Participants were asked to perform three different voluntary movement tasks involving repetitive index finger actions: pressing, tapping at slow speed, and tapping at fast speed. These tasks were chosen to represent behaviors that have different probabilities of triggering motor impairment in patients with PD, as reported in previous literature (17, 23, 29). We tested the performance of the patients on the side most severely affected by the disease, as indicated by the bradykinesia hemibody scores (10 patients on the left and 9 patients on the right) in MDS-UPDRS III. In healthy controls, the side for performing the movement tasks was pseudorandomly chosen to eventually match the respective subsample sizes of patients (10 controls on the left and 10 controls on the right). Before starting each trial, participants were asked to place their arm on an armrest and place their index finger on the pressure sensing board. They were asked to start the index finger movements as soon as a white cross appeared at the center of the computer screen.
