Expecting social punishment facilitates control over a decision under uncertainty by recruiting medial prefrontal cortex

In many decision-making situations, uncertainty facilitates suboptimal choices. However, when individuals are in a socially dangerous situation such that wrong choice would lead to a social punishment such as blame of the supervisor, they might try to minimize suboptimal choices to avoid it. In this functional MRI study, 46 participants performed a choice task in which the probability of a correct choice with a given cue and the conditional probability of blame feedback (by making an incorrect choice) changed continuously. Using computational models of behavior, we found that participants optimized their decision by suppressing the decision noise induced by uncertainty. Simultaneously, expecting blame significantly deteriorated participants mood. Model-based fMRI analyses and dynamic causal modeling revealed that the optimization mechanism based on the expectation of being blamed was controlled by a neural circuit centered on right medial prefrontal cortex. These results show novel behavioral and neural mechanisms regarding how humans optimize uncertain decisions under the expectation of being blamed that negatively influences mood.\n\nSignificance StatementPeople occasionally encounter a situation that forces us to make an optimal decision under uncertainty, which is difficult, and a failure to make a good choice might be blamed by their supervisor. Although it might be hard to make right decision, they make more effort to make a good decision, which might help them to escape from the aversive outcome. However, such kind of stressful situation influences our mood to be negative. Using the computational modelling, we showed that participants computed how it is likely to be blamed and this computation motivated people to control uncertainty-induced decision noise by recruiting a neural circuit centered on the medial prefrontal cortex. However, an expectation of being blamed significantly deteriorated participants mood.