Neural Correlates of the Contextual Interference Effect in Motor Learning: A Transcranial Magnetic Stimulation Investigation
Neural Correlates of the Contextual Interference Effect in Motor Learning: A Transcranial Magnetic Stimulation Investigation
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DOI：
10.1080/00222895.2010.492720
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发表时间：
2010-01-01
影响因子：
1.4
通讯作者：
Wu, Allan D.
中科院分区：
文献类型：
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作者：
Lin, Chien-Ho (Janice);Winstein, Carolee J.;Wu, Allan D.
作者应用经颅磁刺激(TMS)研究了初级运动皮质(M1)在运动学习中的背景干扰效应中的因果作用。以前使用非焦点TMS线圈的研究表明，M1在高干扰练习条件下发挥着偶然的作用，但这一假设尚未得到证实。在第一个实验中，参与者按顺序或随机顺序练习了3个快速屈肘-伸展任务，并通过延迟保持测试评估学习情况。TMS在练习过程中使用中心位于对侧M1上方的圆形线圈在反馈后立即传递。每个参与者都有3种TMS条件中的一种：无TMS、真实TMS或假TMS。虽然在习得过程中，两组之间没有显著差异，但随机组的保持效果好于阻断组。随机练习的学习效益在真实TMS条件下有所减弱，但在假TMS或无TMS条件下不会减弱。在第二个实验中，作者研究了在随机练习条件下，阈值上TMS和阈值下TMS对M1、外侧运动前皮质和外周手臂的刺激对运动学习的影响。作者发现，与其他刺激条件相比，只有在M1上的阈值以上的TM才会产生显著的保持中断。结果表明，M1内的高阈值神经元群体对于随机而不是阻断的练习后增强记忆能力具有重要意义。结果还支持早期试验间隔是练习期间M1活动的关键时期。总体而言，这些结果表明，M1内的神经回路有助于运动学习过程，这取决于学习者的训练经验。结果有助于了解M1在高干扰练习条件下在产生学习优势方面所起的关键和特定作用。
The authors applied transcranial magnetic stimulation (TMS) to investigate the causal role of the primary motor cortex (M1) for the contextual-interference effect in motor learning. Previous work using a nonfocal TMS coil suggested a casual role for M1 during high-interference practice conditions, but this hypothesis has not yet been proven. In the 1st experiment, participants practiced 3 rapid elbow flexion-extension tasks in either a blocked or random order, with learning assessed by a delayed retention test. TMS was delivered immediately after feedback during practice using a circular coil, centered over the contralateral M1. Each participant practiced with 1 of 3 TMS conditions: no TMS, real TMS, or sham TMS. Although no significant differences were observed between groups during acquisition, retention of the random group was better than the blocked group. The learning benefits of random practice were attenuated in the real-TMS condition, but not in the sham-TMS or no-TMS conditions. In the 2nd experiment, the authors studied the effects of suprathreshold TMS and subthreshold TMS over M1, lateral premotor cortex, and peripheral arm stimulation using a focal figure-8 coil on motor learning under random practice conditions. The authors found that only suprathreshold TMS on M1 produced significant disruption of retention compared to the other stimulation conditions. Results suggest that a high-threshold neuronal population within M1 is causally important for enhanced retention following random, but not block, practice. Results also support the early intertrial interval as a critical period of M1 activity during practice. Overall, these results suggest neural circuits within M1 contribute to motor learning processing that depends on learners' training experience. Results contribute to knowledge of the critical and specific role that M1 plays in generating a learning advantage following high-interference practice conditions.