LEARNING A NEW VISUOMOTOR TRANSFORMATION - ERROR-CORRECTION AND GENERALIZATION
LEARNING A NEW VISUOMOTOR TRANSFORMATION - ERROR-CORRECTION AND GENERALIZATION
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DOI：
10.1016/0926-6410(95)90014-4
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发表时间：
1995-10-01
期刊：
影响因子：
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通讯作者：
BURNOD, Y
中科院分区：
文献类型：
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作者：
ROBYBRAMI, A;BURNOD, Y
使用瞄准工具需要学习视觉和本体感觉信息与运动指令之间的新转换。我们通过量化在屏幕平面上的标准鼠标光标设备上添加的旋转偏向(逆时针60度，然后顺时针)的短暂适应阶段的运动运动学来研究这个问题。控制瞄准的运动几乎是线性的，速度曲线呈钟形。这种偏差导致了相当的初始方向误差，通常在20次试验内就能得到纠正。学习轨迹是螺旋线和快慢直线运动的组合。手的姿势因偏向而略有改变(不到10度)。这些特征提出了三个校正过程：基于评估光标与目标的相对位置的在线连续校正、基于评估光标与目标方向与有效光标方向之间的偏差角度的离散校正、以及记忆试测校正。根据神经生理学数据和神经网络模型对这些结果进行了解释，这些结果表明，皮层区域执行的视觉运动转换是通过将视觉信息投射到随手臂旋转的参照系上来实现的。当目标的方向改变时，初始定向误差再次出现，并随着改变程度的增加而增加。有限的概括表明，相对于目标方向的编码存储偏差校正，并且将朝向新方向的移动计算为先前学习的偏差在新视觉方向上的投影。
The use of an aiming tool requires learning a new transformation between visual and proprioceptive information and motor command. We have examined this question by quantifying the kinematics of the movement during the transitory phase of adaptation to a rotational bias (60 degrees counterclockwise, then clockwise) added to a standard mouse-cursor device in the plane of the screen. Control-aiming movements were almost linear with a bell-shaped velocity profile. The bias induced an equivalent initial directional error which was usually corrected within 20 trials. The learning trajectories were combinations of spirals and fast or slow straight movements. The posture of the hand was slightly (less than 10 degrees) modified by the bias. These features suggest three corrective processes: on-line continuous correction based on evaluation of the relative cursor-to-target position, discrete correction based on assessment of the discrepancy angle between the cursor-to-target direction and the effective cursor direction, and memorization of trial-to-trial correction. These results are interpreted in the light of neurophysiological data and neural net modeling, which suggest that the visuomotor transformation performed by cortical areas for reaching is effected by projecting the visual information on a reference frame that rotates with the arm. The initial directional error reappeared when the direction of the target was changed and increased with degree of change. The limited generalization suggests that bias correction is stored in relation to the coding of the target direction and that movement towards a new direction is computed as a projection of the previously learned bias on the new visual direction.