Tourette subjects must be 18-65 years of age of any race, gender, or handedness. They must be able to sit for at least 2 hours and remain at the testing site for up to 8 hours. They must be able to follow instructions and participate in reporting sensory experiences. The upper extremity tic to be studied must occur at least once a minute, but no more frequently than once every 5 seconds. Individuals with comorbid attention deficit disorder (ADD or ADHD) or with obsessive-compulsive disorder (OCD) will not be excluded.