Dissociating the roles of episodic retrieval and contingency awareness in valence contingency learning

In the valence contingency learning task (VCT), participants evaluate target words which are preceded by nonwords. Nonwords are predictive for positive/negative evaluations. Previous studies demonstrated that this results in (a) reliable contingency learning effects, reflected in better performance for highly contingent nonword-valence pairings and (b) less reliable evaluative conditioning (EC) effects, reflected in more positive ratings of nonwords that were highly predictive of positive (vs. negative) evaluative responses. In a highly-powered (N = 129) preregistered study, we investigated both effects and assessed whether they are a consequence of episodic retrieval of incidental stimulus-response (SR) episodes and/or propositional learning (indicated by contingency awareness). Participants were either explicitly instructed about contingencies (instructed learning group) or not (incidental learning group). Both groups then worked through the VCT, an explicit rating task, and a contingency awareness test. Both groups showed contingency learning effects and EC effects for nonwords. Multi-level analyses showed that controlling for previous SR co-occurrences fully accounted for contingency learning effects in the incidental learning group. In the instructed learning group, a residual effect of genuine valence contingency learning remained. Nonword-specific contingency awareness in turn fully accounted for EC effects in both learning groups, indicating that genuine contingency learning effects reflect propositional learning.