ABA Fundamentals

Avoidance responding as a function of stimulus duration and relation to free shock.

Shimoff (1972) · Journal of the experimental analysis of behavior 1972
★ The Verdict

Tight warning-to-consequence timing triggers fast early avoidance; even a small gap kills that burst.

✓ Read this if BCBAs designing avoidance or safety protocols in clinics or labs.
✗ Skip if Practitioners who only use positive reinforcement without warnings.

01Research in Context

01

What this study did

The team tested how long a warning tone lasts and how soon shock follows it. They watched how fast avoidance starts in the first five seconds of the tone.

They changed tone length and the gap between tone and shock. They wanted to see how these timing tweaks affect early avoidance bursts.

02

What they found

Longer tones with no gap made the fastest early responses. When the gap grew, those early bursts faded away.

Shorter tones never showed the same jump in speed, even when shock came right away.

03

How this fits with other research

Nevin (1969) saw the opposite in monkeys: longer safe periods cut overall responses, not boost them. The key difference is timing focus. The monkey study looked at total responses across the whole trial. The current paper zooms in on the first five seconds of the warning tone.

Ono et al. (2021) later showed the same timing rule works with people avoiding point-loss. Bigger warned loss sped up clicks, just like longer tones sped up lever presses here.

Garcia et al. (1971) also found shorter safe periods give higher rates. Together these papers show that tighter stimulus-shock timing, not just stimulus length, drives early avoidance bursts.

04

Why it matters

When you run avoidance or escape programs, the seconds right after the warning signal matter most. Keep the delay between warning and consequence short to spark quick learner action. If you need to slow things down, insert a brief gap or use a shorter warning stimulus. These tiny timing tweaks can shape how fast your client responds in safety drills or DRL-based behavior chains.

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→ Action — try this Monday

Cut your warning-to-task delay to under three seconds and watch response speed rise.

02At a glance

Intervention
not applicable
Design
single case other
Population
other
Finding
not reported

03Original abstract

Response-independent pairings of a tone and a brief shock were superimposed on uncued avoidance responding in four groups of rhesus monkeys. For one group, tone presentations were immediately followed by an unavoidable electric shock; for the remaining groups, gaps of 5, 20, and 80 sec intervened between tone termination and shock delivery. These temporal values subsume paradigms usually treated as discrete procedures; the conditioned emotional response procedure (0-sec gap between tone and shock), trace procedure (5-sec gap) and safety-signal training (80-sec gap). Within each group, tone durations of 10, 20, 40, and 80 sec were examined. A response pattern marked by maximum response rate in the initial 5 sec of the tone followed by deceleration before shock was observed when shock immediately followed the tone, but not when gaps were interposed between the tone and shock. Response rates in the first 5 sec of the tone were a function of both tone duration and duration of the gap. When the gap was 0 to 5 sec, initial response rates were highest in longer duration tones; this relationship between tone duration and initial tone response rate was not observed for longer gaps.

Journal of the experimental analysis of behavior, 1972 · doi:10.1901/jeab.1972.17-451