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Neural Architecture for Feature Binding in Visual Working Memory

Published version
Peer-reviewed

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Authors

Schneegans, Sebastian  ORCID logo  https://orcid.org/0000-0002-1246-2259
Bays, PM 

Abstract

Binding refers to the operation that groups different features together into objects. We propose a neural architecture for feature binding in visual working memory that employs populations of neurons with conjunction responses. We tested this model using cued recall tasks, in which subjects had to memorize object arrays composed of simple visual features (color, orientation, and location). After a brief delay, one feature of one item was given as a cue, and the observer had to report, on a continuous scale, one or two other features of the cued item. Binding failure in this task is associated with swap errors, in which observers report an item other than the one indicated by the cue. We observed that the probability of swapping two items strongly correlated with the items' similarity in the cue feature dimension, and found a strong correlation between swap errors occurring in spatial and nonspatial report. The neural model explains both swap errors and response variability as results of decoding noisy neural activity, and can account for the behavioral results in quantitative detail. We then used the model to compare alternative mechanisms for binding nonspatial features. We found the behavioral results fully consistent with a model in which nonspatial features are bound exclusively via their shared location, with no indication of direct binding between color and orientation. These results provide evidence for a special role of location in feature binding, and the model explains how this special role could be realized in the neural system.

Description

Keywords

cued recall, feature binding, population coding, visual working memory

Journal Title

Journal of Neuroscience

Conference Name

Journal ISSN

0270-6474
1529-2401

Volume Title

37

Publisher

Society for Neuroscience
Sponsorship
Wellcome Trust (106926/Z/15/Z)
This work was supported by the Wellcome Trust.