Cognitive strategy usage in long-term survivors of severe traumatic brain injury with persisting impulsive aggression

Impulsive aggression (IA) is a relatively common phenomenon in the general nonpatient population and IA, among other forms of impaired self regulatory behavior, is common sequelae of traumatic brain injury. Impaired self regulatory behavior has been associated with dysfunction of orbital frontal cortex. This study examined strategy development and usage in a group of survivors of traumatic brain injury (TBI) who exhibited persisting problems with impulsive expressions of aggression. All participants were administered the Revised Strategy Application Task (R-SAT) and a series of personality questionnaires. The results indicated that the subjects with IA selected and used strategies that were significantly less efficient than those of the nonaggressive controls. The present study confirms, using an explicit and direct measure, previously reported deficits in strategy usage in IA and supports the notion of inefficient cognitive processing indicated by event related potential (ERP) studies. Additionally, as impaired performance on the R-SAT has been associated with lesions of ventromedial prefrontal cortex, this study provides the first concrete neuropsychological data implicating this region in IA. Further study is necessary to clarify the nature of the apparent orbital frontal dysfunction in IA and to delineate the role of impaired strategic processing and related deficits in the genesis and expression of impulsive aggression.