Role of the striatum in counterfactual information seeking

After making a choice, we sometimes seek information to explore alternative realities (i.e. the outcome of an option that we have not chosen). Recent research suggests that people have a strong urge to seek such counterfactual information (counterfactual curiosity), even though it can lead to negative emotions, such as regret. In the present study, we used an adapted Balloon Analogue Risk Task with functional magnetic resonance imaging to investigate brain regions associated with counterfactual curiosity. We replicated previous behavioral findings that people are willing to find out counterfactual information (how much more they could have won) after winning their game. We also observed the emotional cost associated with counterfactual curiosity, such that participants felt stronger negative emotions after seeking counterfactual information. Brain imaging results revealed that the choice to seek counterfactual information is associated with stronger activity in the caudate, brain regions implicated in processing of intrinsic and extrinsic rewards. In addition, the caudate and the nucleus accumbens showed greater activity when participants realized that they could have won more points. These results suggest that the striatum plays a crucial role in seeking and processing counterfactual information.