scholarly journals Peer Review #1 of "Neural processing of working memory in adults with ADHD in a visuospatial change detection task with distractors (v0.2)"

Author(s):  
I Wiegand
PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5601 ◽  
Author(s):  
Chao Gu ◽  
Zhong-Xu Liu ◽  
Rosemary Tannock ◽  
Steven Woltering

Individuals with Attention-Deficit Hyperactivity Disorder (ADHD) are often characterized by deficits in working memory (WM), which manifest in academic, professional, and mental health difficulties. To better understand the underlying mechanisms of these presumed WM deficits, we compared adults with ADHD to their peers on behavioral and neural indices of WM. We used a visuospatial change detection task with distractors which was designed to assess the brain’s ability to effectively filter out distractors from WM, in addition to testing for effects of WM load. Twenty-seven unmedicated adults with ADHD were compared to 27 matched peers on event-related potential (ERP) measures of WM, i.e., the contralateral delay activity (CDA). Despite severe impairments in everyday life functioning, findings showed no difference in deficits in behavioral tests of working memory for adults with ADHD compared to their peers. Interestingly, there were differences in neural activity between individuals with ADHD and their peers showing that the CDA of individuals with ADHD did not distinguish between high, distractor, and low memory load conditions. These data suggest, in the face of comparable behavioral performance, a difference in neural processing efficiency, wherein the brains of individuals with ADHD may not be as selective in the allocation of neural resources to perform a WM task.


2021 ◽  
Author(s):  
Ilenia Paparella ◽  
Liuba Papeo

Working memory (WM) uses knowledge and relations to organize and store multiple individual items in a smaller set of structured units, or chunks. We investigated whether a crowd of individuals that exceeds the WM is retained and, therefore, recognized more accurately, if individuals are represented as interacting with one another –i.e., they form social chunks. Further, we asked what counts as a social chunk in WM: two individuals involved in a meaningful interaction or just spatially close and face-to-face. In three experiments with a delayed change-detection task, participants had to report whether a probe-array was the same of, or different from a sample-array featuring two or three dyads of bodies either face-to-face (facing array) or back-to-back (non-facing array). In Experiment 1, where facing dyads depicted coherent, meaningful interactions, participants were more accurate to detect changes in facing (vs. non-facing) arrays. A similar advantage was found in Experiment 2, even though facing dyads depicted no meaningful interaction. In Experiment 3, we introduced a secondary task (verbal shadowing) to increase WM load. This manipulation abolished the advantage of facing (vs. non-facing) arrays, only when facing dyads depicted no meaningful interactions. These results show that WM uses representation of interaction to chunk crowds in social groups. The mere facingness of bodies is sufficient on its own to evoke representation of interaction, thus defining a social chunk in WM; although the lack of semantic anchor makes chunking fainter and more susceptible to interference of a secondary task.


2021 ◽  
pp. 1-19
Author(s):  
Johanna Kreither ◽  
Orestis Papaioannou ◽  
Steven J. Luck

Abstract Working memory is thought to serve as a buffer for ongoing cognitive operations, even in tasks that have no obvious memory requirements. This conceptualization has been supported by dual-task experiments, in which interference is observed between a primary task involving short-term memory storage and a secondary task that presumably requires the same buffer as the primary task. Little or no interference is typically observed when the secondary task is very simple. Here, we test the hypothesis that even very simple tasks require the working memory buffer, but interference can be minimized by using activity-silent representations to store the information from the primary task. We tested this hypothesis using dual-task paradigm in which a simple discrimination task was interposed in the retention interval of a change detection task. We used contralateral delay activity (CDA) to track the active maintenance of information for the change detection task. We found that the CDA was massively disrupted after the interposed task. Despite this disruption of active maintenance, we found that performance in the change detection task was only slightly impaired, suggesting that activity-silent representations were used to retain the information for the change detection task. A second experiment replicated this result and also showed that automated discriminations could be performed without producing a large CDA disruption. Together, these results suggest that simple but non-automated discrimination tasks require the same processes that underlie active maintenance of information in working memory.


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