Abstract

Effective learning and memory underlie successful human behaviour. Much experimental evidence suggests that multiple parallel memory streams operate over different time scales. As an example, doctors learn and retain knowledge about diseases over years, but then acquire, utilise and often forget details of an individual patient over just a few days. Much recent work has focused on the role of dopamine in information acquisition (learning). Here we investigate the role of dopamine in consolidating information over time (memory). We recently tested patients with Parkinson's ON and OFF medication on a computerised cognitive task of learning, reasoning and memory. Dopamine therapy did not influence initial learning, but did significantly benefit memory consolidation over around 30 min. Further pilot work is first exploring which dopamine receptors may be involved in memory consolidation by looking at the relative benefit of levodopa (D1-D5) and certain dopamine agonists (D2-4) on memory. Second we predict that memory consolidation will be impaired in patients with Alzheimer's disease and vascular dementia and we will test this using our task. On the basis of this pilot work, we plan to investigate the possibility of dopaminergic therapy in patients with memory consolidation deficits.