Abstract
The nature of feature-bound object representations in visual working memory (VWM) remains unclear. Many studies claim that compared with single features, feature binding representations are held by a resource-limited system, and are fragile. Using an experimental paradigm combining redundancy gain and object reviewing tasks (Saiki, 2016), the current study showed that color-shape binding representations for multiple objects are maintained in a robust fashion in VWM. A set of features was presented in a two-object memory display, followed by a linking display in which placeholders either moved or stayed. Then a single object probe was presented, and participants judged if it contained any features of the memory display, regardless of object correspondence. The index of feature co-activation measures the advantage of color-shape conjunction relative to single features in memory matching. Object specific preview benefit (OSPB) index reflects the advantage of object correspondence in access to a task relevant memory representation, either conjunction or single feature whichever matches first. The cost of object motion on these indices can test two hypotheses on the nature of the binding memory. If objects' motion destroys fragile binding memory, the feature co-activation should be reduced, while OSPB remains intact because single feature memory is still accessible. If the binding memory is robust and the cost of motion reflects the tracking failure of object VWM, OSPB should be impaired, while feature co-activation remains intact. A series of experiments revealed strong feature co-activation and OSPB when objects are stationary, replicating previous work. Critically, feature co-activation was retained regardless of object motion, whereas OSPB was substantially reduced when objects moved, supporting the hypothesis of robust color-shape binding in VWM. The cost of object motion in the memory matching performance likely reflects the tracking failure of object VWM, and feature binding memory survives dynamic object tracking.
Meeting abstract presented at VSS 2018