Figure 2.

Mean performance across all animals and odor sets for the first 50 and last 50 trials. During the first 50 trials with a new odor set, animals were significantly impaired in discriminating 10c from 10c − 1, whereas replacement of the missing component with a contaminant improved discrimination from 10c in a dose-dependent manner. Performance improved with additional training, with no differential performance between odorants during the last 50 trials. Bars labeled with the same letter are not significantly different from each other, whereas different letters signify significant differences. Error bars are standard error of the mean.