Taste aversion

As taste aversion rejecting certain taste stimuli and in a broader sense a reluctance is referred to certain foods that can increase to the point of nausea. There are congenital and acquired taste aversions. Bitter taste is rejected by newborn as well as the flavor sour. In the technical literature is also spoken of taste aversion learning, and it is a form of classical conditioning.

General

If after enjoying a meal nausea, develops the person usually an aversion to this food, even if the nausea has other causes. This effect is explained by the so-called classical conditioning. The food is permanently associated with the unique negative experience of nausea. This mechanism has described as " sauce - bearnaise syndrome," the psychologist Martin Seligman. He even had a short time after a dinner at which he had eaten a filet with béarnaise sauce, pass. Although he knew that the cause was a gastrointestinal flu, he developed a lasting disgust at the sauce, but not before the meat. " The taste of a dish that has already consumed half a lifetime without an unpleasant injury, is apparently quite immune to the learned aversion. "

Research

John Garcia

In a now classic experiment arrangement of the American psychologist John Garcia offered the mid -1950s, is rats with the sweetener saccharin sweetened harmless water, drank it willingly. Simultaneously or subsequently, he sat out the rats of strong X-ray radiation, which causes nausea and vomiting. After the occurrence of these symptoms, the rats refused to saccharin again offered.

The structure was aligned to the then knowledge of the classical conditioning with X-rays as the unconditioned stimulus ( U.S.), nausea as unconditioned response (UR), saccharin as the conditioned stimulus ( CS) and the transmitted nausea as a conditioned response (CR). Garcia experimented with a variety of materials, selected for publication but wisely saccharin because it is colorless and odorless and has no taste than sweetness; thus it could be ensured that the rats were conditioned solely on the sweet flavor. Likewise, X-ray radiation was used because it is imperceptible and the rats, the nausea could not be attributed to them. In order to obtain more certainty that the rats are anesthetized later for the duration of the irradiation.

The experiment showed some special features. On the one hand sufficed the unique simultaneous presentation of the unconditioned and the conditioned stimulus to achieve the unconditioned response (nausea ), whereas in all previous conditioning experiments several iterations were needed. This phenomenon is referred to as one- trial learning. Furthermore, it was observed that the conditioning will still work if the two stimuli are presented at different times. Galt until then the empirically determined rule of thumb that U.S. and CS must be presented not offset more than a minute, so here provided displacements of several hours still the same result; only condition was that no further significant stimuli were presented in the meantime. This phenomenon is referred to as Long-delay learning.

Garcia effect and Preparedness

Based on these observations, one conjectured that certain stimulus-response combinations are easier to learn than others; This challenged the then prevailing Äquipotentialitätshypothese in question, all responses can be conditioned to all stimuli to the same extent, according to the principle. 1966 showed a result of experiments J. Garcia and RA Koelling that certain stimulus-response combinations are not conditionable other but it's great ( Garcia effect) and thus refuted the Äquipotentialitätshypothese. It was concluded that the learning behavior is influenced by biological factors and anchored search for explanations. Garcia presented a concept called belongingness that certain stimuli and responses ascribed special properties. However, greater attention and approval was Martin Seligman's theory of preparedness, according to the organisms to specific stimulus -response connections evolutionary biology, that are genetically prepared. Accordingly, certain stimulus-response connections owing to natural selection are species specific lighter or faster learned to promote the adaptation to the environment.

Others

In the pest control that works among others with poisoned bait, bait shyness is a problem dar. Survived a pest poisoning and brings intoxication and bait each other, so he developed bait -shy and will no longer jump to similar lures. Therefore used preferentially poisons that act slowly and make an impact until several days later. The animal is then exposed in the meantime other stimuli and brings the poisoning is no longer with the trigger in conjunction.