scholarly journals Transcranial direct current stimulation (tDCS) facilitates overall visual search response times but does not interact with visual search task factors

PLoS ONE ◽  
2018 ◽  
Vol 13 (3) ◽  
pp. e0194640 ◽  
Author(s):  
Kyongje Sung ◽  
Barry Gordon
Keyword(s):  
Visual Search ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Search Task ◽  
Visual Search Task ◽  
Response Times ◽  
Direct Current Stimulation

Converging Evidence That Neural Plasticity Underlies Transcranial Direct-Current Stimulation

2021 ◽  
Vol 33 (1) ◽  
pp. 146-157
Author(s):  
Chong Zhao ◽  
Geoffrey F. Woodman
Keyword(s):  
Visual Search ◽  
Direct Current ◽  
Neural Plasticity ◽  
Transcranial Direct Current Stimulation ◽  
Time Course ◽  
Memory Task ◽  
Long Term Memory ◽  
Visual Stream ◽  
Direct Current Stimulation ◽  
The Brain

It is not definitely known how direct-current stimulation causes its long-lasting effects. Here, we tested the hypothesis that the long time course of transcranial direct-current stimulation (tDCS) is because of the electrical field increasing the plasticity of the brain tissue. If this is the case, then we should see tDCS effects when humans need to encode information into long-term memory, but not at other times. We tested this hypothesis by delivering tDCS to the ventral visual stream of human participants during different tasks (i.e., recognition memory vs. visual search) and at different times during a memory task. We found that tDCS improved memory encoding, and the neural correlates thereof, but not retrieval. We also found that tDCS did not change the efficiency of information processing during visual search for a certain target object, a task that does not require the formation of new connections in the brain but instead relies on attention and object recognition mechanisms. Thus, our findings support the hypothesis that direct-current stimulation modulates brain activity by changing the underlying plasticity of the tissue.

When visual search target is rare: overweighting or under weighting the probability?

2018 ◽  
Vol 62 (1) ◽  
pp. 1520-1524
Author(s):  
Hanshu Zhang ◽  
Joseph W. Houpt
Keyword(s):  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Response Times ◽  
Threshold Model ◽  
Decision Makers ◽  
Target Presence ◽  
Model Assumption ◽  
Search Tasks ◽  
Low Prevalence

The prevalence of items in visual search may have substantial performance consequences. In laboratory visual search tasks in which the target is rare, viewers are likely to miss the target. A dual-threshold model proposed by Wolfe and Van Wert (2010) assumes that in the low prevalence condition, viewers shift their criteria resulting in more miss errors. However, from the prospective of prospect theory (Kahneman & Tversky, 1979), decision makers tend to overweight small probability. To explore how viewers subjectively weight the probability in the low prevalence visual search task, we compared viewers’ criteria with the optimal criteria by presenting different probability descriptions for a fixed prevalence rate. The data from this experiment indicated that target presence had an effect on viewers’ accuracy and response times but not probability descriptions. Viewers’ criteria under different probability descriptions were higher than optimal. These results are in accordance with the dual-threshold model assumption that viewers respond “target absent” more frequently than optimal, leading to more miss errors in the low prevalence condition.

Augmenting Visual Search Performance With Transcranial Direct Current Stimulation (tDCS)

2015 ◽  
Vol 27 (6) ◽  
pp. 335-347 ◽  
Author(s):  
Justin M. Nelson ◽  
R. Andy McKinley ◽  
Lindsey K. McIntire ◽  
Chuck Goodyear ◽  
Craig Walters
Keyword(s):  
Visual Search ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Search Performance ◽  
Direct Current Stimulation

Transcranial Direct Current Stimulation Combined With Cognitive Training Induces Response Inhibition Facilitation Through Distinct Neural Responses According to the Stimulation Site: A Follow-up Event-Related Potentials Study

