不同运动诱发模式下运动皮层神经控制机制研究

The neural control of actions by different forms of movement initiation

人类运动主要是在两种情境下诱发:一种是由外界刺激诱发,另一种是由自发意志引起。大量的研究已经证明,两种情境下诱发的运动分别由不同的大脑运动神经系统控制。然而目前为止,我们对这两种不同的运动始发控制系统对运动的准备以及运动执行的影响以及背后的神经机制并不完全清楚。本研究采用脑电技术,通过实验设计系统地探析了不同的运动诱发模式,即刺激诱发运动条件和自发运动条件的神经活动差异及其分别对运动表现的影响。本研究的结果显示,与刺激诱发条件相比,自发运动条件下对侧初级运动皮层在运动准备阶段有显著的运动准备电位,而在运动执行阶段没有差异。而两种条件下的同侧初级运动皮层的运动电位在运动执行阶段呈现显著差异。我们同时也发现了两种条件下对侧和同侧初级运动皮层分别对运动起到了相关运动激活和无关运动抑制的作用。我们的研究表明初级运动皮层对运动准备和执行的控制作用受不同运动诱发模式的影响。

Human action can be studied in two paradigmatic situations. On one hand,people act in response to external events. On the other hand,people act in a particular way to achieve certain desired effects in their environment based on an intention without a stimulus. An increasing number of evidence has shown that two modes of action seem to be controlled by different neural pathways in the brain. However,it is still unclear that the mechanism underlying the control of two initiating networks on the movement preparation and execution. In the current study,we applied EEG technique to investigate the control of two initiating networks on the movement preparation and execution. We found that the typical readiness potential（RP） over the contrlateral primary motor cortex in the preparation period of self-initiated movement.However,the difference in the period of movement execution was found over the ipsilateral motor cortex. Furthermore,we suggested that the contralateral negativity corresponded to an activation of the motor command whereas the ipsilateral negativity corresponded to an inhibition of the non-required response. Our findings suggested the different roles of contralateral and ipsilateral motor cortex on the motor preparation and execution depending on how the movement was initiated.