This study will examine brain activity associated with the involuntary urges or uncontrolled movements, called "tics," experienced by people who have Tourette syndrome (TS). Before people with TS actually develop a tic, whether it is a movement or a vocal tic (like a cough or bark), they feel the urge to tic. This study will look at brain activity during the time of this urge and how brain activity may differ in people with TS and without TS.