Conditioned taste aversion

Conditioned taste aversion occurs when an animal associates the taste of a certain food with symptoms caused by a toxic, spoiled, or poisonous substance. Generally, taste aversion is developed after ingestion of food that causes nausea, sickness, or vomiting. The ability to develop a taste aversion is considered an adaptive trait or survival mechanism that trains the body to avoid poisonous substances (e.g., poisonous berries) before they can cause harm. The association reduces the probability of consuming the same substance (or something that tastes similar) in the future, thus avoiding further poisoning. It is an example of classical conditioning or Pavlovian conditioning.

Studies on conditioned taste aversion which involved irradiating rats were conducted in the 1950s by Dr. John Garcia, leading to it sometimes being called the Garcia effect.

Conditioned taste aversion sometimes occurs when sickness was merely coincidental and not related to the substance that caused the sickness. For example, a person who becomes very sick after consuming vodka-and-orange-juice cocktails may then become averse to the taste of orange juice, even though the sickness was caused by the over-consumption of alcohol. Under these circumstances, conditioned taste aversion is sometimes known as the "Sauce-Bearnaise Syndrome", a term coined by Seligman and Hager.

While studying the effects of radiation on various behaviors in the mid to late 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.

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