The Neural Basis Of Disgust:Evidence From Patterns Of Induced And Spontaneous Neural Activity In The Brain

BackgroundDisgust is one of the basic emotions of human beings.It is an emotion induced by something unpleasant and repugnant.It is a defensive emotion that protects human safety by preventing the ingestion of inappropriate objects and by resisting possible diseases.Disgust sensitivity is the tendency of the individual to the disgust experience caused by the disgust stimulus,and it is a stable personality trait of the individual.In recent years,more and more researches on disgust have shown the relationship between disgust and various psychopathologies.ObjectiveTo explore the neural basis of the processing of disgust stimuli and the brain activation patterns of individuals with different disgust sensitivities.MethodsIn the first study,we collected task-state f MRI papers published before January 2021 using disgust stimuli as experimental materials.The papers were classified according to different disgust stimuli,and the activation likelihood estimation(ALE)was used for metaanalysis to obtain the common brain regions for processing disgust stimuli.In the study 2,Disgust Scale-Revise(DS-R)Scale was used to evaluate individual disgust sensitivity,and resting state EEG and resting state f MRI techniques were used to record the brain signals of the subjects in the resting state with closed eyes.The score of disgust sensitivity was correlated with the brain signals in the resting state.In order to reveal the spontaneous brain activation patterns related to disgust sensitivity from the perspective of individual differences.ResultsMeta-analysis results showed that bilateral amygdala was found to be the co-activated brain region(right amygdala coordinates: x = 24,y =-2,z =-20,left amygdala coordinates:x =-20,y =-4,z =-18).The results of low frequency fluctuation showed that disgust sensitivity was negatively correlated with spontaneous activity of the right superior cerebellar gyrus(r =-0.38,P < 0.001),was positively correlated with spontaneous activity of the right superior frontal gyrus(r = 0.41,P < 0.001),which is a brain region associated with inhibition.The results of microstate resting EEG showed that the disgust sensitivity score was correlated with the duration of microstate C(r = 0.221,P < 0.001),incidence(r= 0.229,P < 0.001),contribution(r = 0.365,P < 0.001),while microstate C is highly correlated with the anterior default mode network,which is considered to be the network related to the information of its own internal receptors of physical and emotional combination.Conclusion1.The specific brain region of disgust processing independent of external features is bilateral amygdala,and disgust is a characteristic of basic emotions.2.Individuals with high disgust sensitivity had higher activation in the right superior frontal gyrus and stronger motivation to inhibit external stimulus.3.Individuals with high disgust sensitivity may be over-alert to their own internal information perception and external information processing.