Task Shifting in Dual-Task Settings

2002 ◽  
Vol 94 (2) ◽  
pp. 407-414 ◽  
Author(s):  
Shulan Hsieh
Keyword(s):  
Dual Task ◽  
Time Course ◽  
Reaction Times ◽  
Task Shifting ◽  
Central Executive ◽  
Time Cost ◽  
Main Interest ◽  
Task Set ◽  
Shift Cost

When a participant is asked to perform two tasks in alternation, their mean reaction times were slower than when they performed the same tasks repeatedly. This “shift cost” has been hypothesized to reflect the time course of a single central executive that exerts control over thought and actions in task shifting. This study attempted to test this hypothesis using dual-task methodology. Participants were asked to carry out both a subtracting task and a rule-shifting task simultaneously. The main interest is to examine the effect of dual task on the magnitude of shift cost. The results showed that performing a concurrent subtracting task significantly interfered with the shifting operation resulting in over-additive time cost for shifting of task set. We further suggest that such interference may arise from the competition between activations of various rules.

Talking is harder than listening: The time course of dual-task costs during naturalistic conversation.

2017 ◽  
Vol 71 (2) ◽  
pp. 111-119 ◽  
Author(s):  
April M. C. Lee ◽  
Stefania Cerisano ◽  
Karin R. Humphreys ◽  
Scott Watter
Keyword(s):  
Dual Task ◽  
Time Course

Learning of across- and within-task contingencies modulates partial-repetition costs in dual-tasking

2021 ◽  
Author(s):  
Lasse Pelzer ◽  
Christoph Naefgen ◽  
Robert Gaschler ◽  
Hilde Haider
Keyword(s):  
Dual Task ◽  
Discrimination Task ◽  
Experimental Approach ◽  
Feature Binding ◽  
Dual Tasking ◽  
Single Task ◽  
Task Set ◽  
Task Processing ◽  
Tone Discrimination ◽  
Task Sets

AbstractDual-task costs might result from confusions on the task-set level as both tasks are not represented as distinct task-sets, but rather being integrated into a single task-set. This suggests that events in the two tasks are stored and retrieved together as an integrated memory episode. In a series of three experiments, we tested for such integrated task processing and whether it can be modulated by regularities between the stimuli of the two tasks (across-task contingencies) or by sequential regularities within one of the tasks (within-task contingencies). Building on the experimental approach of feature binding in action control, we tested whether the participants in a dual-tasking experiment will show partial-repetition costs: they should be slower when only the stimulus in one of the two tasks is repeated from Trial n − 1 to Trial n than when the stimuli in both tasks repeat. In all three experiments, the participants processed a visual-manual and an auditory-vocal tone-discrimination task which were always presented concurrently. In Experiment 1, we show that retrieval of Trial n − 1 episodes is stable across practice if the stimulus material is drawn randomly. Across-task contingencies (Experiment 2) and sequential regularities within a task (Experiment 3) can compete with n − 1-based retrieval leading to a reduction of partial-repetition costs with practice. Overall the results suggest that participants do not separate the processing of the two tasks, yet, within-task contingencies might reduce integrated task processing.

scholarly journals The effect of high-frequency rTMS of the left dorsolateral prefrontal cortex on the resolution of response, semantic and task conflict in the colour-word Stroop task

2021 ◽  
Author(s):  
Benjamin A. Parris ◽  
Michael G. Wadsley ◽  
Gizem Arabaci ◽  
Nabil Hasshim ◽  
Maria Augustinova ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Task Performance ◽  
Stroop Task ◽  
Word Reading ◽  
Reaction Times ◽  
Task Conflict ◽  
General Effect ◽  
Task Set ◽  
Left Dlpfc ◽  
Dorsolateral Prefrontal

