The expanding role of dopamine

Abstract

Evidence increasingly suggests that dopaminergic neurons play a more sophisticated role in predicting rewards than previously thought.

Keywords: dopamine; neuroscience; prediction error; rat; single unit.

Figure 1.. The activity of dopaminergic neurons helps rats to integrate separate experiences to predict when a reward will be given.

(A) Schematic of the task used by Sadacca et al. In the pre-conditioning phase, rats learn to associate a clicker with a tone. In a subsequent conditioning phase, the rats learn to link the tone with a food reward. In the final test phase, the rats hear the clicker, and behave as if they expect a reward. (B) Three potential associative retrieval mechanisms that might support integrative inference about the stimulus. Left: during the conditioning phase, presenting the tone could call the clicker to mind, allowing both stimuli to be linked to a reward. Middle: after conditioning, the mental replay of experiences may permit the relationships between separate sets of stimuli to be learned. Right: in the test phase, the rats may make new inferences that cause the rats to expect a reward when they hear the clicker.