Evaluative influences of CS-US pairings are non-reciprocal

Three experiments examined the reciprocity of evaluative effects following CS-US pairing. In all three experiments, CS evaluations were assimilated to the valence of the US they were paired with (i.e., an evaluative conditioning effect), whereas US evaluations became less extreme (i.e., a US devaluation effect). Of importance, however, US devaluation proved independent of CS-US pairing. Experiment 1 replicated previous evidence for US devaluation: USs were less intensely evaluated after a conditioning procedure as compared to their normative ratings. Experiment 2 controlled for the effect of CS-US pairing: A US devaluation effect of similar magnitude was observed for USs paired with the CSs or presented alone during the conditioning procedure. Experiment 3 indicated that US habituation drives US devaluation: USs presented and evaluated only once were less devalued than were US paired with CSs or US presented alone during the conditioning procedure, with the latter two US types not differing from each other. Together, these findings suggest that US devaluation is driven by US habituation rather than by a CS-to-US influence in an associative learning procedure. The theoretical implications of these findings for associative and propositional accounts of evaluative learning are discussed