The preview benefit: visual marking, feature-based inhibition, temporal segregation, or onset capture?

The preview effect demonstrates that if observers in a visual search task are allowed a preview of a subset of elements before another subset of elements is added to the display, the first subset of elements no longer competes for attentional selection in the search process. Watson and Humphreys (1997) explained this effect by proposing that the locations of previewed elements are top down inhibited during the preview by a process they refer to as visual marking. The results of recent studies cannot easily be explained by the original visual marking account. As a consequence, three alternative views have emerged. According to one notion, a feature-based inhibition account, the preview benefit is mediated by inhibition applied at the level of feature maps in addition to location-based inhibition. A second view, the temporal segregation hypothesis, assumes that prioritized selection of new elements results from observers being able to selectively attend to one group of elements that can be perceptually segregated from another group on the basis of temporal asynchrony. A third view assumes that the preview benefit is caused by onset capture mediated by the appearance of the new elements. The present paper reviews the key findings concerning the preview benefit with the aim to resolve some of the controversies about how observers prioritize selection of new over old elements. © 2006 Psychology Press Ltd.