Abstract
We are able to guide attentional selection toward features that are relevant to our current goals. Recent work shows that independent features can be preferentially selected in independent locations of the visual field (Adamo, Pun, Pratt, & Ferber, 2008). The present study demonstrates that our ability to control attentional selection is even more sophisticated, such that we can select for different features of different objects, even when those objects share the same spatial location. To test whether or not participants could hold separate attentional control settings for objects that occupy essentially the same spatial region, participants viewed two object outlines (a horizontal and a vertical rectangle) that between conditions were either spatially separated or overlapped in space. Participants were instructed to press a key whenever a target color was presented within a specific rectangle, such as green within the horizontal object, or blue within the vertical object. Before the target appeared, one outline was cued with either green or blue. This cue could match the color, orientation, or both color and orientation of the subsequent stimulus. For spatially separated objects, results confirmed past results showing independent control settings for objects at different locations (Adamo et. al., 2008). Moreover, the effect was equally strong (if not stronger) when the object overlapped in space, suggesting that observers can form complex attentional control settings for different objects, even when those objects appear at the same location. A control experiment showed that this effect was not due to simple visual or response priming following a compatible cue. We suggest that these control settings are determined by the contents of visual working memory. That is, simultaneously storing the attentional control settings for “horizontal/green” and “vertical/blue” may require a memory representation of a horizontal green and a vertical blue object.