The Structural And Functional Brain Basisof Trait Anger On Aggressive Behavior

Aggressive behavior causes damage to the target object,and even threatens his or her life.Moreover,it brings panic to the around people,and then affects social stability and order and the harmonious development of the country.Thus,aggressive behavior has attracted widespread attention of many researchers in sociology and psychology.Based on results of many years' study,researchers have proposed a number of theoretical models to explain the mechanism of aggressive behavior from different perspectives.The most representative model is the General Aggression Model(GAM),and it posits that trait anger being a kind of lasting and stable personality trait influences aggressive behavior and the internal state variables play important roles in the relationship between trait anger and aggressive behavior.However,to date few studies have explored the neural mechanism of trait anger on aggressive behavior.Based on these and GAM,this study aimed at college students who scores high or low in trait anger and used a modified version of the Taylor Aggression Paradigm(TAP)and brain image technologies to explore the structural and functional brain basis of trait anger on aggressive behavior.In study 1,voxel-based morphometry(VBM)was introduced to explore the structural brain basis of trait anger and the brain morphometric mechanism of trait anger on aggressive behavior.The results showed that the volumes of left postcentral gyrus,left superior parietal lobe and left calcarine sulcus of individuals with high trait anger were significantly greater than those of individuals with low trait anger.What's more,the volume of left postcentral gyrus was significantly and positively correlated with reactive aggressive behavior,while the volume of left calcarine sulcus was significantly and negatively correlated with behavior provocation effect.In other words,the left postcentral gyrus might be the structural brain basis of trait anger on reactive aggressive behavior,and the left calcarine sulcus might be the structural brain basis of trait anger on behavior provocation effect.In study 2,regional homogeneity(Re Ho)analysis and functional connectivity(FC)analysis were introduced to explore the functional brain basis of trait anger and the brain functional mechanism of trait anger on aggressive behavior by using resting state f MRI data.The results of regional homogeneity analysis showed that the Re Ho values in right posterior cingulate gyrus,right precentral gyrus,left superior parietal gyrus,right inferior temporal gyrus,left middle occipital gyrus and left precuneus of individuals with high trait anger were significantly different from those of individuals with low trait anger.What's more,the Re Ho values in right precentral gyrus,right inferior temporal gyrus and left middle occipital gyrus were significantly correlated with reactive aggressive behavior,while the Re Ho value in right posterior cingulate gyrus was significantly correlated with behavior provocation effect.In other words,the right precentral gyrus,right inferior temporal gyrus and left middle occipital gyrus might be the functional brain basis of trait anger on reactive aggressive behavior,and the right posterior cingulate gyrus might be the functional brain basis of trait anger on behavior provocation effect.The results of functional connectivity analysis showed that the strength of FC between right amygdale and bilateral medial OFC,left temporal pole and bilateral medial OFC,and right amygdale and right ACC of individuals with high trait anger were significantly weaker than those of individuals with low trait anger.What's more,the strength of FC between left temporal pole and bilateral medial OFC were significantly and negatively correlated with reactive aggressive behavior.In other words,the left temporal pole-left medial OFC connection and the left temporal pole-right medial OFC connection might also be the functional brain basis of trait anger on reactive aggressive behavior.In summary,this study explored the neural mechanism of trait anger on aggressive behavior,which involved not only the brain regions related to automated cognitive processing,but also the brain regions related to effort control.Furthermore,this study provided neuroscientific evidences for the GAM and effort control theory,and had a positive role in understanding the relationship between trait anger and aggressive behavior.