BEHAVIORAL-CONTRAST AND BEHAVIORAL MOMENTUM

In Experiment 1, 5 pigeons were trained to peck a key on multiple schedules of food reinforcement. The reinforcer rate was constant in 1 component and varied between conditions in the alternated component. In the constant component, steady-state response rate and its resistance to both prefeeding and extinction were inversely related to the reinforcer rate in the alternated component. Thus, resistance to both prefeeding and to extinction, like response rate, exhibits behavioral contrast. In Experiment 2, a time-out period between schedule components eliminated contrast effects on steady-state response rate but not on resistance to extinction. The resistance-to-change results contradict expectations derived from current quantitative accounts of steady-state operant behavior and suggest instead that resistance to change depends on the contingency between component stimuli and reinforcers.