The guidance of attention by templates for rejection during visual search.

Abstract

The hypothesis that foreknowledge of nontarget features in visual search is represented by negative search templates ("templates for rejection") that facilitate attentional guidance remains disputed. In five experiments, we investigated this proposal by measuring search performance and electrophysiological markers of target selection (N2pc components) and nontarget suppression (PD components). We compared search tasks where positive or negative cues signaled the color of targets or nontargets, respectively, and tasks with neutral non-informative cues. Positive cues elicited performance benefits relative to neutral cues. Negative cues produced behavioral and electrophysiological costs for target selection, and some evidence for the inhibition of negatively cued nontargets, but there was no support for the proposal that these items initially attract attention. Performance costs for negative cues dissipated after practice with the same negatively cued nontargets for approximately 25-50 trials, and eventually turned into benefits after several hundreds of trials. However, the emergence of negative cue benefits was not accompanied by electrophysiological evidence for faster or more efficient inhibition of nontargets, indicating that they are not produced by learned suppression mechanisms mediated by negative search templates. We conclude that templates for rejection do not facilitate search but normally interfere with target selection. Although negative cue benefits can be observed after extended exposure to the same nontarget features, these benefits do not reflect active attentional guidance, and are likely to be the result of passive habituation processes.