Yadav Goldy, Vassiliadis Pierre, Dubuc Cecile, Hummel Friedhelm C, Derosiere Gerard, Duque Julie
Institute of Neuroscience, Université catholique de Louvain, Brussels 1200, Belgium
Institute of Neuroscience, Université catholique de Louvain, Brussels 1200, Belgium.
eNeuro. 2025 Apr 10;12(4). doi: 10.1523/ENEURO.0410-24.2025. Print 2025 Apr.
Human motor skill acquisition is improved by performance feedback, and coupling such feedback with extrinsic reward (such as money) can enhance skill learning. However, the neurophysiology underlying such behavioral effect is unclear. To bridge this gap, we assessed the effects of reward on multiple forms of motor plasticity during skill learning. Sixty-five healthy participants divided into three groups performed a pinch-grip skill task with sensory feedback only, sensory and reinforcement feedback, or both feedback coupled with an extrinsic monetary reward during skill training. To probe motor plasticity, we applied transcranial magnetic stimulation at rest, on the left primary motor cortex before, at an early-training time point, and after training in the three groups and measured motor-evoked potentials from task-relevant muscle of the right arm. This allowed us to evaluate the amplitude and variability of corticospinal output, GABAergic short-intracortical inhibition, and use-dependent plasticity before training and at two additional time points (early and end training). At the behavioral level, monetary reward accelerated skill learning. In parallel, corticospinal output became less variable early on during training in the presence of extrinsic reward. Interestingly, this effect was particularly pronounced for participants who were more sensitive to reward, as evaluated in an independent questionnaire. Other measures of motor excitability remained comparable across groups. These findings highlight that a mechanism underlying the benefit of reward on motor skill learning is the fine-tuning of early-training resting-state corticospinal variability.
运动表现反馈可改善人类运动技能的习得，将这种反馈与外部奖励（如金钱）相结合能够增强技能学习。然而，这种行为效应背后的神经生理学机制尚不清楚。为了填补这一空白，我们评估了奖励在技能学习过程中对多种形式运动可塑性的影响。65名健康参与者被分为三组，在技能训练期间，分别仅接受感觉反馈、感觉和强化反馈，或两种反馈并伴有外部金钱奖励的情况下执行捏握技能任务。为了探究运动可塑性，我们在三组参与者休息时、训练前的早期训练时间点以及训练后，对左侧初级运动皮层施加经颅磁刺激，并测量右臂与任务相关肌肉的运动诱发电位。这使我们能够在训练前以及另外两个时间点（早期和训练结束时）评估皮质脊髓输出的幅度和变异性、GABA能短程皮质内抑制以及使用依赖性可塑性。在行为层面，金钱奖励加速了技能学习。与此同时，在存在外部奖励的情况下，训练早期皮质脊髓输出的变异性降低。有趣的是，正如在一份独立问卷中所评估的那样，这种效应在对奖励更为敏感的参与者中尤为明显。各组之间运动兴奋性的其他指标保持相当。这些发现突出表明，奖励对运动技能学习有益的一个潜在机制是对训练早期静息状态下皮质脊髓变异性的微调。
