Effect of Task Constraints on Motor Control of Pointing

当人类伸手抓住一个物体时，可以使用许多不同的肌肉和关节组合，而不是实现准确的手部运动和最终的手部放置所严格需要的肌肉和关节组合。因此，当到达同一位置时，有两种一般策略是可能的：a)选择一组关节动作并每次使用相同的关节动作组，或者b)使用一系列不同的关节动作，每个关节动作将手带到相同的位置。使用多个等价的(即，就目标而言)，关节组合在特殊情况下提供优势，例如当一个动作被意外干扰时。科学家们不知道神经系统在日常工作中会在多大程度上使用这种策略。这个项目将通过研究如何到达并指向整个工作空间的目标位置来解决这个问题。手臂和手的运动将使用高速视频分析进行测量。这些实验旨在了解受试者的技能水平、视觉的存在与否以及触觉的方向和曲率等因素是如何影响使用哪种策略的。神经系统控制伸展的正式模型将被用来帮助解释实验结果，并为未来的工作产生预测。

When humans reach to grasp an object, many different combinations ofmuscles and joints can be used than are strictly necessary to achieveaccurate hand motion and final hand placement. Thus, when reaching tothe same location, two general strategies are possible: a) choose oneset of joint motions and use the same set every time, or b) use a rangeof different joint motions, each of which takes the hand to the samelocation. Using multiple, equivalent (i.e., in terms of the goal),joint combinations confers advantages under special circumstances,such as when a movement is unexpectedly disturbed. Scientists do notknow the extent to which the nervous system uses this strategy duringroutine tasks. This project will address this question by studyingreaching and pointing to target locations throughout the workspace. Motion of the arm and hand will be measured using high-speed videoanalysis. The experiments are designed to understand how factors suchas the subject's level of skill, the presence or absence of vision, andthe direction and curvature of the reach, influence which strategy isused. Formal modeling of the nervous system's control of reaching willbe used to help explain the experimental results and generatepredictions for future work.