Brain networks of social action-outcome contingency: The role of the ventral striatum in integrating signals from the sensory cortex and medial prefrontal cortex

- Action-outcome contingency can facilitate social interactions.
- The role of cortical nodes beyond the striatum in this contingency remains unclear.
- The medial prefrontal cortex was sensitive to another's feedback to self-actions.
- The medial prefrontal cortex modulated cortico-striatal functional connectivity.
- Signals in this prefrontal area may gate the input related to value processing.

Social interactions can be facilitated by action-outcome contingency, in which self-actions result in relevant responses from others. Research has indicated that the striatal reward system plays a role in generating action-outcome contingency signals. However, the neural mechanisms wherein signals regarding self-action and others' responses are integrated to generate the contingency signal remain poorly understood. We conducted a functional MRI study to test the hypothesis that brain activity representing the self modulates connectivity between the striatal reward system and sensory regions involved in the processing of others' responses. We employed a contingency task in which participants made the listener laugh by telling jokes. Participants reported more pleasure when greater laughter followed their own jokes than those of another. Self-relevant listener's responses produced stronger activation in the medial prefrontal cortex (mPFC). Laughter was associated with activity in the auditory cortex. The ventral striatum exhibited stronger activation when participants made listeners laugh than when another did. In physio-physiological interaction analyses, the ventral striatum showed interaction effects for signals extracted from the mPFC and auditory cortex. These results support the hypothesis that the mPFC, which is implicated in self-related processing, gates sensory input associated with others' responses during value processing in the ventral striatum.