Following the Path of Discovery
Repeat Famous Experiments and Inventions
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In a now classic experiment, Pavlov first performed a minor operation on a dog to relocate its salivary duct to the outside of its cheek, so that drops of saliva could be more easily measured. The dog, which was food deprived, was then harnessed in an apparatus to keep it steady in order to collect saliva.
Periodically, a bell was rang, followed shortly thereafter by meat being placed in the hungry dog's mouth. Normally, meat causes a hungry dog to salivate, whereas rings have little effect. The dog's salivation to meat is an unconditioned reflex - it is in-born, in that dogs do not have to learn to salivate when food is placed in their mouths. Initially, the dog shows little responsiveness to the bell rings. Over time, however, the dog comes to salivate at the sounding of the bell rings alone. When this occurs, Pavlovian conditioning or classical conditioning has occurred, in that a new, or conditioned, reflex has developed. This confirmed Pavlov theory that the dog had associated the bell ringing with the food.
In 1904 Pavlov was awarded the Nobel Prize for physiology for his work on digestive secretion.
Regretfully, we do not advise students to undertake this Pavlovís seminal experiment since it involves some surgical abilities, out the limits of high school studentsí expertise, and more important, we think that hurting innocent animals is not ethical, at least not for the purpose of a science fair project.
Frederic Skinner's work was influenced by Pavlovís experiments and the ideas of John Watson, father of behaviorism. He especially was interested in stimulus-response reactions of humans to various situations, and experimented with pigeons and rats to develop his theories. He took the notion of conditioned reflexes developed by Ivan Pavlov and applied it to the study of behavior.
One of his best known inventions is the Skinner box (operant conditioning chamber). It contains one or more levers which an animal can press, one or more stimulus lights and one or more places in which reinforcers like food can be delivered.
In one of Skinnersí experiments a starved rat was introduced into the box. When the lever was pressed by the rat a small pellet of food was dropped onto a tray. The rat soon learned that when he pressed the lever he would receive some food. In this experiment the lever pressing behavior is reinforced by food.
If pressing the lever is reinforced (the rat gets food) when a light is on but not when it is off, responses (pressing the lever) continue to be made in the light but seldom, if at all, in the dark. The rat has formed discrimination between light and dark. When one turns on the light, a response occurs, but that is not a Pavlovian conditioned reflex response.
In this experiment Skinner demonstrated the ideas of "operant conditioning" and "shaping behavior." Unlike Pavlov's "classical conditioning," where an existing behavior (salivating for food) is shaped by associating it with a new stimulus (ringing of a bell or a metronome), operant conditioning is the rewarding of an act that approaches a new desired behavior.
Skinner applied his findings about animals to human behavior and even developed teaching machines so students could learn bit by bit, uncovering answers for an immediate "reward." Computer-based self-instruction uses many of the principles of Skinner's technique.
Warning: Pay notice that in this experiment you deal with animals, when not given appropriate care, can transmit disease. As a rule: all the animals you experiment with should be under veterinary supervision.
Experiments with electricity should be performed under the supervision of teachers or adults familiar with electricity safety procedures.
Remember, animals shouldnít be abused in any way. Ask the permission of your school / college / university authorities before you begin an experiment with animals.
Before you begin, consult the link section of this page and especially Frederic Skinner's books. Ensure that you understand the basic principles. Surf the web further and consult your local library, your teachers and other knowledgeable adults and experts.
B. F. Skinner - Science and Human Behavior, Macmillan, 1953
B. F. Skinner - The Behavior of Organisms, Skinner Foundation, 1991
B. F. Skinner - Schedules of Reinforcement, Skinner Foundation, 1997
Skinner's Box Web Resources
A Brief Survey of Operant Behavior - B. F. Skinner Foundation
The Annual Skinner Box Rat Training Competition - Access Excellence
Two Types of Conditioned Reflex and a Pseudo Type - Classics in the History of Psychology
Behaviorism: B. F. Skinner - Linda M. Woolf
Conditioning and Genetics - The Student Room
Pavlov Web Resources
Behavioral Learning - Chapter 15 from Heinemann Psychology
Classical Conditioning Basics - Bob Kentridge
Ivan Pavlov: Biography - The Nobel Foundation
Pavlov's Dogs - The Nobel Foundation
Ivan Pavlov - Mindy Lautenheiser
Pavlov Classical Conditioning - Victor Daniels