Research On The Influence Of Callous-unemotional Trait On The Reward Processing Mechanism Of College Students

Objective: In 2013,the Callous-unemotional trait(CU)was specifically added as a special description of additional symptoms in the item of childhood Conduct Disorder(CD),On the one hand,Callous-unemotional trait is a marker variable of children's conduct disorder,on the other hand,it is also the earliest risk factor of persistent serious violence.In recent years,its positive correlation with personal dangerousness,antisocial behavior and serious aggressive behavior had attracted the attention and research of a large number of scholars..However,there were few studies on callous-unemotional traits and their cognitive function in early adulthood,so this study selected college students as subjects to understand the core dimension of psychopathic traits,which was callous-unemotional traits individuals,and to explore the effects of callous-unemotional traits on brain reward processing and the relationship between them through functional Magnetic Resonance Imaging(fMRI)in early adulthood,and from the neurophysiological aspect,we further explain the behavioral characteristics of high CU traits found in previous behavioral studies,ignoring punishment and pursuing stimulation,so as to provide theoretical support for the scientific formulation of more effective intervention programs for people with CU traits.Method: In this study,functional magnetic resonance imaging(fMRI)was used to study the effect of callous-unemotional traits on reward-related brain activity by calculating whole brain activation and region of interest analysis and adopting the Monetary Incentive Delay task(MID)paradigm.According to the score of the CU trait scale,35 subjects were divided into high score group(n=17)and low score group(n=18).The scores,reward range and reward potency effect of the Callous-unemotional traits scale were analyzed by SPSS19.0 software,and the types of subjects were taken as inter-group variables,and the effect of reward potency and reward range were used as intra-group variables to carry out repeated measurement analysis of variance to compare the differences of reward expectation and reward range effect of each brain region in MID task and reward feedback stage of subjects with high and low CU,to compare the influence of people with different callous-unemotional traits in the process of reward processing.Results:(1)Behavioral science: the average correct rate in monetary incentive delay task was 64.8%,close to 66.7% of the expected;reaction time: the main effect of each factor was not significant,and the interaction between CU grouping,reward valance and reward magnitude was significant.(2)functional Magnetic Resonance Imaging(fMRI): through the analysis of the magnetic resonance imaging images of the subjects' brain,it was found that the expected stage of reward mainly activated the areas of nucleus accumbens,amygdala,caudate nucleus,pallidus and so on,the orbitofrontal cortex,putamen,insular gyrus and hippocampus were activated in the results feedback stage,and the reward amplitude activated the prefrontal cortex,nucleus accumbens,hippocampus,amygdala and insular gyrus,and the reward titer activated the prefrontal lobe,caudate nucleus and posterior cingulate gyrus.Through the analysis of the correlation between the score of the CU scale and the reward range and the reward potency effect,it was found that the reward range effect of the right nucleus accumbens region was negatively correlated with thescore of the CU scale in the expected stage of reward.The triple interaction among the score of CU scale ×reward potency × reward range was significant.There was a significant negative correlation between them in the right insular and caudate nucleus regions,but there was no significant correlation in the reward feedback stage.In the reward expectation and feedback stage,there was no significant correlation between the reward potency and the score of CU scale.Further analysis showed that in the right nucleus accumbens region of the expected stage,there was a significant difference in the reward amplitude effect between the high and low CU score groups,and under the reward condition,the right nucleus accumbens brain activation level of the high CU score group was lower than that of the low CU score group under the same amplitude stimulation,while under the punishment condition,the right nucleus accumbens brain activation level of the high CU score group basically did not change with the punishment magnitude.Conclusion:(1)The results of this study show that The brain regions activated in the expectation stage and the feedback stage of the reward process are different: there are two different response patterns in the expectation and feedback stages of the reward.In the expected stage,the main activated brain areas include nucleus accumbens,amygdala,caudate nucleus and globus pallidus,while in the feedback stage,the main activated brain areas include orbitofrontal cortex,putamen,insular gyrus and hippocampus.(2)CU traits affect individuals' perception of reward magnitude,and the same reward magnitude causes relatively small reward loop excitement in individuals with high CU traits,and the effect is more significant in the reward process than in the punishment process.This difference mainly exists in the expected phrase of the reward rather than in the feedback phrase.(3)the reason why people with high CU traits pursuing reward and ignoring punishment is that they are more likely to enjoy the "want" reward rather than the result of getting the reward,which further explains the reason why CU trait pays attention to reward and neglects punishment.At the same time,because of this characteristic,they have a positive expectation of aggressive behavior,and regard aggressive behavior as an effective way to solve the problem,which may increase the possibility of risky behavior and cause them to do whatever it takes to achieve their ends,so it's easier to commit a crime.