University of Pittsburgh Brain Health Initiative

Inclusion criteria: Former professional football player/exposed group: 1. Professional football retiree aged 29-59 2. Played a minimum of 3 professional football seasons, with a minimum of 3 games in each season 3. Fluent in English (translations are not available/validated for most neuropsychological tests) Control/unexposed group: 1. Age 29-59 male 2. High school education or beyond 3. Fluent in English (translations are not available/validated for most neuropsychological tests) Exclusion criteria: Control/unexposed group: 1. Played organized football beyond high school 2. History of severe TBI 3. Current unstable cardiovascular disorder For both groups: 1. Prior history of psychosis (such as schizophrenia), or other major neurological disorder that would interfere with testing, in the opinion of the primary investigator. 2. Contraindication to MR imaging, such as ferrous metal, pacemakers, or concerns about claustrophobia