Research Of Regulation Effect Of Transcranial Direct Current Stimulation On Emotional Processing

Transcranial direct current stimulation(tDCS)is an effective brain modulation technique and has been widely used in the field of cognitive enhancement and depression treatment.However,the current research is still unclear how tDCS effect the static and dynamic characteristics of the brain during emotional processing and its neuromodulation mechanism are still need to explore,besides the research methods are relatively simple.Therefore,using fusion of multi-method is crucial for exploring the neural mechanism of tDCS act on emotional processing.not only can help understand the process of tDCS affecting emotional processing,but also can further understand the pathological mechanism of tDCS curing emotional disorders such as anxiety and depression,and provide some guidance and optimization for its clinical application.To study the regulation effect of tDCS on emotional processing,emotional electroencephalogram(EEG)experiments were designed by long-term stimulation regulation and different task modes(static/dynamic)induction.41 healthy subjects and 8 depressed patients were recruited,The resting EEG under eight minutes with eyes opening or closing and task EEG before and after the stimulation were collected,and the regulation of tDCS on emotional processing was explored from the subjective scale,behavioral and electrophysiological aspects.The main conclusions obtained are as follows:The sham-controlled study of healthy subjects found that,After anodal tDCS of left DLPFC,the proportion of neutral expressions judged as negative expression was significantly reduced;Rest EEG analysis found that frontal alpha band asymmetry(FAA)in position of F4-F3 was increased;Event-related potential(ERP)analysis found that the P3 amplitude of positive and negative emotions increased significantly which indicating tDCS can improve the attention distribution of healthy subjects during emotional processing.Event-related spectral perturbation(ERSP)analysis found that tDCS can increase EEG energy in the alpha and beta bands during negative emotional processing,especially in the right brain region;The correlation analysis between resting state and task state preliminarily verified that the difference of FAA was negatively correlated with the P3 amplitude of negative stimulus.Exploratory studies on long-term treatment of the depressed patients found that,as the treatment cycle increased,The Hamilton Depression Scale score for depressed patients was significantly reduced,indicating that tDCS can improve the depressive symptoms;the FAA and amplitude of P3 of positive target stimulation was all increased while the negative target was decreased in ERP analysis.ERSP analysis found that tDCS can improve the EEG energy of the theta band during positive emotional processing.The above results confirm that tDCS has a certain regulatory effect on the static traits and dynamic functions of brain in emotional processing.Central nervous electrophysiological detection method can provide objective and feasible evaluation methods and monitoring indicators for emotional cognitive neural response under tDCS intervention,and provide scientific basis and application guidance for using tDCS to treat emotional cognitive impairment in clinical environment.It is worthy to carry out more systematic and in-depth study.