|
School yourself to demureness and patience. Learn to inure yourself to drudgery in science. Learn, compare, collect the facts.
So spoke Ivan Pavlov. In the early 1900’s, Nobel Prize winning scientist Pavlov conducted a series of experiments with dogs that led to the formulation of the theory of what he called ‘conditioned reflexes.’ Pavlov’s ground breaking research actually began as a study into the digestive system of our canine companions. While looking at the connection between salivation and the workings of the stomach, he came to the conclusion that the two processes worked in unison by way of the autonomic nervous system. If the dog did not produce saliva then the stomach would not get the message to begin the digestive process.
Pavlov also experimented with dogs by cutting holes in their cheeks and inserting tubes to measure the rate of salivation. Pavlov would ring a bell immediately prior to serving food to the dogs and measure the salivation rate. He experimented to see if some sort of outside stimulus could produce the same result in the dog. He started by ringing a bell at the same time he served food to the animal. After a while he would ring the bell without serving any food to the dog. Interestingly, he noted that the dog would produce saliva when it heard the bell ring, even when no food was presented to it. Pavlov concluded that this was a learned response. It was, therefore, a conditioned response. He also found that if the bell were rung too often without the production of food, the dog would stop salivating.
In 1903, Pavlov published his findings, giving detailed descriptions of what stimulus produces the strongest and most durable response. Pavlov concluded that animals need to develop conditioned reflexes in order to adapt and survive in the real world, which is always changing. He also held, however, that his new theory of conditioned response could be applied to humans. He believed that it helped to explain the behaviour of psychotic people. He suggested that people who withdrew completely from society were prone to view all stimulus as a possible injury or threat. People who had been in war could also be conditioned to react in a certain way to certain stimuli, like loud noises. They may, for example, dive for cover, in the conditioned reaction to a bomb explosion.
In the 1920’s Pavlov conducted a further series of experiments with dogs. He then trained the dogs to associate a tone with a food reward. The experiments showed that the dogs would show little or no response to the tone by itself (a conditioned stimulus). But when combined with the food (an unconditioned stimulus), a measurable unconditional response (saliva production) would result. When the tone and the food were repeatedly presented together, the dogs formed an association between the two, that is between the conditioned stimulus and the unconditioned stimulus. Such conditioning is known as Pavlovian Conditioning and became a basis for the developing field of behavioural science.
|
| |
