefore suggest that click trains do not influence temporal order perception. Additionally, the previous suggestion that click trains induce an increase in the rate of information processing was not supported for this temporal order task. Further work probing the limits and conditions of the click train effect will help to constrain and extend theoretical accounts of subjective timing.

scholarly journals Evidence for a multicomponent hierarchical representation of dual tasks

2020 ◽  
Author(s):  
Patricia Hirsch ◽  
Clara Roesch ◽  
Iring Koch
Keyword(s):  
Dual Task ◽  
Task Interference ◽  
Dual Tasks ◽  
Hierarchical Representation ◽  
Switch Costs ◽  
Task Processing ◽  
The Individual ◽  
Task Sets ◽  
Dual Task Interference ◽  
And Task

Abstract Recent dual-task studies observed worse performance in task-pair switches than in task-pair repetitions and interpreted these task-pair switch costs as evidence that the identity of the two individual tasks performed within a dual task is jointly represented in a single mental representation, termed “task-pair set.” In the present study, we conducted two experiments to examine (a) whether task-pair switch costs are due to switching cues or/and task pairs and (b) at which time task-pair sets are activated during dual-task processing. In Experiment 1, we used two cues per task-pair and found typical dual-task interference, indicating that performance in the individual tasks performed within the dual task deteriorates as a function of increased temporal task overlap. Moreover, we observed cue switch costs, possibly reflecting perceptual cue priming. Importantly, there were also task-pair switch costs that occur even when controlling for cue switching. This suggests that task-pair switching per se produces a performance cost that cannot be reduced to costs of cue switching. In Experiment 2, we employed a go/no-go-like manipulation and observed task-pair switch costs after no-go trials where subjects prepared for a task-pair, but did not perform it. This indicates that task-pair sets are activated before performing a dual task. Together, the findings of the present study provide further evidence for a multicomponent hierarchical representation consisting of a task-pair set organized at a hierarchically higher level than the task sets of the individual tasks performed within a dual task.

scholarly journals When Two Actors Perform Different Tasks: Still No Evidence for Shared Task-Sets in Joint Task Switching

2021 ◽  
Author(s):  
Motonori Yamaguchi ◽  
Bernhard Hommel
Keyword(s):  
Task Switching ◽  
The Other ◽  
Shared Task ◽  
Joint Condition ◽  
Task Instructions ◽  
Switch Costs ◽  
Joint Task ◽  
Task Sets ◽  
Rule Out

Two different variations of joint task switching led to different conclusions as to whether co-acting individuals share the same task-sets. The present study aimed at bridging this gap by replicating the version in which two actors performed two different tasks. Experiment 1 showed switch costs across two actors in a joint condition, which agreed with previous studies, but also yielded even larger switch costs in a solo condition, which contradicted the claim that actors represent an alternative task as their own when it is carried out by the co-actor but not when no one carries it out. Experiments 2 and 3 further examined switch costs in the solo condition with the aim to rule out possible influences of task instructions for and experiences with the other task that was not assigned to the actor. Before participants were instructed on the second of the two tasks, switch costs were still obtained without a co-actor when explicit task names (“COLOUR” and “SHAPE”) served as go/nogo signals (Experiment 2), but not when arbitrary symbols (“XXXX” and “++++”) served as go/nogo signals (Experiment 3). The results thus imply that switch costs depend on participants’ knowledge of task cues being assigned to two different tasks, but not on whether the other task is performed by a co-actor. These findings undermine the assumption that switch costs in the joint conditions reflect shared task-sets between co-actors in this procedure.

Different Response Patterns Between Auditory Spectral and Spatial Temporal Order Judgment (TOJ)

2013 ◽  
Vol 60 (6) ◽  
pp. 432-443 ◽  
Author(s):  
Leah Fostick ◽  
Harvey Babkoff
Keyword(s):  
Temporal Order ◽  
Temporal Order Judgment ◽  
Spatial Task ◽  
Response Patterns ◽  
Temporal Separation ◽  
Improved Performance ◽  
Different Response ◽  
The Right ◽  
Order Of Presentation ◽  
Temporal Disparity

