Functional MRI Study of Attention in Normal Controls and Traumatic Brain Injured Patients

Inclusion Criteria: * Mild to moderate brain injury patients referred to the UCI Brain Imaging Center. * Mild brain injury patients will be defined as having a Glascow Coma Scale (GCS) scale of 13-15. * Moderate brain injury brain injury patients will be defined as having a Glascow Coma Scale (GCS) scale of 9-12 . * Normal healthy control subjects (20) Exclusion Criteria: * Pre-accident neuropathology, psychopathology, or secondary neuropathological complications, or chemical abuse * Patients who required intracranial surgical intervention * Children, pregnant women, or institutionalized individuals unable to freely give consent * Patients with implanted surgical clips (hemostatic clips) or other ferromagnetic material * Patients engaged in occupations or activities which may cause accidental lodging of ferromagnetic materials, or who may have imbedded metal fragments from military activities * Patients with permanent (tattoo) eye-liner or with facial make-up (severe eye irritation has been reported) * Patients with metallic implants, because they may cause artifacts in diagnostic images due to magnetic field distortion * Patients with implanted prosthetic heart valves * Patients with pacemakers, neuro-stimulation devices * Subjects who have severe claustrophobia.