Ranganathan Rajiv, Wieser Jon, Mosier Kristine M, Mussa-Ivaldi Ferdinando A, Scheidt Robert A
Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, Illinois 60611, Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, Illinois 60611,
Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233.
J Neurosci. 2014 Jun 11;34(24):8289-99. doi: 10.1523/JNEUROSCI.4455-13.2014.
Prior learning of a motor skill creates motor memories that can facilitate or interfere with learning of new, but related, motor skills. One hypothesis of motor learning posits that for a sensorimotor task with redundant degrees of freedom, the nervous system learns the geometric structure of the task and improves performance by selectively operating within that task space. We tested this hypothesis by examining if transfer of learning between two tasks depends on shared dimensionality between their respective task spaces. Human participants wore a data glove and learned to manipulate a computer cursor by moving their fingers. Separate groups of participants learned two tasks: a prior task that was unique to each group and a criterion task that was common to all groups. We manipulated the mapping between finger motions and cursor positions in the prior task to define task spaces that either shared or did not share the task space dimensions (x-y axes) of the criterion task. We found that if the prior task shared task dimensions with the criterion task, there was an initial facilitation in criterion task performance. However, if the prior task did not share task dimensions with the criterion task, there was prolonged interference in learning the criterion task due to participants finding inefficient task solutions. These results show that the nervous system learns the task space through practice, and that the degree of shared task space dimensionality influences the extent to which prior experience transfers to subsequent learning of related motor skills.
先前对运动技能的学习会形成运动记忆，这些记忆可能会促进或干扰新的但相关的运动技能的学习。运动学习的一种假设认为，对于具有冗余自由度的感觉运动任务，神经系统会学习任务的几何结构，并通过在该任务空间内进行选择性操作来提高表现。我们通过研究两项任务之间的学习迁移是否取决于它们各自任务空间之间的共享维度，来检验这一假设。人类参与者佩戴数据手套，通过移动手指来学习操纵电脑光标。不同组的参与者学习两项任务：每组独有的先前任务和所有组共有的标准任务。我们在前一项任务中操纵手指动作与光标位置之间的映射，以定义与标准任务共享或不共享任务空间维度（x-y轴）的任务空间。我们发现，如果先前任务与标准任务共享任务维度，那么在标准任务表现上会有初始促进作用。然而，如果先前任务与标准任务不共享任务维度，由于参与者找到低效的任务解决方案，在学习标准任务时会有长期干扰。这些结果表明，神经系统通过练习学习任务空间，并且共享任务空间维度的程度会影响先前经验转移到后续相关运动技能学习的程度。
