Sam Gershman

Title: Believing in dopamine.

Affiliation: Department of Psychology and Center for Brain Science, Harvard University.

Abstract:

The temporal difference learning model has successfully accounted for many aspects of phasic dopamine activity, but a number of major discrepancies have been discovered. Some of these discrepancies can be traced back to the choice of stimulus representation used by early models. In the real world, stimuli often provide ambiguous information about the underlying state, in which case the optimal representation is a conditional distribution over states given the observed stimuli —- the belief state. I will present two studies of VTA dopamine neurons done in collaboration with Nao Uchida’s lab (one using calcium imaging, and one using single-unit recordings). Both studies provide evidence for signatures of belief states in the dopamine system.

Lab website