ABA Fundamentals

Effects of reinforcer magnitude on responding under differential-reinforcement-of-low-rate schedules of rats and pigeons.

Doughty et al. (2002) · Journal of the experimental analysis of behavior 2002
★ The Verdict

Large reinforcers speed up responding and break DRL efficiency in animals, so keep rewards small when you first teach clients to wait.

✓ Read this if BCBAs using DRL to reduce problem behavior in any setting.
✗ Skip if Clinicians who only use fixed-ratio or token systems.

01Research in Context

01

What this study did

The team tested rats and pigeons on a DRL schedule.

DRL means the animal must wait a set time between responses.

If the animal responds too soon, no food arrives and the timer resets.

They gave small, medium, or large food piles after the wait.

Then they counted how fast the animals pressed or pecked.

02

What they found

Bigger food piles made the animals press faster.

Faster pressing meant more mistimed responses.

More mistimed responses meant less food overall.

Large reinforcers hurt DRL efficiency.

03

How this fits with other research

Zhou et al. (2018) extends this work to children with ID/DD.

They used full-session DRL and saw problem behavior drop.

Their human data show DRL can work in clinics, but they did not test reinforcer size.

Reed (2003) used rats like Doughty et al. (2002) but changed signal, not size.

Both studies show reinforcer details control response rate.

04

Why it matters

When you thin reinforcement with DRL, start with small, quick rewards.

Big rewards may push the client to respond too soon and lose chances.

Watch response speed after you raise the reinforcer size.

If speed jumps, shrink the reward or stretch the wait time again.

Free CEUs

Want CEUs on This Topic?

The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.

Join Free →
→ Action — try this Monday

Cut the size or length of the reinforcer in half during DRL sessions and track if response bursts drop.

02At a glance

Intervention
other
Design
single case other
Sample size
14
Population
not specified
Finding
negative
Magnitude
medium

03Original abstract

Experiment I investigated the effects of reinforcer magnitude on differential-reinforcement-of-low-rate (DRL) schedule performance in three phases. In Phase 1, two groups of rats (n = 6 and 5) responded under a DRI. 72-s schedule with reinforcer magnitudes of either 30 or 300 microl of water. After acquisition, the water amounts were reversed for each rat. In Phase 2, the effects of the same reinforcer magnitudes on DRL 18-s schedule performance were examined across conditions. In Phase 3, each rat responded unider a DR1. 18-s schedule in which the water amotnts alternated between 30 and 300 microl daily. Throughout each phase of Experiment 1, the larger reinforcer magnitude resulted in higher response rates and lower reinforcement rates. The peak of the interresponse-time distributions was at a lower value tinder the larger reinforcer magnitude. In Experiment 2, 3 pigeons responded under a DRL 20-s schedule in which reinforcer magnitude (1-s or 6-s access to grain) varied iron session to session. Higher response rates and lower reinforcement rates occurred tinder the longer hopper duration. These results demonstrate that larger reinforcer magnitudes engender less efficient DRL schedule performance in both rats and pigeons, and when reinforcer magnitude was held constant between sessions or was varied daily. The present results are consistent with previous research demonstrating a decrease in efficiency as a function of increased reinforcer magnituide tinder procedures that require a period of time without a specified response. These findings also support the claim that DRI. schedule performance is not governed solely by a timing process.

Journal of the experimental analysis of behavior, 2002 · doi:10.1901/jeab.2002.78-17