title: Dopamine ramps are a consequence of reward prediction errors.
abstract: Temporal difference learning models of dopamine assert that phasic levels of dopamine encode a reward prediction error. However, this hypothesis has been challenged by recent observations of gradually ramping stratal dopamine levels as a goal is approached. This note describes conditions under which temporal difference learning models predict dopamine ramping. The key idea is representational: a quadratic transformation of proximity to the goal implies approximately linear ramping, as observed experimentally.
authors: Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, U.S.A. sjgershm@mit.edu.
authors: Samuel J
authors: SJ
authors: Gershman
mesh_terms: D000465:Algorithms; D000818:Animals; D003342:Corpus Striatum / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism*; D006040:Goals; D007858:Learning / Q000502:physiology*; D018782:Maze Learning / Q000502:physiology; D008959:Models, Neurological; D051381:Rats; D012201:Reward; D013028:Space Perception / Q000502:physiology
chemical_list: D004298:Dopamine