ERRORS IN POINTING ARE DUE TO APPROXIMATIONS IN SENSORIMOTOR TRANSFORMATIONS
ERRORS IN POINTING ARE DUE TO APPROXIMATIONS IN SENSORIMOTOR TRANSFORMATIONS
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DOI：
10.1152/jn.1989.62.2.595
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发表时间：
1989-08-01
影响因子：
2.5
通讯作者：
FLANDERS, M
中科院分区：
文献类型：
--
作者：
SOECHTING, JF;FLANDERS, M
1.我们定义了一个外部参照系来表示一个点在非个人空间中相对于人类受试者肩膀的位置，我们定义了一个内在参照系来表示手臂和前臂的方向。2.我们考察了两种实验条件下外在和内在参照系中的坐标之间的关系：当被试在黑暗中通过指向虚拟目标做出不准确的动作时，当被试在光线下通过指向实际目标进行准确动作时。3.当被试做出不准确的动作时，手臂在其最终位置的方位角(内部坐标)与目标的外部坐标之间存在近于线性的关系。当他们做出准确的动作时，这些关系更具非线性。4.具体而言，手臂和前臂的仰角主要取决于目标距离和仰角，而两个偏航角主要取决于目标的方位。5.我们认为，指点错误的发生是因为受试者实现了从外部坐标到内部坐标的线性近似转换，并且这种转换是将目标位置的可视表示转换为适当的肌肉活动模式的过程中的一个步骤。
1. We define an extrinsic frame of reference to represent the location of a point in extrapersonal space relative to a human subject's shoulder, and we define an intrinsic frame of reference to represent the orientation of the arm and forearm. 2. We examined the relations between coordinates in the extrinsic and intrinsic frames of reference under two experimental conditions: when subjects made inaccurate movements by pointing to virtual targets in the dark and when they made accurate movements by pointing to actual targets in the light. 3. When subjects made inaccurate movements, there was a close-to-linear relationship between the orientation angles of the arm (intrinsic coordinates) at its final position and the extrinsic coordinates of the target. When they made accurate movements, these relationships were more nonlinear. 4. Specifically, arm and forearm elevations depended principally on target distance and elevation, whereas the two yaw angles depended mainly on the target's azimuth. 5. We propose that errors in pointing occur because subjects implement a linear approximation to the transformation from extrinsic to intrinsic coordinates and that this transformation is one step in the process of transforming a visually derived representation of target location into an appropriate pattern of muscle activity.