Massion J, Ioffe M, Schmitz C, Viallet F, Gantcheva R
Laboratoire de Neurobiologie et Mouvements, CNRS, 31 chemin Joseph Aiguier, F-13402 Marseille Cedex 20, France.
Exp Brain Res. 1999 Sep;128(1-2):229-35. doi: 10.1007/s002210050842.
Anticipatory adjustments of forearm posture are associated with a voluntary load-lifting movement in bimanual load-lifting tasks. Three aspects of these adjustments are analyzed: their goal, their central organization, and their acquisition. The goal of the anticipatory adjustment in this task is to minimize the perturbation of forearm posture that occurs during unloading. The central organization is based on two parallel controls responsible, respectively, for the lifting movement of the moving forearm and the anticipatory postural adjustment of the postural forearm, their coordination depending on a central timing signal. The acquisition of the anticipatory postural adjustment was tested using a paradigm where the voluntary movement performed by one hand triggered, via an electronic switch, the load release of the postural forearm. It was achieved after 40-60 trials and was not graded as a function of the voluntary movement parameters, but of the disturbance of the postural arm about to occur. The learned anticipation was not transferred when, after a first acquisition session with one forearm as the postural forearm, a second learning session was performed with the other forearm as the postural forearm. The acquisition was tested in Parkinsonian and in hemiparetic patients with capsular lesion. The highest acquisition deficit was observed in hemiparetic patients, when the contralateral forearm was the postural forearm; the deficit was less important when the ipsilateral arm was postural. Surprisingly, the anticipatory postural adjustments in hemiparetic patients were rather well preserved when the natural load-lifting task was tested. These results suggest that the basal-ganglia SMA circuit and M1 premotor areas are important in the acquisition process.
在双手提举任务中，前臂姿势的预期调整与自愿提举动作相关。分析了这些调整的三个方面：其目标、中枢组织和习得过程。该任务中预期调整的目标是将卸载过程中发生的前臂姿势扰动降至最低。中枢组织基于两个并行控制，分别负责活动前臂的提举动作和姿势前臂的预期姿势调整，它们的协调依赖于一个中枢定时信号。使用一种范式测试预期姿势调整的习得，即一只手执行的自愿动作通过电子开关触发姿势前臂的负载释放。经过40 - 60次试验后实现，且不是根据自愿运动参数分级，而是根据即将发生的姿势手臂的干扰分级。当以一只前臂作为姿势前臂进行第一次习得训练后，再以另一只前臂作为姿势前臂进行第二次学习训练时，习得的预期不会转移。在帕金森病患者和患有囊膜病变的偏瘫患者中测试了习得情况。当对侧前臂为姿势前臂时，在偏瘫患者中观察到最高的习得缺陷；当同侧手臂为姿势时，缺陷不那么明显。令人惊讶的是，在测试自然提举任务时，偏瘫患者的预期姿势调整相当良好地得以保留。这些结果表明基底神经节辅助运动区回路和M1运动前区在习得过程中很重要。
