Hand and joint paths during reaching movements with and without vision
Hand and joint paths during reaching movements with and without vision
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DOI：
10.1007/s002210050503
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发表时间：
1998-09-01
影响因子：
2
通讯作者：
Scott, SH
中科院分区：
文献类型：
--
作者：
Sergio, LE;Scott, SH
本研究探讨是否指向运动的运动学改变的感觉系统用于选择空间目标和引导运动。将人类受试者视觉引导到达运动的手和关节路径与两种非视觉条件进行比较，其中只有本体感觉可用：（1）带眼罩的相同受试者的运动，以及（2）先天失明受试者的运动。虽然手路径曲率总体上是相当小的，有视力的受试者戴着眼罩显示出统计学上的手路径曲率增加相比，他们的视觉引导的运动。蒙眼受试者也表现出更大的手路径曲率比盲人受试者。这些增加的手路径曲率为蒙眼科目并不总是导致关节路径曲率的减少。虽然盲人受试者和视力正常的受试者在某些运动方向上使用视觉存在差异，但这两组之间没有系统性差异。关节路径曲率的大小在运动方向上的变化比手路径曲率大得多。我们发现在联合路径曲率的变化相关的两个因素，一个空间和一个几何。对于所有受试者组，关节路径曲率往往是较小的矢状面运动比横向或对角运动。此外，我们发现关节路径曲率的大小也与每个关节处的相对运动有关。关节路径曲率往往增加时，运动主要涉及肩角的变化，是最小的运动主要涉及肘关节运动。盲人和有视力的受试者的手轨迹的一贯小曲率强调了运动系统产生目标导向的到达运动的强大趋势，即使在生命早期被剥夺视觉反馈时，手轨迹相对较直。
This study examines whether the kinematics of pointing movements are altered by the sensory systems used to select spatial targets and to guide movement. Hand and joint paths of visually guided reaching movements of human subjects were compared with two non-visual conditions where only proprioception was available: (1) movements of the same subjects with blindfolds, and (2) movements by congenitally blind subjects. While hand-path curvatures were overall quite small, sighted subjects wearing a blindfold showed a statistical increase in hand-path curvature compared with their visually guided movements. Blindfolded subjects also showed greater hand-path curvature than blind subjects. These increases in hand-path curvature for blindfolded subjects did not always lead to a decrease in joint-path curvature. While there were differences between blind subjects and sighted subjects using vision for some movement directions, there was no systematic difference between these two groups. The magnitude of joint-path curvature showed much greater variation than hand-path curvature across the movement directions. We found variation in joint-path curvature to be correlated to two factors, one spatial and one geometrical. For all subject groups, joint-path curvature tended to be smaller for sagittal-plane movements than for transverse or diagonal movements. As well, we found that the magnitude of joint-path curvature was also related to the relative motion at each joint. Joint-path curvature tended to increase when movements predominantly involved changes in shoulder angle and was minimal when movements predominantly involved elbow motion. The consistently small curvatures of hand trajectory across blind and sighted subjects emphasize the powerful tendency of the motor system to generate goal-directed reaching movements with relatively straight hand trajectories, even when deprived of visual feedback from very early in life.