ABA Fundamentals

Timing of avoidance responses by rats.

Libby et al. (1974) · Journal of the experimental analysis of behavior 1974
★ The Verdict

Learners time avoidance acts in proportion to the interval length, so prompt placement should follow the same ratio, not fixed seconds.

✓ Read this if BCBAs who use negative-reinforcement or avoidance-based shaping with any learner.
✗ Skip if Clinicians who work only with pure DRO or reinforcement-only protocols.

01Research in Context

01

What this study did

Mulvaney et al. (1974) watched rats in a shuttlebox with no warning lights or tones.

The rats could cross to the other side at any time to avoid mild shock.

The team tested three interval lengths: 10, 20, and 40 seconds.

02

What they found

The rats did not wait a fixed number of seconds.

Instead, they spaced their crossings in proportion to the interval in force.

Longer intervals produced wider, steady timing waves of avoidance.

03

How this fits with other research

Leander et al. (1972) first showed that unsignalled shuttlebox avoidance is learned quickly and reaches high efficiency. Mulvaney et al. (1974) zoom in and explain how the animal times those same responses once the skill is stable.

KIEFFETHOMAS (1965) found rats pause longer before tougher ratio schedules. Mulvaney et al. (1974) extend this timing skill to negative reinforcement, showing proportional waiting inside each shock-avoidance cycle.

Blough (1971) showed rats time their responses from clear warning signals. Mulvaney et al. (1974) remove all signals and reveal the animal can still use elapsed clock time, demonstrating flexible temporal control.

04

Why it matters

If you run avoidance or escape programs, do not lock prompts to fixed seconds. Space your cues at one-quarter, one-half, and three-quarters of the total interval you set. This matches the natural gradient the rat data show and should keep human learners in better rhythm with the schedule.

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→ Action — try this Monday

Cut your next avoidance interval into quarters and deliver prompts at the 25%, 50%, and 75% marks instead of at set second counts.

02At a glance

Intervention
other
Design
single case other
Sample size
3
Population
other
Finding
positive

03Original abstract

Three rats were trained on an unsignalled shuttlebox-avoidance task under three response-shock intervals (10, 20, and 40 sec). Under all conditions, subjects developed excellent temporal gradients of avoidance; that is, response rate was an increasing function of time since last response. Although the response rate at any given interval of time after the previous response was inversely related to the response-shock interval, there was an underlying similarity in the temporal gradients for the three intervals. In all cases, response rate relative to the maximum response rate was approximately equal to the proportion of the interval that had elapsed. This suggests that rats in unsignalled avoidance are estimating time from response completion, and that the units of the estimate are proportional parts of the response-shock interval.

Journal of the experimental analysis of behavior, 1974 · doi:10.1901/jeab.1974.22-513