Faculty of Sciences of Sport and Physical Education, Department of Physical Education, University of A Coruña, Av. Ernesto Che Guevara 121, Pazos-Liáns, E-15179 Oleiros, A Coruña, Spain.
University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Groningen, The Netherlands.
Neuroscience. 2021 Jul 1;466:26-35. doi: 10.1016/j.neuroscience.2021.05.001. Epub 2021 May 8.
Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that may improve motor learning. However, the long-term effects of tDCS have not been explored, and the ecological validity of the evaluated tasks was limited. To determine whether 20 sessions of tDCS over the primary motor cortex (M1) would enhance the performance of a complex life motor skill, i.e., typing, in healthy young adults. Healthy young adults (n = 60) were semi-randomly assigned to three groups: the tDCS group (n = 20) received anodal tDCS over M1; the SHAM group (n = 20) received sham tDCS, both while performing a typing task; and the Control group (CON, n = 20) only performed the typing task. Typing speed and errors at maximum (mTT) and submaximal (iTT) speeds were measured before training, and after 10 and 20 sessions of tDCS. Every subject increased maximum typing speed after 10 and 20 tDCS sessions, with no significant differences (p > 0.05) between the groups. The number of errors at submaximal rates decreased significantly (p < 0.05) by 4% after 10 tDCS sessions compared with the 3% increase in the SHAM and the 2% increase in the CON groups. Between the 10th and 20th tDCS sessions, the number of typing errors increased significantly in all groups. While anodal tDCS reduced typing errors marginally, such performance-enhancing effects plateaued after 10 sessions without any further improvements in typing speed. These findings suggest that long-term tDCS may not have functionally relevant effects on healthy young adults' typing performance.
经颅直流电刺激（tDCS）是一种非侵入性脑刺激技术，可能改善运动学习。然而，tDCS 的长期效果尚未得到探索，并且评估任务的生态有效性受到限制。为了确定 20 次经颅直流电刺激初级运动皮层（M1）是否会增强健康年轻成年人复杂生活运动技能的表现，例如打字。将 60 名健康年轻成年人随机分为三组：tDCS 组（n=20）接受 M1 上的阳极 tDCS；假刺激组（SHAM，n=20）接受假刺激，同时进行打字任务；对照组（CON，n=20）仅进行打字任务。在训练前、10 次和 20 次 tDCS 后测量打字速度和最大速度（mTT）和亚最大速度（iTT）的错误。每个受试者在 10 次和 20 次 tDCS 后最大打字速度均增加，组间无显著差异（p>0.05）。与 SHAM 组增加 3%和 CON 组增加 2%相比，10 次 tDCS 后亚最大速度的错误数量显著减少（p<0.05）减少了 4%。在第 10 次和第 20 次 tDCS 之间，所有组的打字错误数量均显著增加。阳极 tDCS 虽能略微减少打字错误，但在 10 次治疗后，这种增强表现的效果趋于平稳，打字速度没有进一步提高。这些发现表明，长期 tDCS 可能对健康年轻成年人的打字表现没有功能相关的影响。
