Mirror pecking and timeout under a multiple fixed-ratio schedule of food delivery.
Under large fixed-ratio schedules, adjunctive responses appear in a clear time order—early mirror pecks, late escape hops—inside the post-reinforcement pause.
01Research in Context
What this study did
Pigeons earned food under two fixed-ratio schedules that alternated. The larger ratio created a longer pause after each pellet.
During every pause the birds could peck a small mirror or hop into a timeout corner. The team logged when each response happened.
What they found
Mirror pecks showed up right after the food and then faded. Timeout hops waited until late in the same pause.
Both responses stayed inside the pause; key pecking for food pushed them out when the ratio clock restarted.
How this fits with other research
Bennett et al. (1973) saw the same mirror pecking under multiple FR schedules and mapped an inverted-U across the whole inter-food interval. de Villiers (1980) zooms in, showing the first half of the pause holds mirror pecks and the second half holds timeouts.
Zeiler (1968) found FR schedules also trigger aggressive pecks toward another bird during the pause. Mirror pecking and timeout hop are gentler topographies of the same schedule-induced family.
Halpern et al. (1966) proved longer ratios make longer pauses. de Villiers (1980) shows practitioners what fills that extra time: adjunctive responses that can be measured or redirected.
Why it matters
If you run large fixed-ratio programs with clients, expect pause-time behavior that isn’t part of the target response. Watch for early, repetitive motor actions and late escape attempts. You can time prompts or deliver competing tasks in the first half of the pause to block early adjunctive behavior, then offer brief choice breaks later to replace timeout hops. Measuring these patterns gives you a fine-grained read on how the schedule feels to the learner.
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02At a glance
03Original abstract
Pigeons were trained to peck a key under a multiple fixed-ratio 25 fixed-ratio 175 schedule of food presentation. In the first condition, either a mirror or the opportunity to produce a 30-second timeout were available. In a second condition, mirror and timeout availability were reversed for the two groups. Following a return to the initial condition, mirror and timeout keys were presented together for all birds. Mirror and timeout responses occurred predominantly in the pause in the larger fixed-ratio component, regardless of whether the opportunities for the two responses were available singly or together. Mirror responding occurred in a greater proportion of the pauses than did timeouts. When the opportunities for both mirror pecking and timeout were available concurrently, they occurred with probabilities similar to those under the single conditions. Within the pause itself, mirror responses most frequently occurred immediately after reinforcement. Timeouts occurred most frequently toward the end of the pause, and some timeouts occurred in the early part of the run. Longer preratio pausing occurred in the larger fixed-ratio component in the conditions in which the mirror was present, whether or not any mirror pecks were recorded.
Journal of the experimental analysis of behavior, 1980 · doi:10.1901/jeab.1980.34-319