Spatio-temporal Patterns Of Functional Networks Under Sad Faces Stimulation In De Pression:A Magnetoencephalography Study

Negative emotional bias is one of the core characteristics in depression.The emotional processing is closely related to abnormal functional networks in depression,and the dysfunction of emotional-related networks has been confirmed.Previous studies have focused on abnormal activity of brain regions in emotional processing.However,how the way of depression patients organizing the brain functional networks in emotional face processing remains to be explored.The main work is to explore the temporal-spatial patterns of individual dynamic functional network in depressive patients based on magnetoencephalography(MEG).The main contents are as follows:1.The functional networks were constructed in gamma band based on MEG data.A dynamic connectivity regression(DCR)algorithm was used to find the change points of time series in response to negative stimuli.The time periods were then divided into partitions and the network based statistics(NBS)was used to identify connections showing significant differences between patients and controls in each partition.The abnormal connectivities of emotional-related networks were discovered in gamma band during early emotional processing in depression,which might be related to the impairment of facial emotional function.2.To further investigate depression recognition performance of spatio-temporal brain networks in low gamma band,the nodal characteristics of patterns were calculated and fed into the support vector machine(SVM).Furthermore,performance was validated and compared via dynamic topological characteristics of individual patterns calculated in alpha and beta band.The best discrimination accuracy was performed in the model of individual spatio-temporal patterns in low gamma band.3.During the dynamic acute state change phases of function connectivity(FC),the relationship between FC and structural connectivity(SC)may be distinctive and embody the abnormality inherent in depression.The FC–SC couplings were then fed into the SVM for depression recognition.The capacity to process negative emotion might be more directly related to the SC abnormally and be indicative of more stringent and less dynamic brain function.4.To investigate the patients who developed from unipolar to bipolar depression(dBD)based on the power energy of whole brain.The result of classification was high between unipolar depression(UD)and dBD.Then,bipolar depression(BD)was added to confirm that dBD was different from BD.5.To further explore the spatial-temporal patterns of functional networks based on six different bands.It was found that in low frequency bands,the spatial-temporal patterns of UD and dBD were significantly similar,which were significantly correlated with clinical symptoms.In gamma band,the spatial-temporal patterns of dBD and BD were significantly similar,and were associated with disease characteristics.