Anticipatory and reactive mechanisms of habituation to visual distractors.

Human attention can rapidly habituate to irrelevant and repetitive visual distractors. Although this phenomenon is well-documented in behavioral studies, the neural mechanisms involved remain largely unknown. In this study, we investigated the neural correlates of attentional habituation using scalp electroencephalography (EEG). Participants performed a visual discrimination task while intermittently presented with salient distractor stimuli. The cost in reaction times (RT) associated with the distractor exhibited the typical time course of habituation, decreasing as a function of repeated exposure to the distractor. We found that this habituation coincided with both reactive and proactive changes in EEG activity. Post-distractor reactive EEG components emerged gradually over the course of the experiment, likely reflecting the operation of an inhibitory network aimed at suppressing distractor interference in the main task. Pre-stimulus α rhythms gradually tuned their power peaks to the anticipated moment of the distractor, suggesting the involvement of predictive inhibitory models based on prior experience with the distractor. Collectively, our findings suggest that attentional habituation involves multi-stage interacting mechanisms that anticipate the occurrence of a distractor and facilitate the rapid reallocation of attentional resources away from the distractor.