变频相位干涉电场刺激对运动皮层兴奋性及运动学习表现的影响

摘要目的：探究变频相位干涉电场刺激（temporal interference electrical fields stimulation, TI）对健康成年人运动皮层兴奋性及运动学习能力的影响,为TI刺激的应用提供依据。方法：采用随机交叉双盲设计,研究对象为健康成年人。试验1：20例受试者完成经颅磁刺激（transcranial magnetic stimulation,TMS）测试,评估刺激前后皮层兴奋性指标的改变,包括运动诱发电位（motor evoked potential, MEP）、静息运动阈值（resting motor threshold, RMT）、短时距皮层内抑制（short-interval intracortical inhibition, SICI）、皮质内促通（intracortical facilitation, ICF）。试验2：16例受试者完成随机反应时任务（random reaction time task, RRTT）和序列反应时任务（serial reaction time task, SRTT）,测试指标包括平均反应时（reaction time, RT）、第一内隐学习（first implicit learning, FIL）、第二内隐学习（second implicit learning, SIL）。通过双因素重复测量方差分析评价TI刺激对受试者运动皮层兴奋性及运动学习能力的影响。结果：试验1：刺激条件和时间对MEP（F=28.787,P<0.001,ηP2=0.602）和RMT（F=23.524,P<0.001,ηP2=0.580）具有显著交互作用,而SICI和ICF无显著交互效应。试验2：与假刺激相比,TI刺激后SRTT中的FIL有显著提升（F=4.601,P=0.049,ηP2=0.235）,而RRTT任务则无显著交互效应。结论：变频TI刺激可以显著增加初级运动皮层的兴奋性,这种调控效应可能有助于促进健康成年人运动学习表现。

Effects of variable frequency temporal interference electrical fields stimulation on motor cortex excitability and motor learning performance

AbstractObjective： To investigate the effects of temporal interference electrical fields （TI） on motor cortical excitability and motor learning abilities in healthy adults, in order to provide evidence for the application of TI stimulation in human. Method： A randomized crossover double-blind design was used with healthy adults participants. Experiment 1： twenty subjects completed transcranial magnetic stimulation （TMS） testing to assess changes in cortical excitability indicators before and after stimulation, including motor evoked potentials （MEP）, resting motor threshold （RMT）, short-interval intracortical inhibition （SICI）, and intracortical facilitation （ICF）. Experiment 2： sixteen subjects completed the random reaction time task （RRTT） and the serial reaction time task （SRTT）, with performance indicators including average reaction time （RT）, first implicit learning （FIL）, and second implicit learning （SIL）. The effects of TI stimulation on cortical excitability and motor learning abilities were evaluated using a two-factor repeated measures analysis of variance. Result： Experiment 1： there were significant interactions between stimulation condition and time on MEP （F=28.787, P<0.001, ηP2=0.602） and RMT （F=23.524, P<0.001, ηP2=0.580）, while SICI and ICF showed no significant interaction effects. Experiment 2： compared to sham stimulation, FIL in SRTT was significantly improved after TI stimulation （F=4.601, P=0.049, ηP2=0.235）, while there was no significant interaction effect in the RRTT task. Conclusion： Variable frequency TI stimulation can significantly increase cortical excitability in the primary motor cortex, and this regulatory effect may contribute to enhancing motor learning performance in healthy adults.