scholarly journals Properties of high-fidelity visual working memory representations for orientation

2013 ◽  
Vol 13 (9) ◽  
pp. 804-804
Author(s):  
R. L. Rademaker ◽  
I. M. Bloem ◽  
P. De Weerd ◽  
A. T. Sack
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
High Fidelity ◽  
Memory Representations

A direct neural measure of variable precision representations in visual working memory

2021 ◽  
Author(s):  
Christian Merkel ◽  
Mandy Viktoria Bartsch ◽  
Mircea A Schoenfeld ◽  
Anne-Katrin Vellage ◽  
Notger G Müller ◽  
...  
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Recall Performance ◽  
Human Subjects ◽  
Item Information ◽  
Estimation Task ◽  
Active Representation ◽  
Contralateral Delay Activity ◽  
Memory Representations ◽  
Precision Estimation

Visual working memory (VWM) is an active representation enabling the manipulation of item information even in the absence of visual input. A common way to investigate VWM is to analyze the performance at later recall. This approach, however, leaves uncertainties about whether the variation of recall performance is attributable to item encoding and maintenance or to the testing of memorized information. Here, we record the contralateral delay activity (CDA) - an established electrophysiological measure of item storage and maintenance - in human subjects performing a delayed orientation precision estimation task. This allows us to link the fluctuation of recall precision directly to the process of item encoding and maintenance. We show that for two sequentially encoded orientation items, the CDA amplitude reflects the precision of orientation recall of both items, with higher precision being associated with a larger amplitude. Furthermore, we show that the CDA amplitude for each item varies independently from each other, suggesting that the precision of memory representations fluctuates independently.

scholarly journals The Neural Codes Underlying Internally Generated Representations in Visual Working Memory

2021 ◽  
pp. 1-16
Author(s):  
Qing Yu ◽  
Bradley R. Postle
Keyword(s):  
Working Memory ◽  
Visual Cortex ◽  
Visual Working Memory ◽  
Subjective Experience ◽  
Neural Representation ◽  
Delayed Recall ◽  
Early Visual Cortex ◽  
Memory Representations ◽  
Internal Sources ◽  
Scaling Analyses

Abstract Humans can construct rich subjective experience even when no information is available in the external world. Here, we investigated the neural representation of purely internally generated stimulus-like information during visual working memory. Participants performed delayed recall of oriented gratings embedded in noise with varying contrast during fMRI scanning. Their trialwise behavioral responses provided an estimate of their mental representation of the to-be-reported orientation. We used multivariate inverted encoding models to reconstruct the neural representations of orientation in reference to the response. We found that response orientation could be successfully reconstructed from activity in early visual cortex, even on 0% contrast trials when no orientation information was actually presented, suggesting the existence of a purely internally generated neural code in early visual cortex. In addition, cross-generalization and multidimensional scaling analyses demonstrated that information derived from internal sources was represented differently from typical working memory representations, which receive influences from both external and internal sources. Similar results were also observed in intraparietal sulcus, with slightly different cross-generalization patterns. These results suggest a potential mechanism for how externally driven and internally generated information is maintained in working memory.

scholarly journals Visual working memory representations are shifted toward irrelevant features of distractors in intervening visual search tasks

2019 ◽  
Vol 19 (10) ◽  
pp. 311b
Author(s):  
Zachary A Lively ◽  
Gavin JP Ng ◽  
Simona Buetti ◽  
Alejandro Lleras
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Visual Working Memory ◽  
Search Tasks ◽  
Memory Representations

Manifold Visual Working Memory

2020 ◽  
pp. 311-332
Author(s):  
Nicole Hakim ◽  
Edward Awh ◽  
Edward K. Vogel
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Neural Activity ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Representations ◽  
Latent Representations ◽  
Definition Of ◽  
Spatial Locations

Visual working memory allows us to maintain information in mind for use in ongoing cognition. Research on visual working memory often characterizes it within the context of its interaction with long-term memory (LTM). These embedded-processes models describe memory representations as existing in three potential states: inactivated LTM, including all representations stored in LTM; activated LTM, latent representations that can quickly be brought into an active state due to contextual priming or recency; and the focus of attention, an active but sharply limited state in which only a small number of items can be represented simultaneously. This chapter extends the embedded-processes framework of working memory. It proposes that working memory should be defined operationally based on neural activity. By defining working memory in this way, the important theoretical distinction between working memory and LTM is maintained, while still acknowledging that they operate together. It is additionally proposed that active working memory should be further subdivided into at least two subcomponent processes that index item-based storage and currently prioritized spatial locations. This fractionation of working memory is based on recent research that has found that the maintenance of information distinctly relies on item-based representations as well as prioritization of spatial locations. It is hoped that this updated framework of the definition of working memory within the embedded-processes model provides further traction for understanding how we maintain information in mind.

scholarly journals The influence of visual working memory representations on attention bias to threat in individuals with high trait anxiety

2019 ◽  
Vol 10 (4) ◽  
pp. 204380871987614
Author(s):  
Nisha Yao ◽  
Marcus A. Rodriguez ◽  
Mengyao He ◽  
Mingyi Qian
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Experimental Studies ◽  
Memory Task ◽  
Attention Bias ◽  
Control Group ◽  
Negative Valence ◽  
Memory Representations ◽  
High Trait Anxiety ◽  
The Relationship

Experimental studies have yielded discrepant results regarding the relationship between anxiety and attention bias to threat. Cognitive factors modulating the presence of threat-related attention bias in anxiety have drawn growing attention. Previous research demonstrated that visual working memory (WM) representations can guide attention allocation in a top-down manner. Whether threat-related WM representations affected the presence of attention bias in anxiety awaits examination. Combining a memory task and a dot-probe task, this study investigated how WM representations of faces with neutral or negative expressions modulated the attention bias to threat among highly anxious individuals versus controls. Results showed that highly anxious individuals developed more pronounced attention bias to threat when maintaining WM representations of negative faces as compared to the control group. There were no significant between-group effects when the WM representations were neutral. These results suggested that highly anxious individuals were more susceptible to the influence of mental representations with negative valence on attention deployment.

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