Temporal order judgment (TOJ) thresholds have been widely reported as valid estimates of the temporal disparity necessary for correctly identifying the order of two stimuli. Data for two auditory TOJ paradigms are often reported in the literature: (1) spatially-based TOJ in which the order of presentation of the same stimulus to the right and left ear differs; and (2) spectrally-based TOJ in which the order of two stimuli differing in frequency is presented to one ear or to both ears simultaneously. Since the thresholds reported using the two paradigms differ, the aim of the current study was to compare their response patterns. The results from three different experiments showed that: (1) while almost none of the participants were able to perform the spatial TOJ task when ISI = 5 ms, with the spectral task, 50% reached an accuracy level of 75% when ISI = 5 ms; (2) temporal separation was only a partial predictor for performance in the spectral task, while it fully predicted performance in the spatial task; and (3) training improved performance markedly in the spectral TOJ task, but had no effect on spatial TOJ. These results suggest that the two paradigms may reflect different perceptual mechanisms.

Design of a 5-SS Spatial Steering Linkage

2012 ◽  
Author(s):  
Mark M. Plecnik ◽  
J. Michael McCarthy
Keyword(s):  
Design Process ◽  
Spatial Task ◽  
Kinematic Synthesis ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Circular Arcs ◽  
Moving Platform ◽  
Vehicle Chassis ◽  
Task Sets ◽  
Functional Defects

This paper presents the kinematic synthesis of a steering linkage that changes track, wheelbase, camber, and wheel height in a turn, while maintaining Ackermann geometry. Each wheel is controlled by a 5-SS platform linkage, which consists of a moving platform connected by five SS chains to the vehicle chassis. Ackermann steering geometry ensures all four wheels will travel on circular arcs that share the same center point. S denotes a spherical or ball-in-socket joint. The kinematic synthesis problem is formulated using seven spatial task positions. The procedure computes the SS chains that guide the platform through the seven task positions, and examines all combinations of five that form a single degree-of-freedom linkage. A kinematic analysis identifies the performance of each design candidate, and eliminates functional defects. In the design process, the task positions are modified randomly within constraints in order to find a useful mechanism design. Mechanisms are deemed useful if they travel smoothly through all seven task positions. Upon analyzing 1000 sets of task positions, only 10 useful mechanisms were found. A second iteration produced 22 useful mechanisms from 1000 task sets. An example of the design of a steering linkage is presented. A video of this linkage can be seen at http://www.youtube.com/watch?v=hEvbDiyQMiw.

Specificity of learning in an auditory temporal‐order task

2000 ◽  
Vol 107 (5) ◽  
pp. 2882-2882
Author(s):  
Beverly A. Wright ◽  
Julia A. Mossbridge
Keyword(s):  
Temporal Order ◽  
Order Task ◽  
Specificity Of Learning

EXPRESS: Rethinking attentional reset: Task sets determine the boundaries of adaptive control

2021 ◽  
pp. 174702182110474
Author(s):  
Lauren Danielle Grant ◽  
Samantha Rose Cerpa ◽  
Daniel Howard Weissman
Keyword(s):  
Adaptive Control ◽  
Visual Features ◽  
Task Structure ◽  
Distractor Interference ◽  
Interference Task ◽  
Perceptual Features ◽  
Congruency Sequence Effect ◽  
Specific Manner ◽  
Context Specific ◽  
Task Sets

Adaptive control processes that minimize distraction often operate in a context-specific manner. For example, they may minimize distraction from irrelevant conversations during a lecture but not in the hallway afterwards. It remains unclear, however, whether (a) salient perceptual features or (b) task sets based on such features serve as contextual boundaries for adaptive control in standard distractor-interference tasks. To distinguish between these possibilities, we manipulated whether the structure of a standard, visual distractor-interference task allowed (Experiment 1) or did not allow (Experiment 2) participants to associate salient visual features (i.e., color patches and color words) with different task sets. We found that changing salient visual features across consecutive trials reduced a popular measure of adaptive control in distractor-interference tasks – the congruency sequence effect (CSE) – only when the task structure allowed participants to associate these visual features with different task sets. These findings extend prior support for the task set hypothesis from somewhat atypical cross-modal tasks to a standard unimodal task. Conversely, they pose a challenge to an alternative “attentional reset” hypothesis, and related views, wherein changing salient perceptual features always results in a contextual boundary for the CSE.

Sign in / Sign up

Export Citation Format

Share Document