Jakobson L S, Servos P, Goodale M A, Lassonde M
Department of Psychology, Queen's University, Kingston, Ontario, Canada.
Brain. 1994 Oct;117 ( Pt 5):1107-13. doi: 10.1093/brain/117.5.1107.
Classic work with split-brain monkeys suggests that the reaching limb can be controlled by either cerebral hemisphere, but that finger control is largely crossed (Haaxma and Kuypers, 1974). Accordingly, one might predict that acallosal subjects should have little difficulty grasping objects presented in the visual field ipsilateral to the hand used, but should have great difficulty forming their grasp when reaching into crossed space. In the present study, we carried out a kinematic analysis of reaching and grasping movements executed by four acallosal subjects and four matched control subjects. Subjects maintained central fixation while reaching with either hand for objects placed in left, central and right space. Relative to controls, acallosal subjects took longer to complete reaches directed across the body midline, and spent more time decelerating. Moreover, unlike controls, their grip formation appeared to be impaired in all regions of space, although this deficit was most pronounced during reaches into crossed space. These results suggest that congenital absence of the corpus callosum is associated with deficits in the control of both the proximal and distal musculature.
对裂脑猴的经典研究表明，伸展的肢体可由任何一个大脑半球控制，但手指的控制在很大程度上是交叉的（哈克斯马和库佩斯，1974年）。因此，有人可能会预测，胼胝体缺失的受试者在抓取呈现于所用手同侧视野中的物体时应该几乎没有困难，但在伸手进入交叉空间时形成抓握应该会有很大困难。在本研究中，我们对四名胼胝体缺失受试者和四名匹配的对照受试者执行的伸手和抓握动作进行了运动学分析。受试者在双手伸向放置于左、中、右空间的物体时保持中央注视。相对于对照组，胼胝体缺失受试者完成越过身体中线的伸展动作所需时间更长，且减速时间更多。此外，与对照组不同，他们在所有空间区域的抓握形成似乎都受损，尽管这种缺陷在伸手进入交叉空间时最为明显。这些结果表明，先天性胼胝体缺失与近端和远端肌肉组织控制方面的缺陷有关。
