Figure 1: Mean number (+ S.E.M.) of the number of sequences performed correctly by the Early (EPD) and Intermediate (MPD=IPD) PD patients, and Control (CT) subjects, during performance of the trained sequence (TS) in a single-task (ST) condition, in testing sessions run before (BT) and after (AT) training. a. Post-hoc Tukey tests: before training X after training comparison: p<0.001. b. Posthoc Tukey tests: control group x early PD group comparison: p<0.005. c. Post-hoc Tukey tests: control group x intermediate PD group comparison: p< 0.005