Study On Source Localization Of Emotion Reappraisal Based On Simultaneous EEG-fMRI Fused Algorithm

Emotion regulation is an attempt to influence the emotion of oneself or others,and change the intensity of emotional experience and the degree of attention to emotional information.Emotion reappraisal is considered to be the most effective but also one of the most complex form of emotion regulation.Exploring the source activity of the cerebral cortex under the emotion reappraisal task is conducive to understanding the cognitive mechanism of emotion regulation and provides new ideas for clinical research on emotion regulation disorders.Electroencephalography(EEG)and functional magnetic resonance imaging(fMRI),two neuroimaging tools,have attracted increasing attention in clinical and cognitive science due to their complementary time-spatial resolution.To investigate the source activity of cerebral cortex during emotion reappraisal,a novel fused source localization method based on the dipole feature optimization was proposed for simultaneous EEG-fMRI acquired by emotion reappraisal experimental paradigm.First,fMRI-weighted minimum norm estimate was performed.Then considering the computational cost and ensuring the detail and specificity of the EEG source,20 ms EEG sliding time window was used to extract dipole spatial fused feature in each time window.A weighted minimum norm estimation was subsequently performed based on the dynamic fused prior.Comparison of EEG sources was conducted in the two source localization methods.Finally,according to the Desikan-Killiany atlas,68 cortical fusion brain source signals were extracted.Sample entropy was used to analyze the EEG source complexity of emotional tasks.Phase lag index was used to construct a functional EEG source network for EEG source connection analysis of emotion reappraisal.The results showed the dynamic fusion prior source location method based on dipole feature optimization could effectively track the dynamics of the cerebral cortex and recognized brain area during emotion reappraisal tasks with high temporal and spatial resolutions.In the process of emotion reappraisal,with the emergence of late positive potential in the posterior occipital parietal lobe,the active brain regions transferred from the left inferior parietal lobe,right rostral middlel frontal gyrus,left insula to the right superior temporal gyrus and left lateral occipital lobe,and finally activated the right fusiform gyrus,right rostral middle frontal gyrus and left isthmus cingulate gyrus in the late positive potential slow-wave stage.By calculating the sample entropy of EEG source,the significant brain regions were extracted within 1500 ms after the subjects received different emotional stimuli(p<0.05).The active brain region for emotion response is left lateral occipital lobe(negative: 0.688±0.124,neutral: 0.590 ± 0.126).The active brain region for emotion regulation was right rostral middle frontal gurus(negative reappraisal:0.814±0.114,negative: 0.736±0.123).The inhibited brain region for emotion regulation was right superior temporal gyrus(negative: 0.642±0.152,negative reappraisal: 0.546±0.090).The results of EEG source functional network analysis showed that in the process of emotion reappraisal,the alpha band had the highest network density at 0.036,and the beta band had the lowest brain network density at0.009.According to the calculation of betweenness centrality,the central nodes of the emotion reappraisal network under different frequency bands were extracted.These results provided reference of brain regions for the study of cortex EEG source localization related to emotion reappraisal.