Abstract
Many risky choices we make affect others in addition to ourselves, and choices made by others also affect us. To study the neural mechanisms underlying social responsibility, we used the following social decision paradigm. In each trial, participants or their game partner chose between a safe and a risky option in a gamble for money. If the risky option was chosen, the gamble was played out independently for both players, such that both could either win or lose the gamble. Participants reported their momentary happiness after experiencing the outcomes of the gambles. Responsibility influenced happiness: ratings were lower following negative outcomes resulting from participants’ rather than their partner’s choices. The findings of this first behavioural study were replicated in a separate participant sample in the second neuroimaging study. Insula activation was larger in response to negative social outcomes resulting from participants’ rather than their partners’ choices. A computational modelling-based analysis of these data revealed a cluster of voxels in left superior temporal sulcus whose activation fluctuated with reward prediction errors experienced by the game partner, but to a degree that varied depending on who made the choices leading to these prediction errors. These results suggest that the anterior insula and the superior temporal sulcus play complementary roles in the neural mechanisms of social responsibility.
Competing Interest Statement
The authors have declared no competing interest.