 The purpose of this study will be to assess the attentional ability of patients with mild to moderate traumatic brain injury TBI using the functional Magnetic Resonance Imaging fMRI technique. Methodology for specific aim 1: sagittal pilot scan, 3-D anatomical MRI, Whole brain echo-planar imaging EPI, and functional MRI techniques with traumatic brain injured subjects doing a Continuous Performance Test CPT attention task and compare the pattern of activation with those of normal controls to see if there is a failure to activate frontal lobes in the traumatic brain injured subjects. 