Pavlov's dogs:
Noticed dogs salivate at the presentation of food, natural response (unconditioned)
Presented the dog with food whilst ringing the bell
Bell = neutral stimulus (no initial reaction)
Over time, the dogs start to associate the bell with the food
Unconditioned stimulus --> unconditioned response
Neutral stimulus + unconditioned stimulus --> unconditioned response
Conditioned stimulus (NS) --> conditioned response
Dogs began to salivate at sound of a bell