Effort enhances feedback expectation but reduces feedback evaluation in prosocial contexts: A behavioral and ERP study.

Previous research has shown that effort expenditure influences feedback processing in prosocial behavior. However, it remains unclear whether effort enhances or reduces feedback expectations and evaluations in prosocial behavior. Therefore, using event-related potentials (ERP) and multivariate pattern analysis (MVPA), the current study employed a modified prosocial effort task to examine how effort separately affects feedback expectation and evaluation in prosocial behavior. Behaviorally, high effort (vs. low effort) reduced participants' satisfaction when the beneficiary was another person, no such effect was observed when the beneficiary was the self. On the electrophysiological level, during the anticipation stage, the stimulus-preceding negativity (SPN) was more negative under high effort (vs. low effort) conditions. Conversely, during the evaluation stage, the feedback P300 (Fb-P3) and late positive potential (LPP) exhibited smaller responses after exerting high effort (vs. low effort). Moreover, the N2 and theta power were larger when the beneficiary was another person (vs. the self). MVPA revealed that effort distinguishing could be reliably decoded from electroencephalography (EEG) signals, regardless of whether the beneficiary was the self or another person. Taken together, our findings suggest that effort expenditure enhances feedback expectations but reduces subsequent feedback evaluations in prosocial behavior.