Mike and Jeff are brothers who have just moved with their parents into a beautiful old house. Mike soon discovers that if he flu
shes the toilet while Jeff is taking a shower, it will cause the water in the shower to become scalding hot. Naturally, Jeff screams as his reflexes cause him to leap backward in pain. After Mike has repeated this procedure several times, Jeff has begun to twitch involuntarily every time he hears any toilet flush. In this example, twitching involuntarily every time he hears the toilet flush would be the
Conditioned stimulus refers to the neutral stimulus that trigger a specific response after being associated for a prolonged period of time with unconditioned stimulus.
In the case above:
- the toilet flush is previously a neutral stimulus that does not trigger any response.
- The toilet flush later on paired with unconditioned stimulus (hot water) that make jeff scream in pain
- Because of this, the toilet flush become a conditioned stimulus. This make jeff associate the toilet flush with hot water and make him twitch whenever he hear toilet flush while bathing.