Research reportThe endowment effect can extend from self to mother: Evidence from an fMRI study

- We explored the neural basis of the extensibility of the endowment effect.
- The endowment effect extended to the goods that mother owned.
- MPFC, insula and ACC were associated with the extensibility of the endowment.
- Activation in MPFC was correlated positively with behavioral indifference point.
- The MPFC could play an important role in the extensibility of endowment effect.

People typically demand more to part with goods they own than they would be willing to pay to acquire identical goods they do not own, a phenomenon known as the endowment effect [1-3]. Recently, a large body of behavioral research has suggested that the endowment effect may actually be a type of self-referent cognitive bias resulting from ownership of an object. However, the neural underpinnings of this effect are not well understood. In the present study, we used functional magnetic resonance imaging (fMRI) to explore whether brain activity can predict the extensibility of the endowment effect to items owned by another individual with a close relationship to the subject. Subjects were asked to decide whether to buy or sell their own or their mothers' possessions at various prices. Behavioral results showed an endowment effect not only for goods owned by the subjects, but also for goods owned by the subjects' mothers, providing evidence for the extensibility of the endowment effect. Neuroimaging data showed activation in the medial prefrontal cortex (MPFC) and insula in both ownership conditions. Also, MPFC activation was positively correlated with the behavioral indifference point in the sell-for-self and sell-for-mother conditions. Furthermore, psychophysiological interaction (PPI) analysis revealed that MPFC activation was accompanied by increased functional integration with insula and striatum. Together, these findings suggest that MPFC may play an important role in the extensibility of the endowment effect.