Evidence for two components of object-based selection

A wealth of research has shown that observers can bias visual processing toward specific locations, but the role of object-based selection is less clear. In support of object-based selection, previous research has shown that when two objects are presented simultaneously, observers are better at reporting two attributed from one of the objects than one attribute from each object. However, there has been controversy over whether this effect is best explained by object-based selection or spatial selection. Our work suggests that there are two separate components of selection in this task: (a) a spatial component that is observed when the relevant targets are cued for observers before the onset of the stimulus display and (b) an object-based component that can still be observed when the first component has been eliminated. The latter effect replicates the initial evidence in favor of object-based selection, and can be demonstrated even when the relevant targets are cued after the offset of the target stimuli.