School of Psychology and Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
School of Psychology and Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
J Neurosci. 2019 Nov 20;39(47):9383-9396. doi: 10.1523/JNEUROSCI.0583-19.2019. Epub 2019 Oct 11.
The addition of rewarding feedback to motor learning tasks has been shown to increase the retention of learning, spurring interest in its possible utility for rehabilitation. However, motor tasks using rewarding feedback have repeatedly been shown to lead to great interindividual variability in performance. Understanding the causes of such variability is vital for maximizing the potential benefits of reward-based motor learning. Thus, using a large human cohort of both sexes ( = 241), we examined whether spatial (SWM), verbal, and mental rotation (RWM) working memory capacity and dopamine-related genetic profiles were associated with performance in two reward-based motor tasks. The first task assessed the participant's ability to follow a slowly shifting reward region based on hit/miss (binary) feedback. The second task investigated the participant's capacity to preserve performance with binary feedback after adapting to the rotation with full visual feedback. Our results demonstrate that higher SWM is associated with greater success and an enhanced capacity to reproduce a successful motor action, measured as change in reach angle following reward. In contrast, higher RWM was predictive of an increased propensity to express an explicit strategy when required to make large reach angle adjustments. Therefore, SWM and RWM were reliable, but dissociable, predictors of success during reward-based motor learning. Change in reach direction following failure was also a strong predictor of success rate, although we observed no consistent relationship with working memory. Surprisingly, no dopamine-related genotypes predicted performance. Therefore, working memory capacity plays a pivotal role in determining individual ability in reward-based motor learning. Reward-based motor learning tasks have repeatedly been shown to lead to idiosyncratic behaviors that cause varying degrees of task success. Yet, the factors determining an individual's capacity to use reward-based feedback are unclear. Here, we assessed a wide range of possible candidate predictors, and demonstrate that domain-specific working memory plays an essential role in determining individual capacity to use reward-based feedback. Surprisingly, genetic variations in dopamine availability were not found to play a role. This is in stark contrast with seminal work in the reinforcement and decision-making literature, which show strong and replicated effects of the same dopaminergic genes in decision-making. Therefore, our results provide novel insights into reward-based motor learning, highlighting a key role for domain-specific working memory capacity.
奖励反馈在运动学习任务中的应用已被证明可以提高学习的保持率，这激发了人们对其在康复中的可能应用的兴趣。然而，使用奖励反馈的运动任务一再显示出在性能上存在很大的个体间变异性。了解这种变异性的原因对于最大限度地发挥基于奖励的运动学习的潜在益处至关重要。因此，我们使用一个包含大量男女参与者的队列（=241），研究了空间工作记忆（SWM）、言语工作记忆和心理旋转（RWM）工作记忆容量以及多巴胺相关的遗传特征是否与两项基于奖励的运动任务的表现相关。第一项任务评估了参与者根据命中/失误（二进制）反馈跟随缓慢变化的奖励区域的能力。第二项任务研究了参与者在适应全视觉反馈的旋转后，用二进制反馈保持表现的能力。我们的结果表明，较高的 SWM 与更大的成功和增强的能力相关，以改变奖励后的到达角度来再现成功的运动动作。相比之下，较高的 RWM 预测了在需要进行大角度调整时表达明确策略的倾向增加。因此，SWM 和 RWM 是成功进行基于奖励的运动学习的可靠但可分离的预测指标。失败后到达方向的变化也是成功率的一个强有力的预测指标，尽管我们没有观察到与工作记忆的一致关系。令人惊讶的是，没有多巴胺相关的基因型可以预测表现。因此，工作记忆容量在决定个体在基于奖励的运动学习中的能力方面起着关键作用。基于奖励的运动学习任务一再显示出导致不同程度任务成功的特质行为。然而，决定个体使用奖励反馈的能力的因素尚不清楚。在这里，我们评估了广泛的可能预测指标，并证明特定领域的工作记忆在决定个体使用奖励反馈的能力方面起着至关重要的作用。令人惊讶的是，多巴胺可用性的遗传变异没有被发现起作用。这与强化和决策文献中的开创性工作形成鲜明对比，这些工作表明相同的多巴胺基因在决策中具有强烈且可重复的影响。因此，我们的研究结果为基于奖励的运动学习提供了新的见解，强调了特定领域工作记忆容量的关键作用。
