Motor Learning Enhances Use-Dependent Plasticity
Motor Learning Enhances Use-Dependent Plasticity
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DOI：
10.1523/jneurosci.3303-16.2017
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发表时间：
2017-03-08
影响因子：
5.3
通讯作者：
Celnik, Pablo
中科院分区：
文献类型：
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作者：
Mawase, Firas;Uehara, Shintaro;Celnik, Pablo
运动行为不仅取决于当前的感觉信号，还取决于最近的经历。例如，朝向特定目标的重复运动会使后续运动偏向该目标方向。这个过程被称为使用依赖性可塑性（UDP），被认为是形成运动记忆的基本且与目标无关的方式。大多数研究认为运动史是导致 UDP 的关键组成部分（Classen 等人，1998 年；Verstynen 和 Sabes，2011 年）。然而，运动重复过程中学习（即提高性能）对 UDP 的影响尚未得到研究。在这里，我们在两个实验中使用经颅磁刺激来评估个体重复强化和非强化动作后初级运动皮层发生的可塑性变化。第一个实验评估了学习技能任务是否会调节 UDP。我们发现，成功学习技能任务的小组比没有积累学习但进行了类似重复动作的小组表现出更高的 UDP。第二个实验旨在了解强化学习在 UDP 中的作用，同时控制奖励幅度和动作运动学。我们发现，在没有光标视觉反馈的情况下为受试者提供二元奖励会导致 UDP 效果增加。获得与他们的行为无关的类似奖励的组中的受试者保持先前诱导的 UDP。我们的研究结果说明了加强一致的行动如何增强依赖于使用的记忆，并提供对调节运动皮层可塑性变化的操作机制的见解。
Motor behaviors are shaped not only by current sensory signals but also by the history of recent experiences. For instance, repeated movements toward a particular target bias the subsequent movements toward that target direction. This process, called use-dependent plasticity (UDP), is considered a basic and goal-independent way of forming motor memories. Most studies consider movement history as the critical component that leads to UDP (Classen et al., 1998; Verstynen and Sabes, 2011). However, the effects of learning (i.e., improved performance) on UDP during movement repetition have not been investigated. Here, we used transcranial magnetic stimulation in two experiments to assess plasticity changes occurring in the primary motor cortex after individuals repeated reinforced and nonreinforced actions. The first experiment assessed whether learning a skill task modulates UDP. We found that a group that successfully learned the skill task showed greater UDP than a group that did not accumulate learning, but made comparable repeated actions. The second experiment aimed to understand the role of reinforcement learning in UDP while controlling for reward magnitude and action kinematics. We found that providing subjects with a binary reward without visual feedback of the cursor led to increased UDP effects. Subjects in the group that received comparable reward not associated with their actions maintained the previously induced UDP. Our findings illustrate how reinforcing consistent actions strengthens use-dependent memories and provide insight into operant mechanisms that modulate plastic changes in the motor cortex.