2020 ◽  
pp. 155005942095896
Author(s):  
Clémence Dousset ◽  
Anaïs Ingels ◽  
Elisa Schröder ◽  
Laura Angioletti ◽  
Michela Balconi ◽  
...  
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Cognitive Rehabilitation ◽  
Response Times ◽  
Inferior Frontal Gyrus ◽  
Training Session ◽  
Event Related Potentials ◽  
Stimulation Site ◽  
Direct Current Stimulation ◽  
Related Potentials

Objective We investigated whether the mid-term impact (1 week posttraining) of a “combined cognitive rehabilitation (CRP)/transcranial direct current stimulation (tDCS) program” on the performance of a Go/No-go task was enhanced compared with isolated CRP and whether it varied according to the stimulation site (right inferior frontal gyrus [rIFG] vs right dorsolateral prefrontal cortex [rDLPFC]). Methods A total of 150 healthy participants were assigned to (1) an Inhibition Training (IT) group, (2) a group receiving active tDCS over the rIFG in combination with IT (IT + IF), (3) a group receiving active tDCS over the rDLPFC in combination with IT (IT + DL), (4) a group receiving IT with sham tDCS (ITsham), and (5) a No-Training (NT) group to control for test-retest effects. Each group undertook 3 sessions of a Go/No-go task concomitant with the recording of event-related potentials (T0, before training; T1, at the end of a 4-day training session [20 minutes each day]; T2, 1 week after T1). Results With the exception of the NT participants, all the groups exhibited improved performances at T2. The IT + DL group exhibited the best improvement profile, indexed by faster response times (RTs) (T0 > T1 = T2), with a reduced rate of errors at the posttraining sessions compared with both T0 and T1. This “inhibitory learning effect” was neurophysiologically indexed by shorter No-go N2d latencies and enhanced No-go P3d amplitudes. Conclusion CRP combined with active tDCS over the rDLPFC appears to be optimal for boosting long-term (one week) inhibitory skills as it induced specific and robust neural changes.

scholarly journals Concurrent Guidance of Attention by Multiple Working Memory Items: Behavioral and Computational Evidence

2019 ◽  
Author(s):  
Cherie Zhou ◽  
Monicque M. Lorist ◽  
Sebastiaan Mathôt
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Visual Working Memory ◽  
Search Task ◽  
Visual Search Task ◽  
Response Times ◽  
Behavioral Data ◽  
Drift Diffusion ◽  
Single Item ◽  
Multiple Item

AbstractDuring visual search, task-relevant representations in visual working memory (VWM), known as attentional templates, are assumed to guide attention. A current debate concerns whether only one (Single-Item-Template hypothesis, or SIT) or multiple (Multiple-Item-Template hypothesis, or MIT) items can serve as attentional templates simultaneously. The current study was designed to test these two hypotheses. Participants memorized two colors, prior to a visual-search task in which the target and the distractor could match or not match the colors held in VWM. Robust attentional guidance was observed when one of the memory colors was presented as the target (reduced response times [RTs] on target-match trials) or the distractor (increased RTs on distractor-match trials). We constructed two drift-diffusion models that implemented the MIT and SIT hypotheses, which are similar in their predictions about overall RTs, but differ in their predictions about RTs on individual trials. Critically, simulated RT distributions and error rates revealed a better match of the MIT hypothesis to the observed data than the SIT hypothesis. Taken together, our findings provide behavioral and computational evidence for the concurrent guidance of attention by multiple items in VWM.Significance statementTheories differ in how many items within visual working memory can guide attention at the same time. This question is difficult to address, because multiple- and single-item-template theories make very similar predictions about average response times. Here we use drift-diffusion modeling in addition to behavioral data, to model response times at an individual level. Crucially, we find that our model of the multiple-item-template theory predicts human behavior much better than our model of the single-item-template theory; that is, modeling of behavioral data provides compelling evidence for multiple attentional templates that are simultaneously active.

