Actor's and observer's primary motor cortices stabilize similarly after seen or heard motor actions
Actor's and observer's primary motor cortices stabilize similarly after seen or heard motor actions
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DOI：
10.1073/pnas.0702453104
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发表时间：
2007-05-22
影响因子：
11.1
通讯作者：
Hari, Riitta
中科院分区：
文献类型：
--
作者：
Caetano, Gina;Jousmaki, Veikko;Hari, Riitta
我们用全头皮脑磁图(MEG)记录了13名健康受试者的有节奏的脑活动，这些受试者正在表演、看到或听到右手食指敲击鼓膜的声音。在演员的初级运动(ML)皮层，约20赫兹的脑节律水平开始下降，作为M1激活的标志，动作前约2 S，然后增加，敲击后明显反弹约0.6 S，作为M1稳定的标志。观察者的M1大脑皮层也出现了非常类似的时间过程：激活虽然没有演员那么强烈，但在动作前大约开始于0.8%S，随后出现反弹。当受试者刚刚听到敲击声时，看不到动作前的激活，但随着声音反弹。接近10赫兹的体感节律在自己动作和观看动作前也开始降低，在自己动作后恢复到基线水平，比观察动作晚于0.6 S。这种延迟可能反映了本体感输入到大脑皮层，只有在自己的行动中才能获得，因此可能与大脑对代理感的签名有关。在第一人称和第三人称动作中，运动皮质的反应性惊人地相似，这扩大了先前关于主体间理解的大脑机制的数据。除了在自己和观察(预测)动作之前激活运动皮质外，观看者和听者的M1皮层在快速运动动作后以非常相似的方式稳定下来。
We quantified rhythmic brain activity, recorded with whole-scalp magnetoencephalography (MEG), of 13 healthy subjects who were performing, seeing, or hearing the tapping of a drum membrane with the right index finger. In the actor's primary motor (Ml) cortex, the level of the approximate to 20-Hz brain rhythms started to decrease, as a sign of M1 activation, approximate to 2 s before the action and then increased, with a clear rebound approximate to 0.6 s after the tapping, as a sign of M1 stabilization. A very similar time course occurred in the M1 cortex of the observer: the activation, although less vigorous than in the actor, started approximate to 0.8 s before the action and was followed by a rebound. When the subject just heard the tapping sound, no preaction activation was visible, but a rebound followed the sound. The approximate to 10-Hz somatosensory rhythm, which also started to decrease before own and viewed actions, returned to the baseline level approximate to 0.6 s later after own actions than observed actions. This delay likely reflects proprioceptive input to the cortex, available only during own actions, and therefore could be related to the brain signature of the sense of agency. The strikingly similar motor cortex reactivity during the first and third person actions expands previous data on brain mechanisms of intersubjective understanding. Besides motor cortex activation before own and observed (predicted) actions, the M1 cortex of both the viewer and the listener stabilized in a very similar manner after brisk motor actions.