The neural dynamics underlying the interpersonal effects of emotional expression on decision making.

Although numerous studies explore the effects of emotion on decision-making, the existing research has mainly focused on the influence of intrapersonal emotions, leaving the influence of one person's emotions on another's decisions underestimated. To specify how interpersonal emotions shape decision-making and delineate the underlying neural dynamics involved, the present study examined brain responses to utilitarian feedback combined with angry or happy faces in competitive and cooperative contexts. Behavioral results showed that participants responded slower following losses than wins when competitors express happiness but responded faster following losses than wins when cooperators express anger. Importantly, angry faces in competitive context reversed the differentiation pattern of feedback-related negativity (FRN) between losses and wins and diminished the difference between losses and wins on both P300 and theta power, but only diminished the difference on FRN between losses and wins in cooperative context. However, when partner displays happiness, losses versus wins elicited larger FRN and theta power in competitive context but smaller P300 in both contexts. These results suggest that interpersonal emotions shape decisions during both automatic motivational salience valuation (FRN) and conscious cognitive appraisal (P300) stages of processing, in which different emotional expressions exert interpersonal influence through different routes.