Results of Experiment 1. The detectability (d′) of nine flavor mixtures constructed by combining three concentrations each of the gustatory flavorant sucrose and the olfactory flavorant vanillin. The concentrations of sucrose, S1, S2, and S3, and the concentrations of vanillin, V1, V2, and V3, were determined individually for each subject to produce 65%, 75%, and 85% correct responses in a sequential two-alternative forced choice. On each trial the subject chooses the observation interval that contained a flavorant.