jumping stand

n. A small raised stand on which a rat or other small animal was placed and trained to jump toward one of two doors, which were labeled with stimuli between which the rat was being trained to discriminate. If the rat made the correct choice, the door opened and the rat found food behind it. If the rat made the wrong choice, the door would be locked and the rat would fall, usually into a net below but sometimes into iced water or something else.