AbstractPrevious work investigating the effect of rTMS of left Dorso-Lateral Prefrontal Cortex (DLPFC) on Stroop task performance reports no changes to the Stroop effect but reduced reaction times on both congruent and incongruent trials relative to sham stimulation; an effect attributed to an enhanced attentional (or task) set for colour classification. The present study tested this account by investigating whether, relative to vertex stimulation, rTMS of the left DLPFC modifies task conflict, a form of conflict that arises when task sets for colour classification and word reading compete, given that this particular type of conflict would be reduced by an enhanced task set for colour classification. Furthermore, the present study included measures of other forms of conflict present in the Stroop task (response and semantic conflict), the potential effects on which would have been hidden in previous studies employing only incongruent and congruent stimuli. Our data showed that left DLPFC stimulation had no effect on the magnitude of task conflict, nor did it affect response, semantic or overall conflict (where the null is supported by sensitive Bayes Factors in most cases). However, consistent with previous research left DLPFC stimulation had the general effect of reducing reaction times. We, therefore, show for the first time that relative to real vertex stimulation left DLPFC stimulation does not modify Stroop interference. Alternative accounts of the role of the left DLPFC in Stroop task performance in which it either modifies response thresholds or facilitates responding by keeping the correct response keys active in working memory are discussed.

Attentional Dysfunction of the Central Executive in Ad: Evidence from Dual Task and Perseveration Errors

Cortex ◽  
2006 ◽  
Vol 42 (7) ◽  
pp. 1015-1020 ◽  
Author(s):  
Maria Victoria Sebastian ◽  
Julio Menor ◽  
Maria Rosa Elosua
Keyword(s):  
Dual Task ◽  
Central Executive ◽  
Attentional Dysfunction

scholarly journals Mood congruency effects are mediated by shifts in salience and central executive network efficiency

2019 ◽  
Vol 14 (9) ◽  
pp. 987-995 ◽  
Author(s):  
Julian Provenzano ◽  
Philippe Verduyn ◽  
Nicky Daniels ◽  
Philippe Fossati ◽  
Peter Kuppens
Keyword(s):  
Neural Networks ◽  
Mood Induction ◽  
Reaction Times ◽  
Central Executive ◽  
Network Organization ◽  
Transient Effects ◽  
Network Efficiency ◽  
Macro Scale ◽  
Central Executive Network ◽  
Time Point

Abstract Emotions are not confined to short momentary states but carry on over time, facilitating the perception and interpretation of the environment in mood-congruent ways. Yet, the (neural) mechanism linking affective stimulation at a certain time-point to such altered, mood-congruent processing of stimuli presented at a subsequent time-point remains unknown. Recent research suggests that such a link could be explained by transient effects of affective stimulation on the organization of intrinsic macro-scale neural networks. It remains, however, unclear whether these changes in network organization are influencing subsequent perception in a mood-congruent way. Addressing this gap the current study investigated whether changes in network organization, measured in terms of network efficiency, mediate the relation between mood induction and mood-congruent processing as measured by reaction times during an emotional Stroop task. The results demonstrated that negative mood induction increased the efficiency of the salience network and decreased the efficiency of the central executive network. This modulation of network efficiency fully mediated the effects of mood induction on reaction times to negative words. These findings indicate that transient shifts in the organization of macro-scale neural networks are an essential part of the emotional response and can help to explain how affect shapes our interaction with the environment.

scholarly journals Asymmetric interference between cognitive task components and concurrent sensorimotor coordination

2018 ◽  
Vol 120 (1) ◽  
pp. 330-342
Author(s):  
Joshua Baker ◽  
Antonio Castro ◽  
Andrew K. Dunn ◽  
Suvobrata Mitra
Keyword(s):  
Information Processing ◽  
Dual Task ◽  
Time Course ◽  
Cognitive Task ◽  
Tracking Task ◽  
Cognitive Tasks ◽  
State Monitoring ◽  
Sensorimotor Coordination ◽  
Dual Tasking ◽  
Task Conditions

