Talk:Conditioned taste aversion

Merge with conditioned taste aversion

• Both articles talk about the same thing and both have good info that can be supplemented. However, both titles are valid according to dictionaries and encyclopedias of psychology. So, I don't know which one to pick.--Janarius 13:45, 27 September 2006 (UTC)

Incorrect categorization

It is incorrect to class Taste Aversion (TA) as Classical Conditioning (CC) and to categorise Conditioned Taste Aversion as being identical with TA. While TA has some characteristics similar to CC is not the same thing.

Classical Conditioning results from procedures in which a neutral, conditioned stimulus (CS), in the classic example a ringing bell, is paired with a natural, unconditioned stimulus (US), presentation of food, which normally produces an unconditioned response (UR), salivation. After a number of trials presentation of the artificial CS alone will elicit a conditioned response (CR) that is identical to the UR. Presentation of the CS without presentation of US will eventually lead to extinction of the CR.

                US -> UR  |  CS + US -> UR  |  CS -> CR

This is Classical Conditioning. For a process to be classed as CC it must fulfil all these characteristics, notably pairing of a neutral stimulus with a natural one over a number of trials to produce an unnatural response to the otherwise neutral stimulus.

TA occurs when an individual associates the taste of substance with illness. For TA to occur there is no pairing of CS with with US. The spoiled food, bad water, poisonous berry etc. that precipitates the illness is harmful and can only be regarded as a natural US and not as a neutral CS. Nor is there any repetition across a number of trials. As an example, instead a ringing bell producing vomiting it would be a poison producing vomiting , which is a natural UR, not an artificial CR. Bad food makes you ill. US -> UR.

Finally, TA in an individual may never be extinguished, and some people may spend the rest of their lives with an apparently irrational dislike of certain foods, and as an anecdote most adults recognise, there are a number of alcoholic drinks they will never go near after (more than) one too many.

Taste Aversion is a natural process that serves as a survival mechanism. It may be classed as Associative Learning, but it is no more Classical Conditioning than not putting your head in a fire after having been burned is. --Kro666 14:31, 1 April 2007 (UTC)

Ridiculous. Look at it this way: The unconditioned stimulus is illness which leads to the unconditioned response, aversion. Pairing a flavour (CS) with illness leads to that flavour resulting in aversion (CR). It seems to me that conditioned taste aversion meets your proposed characteristics of classical conditioning. Furthermore, conditioned taste aversion DOES extinguish if the subject is repeatedly exposed to the flavour without the illness. People spend their lives with tastee aversions because they avoid the food forever. If a person was to force themselves to consume the food and no illness resulted, they would eventually extinguish their aversion.

"Not putting your head in a fire" after having been burned may not be classical conditioning, but fear of fire after having been burned is.

Pain -> Fear | Fire + Pain -> Fear | Fire -> Fear

This article is poor in general, but this specifically seems silly: "Taste aversion does not require cognitive awareness to develop--that is, the subject does not have to think, "Wow, this tastes like the stuff that got me sick." In fact, the subject may hope to enjoy the substance, but the body handles it reflexively. Conditioned taste aversion illustrates the argument that in classical conditioning, a response is elicited." But perhaps I'm just too deeply involved in learning research. Does the layman actually think that learning depends on awareness?

Something that I DO think would come under "interesting notes", if someone who cares about wikipedia wants to look into it, is the finding that vampire bats do not display conditioned taste aversion. Presumably, it would be evolutionarily undesireable for them to develop taste aversion, since they only consume one thing. If they find blood aversive, they'll die. (Note: Vampire bats CAN discriminate flavours, so this is not a case of them simply not having the physical system required.) This research is fairly recent and would be easily found on PubMed. — Preceding unsigned comment added by 76.11.30.187 (talk) 01:12, 2 May 2007‎

Some considerations

1. “Taste aversion” and “conditioned taste aversion” are not the same thing, not in terms of behavior. The expression “conditioned taste aversion” implies learning, while simply “taste aversion” doesn’t. It has been demonstrated that animals reject innately certain substances, such as quinine. Therefore, aversion to a taste without the intervention of learning is possible and common. That’s why CTA memory is sometimes referred to as “taste recognition memory”, pointing to the fact that the rejection to a taste has been acquired.

