Sakamoto Masanori, Muraoka Tetsuro, Mizuguchi Nobuaki, Kanosue Kazuyuki
Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan.
Exp Brain Res. 2009 Oct;199(1):17-25. doi: 10.1007/s00221-009-1962-7. Epub 2009 Aug 8.
Excitability of the corticospinal pathway increased during observation of an action. The present study investigated whether corticospinal excitability during an action observation is modulated by physical movement executed by the observers themselves. Participants alternately repeated the observation of a pinching action with the thumb and index finger and execution (30 times) of the same action. Motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation were recorded from the first dorsal interosseous muscle during observation of the action. MEP amplitude gradually increased with the number of executions of the same action. However, MEP amplitude did not change when the participants only repeated observation of the pinching action or when the participants alternately repeated observation of the pinching action and execution of the isometric abduction of the index finger. These findings suggest that enhancement of cotricospinal excitability is dependent on the execution of a particular action that is very similar to the observed action.
在观察动作期间，皮质脊髓通路的兴奋性增加。本研究调查了在动作观察期间，皮质脊髓兴奋性是否受观察者自身执行的身体动作调节。参与者交替重复观察用拇指和食指捏的动作以及执行（30次）相同动作。在观察动作期间，从第一背侧骨间肌记录经颅磁刺激诱发的运动诱发电位（MEP）。MEP波幅随着相同动作执行次数的增加而逐渐增大。然而，当参与者仅重复观察捏的动作时，或者当参与者交替重复观察捏的动作和执行食指等长外展动作时，MEP波幅没有变化。这些发现表明，皮质脊髓兴奋性的增强依赖于执行与观察动作非常相似的特定动作。
