How does dopamine modulate learning in humans?

Dopamine is thought to play a key role in motivation, affect and learning. We are interested in understanding how dopamine modulates learning in both the striatum and the hippocampus. Dopamine neurons project directly to the striatum and the hippocampus and dopamine plays an important role in modulating plasticity in both regions. We are conducting studies to understand what the implications are for how people learn, what they remember, and how learned experiences guide decisions.
To understand how dopamine modulates learning, we are looking at how changes to dopamine levels impact learning and decision making. We do so by looking at behavior in diseases that affect dopamine transmission (such as Parkinson's disease and schizophrenia), by manipulating dopamine levels in healthy people (pharmacologically), and by linking individual variability in dopaminergic transmission to variability in behavior (genetics).