Sasaki K, Gemba H, Tsujimoto T
Department of Physiology, Faculty of Medicine, Kyoto University, Japan.
Brain Res. 1990 Jun 11;519(1-2):343-6. doi: 10.1016/0006-8993(90)90099-w.
Latent time of the hand movement in response to a visual stimulus was found to be very short when a monkey was enough trained with a visual imperative stimulus preceded by a visual warning stimulus at a fixed time interval. Cerebellar hemispherectomy scarcely prolonged the reaction time of the warning-imperative, visually initiated (W-VI) movement in contrast to its marked delaying action upon the simple visually initiated reaction-time (S-VI) movement. Between the warning and imperative stimuli, sustained surface-negative, depth-positive field potentials were recorded in various areas of the prefrontal and premotor cortices and the supplementary motor area of both cerebral hemispheres, besides gradually increasing surface-negative, depth-positive deflections in the motor and somatosensory cortices contralateral to the moving hand. These observations suggest that the sustained activities in the prefrontal and premotor cortices elicited by the warning stimulus overcome deficiency of the cerebellar function for performing fast and stable timing movements.
当猴子在固定时间间隔的视觉警告刺激之后接受足够的视觉指令刺激训练时，发现其手部对视觉刺激做出反应的潜伏时间非常短。与小脑半球切除术对简单视觉引发反应时间（S-VI）运动有明显延迟作用相反，它几乎没有延长警告-指令性视觉引发（W-VI）运动的反应时间。在警告刺激和指令刺激之间，除了与运动手对侧的运动和体感皮层中表面负向、深度正向偏转逐渐增加外，还在前额叶和运动前皮层的各个区域以及两个大脑半球的辅助运动区记录到持续的表面负向、深度正向场电位。这些观察结果表明，警告刺激引发的前额叶和运动前皮层的持续活动克服了小脑功能在执行快速稳定定时运动方面的不足。
