Surface-based constraints on target selection and distractor rejection: evidence from preview search.

In preview search when an observer ignores an early appearing set of distractors, there can subsequently be impeded detection of new targets that share the colour of this preview. This "negative carry-over effect" has been attributed to an active inhibitory process targeted against the old items and inadvertently their features. Here we extend negative carry-over effects to the case of stereoscopically defined surfaces of coplanar elements without common features. In Experiment 1 observers previewed distractors in one surface (1000ms), before being presented with the target and new distractors divided over the old and a new surface either above or below the old one. Participants were slower and less efficient to detect targets in the old surface. In Experiment 2 in both the first and second display the items were divided over two planes in the proportion 66/33% such that no new planes appeared following the preview, and there was no majority of items in any one plane in the final combined display. The results showed that participants were slower to detect the target when it occurred in the old majority surface. Experiment 3 held constant the 2D properties of the stimuli while varying the presence of binocular depth cues. The carry-over effect only occurred in the presence of binocular depth cues, ruling out any account of the results in terms of 2-D cues. The results suggest well formed surfaces in addition to simple features may be targets for inhibition in search.