scholarly journals Active Working Memory and Simple Cognitive Operations

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.

2021 ◽  
Author(s):  
Johanna Kreither ◽  
Orestis Papaioannou ◽  
Steven J Luck

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 abruptly disrupted following 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.


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.


2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Sangil Lee ◽  
Minho Lee ◽  
Hyeonggyu Park ◽  
Mun-Seon Chang ◽  
Ho-Wan Kwak

The goal of the present study was to examine whether intention type affects eye movement patterns in a change detection task In addition, we assessed whether the eye movement index could be used to identify human implicit intent. We attempted to generate three types of intent amongst the study participants, dividing them into one of three conditions; each condition received different information regarding an impending change to the visual stimuli. In the “navigational intent” condition, participants were asked to look for any interesting objects, and were not given any more information about the impending change. In the “low-specific intent” condition, participants were informed that a change would occur. In the “high-specific intent” condition, participants were told that a change would occur, and that an object would disappear. In addition to this main change detection task, participants also had to perform a primary task, in which they were required to name aloud the colors of objects in the pre-change scene. This allowed us to control for the visual searching process during the pre-change scene. The main results were as follows: firstly, the primary task successfully controlled for the visual search process during the pre-change scene, establishing that there were no differences in the patterns of eye movements across all three conditions despite differing intents. Secondly, we observed significantly different patterns of eye movement between the conditions in the post-change scene, suggesting that generating a specific intent for change detection yields a distinctive pattern of eye-movements. Finally, discriminant function analysis showed a reasonable classification rate for identifying a specific intent. Taken together, it was found that both participant intent and the specificity of information provided to the participants affect eye movements in a change detection task.


2011 ◽  
Vol 23 (12) ◽  
pp. 4048-4056 ◽  
Author(s):  
Anna M. Arend ◽  
Hubert D. Zimmer

In the lateralized change detection task, two item arrays are presented, one on each side of the display. Participants have to remember the items in the relevant hemifield and ignore the items in the irrelevant hemifield. A difference wave between contralateral and ipsilateral slow potentials with respect to the relevant items, the contralateral delay activity, can be calculated. As its amplitude varies with the number of items held in working memory (WM) and reaches its asymptote with WM capacity, it is considered a pure neural correlate of visual WM load. However, in addition to this contralateral delay activity, load-dependent activity has also been observed over the hemisphere ipsilateral to the relevant hemifield, suggesting that the ipsilateral hemisphere is also involved in memory-related processes. This ipsilateral activity might either reflect a bilateral processing of relevant or else a lateralized processing of irrelevant, to-be-filtered-out items. As in the lateralized change detection task, the number of items on both sides of the display is typically identical, it was not possible to decide between these alternatives yet. To disentangle the influence of relevant and irrelevant items, we orthogonally varied the number of both types of items. Processing of relevant items caused purely contralateral load-dependent activity. Ipsilateral slow potentials were influenced by the number of irrelevant items only if visual WM load was low, but not if it was high. This suggests that whether irrelevant items are processed or filtered out depends on visual WM load.


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