Petrovich Pavlov (1849-1936) (Classical Conditioning)
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)
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.
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Classical Conditioning and Little Albert
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
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,
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
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.
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.
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.
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