 - Severe traumatic brain injury TBI - permanent or temporary impairments of cognitive, physical, and psychosocial functions with an associated diminished or altered state of consciousness - as indicated by neuropsychological screening which is currently performed routinely on patients by the TBI program at WRAMC and noted in the patients medical record. Subjects with diagnosis of mild TBI following TBI testing, but with a normal score 42 on the Test of Memory Malingering TOMM parts 1 or 2 can be included in the study. 