The Role of Location in Feature Binding in Working Memory

We tested two competing hypotheses about the nature of multi-featured object representations in visual working memory (vWM). One is that all object features are integrated into an object file. The other is that locations are critical for maintaining the bindings of visual features of an object. We developed an experimental paradigm that bridges the vWM and object-file literatures. Several multi-featured objects were presented simultaneously, followed by a retention interval in which placeholders either moved or not. Participants were then given one feature of a randomly chosen object as a cue and prompted to report the other two features of the same object. Applying multinomial process tree (MPT) models to evaluate the competing accounts of how multi-featured objects are represented in memory, we found evidence supporting the object-file theory and challenging the location-binding hypothesis. We conclude that bindings of features within the object can be maintained after motion. Furthermore, pairwise bindings between color and shape are robust against motion, implying that location is not essential for visual feature bindings.