Koyama Soichiro, Tanaka Satoshi, Tanabe Shigeo, Sadato Norihiro
Division of Cerebral Integration, National Institute for Physiological Sciences, Aichi 444-8585, Japan; School of Life Sciences, The Graduate University for Advanced Studies, Kanagawa 240-0193, Japan; Department of Rehabilitation, Kawamura Hospital, Gifu 501-3144, Japan.
Laboratory of Psychology, Hamamatsu University School of Medicine, Shizuoka 431-3192, Japan.
Neurosci Lett. 2015 Feb 19;588:49-53. doi: 10.1016/j.neulet.2014.11.043. Epub 2014 Nov 28.
Transcranial direct current stimulation (tDCS) is a noninvasive technique that modulates motor performance and learning. Previous studies have shown that tDCS over the primary motor cortex (M1) can facilitate consolidation of various motor skills. However, the effect of tDCS on consolidation of newly learned ballistic movements remains unknown. The present study tested the hypothesis that tDCS over M1 enhances consolidation of ballistic thumb movements in healthy adults. Twenty-eight healthy subjects participated in an experiment with a single-blind, sham-controlled, between-group design. Fourteen subjects practiced a ballistic movement with their left thumb during dual-hemisphere tDCS. Subjects received 1mA anodal tDCS over the contralateral M1 and 1mA cathodal tDCS over the ipsilateral M1 for 25min during the training session. The remaining 14 subjects underwent identical training sessions, except that dual-hemisphere tDCS was applied for only the first 15s (sham group). All subjects performed the task again at 1h and 24h later. Primary measurements examined improvement in peak acceleration of the ballistic thumb movement at 1h and 24h after stimulation. Improved peak acceleration was significantly greater in the tDCS group (144.2±15.1%) than in the sham group (98.7±9.1%) (P<0.05) at 24h, but not 1h, after stimulation. Thus, dual-hemisphere tDCS over M1 enhanced consolidation of ballistic thumb movement in healthy adults. Dual-hemisphere tDCS over M1 may be useful to improve elemental motor behaviors, such as ballistic movements, in patients with subcortical strokes.
经颅直流电刺激（tDCS）是一种调节运动表现和学习的非侵入性技术。先前的研究表明，经颅直流电刺激初级运动皮层（M1）可促进各种运动技能的巩固。然而，经颅直流电刺激对新学的爆发性动作巩固的影响尚不清楚。本研究检验了以下假设：对M1进行经颅直流电刺激可增强健康成年人爆发性拇指动作的巩固。28名健康受试者参与了一项单盲、假刺激对照、组间设计的实验。14名受试者在双侧半球经颅直流电刺激期间用左手拇指练习爆发性动作。在训练期间，受试者在对侧M1接受1mA阳极经颅直流电刺激，在同侧M1接受1mA阴极经颅直流电刺激，持续25分钟。其余14名受试者接受相同的训练，只是双侧半球经颅直流电刺激仅在前15秒施加（假刺激组）。所有受试者在1小时和24小时后再次执行任务。主要测量指标是刺激后1小时和24小时爆发性拇指动作的峰值加速度改善情况。刺激后24小时，经颅直流电刺激组（144.2±15.1%）的峰值加速度改善显著大于假刺激组（98.7±9.1%）（P<0.05），但在1小时时并非如此。因此，对M1进行双侧半球经颅直流电刺激可增强健康成年人爆发性拇指动作的巩固。对M1进行双侧半球经颅直流电刺激可能有助于改善皮质下中风患者的基本运动行为，如爆发性动作。
