Anticipatory distractor suppression elicited by statistical regularities in visual search

Abstract

Salient yet irrelevant objects often capture our attention and interfere with our daily tasks. Distraction by salient objects can be reduced by suppressing the location where they are likely to appear. The question we addressed here was whether suppression of frequent distractors is already implemented beforehand, in anticipation of the stimulus. Using electroencephalography (EEG), we recorded cortical activity of human participants searching for a target while ignoring a salient distractor. The distractor was presented more often at one location than at any other location. We found reduced capture for distractors at frequent locations, indicating that participants learned to avoid distraction. Critically, we found evidence for proactive suppression as already prior to display onset, there was enhanced power in parieto-occipital alpha oscillations contralateral to the frequent distractor location - a signal known to occur in anticipation of irrelevant information. Locked to display onset, event-related potentials analysis showed a distractor-suppression-related PD component for this location. Importantly, this PD was found regardless of whether distracting information was presented at the frequent location. In addition, there was an early PD component representing an early attentional index of the frequent distractor location. Our results are show anticipatory (proactive) suppression of frequent distractor locations in visual search already starting prior to display onset.