Learning food-avoidance

Food avoidance learning has been used to examine birds responsiveness to the color (Mason Reidinger 1983), taste (Westbrook et al. 1980), and odor (Mason Silver 1983). In each of these cases, similar procedures were used Mason and Reidinger (1983) is used here as an example. 

Avoid allergenic ingredients in ready-made food by learning how to interpret ingredient lists... 

There was food for thought as well in two compelling February horrors. One occurred halfway around the world, in Europe, where LeMay had flown so often before. The other began nearby. The hardbitten general from Ohio who despised failure and was failing in Japan could not have avoided learning in detail of both. 

Treatment simply involves avoiding dietary sources of fructose and compounds that are metabolised to fructose such as sucrose and sorbitol. Children develop a natural aversion to sweet foods and learn to avoid fructose. A positive outcome is that they are relatively free from dental caries. 

Plant-based therapies originate from an evolutionary model, refined and e5q)anded by learning and culture [HAR 05]. The use of biodiversity surrounding human beings for medical purposes is an approach originating fi-om food avoidance/selection relationships, as well as informed self-medication behaviors observed in some animal species. These behaviors are nevertheless rarely integratively studied a solid interpretation, therefore. 

The tests generally involve some form of maze but the simplest is the passive avoidance test. In this the animal learns that in a certain environment it will be punished with an electric shock for some particular action, like stepping onto a special part of the floor of the test chamber. The test of memory is how long the rat avoids (remains passive to) making the movement that will initiate the shock. Of course, drugs that reduce the animal s anxiety also modify the response. Using a maze in its simplest T shape, the animal is placed at the base of the vertical arm and a food reward at the end of one of the horizontal arms. Clearly the animal has to learn which arm contains the reward. Memory is assessed by the time taken for a food-deprived animal to reach the reward and the number of false arm entries. This simple system can be made more complex by introducing many more arms and branches but the principle is the same. 

Visual and chemical cues interact in foraging by natricine snakes. Even visual cues alone can elicit prey attack, especially in aquatic foraging (Drummond, 1985). Aposematic color patterns of prey enhance the learning of prey that induces illness. Garter snakes, Thamnophis radix hay deni, were exposed to fish and earthworms presented on black-and-yellow forceps, and then inj ected with lithium chloride (LiCl). Control prey was offered on green forceps. Later, the snakes avoided food from either forceps, but the aversion to prey paired with black-andyellow was stronger (Terrick etal, 1995). 

Other physiological effects of defensive chemicals have not been observed or studied for plant-herbivore interactions. For example, studies of chemically defended sessile invertebrates have shown that some compounds have emetic properties against fish predators, and that fishes can learn quickly to avoid these chemicals after regurgitating ingested food.206,258 Macroalgal compounds could potentially act in similar ways, but such effects have never been documented. 

At the present time we use a battery of three learning and memory tests. These are (1) Unlearned behavior is measured by activity (2) Ability for new learning is determined by comparing experimental and control animals on their time to learn to respond to a signal and retreat to a safe area thereby avoiding an electric shock and (3) Memory (or old learning) is measured by ability to press four levers in a given sequence for a receipt of a food reward. 

Animals are intelligent and can learn. The role of learning in food and toxin avoidance should not be underestimated, but it has not been studied in most species. 

The first of the accessory food factors to be isolated and identified was found to be chemically an amine therefore, in 1912, Funk coined the term vitamine, from the Latin vita for life and amine, for the prominent chemical reactive group. Although subsequent accessory growth factors were not found to be amines, the name has been retained - with the loss of the final -e to avoid chemical confusion. The decision as to whether the word should correctly be pronounced vitamin or veitamin depends in large part on which system of Latin pronunciation one learned - the Oxford English Dictionary permits both. 

The red eft stage of the red-spotted newt contains toxic, bad-tasting chemicals in its skin. As a result, many potential predators learn to avoid this animal, and will not eat red efts. The range of the red salamander Pseudotriton ruber) overlaps part of the larger range of the red-spotted newt in the eastern United States. It appears that the superficially similar but non-toxic red salamander may be a mimic of the color of the red eft, taking advantage of the fact that many predators avoid this animal as food. 

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