Desmurget Michel, Turner Robert S, Prablanc Claude, Russo Gary S, Alexander Garret E, Grafton Scott T
Institut National de la Santé et de la Recherche Médicale (INSERM), Bron, France.
J Exp Psychol Hum Percept Perform. 2005 Dec;31(6):1510-36. doi: 10.1037/0096-1523.31.6.1510.
Six results are reported. (a) Reaching accuracy increases when visual capture of the target is allowed (e.g., target on vs. target off at saccade onset). (b) Whatever the visual condition, trajectories diverge only after peak acceleration, suggesting that accuracy is improved through feedback mechanisms. (c) Feedback corrections are smoothly implemented, causing the corrected and uncorrected velocity profiles to exhibit similar shapes. (d) Initial kinematics poorly predict final accuracy whatever the condition, indicating that target capture is not the only critical input for feedback control. (e) Hand and eye final variability are unrelated, suggesting that gaze direction is not a target signal for arm control. (f) Extent errors are corrected without modification of movement straightness; direction errors cause path curvature to increase. Together these data show that movements with straight paths and bell-shaped velocity profiles are not necessarily ballistic.
报告了六个结果。(a) 当允许对目标进行视觉捕捉时(例如,扫视开始时目标可见与不可见),到达精度会提高。(b) 无论视觉条件如何,轨迹仅在峰值加速度之后发散,这表明精度是通过反馈机制提高的。(c) 反馈校正平稳实施,使校正和未校正的速度曲线呈现相似的形状。(d) 无论何种条件,初始运动学都不能很好地预测最终精度,这表明目标捕捉不是反馈控制的唯一关键输入。(e) 手和眼的最终变异性无关,这表明注视方向不是手臂控制的目标信号。(f) 范围误差在不改变运动直线度的情况下得到校正;方向误差会导致路径曲率增加。这些数据共同表明,具有直线路径和钟形速度曲线的运动不一定是弹道式的。