corrupt neural representations of value

Moral systems universally prohibit harming others for personal gain. However, we know little about how such principles guide moral behavior. Using a task that assesses the financial cost participants ascribe to harming others versus themselves, we probed the relationship between moral behavior and neural representations of profit and pain. Most participants displayed moral preferences, placing a higher cost on harming others than themselves. Moral preferences correlated with neural responses to profit, where participants with stronger moral preferences had lower dorsal striatal (DS) responses to profit gained from harming others. Lateral prefrontal cortex (LPFC) encoded profits gained from harming others, but not self, and tracked the blameworthiness of harmful choices. Moral decisions also modulated functional connectivity between LPFC and the profit-sensitive region of DS. The findings suggest moral behavior in our task is linked to a neural devaluation of reward realized by a prefrontal modulation of striatal value representations. Despite the diversity of human moral values, there is a universal prohibition on harming others for personal gain1,2. Humans avoid harming others to a remarkable degree compared with other species3, and are even willing to incur significant personal costs to alleviate others’ suffering4,5. Why, and how, people forgo self-interest for the sake of others’ welfare remains an enduring puzzle. Recent work has implicated specific brain regions in moral decision making6–9 and probed how moral behavior relates to social cognitive processes such as empathy and mentalizing10–14. However, little is known about the neural computations supporting moral decisions to avoid harming others for personal gain, and whether individual differences in these computations predict variation in actual moral behavior. We measured moral preferences in a task where participants could trade personal profits against pain experienced by either themselves or an anonymous other person (Fig. 1a). Most people required more financial compensation to increase others’ pain compared with their own15,16. In other words, profiting from another’s pain had lower subjective value than profiting from one’s own pain. One possible explanation for this moral preference is that another’s pain is