Your happy expressions encourage me to take risks: ERP evidence from an interpersonal gambling game.

Although the influence of endogenous emotion on decision-making has been widely studied, the effect of interpersonal emotions on risk decision-making is less understood. To address this issue, participants were asked to perform an interpersonal gambling game after perceiving their cooperator's facial emotions. The results found that the cooperator's happy expressions increased individuals' risk-approaching choice compared with angry expressions. Moreover, happy expressions induced larger P300 potentials in the option assessment stage, and diminished the differences between losses and wins in feedback-related FRN/RewP in the outcome valuation stage. Additionally, single-trial analysis found that the neural response induced by interpersonal expressions and feedback could predict participants' subsequent decision-making. These findings suggest that interpersonal emotions shape individuals' risk preference through enhancing in-depth valuation in the option assessment stage and early motivational salience valuation in the outcome valuation stage.