Social exclusion enhances the processing of emotional crowd faces: Evidence from ERPs

Social exclusion, a negative emotional experience triggered by interpersonal rejection, has detrimental effects on both social interactions and mental health. While our previous transcranial magnetic stimulation (TMS) study provided causal evidence indicating that social exclusion significantly impacts the perception of crowd facial expressions, the neural correlates underlying this effect across distinct event-related potential (ERP) components remain poorly understood. To address this issue, the present study used ERPs to extend our neurophysiological insights into this phenomenon. Participants' brain activity was recorded while they performed an emotion discrimination task, viewing happy or disgust crowd faces (Experiment 1) or single faces (Experiment 2) following experiences of social inclusion or exclusion through a Cyberball game. Results from Experiment 1 indicated that social exclusion enhanced neural responses to both happy and disgust crowd faces, evidenced by larger mean amplitudes of the N170 and late positive potential (LPP) components. This neural enhancement was also correlated with greater need threat, as higher levels of need threat were associated with larger neural responses to emotional crowd faces. In contrast, Experiment 2 found no exclusion-related neural effects when participants viewed single faces. These neural results may reconcile the social reconnection hypothesis with the rejection sensitivity model by demonstrating that social exclusion increases responsiveness to socially affective information extracted from groups. In everyday social interactions, this increased responsiveness could influence how people read and evaluate emotional signals in crowds, ultimately affecting social judgment and adaptive behavior.