
Moral decision-making: computational insights and neural mechanisms
Description
Universal moral codes prohibit harming others for personal gain. Previous work has identified brain networks and neuromodulator systems involved in moral cognition, but how these systems compute and shape moral values during decision-making remains unknown. Here I will describe a novel computational framework for examining the neural mechanisms of moral decision-making in humans. We invited participants to trade off profits for themselves against pain for either themselves or another person, and built computational models to quantify the relative values people ascribed to pain for themselves and others. Across several experiments we found that most people would rather harm themselves than a stranger for profit. Neuroimaging revealed that these moral preferences were associated with reduced sensitivity in the striatum to profits gained from harming others. The dorsolateral prefrontal cortex encoded the normative value of profits gained from harming others, and showed an increased negative connectivity with the striatum during the exercise of moral choices. Pharmacological studies showed that serotonin and dopamine play distinct roles in shaping moral preferences. These findings have have implications for potential treatments of social dysfunction that is a common feature as well as a risk factor for many psychiatric disorders.