Self-reference processing of fat-face and sick-face in individuals with different disgust sensitivity: Evidence from behavioral and neuroelectrophysiology

Self-reference effect has been widely discussed. Previous scholars believed that self-related information can be processed faster is due to the positive attribute of self-concept which speeds up self-related information processing. When self-related information is given negative attributes, the self-reference effect will be weakened. In this study, fat and sick, two kinds of stimuli associated with disgust characteristics, were added to self- and other-faces. We found that disease stimuli, which are closely related to survival threats, eliminated the self-reference effect while the obesity stimuli only weakened the self-reference effect to a certain extent. Event-related potential (ERP) analysis demonstrated that sick-faces have a greater amplitude than standard-faces in the EPN and LPP components. We believe that this may be due to the urgency of the disease threat, which leads to the selective attention to the disease threat in the early perception stage and the allocation of more attention resources for rapid response in the later stage. In addition, we found that disgust sensitivity specifically maintains individuals' self-referential effects by dissociating individuals from others in disease contexts. These results further support the behavioral immune function of disgust as a gatekeeper of the self in potentially contaminated environments. In conclusion, our study showed that in the face of survival threat, the self-reference effect is eliminated, and disgust tried to slow down this elimination effect to protect self. This study extends the behavioral immunity theory to some extent and further deepens the understanding of the relationship between disgust and self.