Effect of Task Constraints on Motor Control of Pointing

当人类伸手去抓住一个物体时，可以使用许多不同的肌肉和关节组合，而不是严格要求精确的手部运动和最终的手部位置。 因此，当到达相同的位置时，有两种一般策略是可能的：a）选择一组关节运动，每次使用相同的一组，或者B）使用一系列不同的关节运动，每一个都将手带到同一个位置。 使用多个，等效（即，就目标而言），在特殊情况下，如运动受到意外干扰时，关节组合具有优势。 科学家们不知道神经系统在日常工作中使用这种策略的程度。 这个项目将通过研究在整个工作空间中重新进入和指向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。 实验的目的是为了了解诸如受试者的技能水平、视觉的存在或缺失、伸手的方向和弯曲度等因素如何影响使用哪种策略。 神经系统控制伸手的正式模型将被用来帮助解释实验结果，并为未来的工作做出预测。

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.