Fig. 1. Generalization matrix between 1-octanol, benzyl acetate, eugenol and geranyl acetate. Each subject was conditioned with one of these odors and then tested with two of them (one of the test odors may have been the same as the conditioned odor). Thick horizontal bars represent median values for the duration of the proboscis extension response during the extinction (unrewarded) test trials. Error bars are the 25 and 75 percentiles (when the tested odor was different from the conditioned odor, these equaled 0 for all but one case). The number of subjects tested in each odor combination is noted.