Neural correlates of outcome processing post dishonest choice: an fMRI and ERP study

A dishonest person often utilizes another person's obliviousness to appropriate the property that belongs to the other person. Previous researchers have studied the making of a dishonest choice and the manipulation of truthful information. Here, we have investigated the neural correlates of processing the outcomes of dishonest decisions. Participants in this study were asked to interact with counterparts in an economic game. They could accept the counterparts' proposals on how to divide the profits (honest choice) or choose the alternative plan that was advantageous to themselves (dishonest choice), playing to the ignorance of their counterparts who had a 50% chance of detecting the situation. Successful dishonest choices (not being detected) would bring large rewards, whereas honest choices would lead to less of a reward, and failed dishonest choices (being caught) would result in no reward. Participants' neural responses during the outcome presentations were recorded by functional magnetic resonance imaging (fMRI) and event-related potential (ERP) methods in different sessions. We found that the outcomes of successful dishonest (vs. honest) choices elicited stronger activations in the ventral striatum and posterior cingulate cortex and a smaller ERP component called feedback-related negativity (FRN), which suggests that positive outcome evaluation and attention processing were aroused by successful dishonest choices. Moreover, the outcomes of failed dishonest (relative to honest) choices were associated with different neural response patterns in the medial orbitofrontal cortex and P3b ERP component between human and computer counterparts, suggesting that processing the output of social decision making (playing human) is different from that of risk taking (playing computer). The findings advanced our understanding about the neural processing of outcome presentation after a dishonest choice has been made.