ABA Fundamentals

Conditioned suppression of counting behavior in rats.

Blackman et al. (1973) · Journal of the experimental analysis of behavior 1973
★ The Verdict

A single fear cue can collapse an entire counting chain, just like it stops simple lever presses.

✓ Read this if BCBAs who use chained tasks or precision-teaching fluency drills.
✗ Skip if Clinicians working only with purely mand-based or DTT programs.

01Research in Context

01

What this study did

The team taught four rats to count. The rats had to press a lever exactly A times, then exactly B times, to earn food.

After the counting chain was rock-solid, the experimenters added a twist. A tone came on for three minutes, and the last five seconds ended with a mild foot-shock. They wanted to see if the warning tone would break the counting chain.

02

What they found

The tone scared the rats. Their lever-pressing dropped so low that they rarely finished the first count.

Because they never reached the A target, reinforcement stopped. The whole counting routine fell apart.

03

How this fits with other research

LYOSLOANE (1964) saw the same thing in pigeons on an FR 150. A warning stimulus early in the ratio stopped the birds cold.

Cherek et al. (1970) used two warning stimuli at once and got even stronger suppression. The 1973 study shows the same fear effect, but now the response is a number chain instead of simple pressing.

Evans (1963) gives a practical buffer: richer reinforcement (VI-1) weakens suppression. If you must use aversive stimuli, thicken the schedule first.

04

Why it matters

Your client’s problem behavior may look like “refusal,” but fear can shut down even well-built skill chains. Check for hidden aversive stimuli—staff tone, room noise, or task cues—that act like the rat’s tone. If you find one, either remove it or strengthen the reinforcement density first.

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→ Action — try this Monday

Audit your client’s task chain for any neutral stimulus that might predict escape or reprimand; remove or re-pair it with dense reinforcement.

02At a glance

Intervention
not applicable
Design
single case other
Sample size
3
Population
not specified
Finding
negative

03Original abstract

Three rats were trained on a schedule in which a response on lever B was reinforced only if it was preceded by a minimum number of consecutive responses on lever A. The minimum requirement was 27 A responses for Rat 1, and 20 A responses for Rats 2 and 3. The schedule maintained high rates of responding on lever A, and a slow, spaced pattern of responding on lever B. The mean number of consecutive responses on lever A was slightly greater than the minimum required. The effect of superimposing on this behavior a stimulus that ended with an unavoidable shock was the suppression of responding on both levers during the pre-shock stimulus. Responses on lever A were more suppressed, and the proportion of relatively short response runs on lever A during the pre-shock stimulus increased. With all three rats, the mean number of consecutive responses on lever A during the pre-shock stimulus decreased to a value below the minimum requirement for reinforcement of the subsequent B response.

Journal of the experimental analysis of behavior, 1973 · doi:10.1901/jeab.1973.19-93