Mesh : Apomorphine / administration & dosage pharmacology Corpus Striatum / drug effects Decision Making Domperidone / administration & dosage pharmacology Dopamine Agonists / administration & dosage pharmacology Dopamine Antagonists / administration & dosage pharmacology Drug Administration Schedule Guidelines as Topic Humans Levodopa / administration & dosage pharmacology Parkinson Disease / diagnosis Substantia Nigra / drug effects Time Factors