On the nature of processes governing defensive burying of aversive flavors and odors in rats

Four experiments are reported which investigated the processes which contribute to the failure of rats to bury fluids that have acquired aversive properties through pairings with lithium chloride toxicosis. Fluids that failed to provide strong olfactory stimulation were avoided but not buried. These solutions, however, produced higher order conditioning of odor-bearing solutions which were buried readily. Various control experiments indicated that these effects depended upon the odorous qualities of the stimulus and not upon simple novelty effects or changes in gustatory stimulation. These data indicate that the inability of aversive gustatory cues to produce burying reflects a constraint on motivational or S-R learning processes.