When emotional responses conflict with self-interested impulses: A transcranial direct current stimulation study of cognitive control in cooperative norm compliance

This study proposes a conflict between the impulse to express negative emotions and the temptation to behave selfishly in the cognitive control processes of complying with cooperative norms. We conduct an experiment with two tasks (cost and no-cost) in a prisoner’s dilemma game with third-party punishment and apply the transcranial direct current stimulation (tDCS) to modulate the right dorsolateral prefrontal cortex (DLPFC). The results indicate significant differences in tDCS effects on third-party punishment between two cost conditions. In the no-cost task, third parties in the cathodal condition report higher negative emotional responses and assign more punishment to norm violators than those in the sham condition. However, the tDCS effect on third-party punishment is not significant in the cost task. Our results help address the inconsistent findings in prior literature regarding the role of the right DLPFC in norm compliance and deepen our understanding of the cognitive control process in enforcing cooperative norms by third parties.