The pleasantness of mixtures in taste and olfaction.

Human subjects rated the perceived intensity and pleasantness of taste mixtures (sucrose-quinine) and odor mixtures (lemon-heptanal or pyridine-lavender). The components of the mixture were judged as less intense when mixed than when judged alone. A multiple regression indicated that the pleasantness of a mixture can be predicted from a weighted additive function of the pleasantness values of the component sensations. Pleasantness values of the componetns had to be estimated from their pleasantness-intensity functions, because the perceived intensities of the components change when the components are combined. Weighting coefficients for the linear regressions were greater for the unpleasant components, especially in the odor mixtures.