Leader or follower? Involvement of the inferior parietal lobule in agency.

Agency is the sense that I am the one generating an action. In this neuroimaging experiment, subjects controlled a circle with a mouse while requested either to lead another circle (i.e., being the agent) or to follow it (i.e., being acted upon). Clusters within the right intraparietal sulcus were associated with following for the most rostral and leading for the most caudal ones. Bilateral activity in the inferior parietal lobule in conditions involving confusion about the origin of the action confirmed its role in agency. A lateralization effect was also found in these conditions, the response being stronger in the left inferior parietal lobule when subjects were not the agent of the performed action, and in the right when they were.