Robust Pavlovian to Instrumental and Pavlovian to Metacognitive Transfers in human reinforcementlearning.

In simple instrumental-learning tasks, humans learn to seek gains and to avoid losses equally well. Yet, two effects of valence are observed. First, decisions in loss-contexts are slower, which is consistent with the Pavlovian-instrumental transfer (PIT) hypothesis. Second, loss contexts decrease individuals confidence in their choices - a bias akin to a Pavlovian-to-metacognitive transfer (PMT). Whether these two effects are two manifestations of a single mechanism or whether they can be partially dissociated is unknown. Here, across six experiments, we attempted to disrupt the PIT effects by manipulating the mapping between decisions and actions and imposing constraints on response times (RTs). Our goal was to assess the presence of the metacognitive bias in the absence of the RT bias. Were observed both PIT and PMT despite our disruption attempts, establishing that the effects of valence on motor and metacognitive responses are very robust and replicable. Nonetheless, within- and between-individual inferences reveal that the confidence bias resists the disruption of the RT bias. Therefore, although concomitant in most cases, PMT and PIT seem to be - partly - dissociable. These results highlight new important mechanistic constraints that should be incorporated in learning models to jointly explain choice, reaction times and confidence.