经颅电刺激下工作记忆和运动想象的相关性研究

The correlation between working memory and motor imagery under transcranial electrical stimulation

目的研究经颅直流电刺激(tDCS)下工作记忆(WM)和运动想象(MI)脑网络拓扑结构和特征参数的相关性。方法采集被试伪/阳极tDCS刺激后观察平面图片想象右手手部动作(伸展手臂)、手指动作(手握水杯)的脑电信号(EEG)以及被试三图、四图WM负载下的EEG做对比分析,对不同难度MI和WM任务的EEG网络特征变化进行分析并对类似难度的MI和WM任务的相同EEG网络特征参数变化率做相关性验证。结果阳极tDCS刺激后MI任务和记忆负载任务中的网络特征参数较伪tDCS刺激均显著增加(P<0.05),同时伸展手臂MI任务与三图负载WM任务的功能脑网络参数呈现一定程度的正相关,手握水杯MI任务与四图负载WM任务亦是如此,且阳极tDCS的介入使这种相关性更加显著。结论阳极tDCS既增强WM也同步改善MI脑网络特征,且二者存在正相关。

Objective To study the correlation between brain network topology and characteristic parameters of working memory(WM)and motor imagery(MI)under transcranial direct current stimulation(tDCS).Methods After the subjects were stimulated,the EEG signals(EEG)of the right hand hand movement(stretching arm)and finger movement(holding cup of water in hand)were imagined by observing the plane pictures,and the EEG under the WM load of the third and fourth pictures of the subjects were used for comparative analysis.The changes of EEG network characteristics of MI and WM tasks with different difficulty were analyzed and the correlation of the change rate of the same EEG network characteristic parameters of MI and WM tasks with similar difficulty was verified.Results Following anodal transcranial direct current stimulation(tDCS),the network characteristic parameters in both motor imagery(MI)tasks and memory load tasks significantly increased compared to sham tDCS stimulation(P<0.05).Additionally,there was a moderate positive correlation between the functional brain network parameters in the arm extension MI task and those in the three-figure load working memory(WM)task.A similar correlation was observed between the cup-grasping MI task and the four-figure load WM task.The intervention of anodal tDCS further enhanced these correlations.Conclusion Anodic tDCS not only enhances WM but also simultaneously improves the characteristics of MI brain network,and there is a positive correlation between them.