Anticipatory Distractor Suppression Elicited by Statistical Regularities in Visual Search

Area of Science:

• Cognitive Neuroscience
• Visual Perception

Background:

• Salient, irrelevant objects capture attention, hindering task performance.
• Suppressing predictable distractor locations can mitigate attentional capture.
• Anticipatory mechanisms may play a role in proactive distractor suppression.

Purpose of the Study:

• To investigate whether suppression of frequent distractor locations occurs proactively, in anticipation of stimulus onset.
• To examine the neural correlates of anticipatory suppression using electroencephalography (EEG).

Main Methods:

• EEG recordings were used to measure cortical activity in participants performing a visual search task.
• Participants searched for a target while ignoring a salient distractor presented more frequently at one location.
• Analysis focused on pre-stimulus alpha oscillations and event-related potentials (ERPs), specifically the distractor positivity (P_D).

Main Results:

• Reduced attentional capture by distractors at frequent locations was observed, indicating learned avoidance.
• Enhanced power in parieto-occipital alpha oscillations contralateral to the frequent distractor location was found prior to display onset.
• A distractor suppression-related distractor positivity (P_D) component was identified locked to display onset, irrespective of distractor presence, and an early P_D indicated attentional indexing.

Conclusions:

• The study provides evidence for proactive suppression of frequent distractor locations in visual search.
• This anticipatory suppression mechanism begins before stimulus onset, indexed by alpha oscillations.
• Findings suggest that the brain actively prepares to ignore predictable irrelevant information, optimizing attentional control.