they used a baby boy, nicknamed little albert
-at 9 months showed no fear of a laboratory white rat
-at 11 months old, whenever the rat was placed in his lap a loud noise was made by banging together two steel bars behind his back
the loud noise = an unconditioned stimulus
alberts responce to the noise (crying) = unconditioned responce
before conditioning, the rat = neutral stimulus
after only the third trial, albert showed fear whenever he saw the rat