Abstract
Theories have proposed that attention is used to maintain feature bindings in visual working memory. Previously, we showed that people overtly shift gaze to the locations of objects held in visual working memory to aid maintenance. To test the hypothesis that the primary role of such overt attentional selection during working memory retention is to maintain the bindings of object features we compared eye movement behavior in two conditions. In the conjunction condition, we tracked subjects' eye movements while they were required to remember the shape and color of one, three, or six objects to perform a change-detection task. In the color-only condition, subjects remembered just the color of single-feature objects. If spatial attention mechanisms are primarily used to maintain feature bindings and not features themselves, then we should observe significantly more fixations of the locations of conjunction objects compared to color-only memory items. However, the pattern of eye movements we observed during the retention intervals was similar across conditions. That is, observers fixated the locations of the objects whether they were remembering one feature or a conjunction of features and fixating an item during the retention interval that then changed improved change-detection accuracy. These findings suggest that spatial selection mechanisms operating during visual working memory tasks aid maintenance of both simple features and more complex object representations.