ABA Fundamentals

Effects of d-amphetamine, cocaine, and phencyclidine on the acquisition of response sequences with and without stimulus fading.

Moerschbaecher et al. (1980) · Journal of the experimental analysis of behavior 1980
★ The Verdict

Gradual cue fading can protect new skills from drug-related errors.

✓ Read this if BCBAs teaching chained tasks to clients on stimulant or antipsychotic meds.
✗ Skip if Clinicians working only with med-free clients or simple single-response programs.

01Research in Context

01

What this study did

Pigeons had to learn a four-step pecking order.

Some birds learned while the lights slowly changed. Others got no help.

The team then gave low doses of speed, cocaine, or PCP. They counted wrong steps.

02

What they found

Drugs made birds mess up more when cues did not fade.

Fading cut the extra errors. The birds reached the same final accuracy.

03

How this fits with other research

Goldman et al. (1979) saw the same drugs hurt learning without any prompts. The new study shows fading can shield the skill.

Palya (1985) later added probe rewards during fading and got even faster learning, no drugs needed.

FARMELong (1963) found harder sequences break sooner under drugs. Fading works like making the task easier step by step.

04

Why it matters

If a client’s medication makes new skills slip, try fading the cues. Start with full prompts and melt them out slowly. You may keep accuracy while the dose stays the same.

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Break the next chain into four steps and keep the prompt one light longer before you fade.

02At a glance

Intervention
prompting and fading
Design
single case other
Population
not specified
Finding
positive
Magnitude
medium

03Original abstract

In each of three components of a multiple schedule, monkeys were required to emit a different sequence of four responses in a predetermined order on four levers. Sequence completions produced food on a fixed-ratio schedule. Errors produced a brief timeout. One component of the multiple schedule was a repeated-acquisition task where the four-response sequence changed each session (learning). The second component of the multiple schedule was also a repeated-acquisition task, but acquisition was supported through the use of a stimulus-fading procedure (faded learning). In a third component of the multiple schedule, the sequence of responses remained the same from session to session (performance). At higher doses, d-amphetamine, cocaine, and phencyclidine decreased the overall rate of responding and increased the percent errors in all three components. At lower doses, however, the three drugs produced selective effects on errors. Errors were increased in the learning component at lower doses than those required to disrupt the behavior in the faded-learning component. The performance component tended to be the least sensitive to disruptive drug effects. The data are consistent with the view that stimulus fading can modulate the effects of drugs on acquisition.

Journal of the experimental analysis of behavior, 1980 · doi:10.1901/jeab.1980.33-369