Fleury Lisa, Panico Francesco, Foncelle Alexandre, Revol Patrice, Delporte Ludovic, Jacquin-Courtois Sophie, Collet Christian, Rossetti Yves
INSERM UMR-S, CNRS UMS, Trajectoires Lyon Neuroscience Research Center (CRNL), Bron, France.
Defitech Chair for Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), École polytechnique fédérale de Lausanne (EPFL) Valais, Sion, Switzerland.
Front Psychol. 2022 Sep 27;13:909565. doi: 10.3389/fpsyg.2022.909565. eCollection 2022.
Prism Adaptation (PA) is a useful method to study the mechanisms of sensorimotor adaptation. After-effects following adaptation to the prismatic deviation constitute the probe that adaptive mechanisms occurred, and current evidence suggests an involvement of the cerebellum at this level. Whether after-effects are transferable to another task is of great interest both for understanding the nature of sensorimotor transformations and for clinical purposes. However, the processes of transfer and their underlying neural substrates remain poorly understood. Transfer from throwing to pointing is known to occur only in individuals who had previously reached a good level of expertise in throwing (e.g., dart players), not in novices. The aim of this study was to ascertain whether anodal stimulation of the cerebellum could boost after-effects transfer from throwing to pointing in novice participants. Healthy participants received anodal or sham transcranial direction current stimulation (tDCS) of the right cerebellum during a PA procedure involving a throwing task and were tested for transfer on a pointing task. Terminal errors and kinematic parameters were in the dependent variables for statistical analyses. Results showed that active stimulation had no significant beneficial effects on error reduction or throwing after-effects. Moreover, the overall magnitude of transfer to pointing did not change. Interestingly, we found a significant effect of the stimulation on the longitudinal evolution of pointing errors and on pointing kinematic parameters during transfer assessment. These results provide new insights on the implication of the cerebellum in transfer and on the possibility to use anodal tDCS to enhance cerebellar contribution during PA in further investigations. From a network approach, we suggest that cerebellum is part of a more complex circuitry responsible for the development of transfer which is likely embracing the primary motor cortex due to its role in motor memories consolidation. This paves the way for further work entailing multiple-sites stimulation to explore the role of M1-cerebellum dynamic interplay in transfer.
棱镜适应（PA）是一种研究感觉运动适应机制的有用方法。适应棱镜偏差后的后效应构成了适应性机制发生的探测指标，目前的证据表明小脑在这一水平上发挥了作用。后效应是否可转移到另一任务，对于理解感觉运动转换的本质以及临床应用都具有重要意义。然而，转移过程及其潜在的神经基质仍知之甚少。已知从投掷到指向的转移仅发生在先前在投掷方面达到较高专业水平的个体（如飞镖玩家）中，新手则不会发生。本研究的目的是确定小脑的阳极刺激是否能促进新手参与者从投掷到指向的后效应转移。健康参与者在涉及投掷任务的PA过程中接受右侧小脑的阳极或假经颅定向电流刺激（tDCS），并在指向任务上测试转移情况。终点误差和运动学参数作为统计分析的因变量。结果表明，主动刺激对减少误差或投掷后效应没有显著的有益影响。此外，转移到指向的总体程度没有变化。有趣的是，我们发现在转移评估期间，刺激对指向误差的纵向演变和指向运动学参数有显著影响。这些结果为小脑在转移中的作用以及在进一步研究中使用阳极tDCS增强PA期间小脑贡献的可能性提供了新的见解。从网络角度来看，我们认为小脑是一个更复杂电路的一部分，该电路负责转移的发展，由于其在运动记忆巩固中的作用，可能包含初级运动皮层。这为进一步开展多部位刺激的工作铺平了道路，以探索M1-小脑动态相互作用在转移中的作用。
