Beisteiner R, Höllinger P, Lindinger G, Lang W, Berthoz A
Department of Clinical Neurology, University of Vienna, Austria.
Electroencephalogr Clin Neurophysiol. 1995 Mar;96(2):183-93. doi: 10.1016/0168-5597(94)00226-5.
The present study was designed in order to contribute towards the understanding of the physiology of motor imagery. DC potentials were recorded when subjects either imagined or executed a sequence of unilateral or bilateral hand movements. The sequence consisted of hand movements in 4 directions, forwards, backwards, to the right and to the left, and varied from trial to trial. The sequence had been cued by visual targets on a computer screen and had to be memorized before the trial was initiated. Changes of DC potentials between task execution and imagination were localized in central recordings (C3, Cz, C4) with larger amplitudes when executing the task than when imagining to do so. Stimulation of peripheral receptors associated with task execution or a different level of activation of the cortico-motoneural system could account for this finding. The main result of the present study was that with unilateral performance, the side of the performing hand (right, left) had localized effects in recordings over the sensorimotor hand area (C3, C4) which were qualitatively the same with imagination and execution and quantitatively similar (i.e., without significant difference). Performance of the right hand augmented negative DC potentials in C3, performance of the left hand augmented amplitudes in C4. This result is consistent with the assumption that the primary motor cortex is active with motor imagery. Finally, the question has been addressed whether motor imagery may involve the left hemisphere to a larger extent than the execution of the movement. It is shown that a particular contribution of the left hemisphere associated with motor imagery may only show up under strictly controlled conditions.
本研究旨在促进对运动想象生理学的理解。当受试者想象或执行一系列单侧或双侧手部动作时，记录直流电位。该序列包括向前、向后、向右和向左4个方向的手部动作，每次试验都有所不同。该序列由计算机屏幕上的视觉目标提示，在试验开始前必须记住。任务执行和想象之间直流电位的变化定位在中央记录部位（C3、Cz、C4），执行任务时的振幅大于想象执行时的振幅。与任务执行相关的外周感受器刺激或皮质-运动神经系统不同程度的激活可以解释这一发现。本研究的主要结果是，在单侧执行任务时，执行手的一侧（右侧、左侧）在感觉运动手部区域（C3、C4）的记录中具有局部效应，在想象和执行时性质相同，数量上相似（即无显著差异）。右手的执行增加了C3处的负直流电位，左手的执行增加了C4处的振幅。这一结果与初级运动皮层在运动想象时活跃的假设一致。最后，研究探讨了运动想象是否比运动执行更多地涉及左半球的问题。结果表明，与运动想象相关的左半球的特殊作用可能只在严格控制的条件下才会显现出来。
