ImPACT Concussion Testing -ImPACT 2005 is a user-friendly, Windows-based computer program that can be administered by a team coach, athletic trainer or physician with minimal training. Reaction time is reliably measured to one hundredth of a second across individual test modules (10 modules total) and allows for an assessment of processing speed as the player fatigues. The test battery consists of a near infinite number of alternate forms by randomly varying the stimulus array for each administration. This feature was built in to the program to minimize the "practice effects" that have limited the usefulness of more traditional neurocognitive tests. ImPACT takes approximately 20 minutes to complete. The program measures multiple aspects of cognitive functioning in athletes.