抄録
Our sense of self is greatly influenced by how, we believe, others view us, and a drive to seek a good reputation has a profound impact on our everyday social decision-making and behaviors. Theoretical research on the evolution of human cooperation also highlights the importance of establishing a good reputation. To depict the neural basis of this enhanced motivation, we conducted functional magnetic-resonance imaging while subjects disclosed their own behavioral tendencies with reference to social norms. The mere presence of observers enhanced the task-related activities in the dorsal striatum and medial prefrontal cortex (mPFC). Moreover, these activities positively correlated with the individual's tendency to behave in a socially desirable manner. As the striatum is part of the brain's reward system, our findings suggest that the motivation for a good reputation, which is an important social reward for humans, shares the same neural basis as that for basic material rewards (e.g., food). Furthermore, considering that the mPFC functions in the formation of reflected self-knowledge, the present study suggests that the dorsal striatum and mPFC constitute a social reward system that motivates us to seek a good reputation when our public aspect of the self is salient and thus play a pivotal role in regulating our social behaviors. [J Physiol Sci. 2008;58 Suppl:S30]
