Classical Conditioning

Ivan Pavlov

Classical Conditioning

PY-100

April 2002

Jason Forsythe

#ABSTRACT

1904 Nobel Prize Winner, Ivan Pavlov was born in Ryazan, Russia on September 14, 1849. Pavlov is best known for his intricate workings with the drooling dog experiment that lead to his further research in conditioning. This experiment, which began in 1889, had an influence on the development of physiologically oriented behaviorist theories of psychology in the early years of the nineteenth century. His work on the physiology of the digestive glands won him the 1904 Nobel Prize in physiology or medicine.

CONTRIBUTIONS

Pavlov's first independent work focused on the physiology of the circulation of the blood (Girogian, 1974). He studied the influence of variations in blood volume on blood pressure. He also investigated the nervous control of the heart, and argued that four types of nerves control rhythm and strength of cardiac contractions. It was during this first independent study that Pavlov used unanesthetized, neurologically intact dogs (Girogian, 1974). This method became the mainstay of Pavlov's methodology.

Pavlov's second independent work centered primarily around digestion. He started studying digestion as early as 1879, and it was his major focus from 1890 to 1897 (Girogian, 1974). His work was an accumulation of observations on the nervous control of one organ system through the method of chronic experiment (Girogian, 1974). The study of digestion involved developing "fistulas" through which secretions from salivary glands, stomach, the pancreas, and small intestine could be collected (Girogian, 1974). His technique was truly unique in that he did not cut the nerve supply nor contaminate the secretions with food.

The most famous and well-known experiment of Pavlov is that he 'conditioned' dogs to start a salivary response to the sound of a bell. He began by measuring the amount of salivation in response to only food. As the experiments continued, he rang a bell as he presented the food (Girogian, 1974). Again, he noted a salivary response. Finally, by only ringing the bell, Pavlov observed the same response as having presented food to the dogs . . . salivation (Girogian, 1974). These experiments defined what has been a "conditioned response".

CLASSICAL CONDITIONING

Classical Conditioning is the type of learning made famous by Pavlov's experiments with dogs. In an article titled, An Animal Owner's Guide to Operant and Classical Conditioning, by Stacy Braslau explained the process of the experiment. Pavlov presented dogs with food, and measured their salivary response (how much they drooled). Then he began ringing a bell just before presenting the food. At first, the dogs did not begin salivating until the food was presented. After a while, however, the dogs began to salivate when the sound of the bell was presented. They learned to associate the sound of the bell with the presentation of the food. As far as their immediate physiological responses were concerned, the sound of the bell became equivalent to the presentation of the food.

Through Ivan Pavlov's experiment with dogs and their reaction to stimulus, he set the basis for Classical conditioning. The methods of how classical conditioning works can be described in the following sequence (Mischel, 1993, p. 296):

1. There exists an unconditioned, natural response, like a reflex (called a UCR)

2. There exists a stimulus that triggers this response (called the UCS)

3. Eventually, the organism (man, dog, ect.) will begin to associate the UCR with the UCS

4. Once the behavior is learned, the UCR may take place even when the UCS is simulated

5. At that point, the response it referred to as conditioned (or a CR)

6. The stimulus is then referred to as a conditioned, or learned as well (or CS)

7. Stimuli unrelated to the UCR may be imposed simultaneously to the UCS

8. Though unrelated, like the UCS, these stimuli will be associated to the UCR

9. Eventually, once learned, even these unrelated stimuli can trigger the CR

The theory of Classical conditioning can be used to describe many events in people's lives. For example, the amount a person likes another person may be associated with how much the other person has come to represent positive stimuli or gratification (Mischel, 1993, p. 297). People may develop certain fears due to negative stimuli that occurred at the same time as another event (Mischel, 1993, p. 297). Freud's interpretation of little Hans, who developed fear of horses after seeing one horse fall and bleed, is an example of phobia development by classical conditioning (Mischel, 1993, p. 299-300). Another example is in Watson's experiment where a boy was exposed simultaneously to rats and a loud noise. The boy subsequently developed a strong aversion to rats, and eventually, all fuzzy things (Mischel, 1993, p. 299). Many of the reasons people avoid certain situations may stem from classical conditioning (Mischel, 1993, p. 302).

Classical conditioning extends to fairly deep levels in human nature.