Preconditioned cues have no value

Elife. 2017 Sep 19:6:e28362. doi: 10.7554/eLife.28362.

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.

Keywords: dopamine; learning; neuroscience; preconditioning; prediction error; rat; second order conditioning.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Conditioning, Classical*
  • Cues*
  • Dopaminergic Neurons / physiology*
  • Models, Neurological
  • Rats