Dopaminergic Modulation of Cognition and Psychomotor Function

A recent study at our lab showed increased episodic memory consolidation and response readiness after treatment with methylphenidate in healthy volunteers. The investigators seek to replicate and extend these findings. Furthermore the pharmacological specificity of these effects will be studied. Since methylphenidate has an effect on two neurotransmitters, dopamine and noradrenaline, either could be responsible for the observed effects. In order to explore the dopaminergic contribution to this effect, the study proposed here includes not only methylphenidate but also levodopa/carbidopa, which only affects dopamine and not noradrenaline. In this study, 20 healthy males and females between 18 and 45 years of age will participate. They will be recruited via advertisements at Maastricht University and in local newspapers. Participants will be treated once with methylphenidate, once with levodopa/carbidopa and once with placebo. All medications will be administered orally with a capsule. It is hypothesized that methylphenidate and levodopa/carbidopa will both enhance episodic memory consolidation and improve response readiness