Citation

Sharpe MJ, Batchelor HM, Schoenbaum G. Elife 2017; 6: e28362.

Affiliation

Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University, Baltimore, United States.

Copyright

(Copyright © 2017, dLife Sciences Plublications, Ltd)

DOI

10.7554/eLife.28362

PMID

28925358

PMCID

PMC5619948

Abstract

Sensory preconditioning has been used to implicate midbrain dopamine in model-based learning, contradicting the view that dopamine transients reflect model-free value. However, it has been suggested that model-free value might accrue directly to the preconditioned cue through mediated learning. Here, building on previous work (Sadacca et al., 2016), we address this question by testing whether a preconditioned cue will support conditioned reinforcement in rats. We found that while both directly conditioned and second-order conditioned cues supported robust conditioned reinforcement, a preconditioned cue did not. These data show that the preconditioned cue in our procedure does not directly accrue model-free value and further suggest that the cue may not necessarily access value even indirectly in a model-based manner. If so, then phasic response of dopamine neurons to cues in this setting cannot be described as signaling errors in predicting value.

Language: en

Keywords

dopamine; learning; neuroscience; preconditioning; prediction error; rat; second order conditioning