Study On Self-specificity During Different Levels Of Consciousness Based On Functional Magnetic Resonance Imaging

With the development of science and technology,neuroimaging methods have been introduced into the study of self-related research,attempted to explain the problem of self from the brain activation pattern.In study,anesthesia is a common experimental design in order to change consciousness levels.However,it is unclear how the brain activation patterns associated with self-related processing change with decreased levels of consciousness.This study is based on the functional magnetic resonance imaging,and designed the auditory-stimuli contrast experiment(listening to subject’s own name and listening to unknown person’s name)during Propofol-induced anesthesia(wakefulness,sedation,unconsciousness).In this study,we analyzed task-related and self-specificity from multiple perspectives including brain regions,the correlation of brain networks and topological properties of brain functional networks.In this study,task-state f MRI datas of 15 subjects were collected and analyzed.Firstly,statistical parameters were obtained by general linear model,and were calculated significant differences between two levels of consciousness.Then the correlation between brain networks was calculated using psychophysiological interaction and independent component analysis,in order to deduce task-regulated co-activation patterns between two networks.Finally,we evaluated topological attributes such as local efficiency and global efficiency,in order to explore interaction between stimulus mode and consciousness level on the large-scale brain functional network.In terms of results,firstly,this study was demonstrated self-specificity from the perspective of brain regions.Self-specific brain regions were included anterior cingulate gyrus,posterior cingulate gyrus,medial prefrontal cortex and insula.During sedation and unconsciousness,no brain region in self-related processing was activated,suggesting that self-related higher cognitive activities were inhibited with decreasing level of consciousness.Secondly,we found that functional connectivities between the default mode network and other networks were significantly increased during the self-processing.However,DMN was significantly inhibited during the decreased level of consciousness,which was similar to the trend of changes in the activated brain regions.Thirdly,according to the analysis of brain interval network topological attributes,it is found that stimulus mode and consciousness level have significant interaction in global efficiency and local efficiency.These results suggest that brain regions and functional connectivity patterns with self-related cognition are specific and significantly affected during Propofol-induced anesthesia.In summary,this study found activated brain regions,correlations in brain networks and topological properties under self-related processing.The changes of brain regions and networks were found during Propofol-induced anesthesia.This research was provided a new perspective for self-related processing,and a novel direction for the anesthetic mechanism of Propofol-induced anesthesia under auditory stimulation test.