Taste aversion
As a taste aversion to reject certain will taste stimuli and by extension an aversion to certain foods referred to, which extends to the disgust can increase. There are innate and acquired taste aversions. Newborns reject the bitter taste as well as the sour taste. The specialist literature also speaks of taste aversion learning, which is a form of classical conditioning .
General
If nausea occurs after eating a meal , the person concerned usually develops an aversion to that food, even if the nausea has other causes. This effect can be explained with the so-called classical conditioning. The feed is permanently with the unique negative experience of nausea associated . The psychologist Martin Seligman described this mechanism as the “sauce béarnaise syndrome”. He vomited a short time after dinner where he had a fillet with bearnaise sauce . Although he knew the cause was gastrointestinal flu , he developed a permanent disgust for the sauce, but not for the meat. "The taste of a dish that has been eaten half a lifetime without unpleasant aftermath is evidently quite immune to the learned aversion."
research
John Garcia
In what is now a classic experimental arrangement, the American psychologist John Garcia offered rats water sweetened with the harmless sweetener saccharine in the mid-1950s , which they willingly drank. At the same time or afterwards he exposed the rats to strong x-rays, which among other things caused nausea and vomiting. After the onset of these symptoms, the rats refused the saccharin solution that was offered again.
The structure was based on the knowledge of classical conditioning at the time, with X-rays as an unconditioned stimulus (US), nausea as an unconditioned response (UR), saccharine solution as a conditioned stimulus (CS) and transmitted nausea as a conditioned response (CR). Garcia experimented with all sorts of substances, but carefully selected saccharine for the publication, because it is colorless and odorless and apart from the sweetness it has no taste of its own; this ensured that the rats were conditioned to the sweet taste alone . X-rays were also used because they are imperceptible and the rats could not attribute the nausea to them. To gain even more certainty, the rats were later anesthetized for the duration of the radiation.
The experiment showed some peculiarities. On the one hand, the single simultaneous presentation of the unconditioned and the conditioned stimulus was sufficient to achieve the unconditioned reaction (nausea), whereas several repetitions were necessary in all previous conditioning attempts. This phenomenon is known as one-trial learning . It was also observed that the conditioning still worked when the two stimuli were presented at different times. Until then, the empirically determined rule of thumb that US and CS may not be shown offset by more than one minute applied, but offset of several hours still provided the same result; The only condition was that no further stimuli worth mentioning were presented in the meantime. This phenomenon is known as long delay learning .
Garcia effect and preparedness
Based on these observations, it was assumed that certain stimulus-response combinations are easier to learn than others; this questioned the equipotentiality hypothesis that was prevalent at the time , according to which in principle all reactions to all stimuli can be conditioned to the same extent. In 1966, follow-up experiments by J. Garcia and RA Koelling showed that certain stimulus-response combinations cannot be conditioned at all, while others are better (Garcia effect) and thus refuted the equipotentiality hypothesis. It was concluded that learning behavior is influenced by biologically anchored factors and explanations were sought. Garcia presented a concept called Belongingness , which ascribes special properties to certain stimuli and reactions. However, Martin Seligman's theory of preparedness , according to which organisms are evolutionarily, ie genetically, prepared for certain stimulus-response connections, received greater attention and approval . According to this, certain stimulus-response connections are learned more easily or more quickly due to natural selection in order to promote adaptation to the environment.
Others
In pest control , which works with poisoned bait, among other things, bait shy is a problem. If a pest survives the poisoning and brings symptoms of poisoning and bait together, it develops bait shy and will no longer jump at similar baits. It is therefore preferred to use poisons that work slowly and only develop their effect a few days later. The animal is then exposed to other stimuli in the meantime and no longer associates the poisoning with the trigger.
Individual evidence
- ^ Martin Seligman: On the generality of the laws of learning . In: Citation Classics . No. February 8 , 1980 ( PDF ).
- ^ Martin Seligman: On the generality of the laws of learning . In: Psychological Review . tape 77 , no. 5 , 1970, p. 406-418 , doi : 10.1037 / h0029790 .
- ↑ Rolf Degen: When the food comes up . In: Tabula . No. 2 , 2005, p. 8–9 ( PDF ).