Brain Research Assessing Impacts of Neurophysiological Processing Speed Training in Veterans

Inclusion Criteria: Ages: 18-35 (Younger Group); Ages 50-80 (Healthy Older Group); Ages 50-85 (persons with a history of mild traumatic brain injury) * English speaking * Veterans with mild traumatic brain injury (mTBI): * A history of mTBI confirmed by the Ohio State University TBI Identification Method-Short Form (including a requirement that the mTBI caused a loss of consciousness lasting less than 30 min). * An additional note will be made for Veterans with mTBI with a report of objective or subjective cognitive decline not meeting the criteria (i.e.- Montreal Cognitive Assessment (MoCA) \>23) for impairment Exclusion Criteria: Failure to provide informed consent * Metal of foreign objects in the body that would interfere with an magnetic resonance imaging (MRI) or transcranial magnetic stimulations (TMS) * History of penetrating head wounds or a diagnosis of moderate/severe TBI * Participants with significant visual field deficits were excluded, as were those with active suicidal ideation * Suicidal ideation will be assessed with the Columbia suicidality scale (C-SSRS) * Participants with active ideation will be referred to the Veteran Crisis Line (988) (or walked) to the Front Door program at the Birmingham East clinic * Participation in a concurrent clinical trial that could affect study outcome (however, participation in standard treatments e.g. occupational therapy or use of prescribed medications such as antidepressants is acceptable) * Smoker \> 1 pack per day * Significant cognitive impairment defined as \<23 on Montreal Cognitive Assessment (MoCA) or diagnosis of mild cognitive impairment or dementia * Visual (corrected acuity \<20/80) and motor capacity (completion of 9-hole pegboard) to use a computerized intervention * In-patient status * Severe visual impairment, which would preclude completion of the assessments * Progressive, degenerative neurologic disease, e.g., Parkinsons Disease, multiple sclerosis * Severe rheumatologic or orthopedic diseases, e.g., awaiting joint replacement Actively taking GABAergic agonist/antagonist medication (benzodiazepines, gabapentin, etc.) * Terminal illness with a life expectancy of less than 12 months, as determined by a physician * Other significant co-morbid diseases that would impair the ability to participate, e.g. renal failure on hemodialysis, severe psychiatric disorder (e.g. bipolar disorder, schizophrenia), heavy alcohol use (\>15 drinks per week); persons with depression will not be excluded * Unable to communicate because of severe hearing loss, speech disorder or language barrier