基于偶极子特征优化的情绪重评同步EEG-fMRI源定位研究

为研究情绪重评时的大脑皮层源活动,针对情绪重评实验范式下采集的15例健康人同步EEG-fMRI数据,首先提出一种新颖的基于偶极子特征优化的融合源定位方法:根据fMRI加权最小范数估计源定位结果,采用20 ms EEG滑动时间窗,提取每个时窗内的偶极子空间融合特征,将其作为动态融合先验进行加权最小范数估计溯源;随后将该结...

Source Localization Study of Simultaneous EEG-fMRI in Emotion Reappraisal Based on Dipole Feature Optimization

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 the simultaneous EEG-fMRI data of 15 healthy subjects acquired by the experimental paradigm of emotion reappraisal. First, fMRI-weighted minimum norm estimate was performed. Then 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. The mechanism comparison of emotion reappraisal was conducted between the results of two source localization methods. Finally, the sample entropy was used to analyze the complexity of EEG source. The experimental results showed that the proposed method could effectively track the dynamics of EEG source on the cerebral cortex and recognized related brain regions during emotion reappraisal task 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 middle 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 right isthmus cingulate gyrus in the late positive potential slow-wave stage (P<0.05). By calculating the sample entropy of EEG source, the significant brain regions were extracted after the subjects received different emotional stimuli within 1500 ms (P<0.05). The active brain region for emotion response was left lateral occipital lobe (negative: 0.688±0.124, neutral: 0.590±0.126). The active brain region for emotion reappraisal was right rostral middle frontal gyms (negative reappraisal: 0.814±0.114, negative: 0.736±0.123). The inhibited brain region for emotion reappraisal was right superior temporal gyrus (negative: 0.642±0.152, negative reappraisal: 0.546±0.090). The obtained results provided the reference of brain regions for the study of cortex EEG source localization related to emotion reappraisal.