Discrete-trials lever pressing in the rat as a function of pattern reinforcement, effortfulness of response, and amount of reward.

Abstract
Acquisition and extinction of discrete-trials lever pressing were studied under conditions of consistent reinforcement, alternating reinforcement, and random partial reinforcement with long and with short runs of unreinforced trials. Effortfulness of response was varied in terms of the number of lever presses required on each trial (1, 5, 10, or 20) and amount of reward in terms of the number of pellets delivered (1 or 6). Interactions of schedule with effortfulness and with reward magnitude are described.