Transfer and durability of acquired patterns of human arm stiffness.
Transfer and durability of acquired patterns of human arm stiffness.
复制标题
人类手臂僵硬的后天模式的转移和持久性。
DOI：
10.1007/s00221-005-0204-x
复制
发表时间：
2006
影响因子：
2
通讯作者：
Ostry,DavidJ
中科院分区：
文献类型：
--
作者：
Darainy,Mohammad;Malfait,Nicole;Towhidkhah,Farzad;Ostry,DavidJ
以前的研究表明，神经系统可以产生预期的调整，改变手臂的机械行为，以抵抗环境干扰。在本文中，我们重点关注受试者将获得的刚度模式转移到工作空间其他部分的能力以及刚度适应的持久性。为了探索刚度控制的转移，受试者在工作空间的左侧接受训练，以抵抗由机器人设备施加的单轴扰动的影响。在训练之后，他们接受了右侧转移的测试。一组受试者在工作空间的左侧和右侧经历了类似的扭矩，而另一组受试者在手上经历了类似的力。在左侧的初始训练之后，观察到的手僵硬椭圆的方向在干扰的方向上旋转。在右侧的测试中，只有当干扰方向导致的扭矩与训练期间经历的扭矩相似时，才观察到转移。因此，结果表明，在该实验的条件下，刚度控制在基于关节或肌肉的坐标系中获得和传递。第二个实验评估了获得的刚度模式的耐久性。受试者接受连续2天的训练，以抵抗单轴干扰。在第三天，扰动的方向改变了90°。观察到对新适应的实质性干扰。这表明，僵硬度训练导致神经信号的持久变化，这些信号是僵硬度控制的基础。
Previous studies have shown that the nervous system can produce anticipatory adjustments that alter the mechanical behavior of the arm in order to resist environmental disturbances. In the present paper, we focus on the ability of subjects to transfer acquired stiffness patterns to other parts of the workspace and on the durability of stiffness adaptations. To explore the transfer of stiffness control, subjects were trained at the left of the workspace to resist the effects of a single-axis disturbance that was applied by a robotic device. Following training, they were tested for transfer at the right. One group of subjects experienced similar torques at the left and right of the workspace, whereas the other group of subjects experienced similar forces at the hand. Following the initial training at the left, the observed orientation of the hand-stiffness ellipse rotated in the direction of the disturbance. In tests at the right, transfer was observed only when the direction of disturbance resulted in torques that were similar to those experienced during training. The results thus suggest that under the conditions of this experiment stiffness control is acquired and transfers in a joint- or muscle-based system of coordinates. A second experiment assessed the durability of an acquired stiffness pattern. Subjects were trained on 2 consecutive days to resist a single-axis disturbance. On a third day, the direction of the disturbance was switched by 90°. Substantial interference with the new adaptation was observed. This suggests that stiffness training results in durable changes to the neural signals that underlie stiffness control.