Behavioral contrast as a function of the duration of an immediately preceding period of extinction.

N and coworkers worked with four pigeons in a small lab chamber. The birds pecked a colored key for food on a variable-interval schedule.

Before each food session, the team introduced a second key where no food was available (extinction). The duration of this extinction period varied randomly across sessions: 0 seconds, 10 seconds, 30 seconds, 2 minutes, 10 minutes, 40 minutes, or 120 minutes.

The question was simple: does a longer extinction period produce a bigger jump in pecking when food becomes available again?

Longer extinction periods made the pigeons peck faster when reinforcement restarted.

Behavioral contrast increased with increasing extinction durations and leveled off at 40 minutes. At 120 minutes the effect was no greater than at 40, showing a clear ceiling.

In plain words, a 40-minute break from reinforcement gave the biggest behavioral contrast; additional time did not add to the effect.

Craig et al. (literature) later showed the opposite trend: repeating short extinction sessions makes future resistance weaker, not stronger. The two papers seem to clash, but they test different things. N et al. looked at one long wait before the next reinforcement, while Craig et al. cycled many short waits. One long wait boosts contrast; many short ones wear the behavior down.

R et al. (literature) used the same basic setup and added a twist: they measured how long each peck lasted. Contrast raised rate but did not shorten peck duration, showing the effect is about how often, not how the movement looks.

P et al. (literature) appeared to contradict the need for long extinction at all. They got peak-shift after only three minutes of change. Their brief stimulus switch produced stimulus-control errors without sustained contrast, suggesting different mechanisms drive short-term shifts versus the robust rate boost seen here.

When you reintroduce reinforcement after a long break, expect a surge in responding. Plan for this burst if you run DRO, DRA, or return from extinction.

An extinction period of roughly 40 minutes may give you the strongest rebound, so adjust criteria and safety plans accordingly.

Use the spike as a teaching moment rather than a surprise.