Adaptation Paths to Novel Motor Tasks Are Shaped by Prior Structure Learning
Adaptation Paths to Novel Motor Tasks Are Shaped by Prior Structure Learning
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DOI：
10.1523/jneurosci.0958-12.2012
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发表时间：
2012-07-18
影响因子：
5.3
通讯作者：
Mehring, Carsten
中科院分区：
文献类型：
--
作者：
Kobak, Dmitry;Mehring, Carsten
经过广泛的实践与运动任务共享结构相似性（e。例如，在一个实施例中，不同的舞蹈动作，或不同的剑法），可以更快地学习相同类型的新任务。根据最近的“结构学习”假设（Braun et al.，2009 a），相关运动技能的这种快速概括依赖于学习由这组技能共享的动力学和运动学关系。因此，运动适应变得受限，有效地导致学习问题的维度降低;与此同时，对结构之外的任务的适应变得偏向于结构。我们通过调查先前学习的结构如何影响随后的运动适应来测试这些预测。人类受试者在3D虚拟现实中进行伸展运动，经历垂直或水平平面的扰动。扰动要么是视觉旋转的角度变化，要么是速度依赖的力量变化的强度。我们发现，经过运动学或动力学扰动的广泛训练后，对未练习的对角扰动的适应发生在沿着先前学习的结构（垂直或水平），并且由此产生的适应轨迹是弯曲的。这种效应是稳健的，可以在单个受试者水平上观察到，并且在试验内和试验间的适应过程中发生。此外，我们证明，结构学习改变不自主的视觉反射，因此并不完全是一个高层次的认知现象。
After extensive practice with motor tasks sharing structural similarities (e. g., different dancing movements, or different sword techniques), new tasks of the same type can be learned faster. According to the recent "structure learning" hypothesis (Braun et al., 2009a), such rapid generalization of related motor skills relies on learning the dynamic and kinematic relationships shared by this set of skills. As a consequence, motor adaptation becomes constrained, effectively leading to a dimensionality reduction of the learning problem; at the same time, adaptation to tasks lying outside the structure becomes biased toward the structure. We tested these predictions by investigating how previously learned structures influence subsequent motor adaptation. Human subjects were making reaching movements in 3D virtual reality, experiencing perturbations either in the vertical or in the horizontal plane. Perturbations were either visuomotor rotations of varying angle or velocity-dependent forces of varying strength. We found that, after extensive training with both kinematic or dynamic perturbations, adaptation to unpracticed, diagonal, perturbations happened along the previously learned structure (vertical or horizontal), and resulting adaptation trajectories were curved. This effect is robust, can be observed on the single-subject level, and occurs during adaptation both within and across trials. Additionally, we demonstrate that structure learning changes involuntary visuomotor reflexes and therefore is not exclusively a high-level cognitive phenomenon.