Abstract
During visual search, inhibition of the return (IOR) of attention to previously examined information facilitates target detection. The inhibitory processes underlying IOR have been shown to be associated with both objects and locations. Recently, Tipper et al. (2003) demonstrated that object-based inhibition could be retrieved from memory after relatively long periods. This study aims to confirm the existence of long-term IOR using object stimuli, and to investigate whether the inhibitory processes involved in IOR generalise to categorically related objects. Different categories of objects were presented, with three exemplars in each category. On the first two presentations of a category, attention was oriented to the left or right side of the object using an exogenous cue. Then on the third presentation, a target requiring a rapid localisation response appeared on the left or right. The interval between the second cue and the target was either short (3 seconds and no intervening objects) or long (21 seconds and 5 intervening objects). In another condition the same object appeared three times, and in a control condition unrelated objects were presented. At the short cue-target interval large IOR effects occurred for identical objects, and significantly smaller IOR effects occurred for both categorically related objects and unrelated objects. At the long cue-target interval IOR was observed for identical objects, but not for categorically related objects. These results suggest that IOR is associated with the specific identity of an object, and not with the semantic category of an object.
This research was supported by BBSRC grant 5/S1355 and a BBSRC studentship.