| The brain coding of decision feedback is the core of behavioral decision research.However,as a kind of behavior decision,most previous researches in the field of moral decision only discussed the stage of decision-making,so that the coding process of the result of moral decision in the brain was not clear.Therefore,this study adopts event-related potentials(ERPs)to carry out two experiments on the brain processing of moral decision-making and its feedback.Experiment 1 explores the brain processing of moral decision stage under different moral dilemmas through the moral dilemma decision task.The behavioral data shows that the proportion of utilitarian choice is significantly higher than non-utilitarian choice for accidental dilemmas,where as the opposite holds for instrumental dilemmas.The response time under accidental dilemmas is significantly greater than instrumental dilemmas.The ERPs data from the frontal-central area shows that P2 amplitude was marginally significantly larger for instrumental than incidental dilemmas and P2 latency was significantly longer for incidental than instrumental dilemmas.The Slow Wave(SW)amplitude was significantly larger for instrumental than incidental dilemmas.Experiment 2,including the decision-making stage and the feedback stage,explores the brain processing of moral feedback under different moral dilemmas.In the decision-making stage,ERPs results and behavioral results are consistent with experiment 1 except that P2 amplitude did not find the main effect of the dilemma.In the feedback stage,the ERPs data from the central-parietal area shows that,in terms of the valence processing,P2 latency has marginal significant main effect,and P2 latency was later for positive feedback than negative feedback.There is a marginal significant interaction effect between dilemma and valence on FRN amplitude,the FRN amplitude was significantly larger for negative feedback than positive feedback in accidental dilemmas,and there is no significant difference in instrumental dilemmas.The main effect of valence on P3 amplitude is significant,the P3 amplitude was significantly larger for negative feedback than positive feedback.The interaction effect between dilemma and valence on P3 amplitude is marginally significant,the P3 amplitude was significantly larger for negative feedback than positive feedback in instrumental dilemmas,and there is no significant difference in accidental dilemmas.In terms of the magnitude processing,the main effect of magnitude on P3 amplitude is significant,the P3 amplitude was significantly larger for small feedback than large feedback.The following two conclusions can be drawn under this research paradigm:First,in the moral decision-making stage,P2 reflects the early emotion experience,and SW is related to cognitive processing.The response time is shorter and the P2 latency is shorter under instrumental dilemmas than that under accidental dilemmas,indicating that individuals have experienced stronger emotional conflicts earlier in instrumental dilemmas.SW amplitude of instrumental dilemmas is larger,indicating that individuals not only have greater emotional conflict in the early period of this dilemma,but also have more cognitive processing in the late period.Second,in the moral feedback stage,FRN reflects the coding of human brain for moral valence feedback.P3 reflects both the coding of human brain for moral valence feedback and moral magnitude feedback,and the coding of moral valence feedback is regulated by moral dilemmas. |