Cognitive Aging: General versus Process-Specific Slowing in a Visual Search Task

1996 ◽  
Vol 40 (3) ◽  
pp. 118-122 ◽  
Author(s):  
Michael F. Gorman ◽  
Donald L. Fisher
Keyword(s):  
Visual Search ◽  
Cognitive Aging ◽  
General Model ◽  
Search Task ◽  
Visual Search Task ◽  
Response Times ◽  
Specific Model ◽  
Younger Adults ◽  
Alternative Process ◽  
General Slowing

The fact that response times increase as one ages has long been established. Previously, a model of general slowing in the nonlexical domains has done a really good job of explaining the differences between older and younger adults. However, an alternative process-specific model has not been conclusively ruled out. This experiment tested general and process-specific models of slowing in the nonlexical domain using older and younger adults performing a visual search task. The task manipulated the presence of the target, the number of search items, and the structure of the display of the search items. It was found that a process-specific model explained significantly more of the variability than a general model of slowing. It was also discovered that the process most greatly affected was that of deciding to terminate a search when no target was present in the display.

Slowing of Strategic and Nonstrategic Processes in a Visual Search Task

1997 ◽  
Vol 41 (1) ◽  
pp. 100-104
Author(s):  
Michael F. Gorman ◽  
Donald L. Fisher
Keyword(s):  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Response Times ◽  
Specific Model ◽  
Decision Processes ◽  
Perceptual Quality ◽  
Younger Adults ◽  
General Slowing

The fact that response times increase as one ages has long been established. Previous research has indicated that a process-specific model does a better job than the model of general slowing in explaining the differences between older and younger adults. This experiment tested a process-specific model of slowing using older and younger adults in a visual search task. The task manipulated the presence of the target, the number of search items, the structure of the display of the search items, the perceptual quality of the search items and the complexity of the response. It was found that encoding, motor, and decision processes were about equally delayed whereas the comparison process was delayed little if any.

scholarly journals Differential effects of left and right prefrontal cortex anodal transcranial direct current stimulation during probabilistic sequence learning

2019 ◽  
Vol 121 (5) ◽  
pp. 1906-1916 ◽  
Author(s):  
Brian Greeley ◽  
Rachael D. Seidler
Keyword(s):  
Prefrontal Cortex ◽  
Motor Cortex ◽  
Direct Current ◽  
Sequence Learning ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Response Times ◽  
Direct Current Stimulation ◽  
Left And Right ◽  
Prefrontal Cortices

Left and right prefrontal cortex and the primary motor cortex (M1) are activated during learning of motor sequences. Previous literature is mixed on whether prefrontal cortex aids or interferes with sequence learning. The present study investigated the roles of prefrontal cortices and M1 in sequence learning. Participants received anodal transcranial direct current stimulation (tDCS) to right or left prefrontal cortex or left M1 during a probabilistic sequence learning task. Relative to sham, the left prefrontal cortex and M1 tDCS groups exhibited enhanced learning evidenced by shorter response times for pattern trials, but only for individuals who did not gain explicit awareness of the sequence (implicit). Right prefrontal cortex stimulation in participants who did not gain explicit sequence awareness resulted in learning disadvantages evidenced by slower overall response times for pattern trials. These findings indicate that stimulation to left prefrontal cortex or M1 can lead to sequence learning benefits under implicit conditions. In contrast, right prefrontal cortex tDCS had negative effects on sequence learning, with overall impaired reaction time for implicit learners. There was no effect of tDCS on accuracy, and thus our reaction time findings cannot be explained by a speed-accuracy tradeoff. Overall, our findings suggest complex and hemisphere-specific roles of left and right prefrontal cortices in sequence learning. NEW & NOTEWORTHY Prefrontal cortices are engaged in motor sequence learning, but the literature is mixed on whether the prefrontal cortices aid or interfere with learning. In the current study, we used anodal transcranial direct current stimulation to target left or right prefrontal cortex or left primary motor cortex while participants performed a probabilistic sequence learning task. We found that left prefrontal and motor cortex stimulation enhanced implicit learning whereas right prefrontal stimulation negatively impacted performance.

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