Classical conditioning: Ivan Pavlov

• Before conditioning:

  The dogs had learned to associate the tone (CS) with being fed, and they began to salivate (CR) in anticipation of food. An unconditioned stimulus (food) produces an unconditioned response (salivation), and a neutral stimulus (bell) does not produce a response.
• During conditioning:

  The conditioned stimulus was the ringing of the bell, and the conditioned response was salivation.
• After conditioning:

  The conditioned stimulus alone triggers the conditioned response.