Taste aversion
Encyclopedia
Conditioned taste aversion, also known as Garcia effect (after Dr. John Garcia
), and as "Sauce-Bearnaise Syndrome", a term coined by Seligman
and Hager, is an example of classical conditioning
or Pavlovian conditioning. Conditioned taste aversion occurs when a subject associates the taste
of a certain food with symptoms caused by a toxic
, spoiled, or poison
ous substance. Generally, taste aversion is caused after ingestion of the food 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. This association is meant to prevent the consumption of the same substance (or something that tastes similar) in the future, thus avoiding further poisoning. However, conditioned taste aversion sometimes occurs in subjects when sickness was merely coincidental and not related to the food (for example, a subject who gets a cold or the flu shortly after eating bananas might develop an aversion to the taste of bananas).
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.
occurs, if ever. Also, as in nature, a food does not have to cause the sickness for it to become aversive. A human who eats sushi
for the first time and who happens to come down with an unrelated stomach virus or influenza
may still develop a taste aversion to sushi. Even something as obvious as riding a rollercoaster (causing nausea) after eating the sushi will influence the development of taste aversion to sushi. Humans might also develop aversions to certain types of alcohol because of vomiting during intoxication.
Taste aversion is a common problem with chemotherapy
patients, who become nauseated because of the drug therapy but associate the nausea with consumption of food.
and clementines
because they look similar to oranges, and might lead one to think that they are also dangerous.
John Garcia (psychologist)
John Garcia is an American psychologist, most known for his research on taste aversion learning. Garcia studied at the University of California-Berkeley, where he received his A.B., M.A., and Ph.D. degrees in 1955 at the age of 38...
), and as "Sauce-Bearnaise Syndrome", a term coined by Seligman
Martin Seligman
Martin E. P. "Marty" Seligman is an American psychologist, educator, and author of self-help books. His theory of "learned helplessness" is widely respected among scientific psychologists....
and Hager, is an example of classical conditioning
Classical conditioning
Classical conditioning is a form of conditioning that was first demonstrated by Ivan Pavlov...
or Pavlovian conditioning. Conditioned taste aversion occurs when a subject associates the taste
Taste
Taste is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food, certain minerals, and poisons, etc....
of a certain food with symptoms caused by a toxic
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
, spoiled, or poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
ous substance. Generally, taste aversion is caused after ingestion of the food causes nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, sickness
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
, 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. This association is meant to prevent the consumption of the same substance (or something that tastes similar) in the future, thus avoiding further poisoning. However, conditioned taste aversion sometimes occurs in subjects when sickness was merely coincidental and not related to the food (for example, a subject who gets a cold or the flu shortly after eating bananas might develop an aversion to the taste of bananas).
Garcia's study
While studying the effects of radiation on various behaviours during the 1950s, Dr. John GarciaJohn Garcia (psychologist)
John Garcia is an American psychologist, most known for his research on taste aversion learning. Garcia studied at the University of California-Berkeley, where he received his A.B., M.A., and Ph.D. degrees in 1955 at the age of 38...
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
Classical conditioning
Classical conditioning is a form of conditioning that was first demonstrated by Ivan Pavlov...
. 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.
Taste aversion in humans
Taste aversion is fairly common in humans. When humans eat bad food (e.g., spoiled meat) and get sick, they may find that food aversive until extinctionExtinction (psychology)
Extinction is the conditioning phenomenon in which a previously learned response to a cue is reduced when the cue is presented in the absence of the previously paired aversive or appetitive stimulus.-Fear conditioning:...
occurs, if ever. Also, as in nature, a food does not have to cause the sickness for it to become aversive. A human who eats sushi
Sushi
is a Japanese food consisting of cooked vinegared rice combined with other ingredients . Neta and forms of sushi presentation vary, but the ingredient which all sushi have in common is shari...
for the first time and who happens to come down with an unrelated stomach virus or influenza
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
may still develop a taste aversion to sushi. Even something as obvious as riding a rollercoaster (causing nausea) after eating the sushi will influence the development of taste aversion to sushi. Humans might also develop aversions to certain types of alcohol because of vomiting during intoxication.
Taste aversion is a common problem with chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
patients, who become nauseated because of the drug therapy but associate the nausea with consumption of food.
Applications of taste aversion
Taste aversion has been demonstrated in a wide variety of both captive and free-ranging predators. In these studies, animals that consume a bait laced with an undetectable dose of an aversion agent avoid both baits and live prey with the same taste and scent as the baits. When predators detect the aversion agent in the baits, they quickly form aversions to the baits, but discriminate between these and different-tasting live prey. The use of conditioned taste aversion in wildlife management has so far been resisted by governmental wildlife managers, mainly because of a lack of understanding of the process.Stimulus generalization
Stimulus generalization is another learning phenomenon that can be illustrated by CTA. This phenomenon demonstrates that we tend to develop aversions even to types of food that resemble the foods which cause us illness. For example, if one eats an orange and gets sick, one might also avoid eating tangerinesTangerine
__notoc__The tangerine is an orange-colored citrus fruit which is closely related to the Mandarin orange . Taxonomically, it should probably be formally named as a subspecies or variety of Citrus reticulata; further work seems to be required to ascertain its correct scientific name...
and clementines
Clementine
A clementine is a variety of mandarin orange , so named in 1902. The exterior is a deep orange colour with a smooth, glossy appearance. Clementines can be separated into seven to fourteen segments. They tend to be very easy to peel, like a tangerine, but are almost always seedless...
because they look similar to oranges, and might lead one to think that they are also dangerous.