Everyday cognitive tasks are frequently performed under dual-task conditions alongside continuous sensorimotor coordinations (CSCs) such as driving, walking, or balancing. Observed interference in these dual-task settings is commonly attributed to demands on executive function or attentional resources, but the time course and reciprocity of interference are not well understood at the level of information-processing components. Here we used electrophysiology to study the detailed chronometry of dual-task interference between a visual oddball task and a continuous visuomanual tracking task. The oddball task’s electrophysiological components were linked to underlying cognitive processes, and the tracking task served as a proxy for the continuous cycle of state monitoring and adjustment inherent to CSCs. Dual-tasking interfered with the oddball task’s accuracy and attentional processes (attenuated P2 and P3b magnitude and parietal alpha-band event-related desynchronization), but errors in tracking due to dual-tasking accrued at a later timescale and only in trials in which the target stimulus appeared and its tally had to be incremented. Interference between cognitive tasks and CSCs can be asymmetric in terms of timing as well as affected information-processing components. NEW & NOTEWORTHY Interference between cognitive tasks and continuous sensorimotor coordination (CSC) has been widely reported, but this is the first demonstration that the cognitive operation that is impaired by concurrent CSC may not be the one that impairs the CSC. Also demonstrated is that interference between such tasks can be temporally asymmetric. The asynchronicity of this interference has significant implications for understanding and mitigating loss of mobility in old age, and for rehabilitation for neurological impairments.

Binding of Event Files in a (go/no-go) Simon Task With an Accessory Peripheral Signal

2009 ◽  
Vol 56 (2) ◽  
pp. 100-111 ◽  
Author(s):  
Kathleen Maetens ◽  
David Henderickx ◽  
Eric Soetens
Keyword(s):  
Simon Effect ◽  
Time Course ◽  
Simon Task ◽  
Reaction Times ◽  
Response Signal ◽  
Event File ◽  
Response Information ◽  
Event Files ◽  
Accessory Stimulus ◽  
Accessory Signal

To understand the relation between the Simon effect and the time course of relevant and irrelevant code activations, we presented the response signal before or simultaneously with a go/no-go signal in an accessory Simon task. A peripheral accessory signal could appear before, simultaneously with or after the go/no-go signal. We observed a Simon effect when the accessory signal was presented just before or simultaneously with the go signal, irrespective of the delay between response and go/no-go signal. The Simon effect reversed when the accessory signal was presented 150 ms after the go signal when response information was presented first and the participants had to make a go/no-go decision afterwards or when they had to select a response when the go signal appeared. The reversal did not occur when both decisions were required at the same time. Our data suggest that the integration and release of event files are involved in the occurrence of the reversal. Response activation induced by the accessory stimulus facilitates/interferes with the response when it is presented before the event file is integrated. When the accessory stimulus is presented after integration, the automatically activated response is inhibited, causing a delay in the corresponding reaction times.

THE INFLUENCE OF TDCS INTENSITY ON DECISION-MAKING TRAINING AND TRANSFER OUTCOMES

2020 ◽  
Author(s):  
Shane E Ehrhardt ◽  
Hannah L. Filmer ◽  
Yohan Wards ◽  
Jason B Mattingley ◽  
Paul E Dux
Keyword(s):  
Dual Task ◽  
Reaction Times ◽  
Performance Outcomes ◽  
Single Task ◽  
Training Performance ◽  
Dual Task Performance ◽  
Task Component ◽  
Task Practice ◽  
Task Training ◽  
Performance Gains

