Dopamine Effect on Inhibitory Control

Parkinson's patients will be allowed to the first-morning dose of levodopa medicament (levodopa, dopamine agonists, anticholinergic drugs, or a combination of levodopa and an anticholinergic drug) which normally allowed the patient to attain the best control of symptoms one hour before being tested (19). Patients will perform both the stop-signal task and the go-only task. Experimental conditions will be counterbalanced across patients.

Parkinson's patients will not take medications overnight prior to the study (20). Patients will perform both the stop-signal task and the go-only task. Experimental conditions will be counterbalanced across patients. This intervention will be given on a different day with respect to the Medication ON intervention. The order of intervention will be counterbalanced across subjects

Healthy controls will perform the stop signal task and the go-only task in the same day. The order of administration will be counterbalanced.

Parkinson's patients will not take medications overnight prior to the study (20). Patients will perform both the stop-signal task and the go-only task. Experimental conditions will be counterbalanced across patients. This intervention will be given on a different day with respect to the Medication ON intervention. The order of intervention will be counterbalanced across subjects

Parkinson's patients will be allowed to the first-morning dose of levodopa medicament (levodopa, dopamine agonists, anticholinergic drugs, or a combination of levodopa and an anticholinergic drug) which normally allowed the patient to attain the best control of symptoms one hour before being tested (19). Patients will perform both the stop-signal task and the go-only task. Experimental conditions will be counterbalanced across patients.