Ventromedial prefrontal cortex shields value computations from bodily arousal in decision making

Emotional reactions to norm violations influence how people trade-off selfish interests against social norms, but it remains unknown which brain regions causally contribute to integrating physiological arousal associated with norm violations into the decision process. Here, we provide evidence that the ventromedial prefrontal cortex (vmPFC) causally contributes to decoupling value computations in normative choice from physiological arousal. Excitatory brain stimulation over the vmPFC reduced aversion to disadvantageous inequality in an Ultimatum game and increased post-decision confidence after acceptance of unfair monetary splits. Physiological arousal as measured via heart rate changes was increased in response to splits perceived as unfair. Enhancing vmPFC excitability reduced the sensitivity to unfairness not by directly inhibiting physiological arousal but by blocking its influence on the decision process. This suggests that vmPFC causally moderates how physiological responses to norm violations affect trade-offs between self-interests and norm considerations, highlighting its key role for integrating emotional and cognitive processes in decision making.