Visual attention is shaped by statistical regularities in the environment, with spatially predictable distractors being proactively suppressed. The neural mechanisms underpinning this suppression remain poorly understood. In this study, we employed magnetoencephalography (MEG) and multivariate classification analysis to investigate how predicted distractor locations are proactively processed in the human brain. Male and female human participants engaged in a statistical learning visual search task that required them to identify a target stimulus while ignoring a colour-singleton distractor. Critically, the distractor appeared more frequently on one side of the visual field, creating an implicit spatial prediction. Our results revealed that distractor locations were encoded in temporo-occipital brain regions prior to the presentation of the search array, supporting the hypothesis that proactive suppression guides visual attention away from predictable distractors. The neural activity patterns corresponding to this pre-search distractor processing extended to post-search activity during late attentional stages (∼200 ms), suggesting an integrated suppressive mechanism. Notably, this generalization from pre- to post-search phases was absent in the early sensory processing stages (∼100 ms), suggesting that post-search distractor processing is not merely a continuation of sustained proactive processing, but involves re-engagement of the same mechanism at distinct stages. These findings establish a mechanistic link between proactive and reactive processing of predictable distractors, demonstrating both shared and unique contributions to attentional selection. Significance Statement In a world full of distractions, anticipating and ignoring irrelevant stimuli is crucial. The brain suppresses distractions both proactively (by preparing for expected distractions) and reactively (by responding after they appear). Yet, how these processes interact is unclear. In this study, we used MEG and multivariate classification during a visual search task, where distractors appeared more frequently on one side, enabling unconscious learning of their likely location. Our results indicate that the brain encodes the distractor’s location even before the search begins, showing proactive processing. Moreover, we found a connection between this early suppression and the brain’s later response to the distractors, suggesting that proactive and reactive distractor processing rely on shared mechanisms.
Ferrante et al. (Mon,) studied this question.