COMPARISON OF MODELS OF ODOR INTERACTION

Subjects rated the overall perceived intensity of concentrations of th e odorants cineole, geraniol, hexyl salicylate, and linalyl acetate sm elled alone and in binary mixtures. The subjects also rated intensity of specified constituents (e.g. amount of cineole in cineole, and in m ixtures of cineole and linalyl acetate). The intensity of the stronger component alone offered a close description of perceived intensity. I n addition to the Stronger Component model, two other psychological mo dels (Vector and U model) and two psychophysical models (UPLZ and Equi ratio Mixture model) offered descriptions ranging from fair to very go od. Psychological models gave better fits, but lack explanatory power. Some results indicated that weaker odors add more potently than stron ger odors, an outcome incompatible with these models. The psychophysic al models, based on the additivity of single components, generally ove restimated perceived intensity. Judgments of individual qualities gave only slight encouragement to any expectation of differences in maskin g or maskability among odorants. The results highlight the need to tes t particular critical hypotheses regarding how people perceive mixture s.