The Effects of Transcranial Direct Current Stimulation on Dual-Task Interference Depend on the Dual-Task Content

Recently, some studies revealed that transcranial direct current stimulation (tDCS) reduces dual-task interference. Since there are countless combinations of dual-tasks, it remains unclear whether stable effects by tDCS can be observed on dual-task interference. An aim of the present study was to investigate whether the effects of tDCS on dual-task interference change depend on the dual-task content. We adopted two combinations of dual-tasks, i.e., a word task while performing a tandem task (word-tandem dual-task) and a classic Stroop task while performing a tandem task (Stroop-tandem dual-task). We expected that the Stroop task would recruit the dorsolateral prefrontal cortex (DLPFC) and require involvement of executive function to greater extent than the word task. Subsequently, we hypothesized that anodal tDCS over the DLPFC would improve executive function and result in more effective reduction of dual-task interference in the Stroop-tandem dual-task than in the word-tandem dual-task. Anodal or cathodal tDCS was applied over the DLPFC or the supplementary motor area using a constant current of 2.0 mA for 20 min. According to our results, dual-task interference and the task performances of each task under the single-task condition were not changed after applying any settings of tDCS. However, anodal tDCS over the left DLPFC significantly improved the word task performance immediately after tDCS under the dual-task condition. Our findings suggested that the effect of anodal tDCS over the left DLPFC varies on the task performance under the dual-task condition was changed depending on the dual-task content.

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Dual-task Interference in a Simulated Driving Environment: Serial or Parallel Processing?

10.1101/853119 ◽

2019 ◽

Author(s):

Mojtaba Abbas-Zadeh ◽

Gholam-Ali Hossein-Zadeh ◽

Maryam Vaziri-Pashkam

Keyword(s):

Task Performance ◽

Dual Task ◽

Task Condition ◽

Desktop Computer ◽

Task Interference ◽

Dual Task Condition ◽

Simulated Driving ◽

Evidence Accumulation ◽

Dual Task Performance ◽

Dual Task Interference

AbstractWhen humans are required to perform two tasks concurrently, their performances decrease as the two tasks get closer together in time. This effect is known as dual-task interference. This limitation of the human brain could have lethal effects during demanding everyday tasks such as driving. Are the two tasks processed serially or in parallel during dual-task performance in naturalistic settings? Here, we investigated dual-task interference in a simulated driving environment and investigated the serial/parallel nature of processing during dual-task performance. Participants performed a lane change task on a desktop computer, along with an image discrimination task. We systematically varied the time difference between the onset of the two tasks (Stimulus Onset Asynchrony, SOA) and measured its effect on the amount of dual-task interference. Results showed that the reaction times (RTs) of two tasks in the dual-task condition were higher than those in the single-task condition. SOA influenced RTs of both tasks when they were presented second and the RTs of the image task when it was presented first. Manipulating the predictability of the order of the two tasks, we showed that unpredictability attenuated the effect of SOA by changing the order of the response to the two tasks. Next, using drift-diffusion modeling, we modeled the reaction time and choice of the subjects during dual-task performance in both predictable and unpredictable task order conditions. The modeling results indicated that performing two tasks concurrently, affects both the rate of evidence accumulation and the delays outside the evidence accumulation period, suggesting that the two tasks are performed in a partial-parallel manner. These results extend the findings of previous dual-task experiments to more naturalistic settings and deepen our understanding of the mechanisms of dual-task interference.

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Effects of cognitive and motor dual-tasks on oropharyngeal swallowing assessed with FEES in healthy individuals

Scientific Reports ◽

10.1038/s41598-020-77421-3 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Paul Muhle ◽

Inga Claus ◽

Bendix Labeit ◽

Mao Ogawa ◽

Rainer Dziewas ◽

...

