Schieber M H
Department of Neurology and Neurological Surgery, Washington University School of Medicine, St Louis, MO 63110.
Trends Neurosci. 1990 Nov;13(11):440-5. doi: 10.1016/0166-2236(90)90093-p.
The ability to individuate movements--that is, the ability to move one or more body parts independently of the movement or posture of other contiguous body parts--imparts an increasing flexibility to the motor repertoire of higher mammals. The movements used in walking, grasping, or eating contrast greatly with the phylogenetically more recent movements of the same body parts used, respectively, in dancing, playing a musical instrument, or talking. The movements used in the latter functions depend critically on the primary motor cortex (area 4). With advances in our understanding of the output organization of the motor cortex (reviewed recently by Roger Lemon), which have been based largely on studies of the hand area in primates, we can now consider more fully certain problems inherent in moving body parts individually, and some ways in which the motor cortex might accomplish this feat.
区分动作的能力——即独立于其他相邻身体部位的动作或姿势来移动一个或多个身体部位的能力——赋予了高等哺乳动物运动技能越来越高的灵活性。行走、抓握或进食时所使用的动作，与同一身体部位在跳舞、演奏乐器或说话时所使用的、在系统发育上更新近的动作形成了极大的反差。后一类功能中所使用的动作严重依赖于初级运动皮层（4区）。随着我们对运动皮层输出组织的理解不断进步（最近罗杰·莱蒙对此进行了综述，这些进展主要基于对灵长类动物手部区域的研究），我们现在可以更全面地考虑单独移动身体部位所固有的某些问题，以及运动皮层可能实现这一壮举的一些方式。
