Fixed-ratio and variable-ratio schedules of brief stimuli in second-order schedules of matching to sample.
Fixed-ratio second-order schedules create long pre-work pauses; variable-ratio schedules or brief stimuli remove them.
01Research in Context
What this study did
Catania (1973) worked with pigeons on a two-layer schedule.
The birds had to finish a small fixed-ratio to see a brief light.
After several of these small ratios they got food.
The team compared fixed-ratio and variable-ratio versions of this setup.
What they found
Long pauses showed up only in the fixed-ratio version.
The birds stalled before starting each small ratio.
When the brief light came on, the pause shrank.
Variable-ratio schedules kept the birds moving with almost no wait time.
How this fits with other research
Halpern et al. (1966) first spotted the fixed-ratio pause.
Catania (1973) proves the pause survives even when food is still far away.
Cullinan et al. (2001) repeated the same FR-VR pause gap, but with tokens instead of food.
Crossman et al. (1985) seems to disagree: tiny FR 1-7 schedules made pauses shrink as the ratio grew.
The clash fades when you see the size range: small ratios act differently from large ones.
Why it matters
Your client may stall before big tasks.
Switch the requirement to a variable ratio and the pause often vanishes.
Add a brief praise flash right before the work starts to cut the wait even more.
Try VR 3-5 plus a quick token or smiley for learners who freeze at the table.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Change the first response requirement from FR to VR and give a 1-s praise flash before the learner starts.
02At a glance
03Original abstract
Eight pigeons matched to sample under second-order schedules of food reinforcement. Under fixed-interval unit schedules, the first correct match to occur after a given period of time was followed by the presentation of a brief stimulus. The termination of the last fixed-interval unit schedule was followed by food according to second-order fixed-ratio and variable-ratio schedules. In Experiment 1, as the number of fixed-interval unit schedules increased, long pauses occurred under the second-order fixed-ratio schedules, but not under the variable-ratio schedules. The similarity of performance measures such as local rate and accuracy indicated that the differences engendered by these two types of schedule are in the duration of the periods of not-responding. In Experiment 2, the addition of a brief stimulus at the end of each unit schedule in chained schedules that had different discriminative stimuli present for the duration of each unit did not substantially affect the performance, and long pauses continued to occur. However, few long pauses occurred under schedules with brief stimulus presentations alone. The most inaccurate performances were engendered by chained schedules without brief stimuli.
Journal of the experimental analysis of behavior, 1973 · doi:10.1901/jeab.1973.20-219