The following schedule of reinforcement as a fundamental determinant of steady state contrast in multiple schedules.
The next component's reinforcement rate, not the current one, drives behavioral contrast in multiple schedules.
01Research in Context
What this study did
The team ran two experiments with pigeons on multiple schedules. They wanted to know what causes contrast effects.
They kept the first component the same and only changed the reinforcement rate in the next component.
What they found
The upcoming component's reinforcement rate controlled the contrast. No other general rate effect appeared.
If the next component had lean reinforcement, birds worked harder in the current one.
How this fits with other research
Hineline et al. (1969) saw the same pattern earlier. They also found that the following schedule sets contrast size.
Rogers-Warren et al. (1976) seems to disagree. They got no contrast when reinforcement rates were equal across components. The key difference is control: equal rates remove contrast, but the following schedule still drives it when rates differ.
McSweeney et al. (1993) later showed contrast peaks when the poorer component lasts 30-60 s. Together, these papers tell us to watch both timing and upcoming reinforcement.
Why it matters
When you run multiple-schedule programs, plan the upcoming reinforcement before you start. If the next block will be lean, expect a burst of responding now. Use this to boost skill trials or to prepare for thin schedules. If you need steady rates, keep upcoming reinforcement rich or equal across components.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Check your schedule rotation: place lean components after rich ones to harness positive contrast.
02At a glance
03Original abstract
Two experiments investigated whether steady-state interactions in multiple schedules depend exclusively on the following schedule of reinforcement. Experiment 1 used a four-component multiple schedule in which two components were associated with the same constant schedule of reinforcement, and where rate of reinforcement was varied in the component that followed one of these. Contrast effects were reliable only in the component that preceded the point of reinforcement variation, although some contrast did occur otherwise. In those instances where contrast other than the following-schedule effect did occur, it was accounted for by the effect of the preceding schedule, an effect for which there were consistent individual differences among subjects, and which varied with component duration. Experiment 2 used a three-component schedule, in which reinforcement rate was varied in the middle component. The results were consistent with Experiment 1, as the following-schedule effect was the only consistent effect that occurred, although an effect of the preceding schedule did occur for some subjects under some conditions, and was especially evident early in training. The conclusion from both experiments is that there is no general effect of relative rate of reinforcement apart from the sum of the effects of the preceding and following schedules, and that the following-schedule effect is the fundamental cause of steady-state interactions.
Journal of the experimental analysis of behavior, 1981 · doi:10.1901/jeab.1981.35-293