ABA Fundamentals

THE EFFECT OF ACCELERATION ON FOOD-REINFORCED DRL AND FR.

BEASLEY et al. (1965) · Journal of the experimental analysis of behavior 1965
★ The Verdict

Heavy stress right before session can crash response rates, so guard the minutes that lead up to therapy.

✓ Read this if BCBAs whose clients travel or face strong sensory input before sessions.
✗ Skip if Clinicians who see clients at home with no commute or wait time.

01Research in Context

01

What this study did

Scientists put rats in a small chamber. The rats pressed a lever for food.

Before each daily session the rats rode in a spinning box. The box created five times normal gravity for five hours.

The rats worked on two schedules: fixed-ratio (FR) and differential-reinforcement-of-low-rate (DRL). The team wanted to see if high gravity changed how the rats worked.

02

What they found

After the gravity ride the rats pressed much less during FR. They took longer breaks between presses.

On DRL they waited even longer than the schedule asked. Their timing spread out.

High gravity acted like a strong stress and knocked down all reinforced behavior.

03

How this fits with other research

Vos et al. (2013) later showed that simply delaying food by a few seconds hurts FR the same way. Their clean test replaced the old gravity idea.

Bauman (1991) proved the real killer is delay, not lever effort. Rats care more about when food arrives than how many presses it costs.

Eisenmajer et al. (1998) added that unsignaled three-second delays wreck both response rate and staying power. The 1965 gravity stress now looks like one more thing that makes food late.

04

Why it matters

When a client suddenly works less, look first at what happened right before session. A bumpy car ride, loud hallway, or long wait can act like mini-gravity. These events delay or weaken reinforcement. Keep arrival calm, start fast, and deliver reinforcers right on time.

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→ Action — try this Monday

Meet the client at the door, skip long hall waits, and give the first reinforcer within two seconds of the first response.

02At a glance

Intervention
other
Design
single case other
Sample size
4
Finding
negative
Magnitude
large

03Original abstract

Performance on DRL 10 sec and FR 5 was studied after exposure to acceleration. After four rats, two on each of the above schedules, had stabilized they were exposed to 5 hr of acceleration at 5 G immediately before daily experimental sessions. Food intake was also studied in rats given access to food daily in their home cages and exposed to acceleration immediately before the free-feeding session. Weight gain of free-feeding animals and reinforcement intake of experimental animals dropped after acceleration. Over-all response rate on the FR was depressed markedly by acceleration but local response rates did not appear to be affected. IRT distributions of DRL sessions after acceleration were markedly shifted toward the long intervals. A sequential plot of IRTs on acceleration days showed an altered, but relatively stable, temporal patterning of responses followed by an abrupt return to the normal baseline toward the end of the session.

Journal of the experimental analysis of behavior, 1965 · doi:10.1901/jeab.1965.8-315