Raw data file for Fig 5A–5D.

A growing body of research demonstrates that distracting inputs can be proactively suppressed via spatial cues, nonspatial cues, or experience, which are governed by more than one top-down mechanism of attention. However, how the neural mechanisms underlying spatial distractor cues guide proactive suppression of distracting inputs remains unresolved. Here, we recorded electroencephalography signals from 110 participants in 3 experiments to identify the role of alpha activity in proactive distractor suppression induced by spatial cues and its influence on subsequent distractor inhibition. Behaviorally, we found novel changes in the spatial proximity of the distractor: Cueing distractors far away from the target improves search performance for the target, while cueing distractors close to the target hampers performance. Crucially, we found dynamic characteristics of spatial representation for distractor suppression during anticipation. This result was further verified by alpha power increased relatively contralateral to the cued distractor. At both the between- and within-subjects levels, we found that these activities further predicted the decrement of the subsequent PD component, which was indicative of reduced distractor interference. Moreover, anticipatory alpha activity and its link with the subsequent PD component were specific to the high predictive validity of distractor cue. Together, our results reveal the underlying neural mechanisms by which cueing the spatial distractor may contribute to reduced distractor interference. These results also provide evidence supporting the role of alpha activity as gating by proactive suppression.

日益增多的研究证据表明，干扰性输入可通过空间线索、非空间线索或过往经验实现主动抑制，该过程受多种注意的自上而下机制调控。然而，空间干扰线索背后的神经机制如何指导干扰性输入的主动抑制，这一核心问题仍未得到解答。本研究通过三项实验记录了110名被试的脑电图（electroencephalography）信号，旨在探究空间线索诱导的干扰物主动抑制过程中阿尔法活动（alpha activity）的作用，及其对后续干扰物抑制的影响。行为学层面的分析显示，干扰物的空间邻近性存在全新效应：将干扰物线索指向远离目标的位置可提升目标搜索绩效，而将干扰物线索指向靠近目标的位置则会损害任务表现。至关重要的是，我们在预期阶段观测到了用于干扰物抑制的空间表征的动态特征，该结果通过与被线索化干扰物相对侧的阿尔法功率（alpha power）相对升高得到了进一步验证。在被试间与被试内两个分析层面上，我们发现此类脑活动还可预测后续PD成分（PD component）的幅值下降，该指标提示干扰物引发的认知干扰得以缓解。此外，预期阶段的阿尔法活动及其与后续PD成分的关联，仅在干扰线索具有高预测效度的条件下存在。综上，本研究结果揭示了空间干扰线索通过何种神经机制助力降低干扰物认知干扰的内在过程。本研究还为阿尔法活动通过主动抑制实现认知门控的理论观点提供了实证支持。