Every day, we are faced with the conflict between the temptation to cheat for financial gains and maintaining a positive image of ourselves as being a “good person.” While it has been proposed that cognitive control is needed to mediate this conflict between reward and our moral self-image, the exact role of cognitive control in (dis)honesty remains elusive. Here we identify this role, by investigating the neural mechanism underlying cheating. We developed a task which allows for inconspicuously measuring spontaneous cheating on a trial-by-trial basis in the MRI scanner. We found that activity in the nucleus accumbens promotes cheating, particularly for individuals who cheat a lot, while a network consisting of posterior cingulate cortex, temporoparietal junction, and medial prefrontal cortex promotes honesty, particularly in individuals who are generally honest. Finally, activity in areas associated with cognitive control (anterior cingulate cortex and inferior frontal gyrus) helped dishonest participants to be honest, whereas it enabled cheating for honest participants. Thus, our results suggest that cognitive control is not needed to be honest or dishonest per se but that it depends on an individual’s moral default.

每天，我们都面临着为经济利益作弊的诱惑与维持自己作为“好人”的正面形象之间的冲突。虽然已经提出需要认知控制来调解奖赏与我们的道德自我形象之间的冲突，但是认知控制在（不诚实）诚实行为中的确切作用仍然难以捉摸。在这里，我们通过研究作弊背后的神经机制来确定这种作用。我们开发了一项任务，该任务允许在MRI扫描仪的逐项试验中对自发作弊进行不明显的测量。我们发现伏隔核的活动促进了作弊，特别是对于那些经常作弊的人，而由后扣带回皮质，颞顶交界和内侧前额叶皮质组成的网络则促进了诚实，特别是对一般诚实的人。最后，与认知控制有关的区域（前扣带回皮层和额下回）的活动帮助不诚实的参与者诚实，而这却欺骗了诚实的参与者。因此，我们的研究结果表明，认知控制本身并不需要诚实或不诚实，而是取决于个人的道德违约行为。