Verschueren S M, Swinnen S P, Dom R, De Weerdt W
Department of Kinesiology, Group Biomedical Sciences K. U. Leuven, Heverlee, Belgium.
Exp Brain Res. 1997 Mar;113(3):497-508. doi: 10.1007/pl00005602.
The basal ganglia have traditionally been associated with motor control functions and this view has prevailed since the late nineteenth century. Recent experimental studies suggest that this neuroanatomical system is also critically involved in motor learning. In the present study, motor learning/transfer capabilities were compared between patients with Parkinson's disease and a group of normal elderly people. Subjects practiced a bimanual coordination task that required continuous flexion-extension movements in the transverse plane with a 90 degrees phase offset between the forearms. During acquisition, augmented visual feedback of the relative motions was provided in real time. The findings revealed improvements in the bimanual coordination pattern across practice in both groups when the augmented concurrent feedback was present. However, when transferred to performance conditions in which the augmented information was withheld, performance deteriorated (relative to the augmented condition) and this effect was more prevalent in the Parkinson patients. More specifically, no improvement in interlimb coordination was observed under nonaugmented feedback conditions across practice. Instead, a drift toward the preferred in-phase and antiphase coordination patterns was evident. The present findings suggest that Parkinson patients can improve their performance on a new motor task, but they remain strongly dependent on augmented visual information to guide these newly acquired movements. The apparent adoption of a closed-loop control mode is accompanied with decreases in movement speed in order to use the feedback to ensure accuracy. When the augmented feedback is withheld and the movement pattern is to be controlled by means of intrinsic information feedback sources, performance is severely hampered. The findings are hypothesized to indicate that learning/transfer is affected in Parkinson patients who apparently prefer some constancy in the environmental contingencies under which practice takes place. The present findings are consistent with the notion that the basal ganglia form a critical neuroanatomical substrate for motor learning.
传统上，基底神经节一直与运动控制功能相关联，自19世纪末以来这种观点一直盛行。最近的实验研究表明，这个神经解剖系统在运动学习中也起着关键作用。在本研究中，比较了帕金森病患者和一组正常老年人的运动学习/迁移能力。受试者练习一项双手协调任务，该任务要求在横平面内进行连续的屈伸运动，前臂之间有90度的相位偏移。在习得过程中，实时提供相对运动的增强视觉反馈。研究结果显示，当存在增强的同时反馈时，两组在练习过程中双手协调模式都有改善。然而，当转移到不提供增强信息的表现条件下时，表现会恶化（相对于增强条件），并且这种影响在帕金森病患者中更普遍。更具体地说，在整个练习过程中，在无增强反馈条件下未观察到肢体间协调性的改善。相反，明显出现了向偏好的同相和反相协调模式的偏移。目前的研究结果表明，帕金森病患者可以在新的运动任务中提高他们的表现，但他们仍然强烈依赖增强的视觉信息来指导这些新习得的动作。明显采用闭环控制模式伴随着运动速度的降低，以便利用反馈来确保准确性。当不提供增强反馈且运动模式要通过内在信息反馈源来控制时，表现会受到严重阻碍。这些研究结果被假设表明，在明显偏好练习发生时环境偶然性具有一定稳定性的帕金森病患者中，学习/迁移受到了影响。目前的研究结果与基底神经节构成运动学习关键神经解剖学基础的观点一致。
