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Classical Conditioning

 

Ivan Petrovich Pavlov (1849-1936) (Classical Conditioning)

Background:
Theory: Classical Conditioning

Ivan Petrovich Pavlov was a Russian Physiologist of circulation and digestion.  He is best known for his work in classical conditioning or stimulus substitution.  He won the Nobel Laureate in Medicine for his work on the physiology of digestion. (Nobel e-Museum) 

Experiments:Drawing of Pavlov's experimental set-up

 

Pavlov was most famous for his experiments with his dogs.  Pavlov noticed that when a hungry dog sees food he salivates.  This is an unconscious, uncontrolled, and unlearned response.  Therefore we call the food an "unconditioned" stimulus and the salivation an "unconditioned" response.  They are naturally connected.  They did not have to be learned, it was already present.

 

Then he started to ring the bell when the food was given.  After a while the dog began to associate the sound of the bell with the food.  The bell now has the ability to elicit the same salivation response as the food.  This is Classic Conditioning.  Pavlov started with two things that were already connected (food and salivation).  Then he added a third thing (the bell).  The third thing became so strongly associated that is was able to produce the old behavior.

 

This information from: http://academic.udayton.edu/elearning/onlineTraining/InstructionalDesign/Models/Behaviorism.htm

 

 

Classical Conditioning and Little Albert

John Watson

John Watson

 

In the early 1900's, American psychologist John Watson founded what was to become Behaviorism. …Behaviorism maintains that human thought and emotions are far too subjective for inclusion in any scientific theory of human behavior. Watson felt that only an individual's external behavior could be objectively recorded and measured -- and hence be appropriate for formal study.

Watson discounted the influence of heredity in favor of learning, creating a psychological model for human behavior that claimed that all human action was the result of learning.

 

Give me a dozen healthy infants, well-formed,
and my own specified world to bring them up in
and I'll guarantee to take any one at random
and train him to become any type of specialist
I might select ... regardless of his talents,
penchants, tendencies, abilities, vocations
and race of his ancestors.

In 1920 Watson performed a ground breaking experiment with his graduate student, Rosalie Rayner, involving a unique subject for psychological study -- a human infant. The subject -- Albert B. destined to be known popularly as Little Albert -- was an orphan residing at a hospital. Watson and Rayner first evaluated Little Albert at the age of nine months and found the infant to be unusually calm and well behaved. Nothing seemed to disturb or frighten him. Unafraid of a tame rat, rabbit, dog and monkey; he also failed to be perturbed by masks or any other inanimate object. Little Albert wasn't even afraid of fire!

Watson and Rayner did discover one thing that frightened Little Albert though: Extremely loud and abrupt noise. Watson could make Albert fearful by placing a steel bar behind the baby's head and smacking it with a hammer.

Now, think back on Pavlov and his drooling dogs: What Watson set out to prove was that behavior is the end result of learning, and that learning is a classically conditioned response to environmental stimulus.

Two months after their initial visit, Watson and Rayner attempted to condition Little Albert to fear a white rat. Rayner supervised the baby while Albert had the opportunity to play with the rat. Behind the infant stood Watson with his hammer and steel bar. Every time Little Albert reached for the rat, Watson smacked the bar with the hammer. Just as before, the loud noise scared the living daylights out of Little Albert.

Just the sort of fellow you want to have over to entertain at your child's next birthday party, right?

In this first round, Albert experienced two pairings of the white rat and loud noise. A week later, the infant experienced five more pairings. After seven incidents, Little Albert exhibited extreme fear at the presence of the rat alone.

Now, thinking back on Pavlov again, before the experiment, or conditioning:

·  The white rat is a neutral stimulus.

·  The loud noise is an unconditioned stimulus.

·  Albert's fear is the unconditioned response.

After conditioning:

·  The white rat becomes a conditioned stimulus.

·  Albert's fear becomes a conditioned reflex.

Also, just as with Pavlov's dogs, Watson and Rayner found that stimulus generalization had taken place. Little Albert became fearful of other furry animals, Watson's hair, a sealskin coat, even a bearded Santa Claus mask.

The result of this experiment? Watson and Rayner became famous overnight. Little Albert was adopted by a family just after completion of the experiment. Later, Watson wrote that even though he believed that Albert's fear would "persist and modify" his personality throughout his life, he could not extinguish the child's conditioned fear because he could not find him.

Uh huh.

This experiment was criticized on many grounds. Watson and Rayner made no effort to measure Albert's fear and distress. This was, after all, an experiment designed by a champion for objective analysis of human behavior. The ethics of the experiment are reprehensible.

This information from http://www.mucknmire.com/wam101/watson.html