Classical conditioning and phobias

Pavlov and his dogs-
Ivan Pavlov explained classical conditioning - a way that animals and people can learn to link two things together. Pavlov was studying eating in dogs by measuring their saliva. Sometimes his dogs started to produce saliva (a response) before their food arrived. He thought this was because they could hear footsteps (a stimulus) of the person carrying the food.

Pavlov tested his idea using a dog that had a tube through its cheek to measure its saliva. First he rang a bell. The dog didn't salivate. Then he rang the bell and gave the dog some food. This was the 'conditioning process and he repeated it many times. He then just rang the bell and the dog salivated even though there wasn't any food. The dog had learned to associate the bell and the food. It had become conditioned to salivate to the bell. This learning process is called classical or pavlovian conditioning. It works for a lot of different behaviours. The general pattern is always the same and special terms are used:

The bell has no effect at the start = neutral stimulus (NS)
The food naturally produces salivation = unconditioned…