Although studies of the effects of lesions in the OFC, and more specifically in the VM PFC, are crucial for understanding the potential role of this brain region in emotion-based rash action, it is more relevant to our trait claim to note that there are individual differences in activity in these brain areas. In a recent fMRI investigation of reactive aggression, Lotze, Veit, Anders, and Birbaumer (2007) found that VM PFC activation correlated positively with SCR during observation of a suffering opponent, apparently associated with compassion for that opponent. This finding is consistent with the view that VM PFC activity contributes to an affective connection with the consequences of one's actions. But there were individual differences in VM PFC activity. In particular, individuals scoring high in psychopathy showed little VM PFC activation: they appeared not to be disturbed by the suffering of the opponent.
