Effects of symmetrical and asymmetrical changeover delays on concurrent performances.
Upcoming wait times suppress switching more than past waits—keep future delays short and signaled.
01Research in Context
What this study did
Pigeons pecked two keys for food. The schedule switched every few minutes. Before each switch the bird had to wait a set time.
The researchers made the wait longer or shorter. They also made the next wait different from the last wait. They counted how often the birds changed keys.
What they found
Longer waits cut key-switching in half. The wait that was still coming mattered more than the wait already served.
If the next wait was four seconds and the last wait was one second, the birds acted like the whole wait was four seconds.
How this fits with other research
Grosch et al. (1981) later showed pigeons pick the key that tells them a wait is coming. The 1971 finding explains why: the upcoming wait drives the choice.
Cullinan et al. (2001) added that the way you signal the wait changes the choice. Together the three papers say: tell the client what wait is next, and keep it short.
Kuroda et al. (2014) moved the idea to discrimination tasks. Birds waited during a delay signal. Full signals kept accuracy high, partial signals hurt it. Same rule: the signal during the wait controls behavior more than the wait already past.
Why it matters
When you set up a DRO, DRL, or any schedule with a wait, state the wait time up front and keep it as short as possible. The learner’s next response depends more on the wait they still face than on the wait they already finished. Use clear signals—timers, countdown boards, or verbal cues—to protect flexible responding and reduce rigid avoidance.
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02At a glance
03Original abstract
Two variable-interval 3-min schedules functioned concurrently to arrange reinforcement of a pigeon's pecks on a single key, the main key. Each schedule was associated with a distinct color of the main key; a response on a second key alternated the color and schedule assignment of the main key. A changeover delay, a period of time following schedule and key-color alternation during which reinforcement of responding on the main key could not occur, was arranged with equal or with unequal durations for the two directions of alternation. Durations were varied from 0.33 sec to 27 sec, in addition to no delay. With equal delays for the two directions of alternation, the pigeon alternated the schedules less often the larger the delay duration. When the delays in the two directions of alternation were unequal, it could be shown that alternation of the schedules was reduced both by a delay just incurred by the last alternation and by a. delay to be incurred by the next. The latter delay was more potent in reducing the frequency of alternations.
Journal of the experimental analysis of behavior, 1971 · doi:10.1901/jeab.1971.16-249