Research Of Transcranial Electrical Stimulation On Brain Functional Network Of Working Memory

As an advanced cognitive function of the brain,working memory plays an important role in peoples daily study,life,work and other aspects.Studies have found that the ability of the working memory system declines with age.How to effectively restore or improve working memory ability is of great significance in clinical research.Neuromodulation technology has been widely used in the intervention of brain activity.Common control technologies include electrical stimulation,magnetic stimulation,etc.Among them,transcranial electrical stimulation,as a non-invasive and safe technology,will also be the development trend of neuromodulation technology.Related research shows that relaxation therapy,repetitive cognitive training,and non-invasive brain stimulation techniques all have good performance on working memory.Through the study of the neurophysiological mechanism of the working memory system and the effect of transcranial electrical stimulation on the working memory system,it will help to better understand the working mechanism of the brain under working memory.Based on existing research,in order to explore the specific effects of transcranial electrical stimulation on the working memory system.In this thesis,starting from the working memory task,first,the control parameters of transcranial electrical stimulation were determined,and collect the EEG data and behavioral data of the subjects under three different regulation modes: transcranial alternating current stimulation,transcranial direct current stimulation and sham stimulation.The specific mechanism of the effect of transcranial electrical stimulation on the working memory system of healthy subjects was explored from the behavioral data and ERP analysis results,and from the time-frequency characteristics and other related EEG rhythm characteristics,to explore the impact of transcranial electrical stimulation on the working memory brain functional network.The influence of network characteristic parameters and its topological structure are explained.The main contents and innovations of this thesis are as follows.1.Starting from the working memory task,this thesis designs a behavioral experimental paradigm and a transcranial electrical stimulation paradigm to study the after-effects of transcranial electrical stimulation on the working memory system,and to explore the specific physiological mechanism of the effect of transcranial electrical stimulation on the working memory system.2.In this thesis,the behavioral data and ERP data were integrated and analyzed,and the accuracy and response time of the behavioral data of the subjects were statistically analyzed,then the ERP component characteristics of the EEG were analyzed.And from the scalp localization topographic map to explore the intuitive effect of transcranial electrical stimulation on the working memory system.3.In this thesis,the time-frequency domain analysis method was used to explore the effect of transcranial electrical stimulation on the EEG characteristic rhythms of the subjects under the working memory task,and the EEG brain functional network under different characteristic rhythms was constructed based on the method of phase synchronization.Finally,using the complex network analysis method in graph theory,the attribute parameters of the brain function network,including betweenness centrality,network efficiency,etc.,are used to analyze the network attributes and network topology in the brain function network.The regulatory effect of transcranial electrical stimulation is described from the aspects of network properties and network structure,and the effect of transcranial electrical stimulation on local connectivity of the brain is explored based on the above results.