IMPAIRMENTS OF REACHING MOVEMENTS IN PATIENTS WITHOUT PROPRIOCEPTION .2. EFFECTS OF VISUAL INFORMATION ON ACCURACY
IMPAIRMENTS OF REACHING MOVEMENTS IN PATIENTS WITHOUT PROPRIOCEPTION .2. EFFECTS OF VISUAL INFORMATION ON ACCURACY
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DOI：
10.1152/jn.1995.73.1.361
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发表时间：
1995-01-01
影响因子：
2.5
通讯作者：
GHILARDI, MF
中科院分区：
文献类型：
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作者：
GHEZ, C;GORDON, J;GHILARDI, MF
1.本研究的目的是确定计算机屏幕上指示手位置的光标的视觉或肢体本身的视觉如何提高由于大纤维感觉神经病而丧失肢体本体感觉的患者伸展运动的准确性。特别是，我们希望确定这类信息对改进规划的贡献，而不是对反馈纠正的贡献。我们分析了受试者在观看电脑屏幕上显示的目标时，在数字化平板电脑上移动手持光标时所产生的空间误差和到达运动的手部轨迹。将在看不到他们的手臂或屏幕光标的情况下进行移动时所犯的错误与同时或在移动之前获得这些信息时所犯的错误进行比较。在运动过程中，监控屏幕光标和在外围视觉中看到他们的肢体都提高了患者运动的准确性。在移动过程中看到光标所产生的改进可以简单地归因于反馈校正。然而，由于靶点并不存在于实际的工作空间中，与肢体视觉相关的改善必须涉及更复杂的矫正机制。在没有视力的试验中，在观察休息或运动时的肢体后进行的试验，也出现了显著的性能改善。特别是，运动中肢体的先前视觉改善了患者在方向错误、路径弯曲和晚期次级运动中改变运动持续时间的能力。当受试者可以在不同方向的目标交替移动时看到屏幕光标时，在范围、方向和曲率方面都产生了类似的改善。观察肢体的效果是短暂的，一旦肢体的视力不再可用，在几分钟内就会衰退。研究认为，肢体视觉后表现的改善是通过肢体内部模型的视觉更新来实现的。静止肢体的视觉可以提供配置信息，而运动肢体的视觉提供附加的动态信息。然而，光标的视觉和由此产生的纠正正在进行的运动的能力主要被认为是提供关于肢体的动态属性及其对神经命令的反应的信息。
1. The aim of this study was to determine how vision of a cursor indicating hand position on a computer screen or vision of the limb itself improves the accuracy of reaching movements in patients deprived of limb proprioception due to large-fiber sensory neuropathy. In particular, we wished to ascertain the contribution of such information to improved planning rather than to feedback corrections. We analyzed spatial errors and hand trajectories of reaching movements made by subjects moving a hand-held cursor on a digitizing tablet while viewing targets displayed on a computer screen. The errors made when movements were performed without vision of their arm or of a screen cursor were compared with errors made when this information was available concurrently or prior to movement.2. Both monitoring the screen cursor and seeing their limb in peripheral vision during movement improved the accuracy of the patients' movements. Improvements produced by seeing the cursor during movement are attributable simply to feedback corrections. However, because the target was not present in the actual workspace, improvements associated with vision of the limb must involve more complex corrective mechanisms.3. Significant improvements in performance also occurred in trials without vision that were performed after viewing the limb at rest or during movements. In particular, prior vision of the limb in motion improved the ability of patients to vary the duration of movements in directional errors, path curvature, and late secondary movements. Comparable improvements in extent, direction, and curvature were produced when subjects could see the screen cursor during alternate movements to targets in different directions.4. The effects of viewing the limb were transient and decayed during a period of minutes once vision of the limb was no longer available.5. It is proposed that the improvements in performance produced after vision of the limb were mediated by the visual updating of internal models of the limb. Vision of the limb at rest may provide configuration information while vision of the limb in motion provides additional dynamic information. Vision of the cursor and the resulting ability to correct ongoing movements, however, is considered primarily to provide information about the dynamic properties of the limb and its response to neural commands.