Neuroscience Seminar Series: Marc Guitart-Masip (Karolinska Institute, Sweden): Dopamine and decision-making, revisited
Thursday, 19 June 2014, 5pm to 6pm
Dopamine and decision-making, revisited
Experimental data overwhelmingly shows that dopamine is involved in reporting reward prediction errors and that the striatum uses this teaching signals to learn instrumental actions. However, the dominant learning model in which these notions are embedded is limited to cases in which the expectation of value or valence is correlated with the need to perform action. I will present a series of human behavioral, neuroimaging and pharmacological studies in which the two factors have been formally orthogonalized. First, I will show a surprising dominance of action over valence in the BOLD signal in the striatum and how administration of levodopa in healthy controls enhances this effect. I will then discuss these findings in relation to new data on the role of dopamine in signaling striatal reward prediction errors using fMRI and a pharmacological manipulation with levodopa. Finally, I will show the severe consequences of the interaction between affect and effect during learning and how dopamine arbitrates between the two.
Host: Mark Walton