Transcranial direct current stimulation (tDCS) has been shown to improve single- and dual-task performance in healthy participants and enhance transferable training gains following multiple sessions of combined stimulation and task-practice. However, it has yet to be determined what the optimal stimulation dose is for facilitating such outcomes. We aimed to test the effects of different tDCS intensities, with a commonly used electrode montage, on performance outcomes in a multi-session single/dual-task training and transfer protocol. In a pre-registered study, 123 participants, who were pseudorandomised across four groups, each completed six sessions (pre- and post-training sessions and four combined tDCS and training sessions) and received 20 minutes of prefrontal anodal tDCS at 0.7 mA, 1.0 mA, 2.0 mA, or 15-second sham stimulation. Response time and accuracy were assessed in trained and untrained tasks. The 1.0 mA group showed substantial improvements in single-task reaction time and dual-task accuracy, with additional evidence for improvements in dual-task reaction times, relative to sham performance. This group also showed near transfer to the single-task component of an untrained multitasking paradigm. The 0.7 mA and 2.0 mA intensities varied in which performance measures they improved on the trained task, but in sum, the effects were less robust than for the 1.0 mA group and there was no evidence for the transfer of performance. Our study highlights that training performance gains are augmented by tDCS, but their magnitude and nature are not uniform across stimulation intensity.

The Time Course of Perceptual Grouping in Natural Scenes

2012 ◽  
Vol 23 (12) ◽  
pp. 1482-1489 ◽  
Author(s):  
Ilia Korjoukov ◽  
Danique Jeurissen ◽  
Niels A. Kloosterman ◽  
Josine E. Verhoeven ◽  
H. Steven Scholte ◽  
...  
Keyword(s):  
Visual Perception ◽  
Perceptual Grouping ◽  
Time Course ◽  
Reaction Times ◽  
Object Classification ◽  
Natural Scenes ◽  
Single Object ◽  
Object A ◽  
Object Parsing ◽  
Different Parts

Visual perception starts with localized filters that subdivide the image into fragments that undergo separate analyses. The visual system has to reconstruct objects by grouping image fragments that belong to the same object. A widely held view is that perceptual grouping occurs in parallel across the visual scene and without attention. To test this idea, we measured the speed of grouping in pictures of animals and vehicles. In a classification task, these pictures were categorized efficiently. In an image-parsing task, participants reported whether two cues fell on the same or different objects, and we measured reaction times. Despite the participants’ fast object classification, perceptual grouping required more time if the distance between cues was larger, and we observed an additional delay when the cues fell on different parts of a single object. Parsing was also slower for inverted than for upright objects. These results imply that perception starts with rapid object classification and that rapid classification is followed by a serial perceptual grouping phase, which is more efficient for objects in a familiar orientation than for objects in an unfamiliar orientation.

Radical scavenging characteristics of condensed tannins from barks of various tree species compared with quebracho wood tannin

Holzforschung ◽  
2011 ◽  
Vol 65 (5) ◽  
Author(s):  
Rei Makino ◽  
Seiji Ohara ◽  
Koh Hashida
Keyword(s):  
Tree Species ◽  
Time Course ◽  
Condensed Tannin ◽  
Radical Scavenging ◽  
Reaction Times ◽  
Gas Chromatography Mass Spectrometry ◽  
Type B ◽  
Pyrolysis Gas ◽  
Nmr Spectrometry ◽  
In The Beginning

Abstract The object of this study was to elucidate the relationship between the chemical structure of purified condensed tannin polymers from tree species and their radical scavenging characteristics. By means of 13C-NMR spectrometry and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), four kinds of proanthocyanidins were identified: prorobinetinidins, profisetinidins, procyanidins, and prodelphinidins. The tannins were submitted to radical scavenging assays with DPPH and galvinoxyl radicals and from the time-course of the reactions was concluded: 1) Tannins with pyrogallol type B-ring scavenge radicals in the beginning faster than those with catechol type B-ring. 2) Tannins with catechol type B-ring needs more time to scavenge the same amount of radicals as those with pyrogallol type B-ring. 3) The IC50 values of tannins with catechol type B-ring decrease after longer reaction times with the galvinoxyl radical. 4) Radical scavenging with DPPH radical proceeds faster than that for the galvinoxyl radical.

Sign in / Sign up

Export Citation Format

Share Document