Proportion of Odorants Impacts the Configural versus Elemental Perception of a Binary Blending Mixture in Newborn Rabbits

摘要

Processing of odor mixtures by neonates is weakly understood. Previous studies showed that a binary mixture of ethyl isobutyrate/ethyl maltol (odorants A/B) blends in newborn rabbits at the 30/70 ratio: Pups would perceive a configural odor in addition to the components' odors. Here, we investigated whether the emergence of this additional odor in AB is determined by specific ratio(s) of A and B. To that goal, we tested whether pups discriminated between AB mixtures with lower (A−B, 8/92 ratio) or higher (A+B, 68/32) proportion of A. In Experiment 1, pups conditioned to A (or B) responded to A−B and A+B but not to AB. In Experiment 2, pups responded to A−B after learning of A− (and to A+B after learning of A+) but not to AB. In Experiment 3, after conditioning to A−B pups responded to A− and B (and to A+ and B after learning of A+B) but not or less to AB. In Experiment 4, pups responded to A−B and A+B after conditioning to AB. These results confirm the configural perception of certain odor mixtures by young organisms and reveal that the proportion of components is a key factor influencing their coding, recognition, and discrimination of complex stimuli.