Inclusion Criteria:  Ages of 9 and 17. Speak and read English fluently.  Healthy Volunteer or  Have sustained a TBI at least 1 year ago, that has affected his or her ability to process emotions.  Exclusion Criteria:  Previous stroke, MS, or neurological injury or disease in the past (like brain tumor or epilepsy) other than TBI.  History of significant psychiatric illness (like bipolar disorder, schizophrenia or psychosis).  Uncontrolled seizures or other unstable medical complications.