Fig. 9

Predicting perception. a The strongest positive correlations between a molecular feature and intensity, pleasantness, and descriptor ratings. All correlations shown are statistically significant (after Bonferroni correction; p < 0.000235). b Perceived intensity and vapor pressure (top; limited to the 319 molecules with available vapor pressure information) and perceived intensity and molecular weight (bottom) (p < 1E − 05). c Pleasantness and molecular complexity (top), and pleasantness and molecular features computed using Eq. (9) in [4]. Eq. (9) equates perceived pleasantness with −2.62 + 0.23* number of atoms (excluding H) + 1.58* presence of oxygen −1.96* presence of sulfur −2.58* presence of an acid group −1.89* presence of an amine group (bottom) (p < 1E−14). d The number of sulfur atoms and ratings for “garlic” (left), “fish” (middle), and “decayed” (right). In all panels, only stimuli diluted at 1/1000 are included in analysis of intensity so that only stimuli diluted to the same level are compared; and only the 778 stimuli perceived to be more intense than water (14.44) were included in the analysis of pleasantness and odor descriptors