Abstract
Post-conditioning US-inflation was used 10 determine the nature of the US representation underlying human evaluative flavor flavor conditioning. In Experiment 1, exposure to inflated USs did not result in the acquired CS+/CS-discrimination becoming more pronounced than in two control groups that received exposure to non-inflated USs or no further USs, suggesting that only the emotional-affective hut not the sensory-descriptive US characteristics are encoded. In Experiment 2, two alternative accounts for this lack of a US-inflation effect were investigated, namely that the asymptote of conditioning was reached before US-inflation, or that the inflated US was not perceived as related to the acquisition US. Because neither of these possibilities was supported, it is concluded that this conditioning preparation evidences learning mediated by the referential system, whereby only the emotional-affective US characteristics arc encoded.