Two Dimensions of Value: Dopamine Neurons Represent Reward But Not Aversiveness

Abstract

Coding Reward Versus Punishment Reinforcement learning is driven by reward prediction error, and a very influential theory has proposed that dopamine neurons provide this signal to teach value to the brain. Although this is called a reward prediction error, it has been assumed to also represent aversiveness. Thus, it was thought that the dopamine signal could be sufficient for learning total value. Fiorillo (p. 546 ) found that dopamine alone was not sufficient to encode value, implying that there must be an analogous signal for aversiveness.