Do salient abrupt onsets trigger suppression?

Abstract

Many studies have indicated that abrupt onsets can capture our attention involuntarily. The present study examined whether task-irrelevant onsets trigger strong suppression of their features, to reduce the ability of the onsets to capture attention. We used a capture-probe paradigm with salient abrupt onsets as precues. Participants performed a search task (70% of the trials) with occasional probe tasks mixed in (30% of the trials). In Experiment 1, two irrelevant-color distractors appeared simultaneously with the target, one of which was always precued by the abrupt onset. The question was whether an abrupt onset cue would promote suppression of the correlated color, thereby impeding recall of probe letters at a location with that color. This did not happen. The same result was obtained in Experiment 2, despite removing the target shape from the probe display to minimize floor effects and despite presenting only one distractor color per trial to further strengthen the onset-color association. In Experiment 3, one of the two irrelevant-color distractors abruptly onsetted 50 ms before the other search elements. Despite efforts to promote suppression of the cued distractor color, probe recall accuracy was again similar for the cued and non-cued distractor colors. We conclude that distractor features are suppressed but that making them especially salient does not noticeably enhance this suppression. The suppression mechanism is therefore geared towards helping observers discriminate between target features and distractor features, not towards beating down the most threatening object.