Human evaluative flavor-flavor conditioning is not sensitive to post-acquisition US-inflation

Post-conditioning US-inflation was used to determine the nature of the US r epresentation underlying human evaluative flavor-flavor conditioning. In Ex periment 1, exposure to inflated USs did not result in the acquired CS+/CS- discrimination becoming more pronounced than in two control groups that rec eived exposure to non-inflated USs or no further USs, suggesting that only the emotional-affective but not the sensory-descriptive US characteristics are encoded. In Experiment 2, two alternative accounts for this lack of a U S-inflation effect were investigated, namely that the asymptote of conditio ning was reached before US-inflation, or that the inflated US was not perce ived as related to the acquisition US. Because neither of these possibiliti es was supported, it is concluded that this conditioning preparation eviden ces learning mediated by the referential system, whereby only the emotional -affective US characteristics are encoded.