Dopaminergic Enhancement of Learning and Memory in Aphasia

Inclusion Criteria for patients with aphasia: * Unilateral cerebrovascular accident (stroke) in the territory of the arteria media * Time post onset: \> 6 months * Aphasia with anomia * Age between 18-75 years * Premorbid right-handedness * Primary language: German Exclusion Criteria for patients and healthy controls: * Known allergy to levodopa or tartrazine * History of medication/drug abuse * Acute nicotine withdrawal or \> 15 cigarettes per day * \> 6 cups/glasses of coffee, caffeine drinks or energy drinks per day * \> 50 grams of alcohol per day * Severe hypertonia (systole \>180 mm Hg) * Severe arteriosclerosis * Diabetes, asthma, or glaucoma * Severe hearing disability * Evidence for severe hippocampal damage * Premorbid depression or psychosis * Medication with dopamine agonists or antagonists * Parkinsonian symptoms * Changes in anticonvulsive medication during the week prior to study enrollment