Empathic choice involves vmPFC value signals that are modulated by social processing implemented in IPL

Empathic decision-making involves making choices on behalf of others in order to maximize their well-being. Examples include the choices that parents make for their children, as well as the decisions of a politician trying to make good choices on behalf of his constituency. We investigated the neurobiological and computational basis of empathic choice using a human fMRI task in which subjects purchased DVDs for themselves with their own money, or DVDs for others with the other's money. We found that empathic choices engage the same regions of ventromedial prefrontal cortex that are known to compute stimulus values, and that these value signals were modulated by activity from a region of inferior parietal lobule (IPL) known to play a critical role in social processes such as empathy. We also found that the stimulus value signals used to make empathic choices were computed using a mixture of self-simulation and other-simulation processes, and that activity in IPL encoded a variable measuring the distance between the other's and self preferences, which provides a hint for how the mixture of self-and other-simulation might be implemented.