Modulation of premotor mirror neuron activity during observation of unpredictable grasping movements
Modulation of premotor mirror neuron activity during observation of unpredictable grasping movements
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DOI：
10.1111/j.1460-9568.2004.03655.x
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发表时间：
2004-10-01
影响因子：
3.4
通讯作者：
Pascual-Leone, A
中科院分区：
文献类型：
--
作者：
Gangitano, M;Mottaghy, FM;Pascual-Leone, A
使用经颅磁刺激，我们探讨了被动观察人类受试者的伸手-抓握运动过程中前运动镜像神经元的特性。使用视频剪辑作为视觉刺激进行两个不同的实验。视频剪辑显示了正常执行（控制刺激）或异常达到抓取运动执行延迟的最大手指孔径的出现时间（实验1），或取代它与不可预知的关闭（实验2）。在观察过程中的不同时间点记录运动诱发电位。皮质兴奋性的配置文件，并与相应的运动的运动配置文件进行比较。被动观察的自然运动诱发的皮质兴奋性的配置文件，这是在一致的时间所示的手指运动的运动配置文件。观察不寻常的运动没有施加任何调制（实验1）或诱发的活动，匹配，在开始时，与观察自然运动（实验2）获得的调制。结果表明，共振电机计划加载作为一个整体，在开始观察，一旦开始倾向于进行其完成，无论视觉线索的变化。结果排除了共振计划的时间碎片化的可能性，因为正在进行的动作的每个阶段的镜像神经元的不同群体的激活。他们进一步支持的概念，作为神经基板的观察-执行匹配系统的镜像系统的作用，并扩展了目前的知识机制，触发内部表示的行动。
Using transcranial magnetic stimulation, we explored the properties of premotor mirror neurons during the passive observation of a reaching-grasping movement in human subjects. Two different experiments were run using video-clips as visual stimuli. Video-clips showed a normally performed (control stimulus) or an anomalous reaching-grasping movement executed by delaying the time of the appearance of the maximal finger aperture (experiment 1), or substituting it with an unpredictable closure (experiment 2). Motor evoked potentials were recorded at different time-points during the observation of the video-clips. Profiles of cortical excitability were drawn and compared with the kinematic profiles of the corresponding movement. Passive observation of the natural movement evoked a profile of cortical excitability that is in concordance with the timing of the kinematic profile of the shown finger movements. Observation of the uncommon movements did not exert any modulation (experiment 1) or evoked an activity that matched, at the beginning, the modulation obtained with observation of the natural movement (experiment 2). Results show that the resonant motor plan is loaded as whole at the beginning of observation and once started tends to proceed to its completion regardless of changes to the visual cues. The results exclude the possibility of a temporal fragmentation of the resonant plan, because activation of different populations of mirror neurons for each phase of the ongoing action. They further support the notion of the role of the mirror system as neural substrate for the observing-execution matching system and extend the current knowledge regarding mechanisms that trigger the internal representation of an action.