PERSPECTIVES

variation (15). It will also be relevant to clarify the regulatory functions of the insula in borderline personality disorder, because this brain region functionally interacts with other limbic brain regions (such as the amygdala) that are implicated in this condition (16). The use of a game theoretic approach to investigate personality disorders may be useful for studying other mental illnesses where social dysfunction is a prominent source of disability and distress, such as schizophrenia or autism. Game theory originated as an instrument of neuroeco-nomic analyses that assume perfect ration-ality of the players, and at first it came as a surprise that economic choices were in fact strongly impacted by emotional and reward-related brain processes. As King-Casas et al. show, it has now evolved into a tool for investigating psychopathological impairment of social interactions. Such advances are needed for patients, thera-pists, and researchers to grapple with social dysfunction, which is among the most im-pairing and least treatable components of severe illnesses such as schizophrenia