Task-specific internal models for kinematic transformations
Task-specific internal models for kinematic transformations
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DOI：
10.1152/jn.01087.2002
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发表时间：
2003-08-01
影响因子：
2.5
通讯作者：
Flanagan, JR
中科院分区：
文献类型：
--
作者：
Tong, C;Flanagan, JR
许多关于运动学习的研究都集中在人们如何使他们的伸手动作适应新的动态和视觉运动扰动，从而改变手的实际或视觉感知的运动。这项工作的一个重要发现是，新动态的学习可以推广到不同的运动任务。因此，对不寻常力场的适应概括为从中心向外的伸展运动到圆周运动（Conditt et al. 1997）。这表明受试者获得了动态环境的内部模型，可用于确定未经训练的运动所需的运动命令。使用任务干扰范式，我们研究了在学习视觉运动转换时是否也观察到跨任务的转移。第一天，所有受试者都适应 +30 度旋转，同时进行从中心向外和向后伸展的动作。延迟 5 分钟后，不同组的受试者在执行连续跟踪任务、8 字形绘图任务或中心向外和向后伸手任务时适应 +30 度旋转。第二天，所有受试者都在 +30 度旋转的伸展任务中重新进行测试。正如预期的那样，在执行相同的触及任务时经历相反旋转的受试者在第 2 天测试时没有表现出对第一次旋转的学习记忆（Krakauer 等人，1999）。相比之下，在执行不同任务时经历相反旋转的两组受试者中没有观察到这种逆行干扰。事实上，他们在第二天的表现与从未经历过相反轮换的对照组相似。这种干扰的缺乏表明视觉运动旋转的记忆资源是特定于任务的。
Numerous studies of motor learning have focused on how people adapt their reaching movements to novel dynamic and visuomotor perturbations that alter the actual or visually perceived motion of the hand. An important finding from this work is that learning of novel dynamics generalizes across different movement tasks. Thus adaptation to an unusual force field generalizes from center-out reaching movements to circular movements (Conditt et al. 1997). This suggests that subjects acquired an internal model of the dynamic environment that could be used to determine the motor commands needed for untrained movements. Using a task interference paradigm, we investigated whether transfer across tasks is also observed when learning visuomotor transformations. On day 1, all subjects adapted to a +30degrees rotation while making center-out-and-back reaching movements. After a delay of 5 min, different groups of subjects then adapted to a +30degrees rotation while performing either a continuous tracking task, a figure-eight drawing task, or the center-out-and-back reaching task. All subjects were then retested the next day on the +30degrees rotation in the reaching task. As expected, subjects who experienced the opposing rotations while performing the same reaching tasks showed no retention of learning for the first rotation when tested on day 2 ( Krakauer et al. 1999). In contrast, such retrograde interference was not observed in the two groups of subjects who experienced the opposing rotations while performing different tasks. In fact, their performance on day 2 was similar to that of control subjects who never experienced the opposite rotation. This lack of interference suggests that memory resources for visuomotor rotations are task specific.