Table 1.

Double-Dummy Design of Study Drug Administration

	t0	t1 (1.5h after t0)	t2 (2.5h after t0)
Haloperidol	Haldol	Placebo	Onset of testing session
Levodopa	Placebo	Madopar	Onset of testing session
Placebo	Placebo	Placebo	Onset of testing session