Figure 1. The 360-degree turn task.

Subjects performed a 360-degree turn into each direction in each medication state. The figure shows the time normalized with respect to baseline performance (“off ”). For each subject, only the worst performance (with regard to the right/left direction) is displayed; case 1 was unable to complete the 360-degree-turn task and therefore the straight walking task is shown (the same subject was unable to complete the task in the “supra-on” condition).