The mirror neuron system (MNS) becomes active during action execution and action observation, which is presumably reflected by reductions in mu (8-13 Hz) activity in the electroencephalogram over the sensorimotor cortex. The function of the MNS is still fiercely debated. The current study aimed to investigate a role of the MNS in anticipating others' actions by examining whether the MNS was activated - indexed by mu power suppression - prior to the onset of observed actions when the onset and type of action could be predicted on the basis of environmental cues. Young adults performed and observed cued grasping and placing actions in a card game in a real-life setting, while the predictability of the observed actions was manipulated using rules. Significant mu suppression, relative to within-trial baseline activity, was found both prior to and during executed actions, but also during action observation, and, crucially, prior to observed actions provided they were predictable. No anticipatory mu reductions were found prior to unpredictable observed actions. These results suggest top-down modulation of MNS activity by conceptual knowledge. This is the first study to demonstrate mu suppression prior to action onset - possibly reflecting MNS anticipatory activity - by explicitly manipulating predictability.

中文翻译：

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在预期即将发生的可预测但并非不可预测的动作期间激活感觉运动皮层。

镜像神经元系统 (MNS) 在动作执行和动作观察期间变得活跃，这可能反映在感觉运动皮层脑电图中 mu (8-13 Hz) 活动的减少。MNS 的功能仍在激烈争论中。当前的研究旨在通过检查 MNS 是否在观察到的动作开始之前被激活（以 mu 功率抑制为指标）来研究 MNS 在预测他人动作中的作用，此时动作的开始和类型可以基于此进行预测的环境线索。年轻人在现实生活中的纸牌游戏中表演和观察提示抓取和放置动作，而观察到的动作的可预测性是使用规则来操纵的。显着的 mu 抑制，相对于试验内基线活动，在执行动作之前和期间都被发现，而且在动作观察期间，而且至关重要的是，在观察到的动作之前，只要它们是可预测的。在不可预测的观察到的动作之前没有发现预期的亩减少。这些结果表明通过概念知识自上而下地调节 MNS 活动。这是第一项通过明确操纵可预测性来证明在行动开始之前 mu 抑制的研究 - 可能反映了 MNS 的预期活动。