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.

在基于模型的学习中，已经使用感觉预处理来暗示中脑多巴胺，这与多巴胺瞬态反应无模型值的观点相矛盾。但是，已经有人提出，无模型的价值可能通过中介学习直接产生于预先设定的提示。在此，以先前的工作（Sadacca等人，2016）为基础，我们通过测试预先设定的提示是否会支持大鼠的预先设定的强化来解决这个问题。我们发现，尽管直接条件提示和二阶条件提示都支持强大的条件增强，但预条件提示却不支持。这些数据表明，在我们的程序中，预处理的提示并不能直接产生无模型值，并且进一步表明，该提示即使以基于模型的方式间接地也不一定可以访问值。如果是这样，