Jeannerod M
Behav Brain Res. 1986 Feb;19(2):99-116. doi: 10.1016/0166-4328(86)90008-2.
The pattern of finger grip formation during natural prehension movements was described in normal subjects with the help of a quantified film technique. Movements were studied in one condition with visual feedback from the moving hand available, and one condition without visual feedback. The studied parameters, including the maximum size of the anticipatory grip and the final size of the grip before contact with the object, were not affected by shifting from one condition of visual feedback to the other. The same technique was applied to a group of patients with cerebral lesions. In two patients with unilateral lesions involving the motor cortex, grip formation with the hand contralateral to the lesion, was found to be severely affected, in that fingers and particularly the index finger, remained stretched until contact with the object was made. In two patients with unilateral lesions in the posterior parietal cortex, grip formation of the contralateral hand was absent specifically in the no-visual feedback condition. The same result was obtained in two other patients with a lesion (subcortical in one case, cortical in the other) of somatosensory pathways corresponding to one hand. These results are interpreted as evidence for the role of cerebral cortex in the control of finger grip formation during prehension of visual objects. Integration at cortical level of visual and somatosensory cues from the involved hand is a necessary condition for grip formation to be adapted to the grasp.
借助一种量化电影技术，描述了正常受试者在自然抓握动作过程中的手指抓握形成模式。在一种情况下，可从移动的手部获得视觉反馈，研究抓握动作；在另一种情况下，则没有视觉反馈。所研究的参数，包括预期抓握的最大尺寸以及与物体接触前抓握的最终尺寸，并不会因从一种视觉反馈条件转换到另一种条件而受到影响。同样的技术应用于一组脑部病变患者。在两名单侧病变累及运动皮层的患者中，发现与病变对侧的手部抓握形成受到严重影响，即手指尤其是食指，在与物体接触之前一直保持伸展状态。在两名单侧顶叶后皮质病变的患者中，特别是在无视觉反馈条件下，对侧手部的抓握形成缺失。在另外两名手部相应体感通路有病变（一例为皮质下病变，另一例为皮质病变）的患者中也得到了相同结果。这些结果被解释为大脑皮层在视觉物体抓握过程中控制手指抓握形成作用的证据。来自受累手部的视觉和体感线索在皮层水平的整合是抓握形成适应抓握动作的必要条件。