2. CTA may or may not be classical conditioning, but for different reasons. Indeed, in CTA learning the taste is the CS, the gastric malaise the US, and the rejection of the taste (aversion) the CR. CTA may not be a classical conditioning because the CR is not a reflexive response. Also, CTA may not be classical conditioning because of the need of only one pairing between CS-US to elicit a robust CTA and, finally, CTA may not be classical conditioning because one may place several hours between the stimuli to be associated (by the way, that’s why many researchers acknowledge CTA as a very useful memory model, because it provides the ability to experimentally separate the elements involved in the acquisition phase of memory). But CTA is still regarded as a classical conditioning because it follows other properties of classical conditioning, such as stimulus generalization, and the need of several unassociated re-exposures to the CS in order to extinguish the learning.

3. For me, the fact that CTA can be learned without the requirement of cognitive awareness is not futile. There is experimental evidence that rodents may still acquire CTA even though US is injected when the animal is deeply anesthetized with pentobarbital. But a closely related learning, the attenuation of neophobia (which refers to the opposite effect to CTA, i.e., acquiring preference for a new taste when it has not been followed by gastric malaise) is prevented by pentobarbital anesthesia applied up to one hour before the first presentation of a taste. This evidence suggests that the nervous system processes acquired aversion and preference in different ways. In fact, it has been demonstrated that both memory processes (CTA and attenuation of neophobia) involve similar as well as dissimilar molecular dynamics. What I do think is futile is the affirmation that “Conditioned taste aversion illustrates the argument that in classical conditioning, a response is elicited”

4. The body does not “handle reflexively” the CTA learning! Taste information is conveyed to brainstem structures by the VII, IX and X cranial nerves, while visceral information is taken by X cranial nerve also to brainstem areas. From here, both visceral and taste inputs ascend to the gustatory insular cortex and other structures such as the amydgala. However, it is not known yet where visceral and sensory inputs become associated. By definition, a reflex involves only peripheral processing. So, CTA cannot be just a reflex; instead, it is a learning processed centrally.

5. Finally, the very key features of CTA, such as the need of only one pairing as well as the possibility to separate stimuli for hours for CTA to be established, are mentioned only as “interesting notes”. These characteristics are far more than that. They give CTA exactly the importance as a memory model it has. And in the “applications of taste aversions” section is omitted the largest use given to this learning: its importance as an experimental memory model. Indeed, there are many labs around the world that make use of CTA as a memory paradigm, and research on this model usually is done in order to explore the acquisition, consolidation and retrieval stages of memory formation more easily.

So I strongly suggest this article to be re-written. SchwarzeSchlange 00:10, 24 July 2007 (UTC)

It's not ridiculous, the definition of classical conditioning is that it is established over a number of trials and can be extinguished. This is not the case for taste aversion, nor for a fear of pain, therefore they are not classical conditioning. There is no discussion, debate or arguemnt on this any more than there is over the definition of a verb or adjective. --80.42.240.179 16:46, 25 July 2007 (UTC)--80.42.240.179 16:42, 25 July 2007 (UTC)

No, it's not ridiculous, it's just poorly argumented. And it's pointless and sterile being dogmatic about definitions. Keep in mind that theory must match facts, not the opposite. Even though CTA does not fulfill the classical conditioning checklist features in full, it does so in many other characteristics. Definitions of natural phenomena must be capable of being corrected, expanded, or even completely discarded in order to be useful. SchwarzeSchlange 16:59, 31 July 2007 (UTC)

Garcia's study

No explanation is given for the idea that '... an external stimuli would not produce an internal response, and vice versa' (last paragraph). Neuroschizl (talk) 15:18, 8 May 2013 (UTC)