Medication Responsiveness in Parkinson's Disease

The TTT, consisting of two targets, will be presented on the screen of the smartphone. Participants will be instructed to alternate between the two targets using their index finger for 30 seconds. The task will always be performed with the left hand first and then with the right hand. The touch-sensitive screen of the smartphone will measure the timing of each touch event, its duration, the coordinates on the phone screen and the amount of pressure applied.