STIMULUS-DRIVEN ATTENTIONAL CAPTURE - EVIDENCE FROM EQUILUMINANT VISUAL OBJECTS

Previous work has shown that abrupt visual onsets capture attention. P ossible mechanisms for this phenomenon include (a) a luminance-change detection system and (b) a mechanism that detects the appearance of ne w perceptual objects. Experiments 1 and 2 revealed that attention is c aptured in visual search by the appearance of a new perceptual object even when the object is equiluminant with its background and thus exhi bits no luminance change when it appears. Experiment 3 showed that a h ighly salient luminance increment alone is not sufficient to capture a ttention. These findings suggest that attentional capture is mediated by a mechanism that detects the appearance of new perceptual objects.