Ivan Pavlov Studied the Reflexive Flow of Saliva in Dogs

Multiple Choice

Ivan Pavlov studied the reflexive flow of saliva in dogs. He used meat powder or other food to trigger the salivation. It was later observed that the salivation in the dog was triggered even before the food was placed in its mouth. In this experiment, ________ was the unconditioned stimulus.

A) food
B) thoughts of anticipation
C) salivation
D) the sight of the food dish