Social exclusion selectively attenuates social reward processing but promotes prosocial evaluations.

Social exclusion threatens belongingness, triggering adaptive reward processing changes. It remains unknown whether exclusion selectively alters social (vs. monetary) reward processing via hypervigilance or compensatory affiliation mechanisms. To address this, we recruited 61 participants to complete a Cyberball-based social exclusion or inclusion induction, with an electroencephalogram recorded during subsequent social and monetary reward tasks. Results revealed that positive versus negative feedback elicited stronger reward positivity in the social inclusion condition, while such an effect was eliminated by social exclusion. However, this interaction effect was absent for P300 during the consummatory stage or the stimulus preceding negativity during the anticipation stage. Meanwhile, social exclusion reduced the delta power, enhanced positive social evaluations, and led to a dissociation between this positive evaluation and the delta power in response to others' social feedback. In contrast, for monetary reward processing, no effects of social exclusion were found. This domain-specific effect was further validated by cross-task comparison. These results suggest that social exclusion selectively attenuates the initial cognitive processing of social rewards, disrupts the association between neural feedback and behavior, and may trigger a dual coping mechanism involving withdrawal self-protective neuroadaptations, and approach-driven prosocial behavioral tendencies.