Contribution of explicit processes to reinforcement-based motor learning
Contribution of explicit processes to reinforcement-based motor learning
复制标题
DOI：
10.1152/jn.00901.2017
复制
发表时间：
2018-06-01
影响因子：
2.5
通讯作者：
Galea, Joseph M.
中科院分区：
文献类型：
--
作者：
Holland, Peter;Codol, Olivier;Galea, Joseph M.
尽管人们对运动学习中奖励的作用越来越感兴趣，但其潜在机制仍不明确。特别是，外显过程对基于奖励的运动学习的贡献尚不清楚。为了解决这个问题，我们检查了受试者（n = 30）学习补偿逐渐引入的25度视觉运动旋转的能力，只有基于奖励的反馈（二元成功/失败）。只有三分之二的受试者（n = 20）在最大角度下成功。其余受试者最初遵循旋转，但经过不同次数的试验后，开始达到不够大的角度，随后恢复到接近基线的表现（n = 10）。此外，那些成功的人通过一个大的显式组件完成了这一点。当他们被要求去除他们所使用的任何策略时，他们的伸入角度就会减少。然而，即使在移除这一显性成分后，两组人都表现出了小程度的剩余记忆。在不正确的（无奖励的）试验后，所有受试者的伸臂角度都发生了更大、更可变的变化。然而，学习失败的受试者表现出对错误的敏感度下降，即使在他们遵循旋转的最初阶段也是如此，这种模式以前在帕金森患者中发现过。在第二个实验中，增加第二个心理旋转任务完全取消了学习（n = 10），而对照组重复了第一个实验的结果（n = 10）。这些结果强调了外显过程在基于强化的运动学习中的关键作用，并且这种形式的学习对中断的易感性对其潜在的治疗益处具有重要意义。新的和值得注意的是，我们证明学习视觉运动旋转只有基于奖励的反馈主要是通过开发一个大的显式组件来完成的。此外，这种形式的学习很容易受到次要任务的干扰。结果表明，利用基于奖励的反馈的未来实验应该旨在剖析内隐和显式强化学习系统的作用。基于奖励的运动学习治疗方法应该意识到对干扰的敏感性。
Despite increasing interest in the role of reward in motor learning, the underlying mechanisms remain ill defined. In particular, the contribution of explicit processes to reward-based motor learning is unclear. To address this, we examined subjects' (n = 30) ability to learn to compensate for a gradually introduced 25 degrees visuomotor rotation with only reward-based feedback (binary success/failure). Only two-thirds of subjects (n = 20) were successful at the maximum angle. The remaining subjects initially followed the rotation but after a variable number of trials began to reach at an insufficiently large angle and subsequently returned to near-baseline performance (n = 10). Furthermore, those who were successful accomplished this via a large explicit component. evidenced by a reduction in reach angle when they were asked to remove any strategy they employed. However, both groups displayed a small degree of remaining retention even after the removal of this explicit component. All subjects made greater and more variable changes in reach angle after incorrect (unrewarded) trials. However, subjects who failed to learn showed decreased sensitivity to errors, even in the initial period in which they followed the rotation, a pattern previously found in parkinsonian patients. In a second experiment, the addition of a secondary mental rotation task completely abolished learning (n = 10), while a control group replicated the results of the first experiment (n = 10). These results emphasize a pivotal role of explicit processes during reinforcement-based motor learning, and the susceptibility of this form of learning to disruption has important implications for its potential therapeutic benefits.NEW & NOTEWORTHY We demonstrate that learning a visuomotor rotation with only reward-based feedback is principally accomplished via the development of a large explicit component. Furthermore, this form of learning is susceptible to disruption with a secondary task. The results suggest that future experiments utilizing reward-based feedback should aim to dissect the roles of implicit and explicit reinforcement learning systems. Therapeutic motor learning approaches based on reward should be aware of the sensitivity to disruption.