Elsinger Catherine L, Rosenbaum David A
Department of Neurology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
Exp Brain Res. 2003 Oct;152(4):499-509. doi: 10.1007/s00221-003-1573-7. Epub 2003 Jul 25.
Although it is well known that the postures adopted at the ends of movements depend on where one starts and how one moves, it is not yet clear whether those differing end postures are selected before movements begin. Two experiments were designed to test the hypothesis that end postures for positioning movements are chosen before movements commence. The experiments were further designed to check whether movements are internally simulated before overt movements occur and end-postures are still being selected. To address these questions we used a movement choice method. Participants were presented with two possible end postures and were asked to choose between them by moving to the one that seemed easier to adopt. End-posture choices were affected by starting positions and also by the movements that would have to be made, as affected by having obstacles in the way. The results suggest that participants relied on feedforward modeling of prospective movements as they selected end postures prior to overt movement production. The fact that the movement choice method could confirm this suggests that the method holds considerable promise as a tool for investigating motor planning.
尽管众所周知，运动结束时所采用的姿势取决于起始位置和运动方式，但尚不清楚这些不同的结束姿势是否在运动开始前就已选定。设计了两个实验来检验这样一个假设，即定位运动的结束姿势是在运动开始前选定的。实验还进一步设计来检验在明显的运动发生之前，运动是否在内部被模拟，并且结束姿势仍在被选择。为了解决这些问题，我们使用了一种运动选择方法。向参与者展示两种可能的结束姿势，并要求他们通过移动到看起来更容易采用的那个姿势来在两者之间做出选择。结束姿势的选择受到起始位置的影响，也受到因途中有障碍物而必须进行的运动的影响。结果表明，参与者在产生明显运动之前选择结束姿势时，依赖于预期运动的前馈模型。运动选择方法能够证实这一点，这一事实表明该方法作为一种研究运动规划的工具具有很大的前景。
