Habituation and simple conditioningHabituation is a simple form of learning. Faced with a persistent or repeated stimulus, an animal may waste time or energy responding each time the stimulus is encountered. Habituation allows the animal to discard such stimuli as irrelevant, and to ignore them. For example, a bird or squirrel foraging near a sidewalk might flee the first few times a human walks past, but eventually it habituates to the human presence and cease to respond. Taken a step further, animals may learn to associate specific stimuli with either a positive (reward) or aversive (punishment) event; this is called conditioning. Pavlov's famous dogs learned to salivate in response to a bell which rang at feeding time. Even when food was withheld, the bell alone was adequate to cause the response. Salivation is the "conditioned response", the bell is the "conditioned stimulus" and the food is the "unconditioned stimulus". A large and complex scientific literature has developed around the phenomenon of conditioning. Current research on honey bee learning and memory relies heavily on a conditioned response. |
Short and longterm storage of informationLet's assume that learning is a costly act for an animal. The costs come in the time it takes to learn something, storage space for information in the brain, and in the neurochemicals required to store the information. If this assumption is true, then animals should learn only those parts of their experience that may be relevant and useful in the future. In general, animals find it convenient to divide learned information into two types. The first is information that may be useful in the next few minutes, but which if remembered later just clutters their thinking. A coyote might note mouse running under a specific bush. This information is useful while the coyote hunts for the mouse, but later on (considering the large number of bushes the coyote might encounter) is probably not helpful. The same coyote may remember the location of a stream where it drinks; the water remains in the same location and a longterm memory of that location could be quite useful. This logic leads to the prediction that short and longterm memory should be handled somewhat different in animal's brains, and that the persistence of a memory should be tied to the length of time over which it might be useful. An excellent example of the importance of longterm memory in animals is the retrieval of cached food. |
Animal IntelligenceHow "intelligent" are animals in their ability to assess, solve-problems, apply insight, and utilize their longterm memory? Certain animals, such as canids, apes, and corvids (crows and their relatives), display surprising abilities. Measuring intelligence, though, is a controversial task, and investigators need to avoid being bound by human-based measures of intelligence when they ask these questions of animals. Intelligence is difficult, if not impossible, to define and measure in humans, much less in animals. It is, however, an interesting topic. I've divided intelligence into five areas, which roughly correspond to mental capacities that a "smart" person might display.
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copyright ©2001 Michael D. Breed, all rights reserved