Taste Aversion - Garcia's Study

Garcia's Study

While studying the effects of radiation on various behaviours during the 1950s, Dr. John Garcia noticed that rats developed an aversion to substances consumed prior to being irradiated. To examine this, Garcia put together a study in which three groups of rats were given sweetened water followed by either no radiation, mild radiation, or strong radiation. When rats were subsequently given a choice between sweetened water and regular tap water, rats who had been exposed to radiation drank much less sweetened water than those who had not. Specifically, the total consumption of sweetened water for the no-radiation, mild radiation and strong radiation rats was 80%, 40% and 10%, respectively.

This finding ran contrary to much of the learning literature of the time in that the aversion could occur after just a single trial and over a long delay. Garcia proposed that the sweetened water became regarded negatively because of the nausea inducing effects of the radiation, and so began the study of conditioned taste aversion.

Many scientists were skeptical of Garcia's findings because it did not follow the basic principles of classical conditioning. However, Garcia replicated his results multiple times. He demonstrated that the particular stimulus used in classical conditioning does matter. An internal stimuli produced an internal response while an external stimuli produced an external response; but an external stimuli would not produce an internal response and vice versa.