Differential neural processing of reward and self-relevance in a social gambling paradigm

We preferentially process self-related information. However, less is known about how this advantage extends to reward processing and if this process is sensitive to a continuum of self-relevance. Specifically, do we dissociate ourselves from all others when processing rewards, or do those we know personally also enjoy self-related biases? To address this, we recorded electroencephalographic (EEG) data from 30 undergraduate student participants who played a simple two-choice "bandit" gambling game where a photo presented before each gamble indicated whether it benefited either the participant, an individual they knew, or a person they did not know. Temporal spatial principal components analysis (tsPCA) of EEG data evoked by target photos revealed a component consistent with attention and early perceptual processing (the P200), while analysis of data evoked by the feedback stimuli revealed a component consistent with reward processing (the reward positivity). Results demonstrated that P200 component scores were larger for self-gambles than both known- and unknown-other target photos. Interestingly, and contrary to previous findings, reward positivity component scores were similar for all gambles independent of perceived ownership. Our findings suggest that, when gambling for individuals on a continuum of self-relevance, the potential for monetary gain based on the self-relevance cues is differentially processed for ourselves while the actual reward is not. We suggest that the known-other gambling target introduced an empathy-like effect, contesting the self-bias in reward processing.