Interaction of visual and proprioceptive feedback during adaptation of human reaching movements
Interaction of visual and proprioceptive feedback during adaptation of human reaching movements
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DOI：
10.1152/jn.00947.2004
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发表时间：
2005-06-01
影响因子：
2.5
通讯作者：
Mussa-Ivaldi, FA
中科院分区：
文献类型：
--
作者：
Scheidt, RA;Conditt, MA;Mussa-Ivaldi, FA
当人们伸手去拿一个物体时，他们的手倾向于做直而平滑的动作。这些轨迹特征抵抗扰动，并且本体感受以及视觉反馈都可以引导执行这种规律性的运动命令的自适应更新。来自两种感觉的信息如何结合起来以生成手臂如何移动的连贯内部表示？在这里，我们表明，消除视觉反馈的手路径偏离直线到达（约束视觉反馈的运动在一个虚拟的，“视觉通道”）防止补偿扰动引起的初始方向误差。由于自适应减少方向误差发生与本体感觉单独，本体感觉和视觉信息不结合在这个达到任务使用固定的，线性加权方案报告的静态任务，不需要手臂运动。一个计算机模型可以解释这些发现，假设初始肢体姿势的本体感受估计用于选择所需的达到和手路径错误的视觉反馈的运动命令，使本体感受估计与肢体位置相对于其目标的视觉中心表示配准。仿真结果表明，初始配置估计误差导致的运动方向的误差，实验观察。配准提高运动精度时，提供了真实的视觉反馈，但不调用时，手路径错误被消除。然而，视觉通道并不排除终端移动功能的调整，最大限度地提高手路径的平滑度。因此，视觉和本体感受反馈可以在到达运动的轨迹控制和最终位置调节期间以根本上不同的方式组合。
People tend to make straight and smooth hand movements when reaching for an object. These trajectory features are resistant to perturbation, and both proprioceptive as well as visual feedback may guide the adaptive updating of motor commands enforcing this regularity. How is information from the two senses combined to generate a coherent internal representation of how the arm moves? Here we show that eliminating visual feedback of hand-path deviations from the straight-line reach (constraining visual feedback of motion within a virtual, "visual channel") prevents compensation of initial direction errors induced by perturbations. Because adaptive reduction in direction errors occurred with proprioception alone, proprioceptive and visual information are not combined in this reaching task using a fixed, linear weighting scheme as reported for static tasks not requiring arm motion. A computer model can explain these findings, assuming that proprioceptive estimates of initial limb posture are used to select motor commands for a desired reach and visual feedback of hand-path errors brings proprioceptive estimates into registration with a visuocentric representation of limb position relative to its target. Simulations demonstrate that initial configuration estimation errors lead to movement direction errors as observed experimentally. Registration improves movement accuracy when veridical visual feedback is provided but is not invoked when hand-path errors are eliminated. However, the visual channel did not exclude adjustment of terminal movement features maximizing hand-path smoothness. Thus visual and proprioceptive feedback may be combined in fundamentally different ways during trajectory control and final position regulation of reaching movements.