Revision:Conditioning and genetics

  • Pav observed the flow of saliva into the dog's mouth and the secretion of gastric juices into the stomach.
  • Firstly Pavlov removed the salivary glands from the dog's body and put it just outside the mouth, so that he could see any saliva secreted.
  • He then starved the dog and attached it so that it would not move. He put a scene with a window in front of the dog.
  • Pavlov rang a bell and then gave the dog food. He repeated this many times and observed that when the bell rang, the dog knew that food was coming.
  • He then rang the bell but did not give the dog food. The dog salivated and this confirmed his theory that the dog had associated the bell ringing with the food.
  • He also tried other stimulus instead of the bell
eg. Light and a metronome ticking.

One of Pavlov's colleagues carried out the following experiment:

  • When a dog is given acid it will react by shaking its head violently, by making movements with its tongue and by salivating.
  • The dog was given vanillan after it had been given the acid, but after numerous repeats of this, the dog did not associate the vanillan with the acid.
  • But when Amyl ethanoate was given to the dog BEFORE the acid the dog made an association.

Operant conditioning - The Skinner Box

  • Operant behaviour is when an animal's spontaneous behaviour has an effect on the environment. If this effect if favourable then the behaviour is reinforced.
  • The Skinner box is a small box for rats. Inside is a lever and a food tray. The box is illuminated.
  • A starved rat is introduced into the box. When the lever is pressed by the rat a small pellet of food is dropped onto the tray. The rat soon learns that when he presses the lever he will receive some food.
  • His lever pressing behaviour is reinforced.
  • For example, when the food is given every two presses of the lever. The rat will carry on pressing the lever but not as often as before. This is known as partial reinforcement.