Section: AP Psychology

7) Richard conditions his fish to swim to the top of the tank whenever he turns on the light in the fish tank.  In this example of classical conditioning, which of the following was most likely the unconditioned stimulus?

1. the light
2. the fish food
3. the fish swimming to the top
4. the sound of the light clicking on
5. an electric shock from a plugged in toaster being dropped into the fish tank 

The fish food is the unconditioned stimulus because it is the "thing" that provokes a response.