When faced with danger, human beings respond with a repertoire of defensive behaviors, including freezing and active avoidance. Previous research has revealed a pattern of physiological responses, characterized by heart rate bradycardia, reduced visual exploration, and heightened sympathetic arousal in reaction to avoidable threats, suggesting a state of attentive immobility in humans. However, the electrocortical underpinnings of these behaviors remain largely unexplored. To investigate the visuocortical components of attentive immobility, we recorded parieto-occipital alpha activity, along with eye movements and autonomic responses, while participants awaited either an avoidable, inevitable, or no threat. To test the robustness and generalizability of our findings, we collected data from a total of 101 participants (76 females, 25 males) at two laboratories. Across sites, we observed an enhanced suppression of parieto-occipital alpha activity during avoidable threats, in contrast to inevitable or no threat trials, particularly toward the end of the trial that prompted avoidance responses. This response pattern coincided with heart rate bradycardia, centralization of gaze, and increased sympathetic arousal. Furthermore, our findings expand on previous research by revealing that the amount of alpha suppression, along with centralization of gaze, and heart rate changes predict the speed of motor responses. Collectively, these findings indicate that when individuals encounter avoidable threats, they enter a state of attentive immobility, which enhances perceptual processing and facilitates action preparation. This state appears to reflect freezing-like behavior in humans.

当面临危险时，人类会以一系列防御行为来回应，包括冻结和主动回避。先前的研究揭示了一种生理反应模式，其特征是心率心动过缓、视觉探索减少和对可避免威胁的交感神经唤醒增强，这表明人类处于注意力不动的状态。然而，这些行为的皮层电基础在很大程度上仍未得到探索。为了研究注意力不动的视觉皮层成分，我们记录了顶枕 α 活动，以及眼球运动和自主神经反应，而参与者则等待可避免、不可避免或没有威胁。为了测试我们研究结果的稳健性和普遍性，我们在两个实验室收集了总共 101 名参与者 （76 名女性，25 名男性） 的数据。在各个站点中，我们观察到在可避免的威胁期间对顶枕 α 活动的抑制增强，这与不可避免或无威胁的试验形成鲜明对比，尤其是在促使回避反应的试验结束时。这种反应模式与心率心动过缓、凝视集中和交感神经唤醒增加相吻合。此外，我们的研究结果扩展了以前的研究，揭示了 α 抑制的数量、凝视的集中化和心率变化可以预测运动反应的速度。总的来说，这些发现表明，当个体遇到可避免的威胁时，他们会进入一种专注不动的状态，这增强了感知处理并促进了行动准备。这种状态似乎反映了人类的冻结样行为。