Keyword(s):

Dual Task ◽

Neurological Diseases ◽

Early Screening ◽

Task Interference ◽

Dual Task Condition ◽

Therapeutic Implications ◽

Task Effects ◽

Post Hoc ◽

Management Of Dysphagia ◽

Dual Task Interference

AbstractDysphagia is frequent in many neurological diseases and gives rise to severe complications such as malnutrition, dehydration and aspiration pneumonia. Therefore, early detection and management of dysphagia is essential and can reduce mortality. This study investigated the effect of cognitive and motor dual-task interference on swallowing in healthy participants, as dual-task effects are reported for other motor tasks such as gait and speech. 27 participants (17 females; 29.2 ± 4.1 years) were included in this prospective study and examined using flexible endoscopic evaluation of swallowing (FEES). Using a previously established FEES-based score, the paradigms “baseline swallowing”, “cognitive dual-task” and “motor dual-task” were assessed. Scores of the three paradigms were compared using a repetitive measures ANOVA and post-hoc analysis. Mean baseline swallowing score in single task was 5 ± 3. It worsened to 6 ± 5 in the cognitive (p = 0.118), and to 8 ± 5 in the motor dual-task condition (p < 0.001). This change was driven by subclinical worsening of premature bolus spillage and pharyngeal residue. Oropharyngeal swallowing is not exclusively reflexive in nature but requires attention, which leads to motor dual-task interference. This has potential diagnostic and therapeutic implications, e.g. in the early screening for dysphagia or in avoiding dual-task situations while eating.

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The Effect of Within Stimulus Presentation in Implicit Sequence Learning

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/154193120504902104 ◽

2005 ◽

Vol 49 (21) ◽

pp. 1836-1840

Author(s):

Timothy A. Nichols ◽

Arthur D. Fisk ◽

Wendy A. Rogers

Keyword(s):

Implicit Learning ◽

Dual Task ◽

Sequence Learning ◽

Traffic Control ◽

Single Stimulus ◽

Implicit Sequence Learning ◽

Multiple Control ◽

Task Interference ◽

Dual Task Condition ◽

Dual Task Interference

The tacit and incidental acquisition of sequential information can occur in tasks from air-traffic control to crossing the streets in a crowded metropolis. The present study investigated how implicit sequence learning occurs when attention is divided amongst tasks. Our conceptualization of implicit sequence learning is that dual task interference arises from multiple control processes in the secondary task. This fits with findings that implicit learning remains intact when a within stimulus dual task is employed, where the stimulus for both tasks is incorporated within a single stimulus. However, a direct comparison with the standard dual task condition has not been presented. This comparison revealed another possible explanation for dual task interference in implicit sequence learning, that longer inter-trial intervals, a function of the within stimulus methodology, result in better performance and implicit learning. The data suggest that implicit learning and overall performance in a task that contains an incidental, consistent structure is optimized when stimuli are contained within a single stimulus.

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Evidence for a multicomponent hierarchical representation of dual tasks

Memory & Cognition ◽

10.3758/s13421-020-01097-3 ◽

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.

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Dual-Task Interference in a Simulated Driving Environment: Serial or Parallel Processing?

Frontiers in Psychology ◽

10.3389/fpsyg.2020.579876 ◽

2021 ◽

Vol 11 ◽

Author(s):

Mojtaba Abbas-Zadeh ◽

Gholam-Ali Hossein-Zadeh ◽

Maryam Vaziri-Pashkam

Keyword(s):

Task Performance ◽

Dual Task ◽

Discrimination Task ◽

Diffusion Modeling ◽

Task Condition ◽

Drift Diffusion ◽

Task Interference ◽

Evidence Accumulation ◽

Dual Task Performance ◽

Dual Task Interference

When humans are required to perform two or more tasks concurrently, their performance declines as the tasks get closer together in time. Here, we investigated the mechanisms of this cognitive performance decline using a dual-task paradigm in a simulated driving environment, and using drift-diffusion modeling, examined if the two tasks are processed in a serial or a parallel manner. Participants performed a lane change task, along with an image discrimination task. We systematically varied the time difference between the onset of the two tasks (Stimulus Onset Asynchrony, SOA) and measured its effect on the amount of dual-task interference. Results showed that the reaction times (RTs) of the two tasks in the dual-task condition were higher than those in the single-task condition. SOA influenced the RTs of both tasks when they were presented second and the RTs of the image discrimination task when it was presented first. Results of drift-diffusion modeling indicated that dual-task performance affects both the rate of evidence accumulation and the delays outside the evidence accumulation period. These results suggest that a hybrid model containing features of both parallel and serial processing best accounts for the results. Next, manipulating the predictability of the order of the two tasks, we showed that in unpredictable conditions, the order of the response to the two tasks changes, causing attenuation in the effect of SOA. Together, our findings suggest higher-level executive functions are involved in managing the resources and controlling the processing of the tasks during dual-task performance in naturalistic settings.

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