Abstract
Various types of aberrant social behaviors may occur after brain injury. Some of these behaviors might be understood as psychological reactions to physical impairment or social difficulties. Others might be better understood as direct consequences of brain injury. Apathy, disinhibition, and executive dysfunction are the three major domains of aberrant social behaviors after injury of the prefrontal cortex and its associated subcortical structures. It is proposed that these three domains are specifically associated with medial prefrontal, orbitofrontal, and dorsolateral prefrontal injury, respectively. However, clinico-anatomical correlations are not always clear in many patients, especially in those after traumatic brain injury. Defining the aberrant social behaviors in the framework of cognitive psychology is important to promote understanding of the neurobiological bases of these changes. Regarding apathy, the definition of “ a quantitative reduction of voluntary, goal-directed behaviors” might provide an adequate framework.