Cognitive Neuroscience Sector, Scuola Internazionale di Studi Superiori Avanzati (International School for Advanced Studies), Via Bonomea, 265, Trieste, Italy.
J Cogn Neurosci. 2011 Dec;23(12):3939-48. doi: 10.1162/jocn_a_00075. Epub 2011 Jun 14.
Embodied theories hold that understanding what another person is doing requires the observer to map that action directly onto his or her own motor representation and simulate it internally. The human motor system may, thus, be endowed with a "mirror matching" device through which the same motor representation is activated, when the subject is either the performer or the observer of another's action ("self-other shared representation"). It is suggested that understanding action verbs relies upon the same mechanism; this implies that motor responses to these words are automatic and independent of the subject of the verb. In the current study, participants were requested to read silently and decide on the syntactic subject of action and nonaction verbs, presented in first (1P) or third (3P) person, while TMS was applied to the left hand primary motor cortex (M1). TMS-induced motor-evoked potentials were recorded from hand muscles as a measure of cortico-spinal excitability. Motor-evoked potentials increased for 1P, but not for 3P, action verbs or 1P and 3P nonaction verbs. We provide novel demonstration that the motor simulation is triggered only when the conceptual representation of a word integrates the action with the self as the agent of that action. This questions the core principle of "mirror matching" and opens to alternative interpretations of the relationship between conceptual and sensorimotor processes.
具身理论认为，理解他人在做什么需要观察者将该动作直接映射到自己的运动表征上，并在内部进行模拟。因此，人类的运动系统可能具有一种“镜像匹配”装置，通过该装置，当主体是他人动作的执行者或观察者时，相同的运动表征被激活（“自我-他人共享表征”）。有人认为，理解动作动词依赖于相同的机制；这意味着对这些词的运动反应是自动的，并且与动词的主语无关。在当前的研究中，要求参与者默读并决定以第一人称（1P）或第三人称（3P）呈现的动作动词和非动作动词的句法主语，同时将 TMS 应用于左手初级运动皮层（M1）。从手部肌肉记录 TMS 诱导的运动诱发电位，作为皮质脊髓兴奋性的衡量指标。运动诱发电位增加 1P 但不增加 3P 的动作动词或 1P 和 3P 的非动作动词。我们提供了新的证据表明，只有当一个词的概念表征将动作与自身作为该动作的主体整合在一起时，才会触发运动模拟。这对“镜像匹配”的核心原则提出了质疑，并为概念和感觉运动过程之间的关系提供了替代解释。
