Evidence for two components of object-based selection

A wealth of research has shown that observers can bias visual processing to ward specific locations, but the role of object-based selection is less cle ar. In support of object-based selection, previous research has shown that when two objects are presented simultaneously, observers are better at repo rting two attributed from one of the objects than one attribute from each o bject. However, there has been controversy over whether this effect is best explained by object-based selection or spatial selection. Our work suggest s that there are two separate components of selection in this task: (a) a s patial component that is observed when the relevant targets are cued for ob servers before the onset of the stimulus display and (b) an object-based co mponent that can still be observed when the first component has been elimin ated. 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.