Temporal control by signals of interval duration within variable-interval schedules.
Stimulus duration can act like a clock inside VI schedules, stretching post-reinforcement pauses and shaping response speed.
01Research in Context
What this study did
Frame et al. (1984) worked with rats on a variable-interval schedule. Each interval came with a light or tone that lasted the same time as the interval.
The team asked: if the stimulus length tells the rat how long it must wait, will the rat pause longer after each sip of sucrose?
What they found
Rats stretched their post-reinforcement pause when the signal lasted longer. They also sped up responses near the end of the interval.
The animals were using the stimulus as a clock inside a VI schedule, something not shown before.
How this fits with other research
Bauman et al. (1996) later saw the same lengthening pauses under progressive-interval schedules, showing the effect holds when intervals grow instead of vary.
McSweeney et al. (1993) found pauses track the past interfood interval, while L et al. show they can also track a signaled future interval. Together they map two levers you can pull to shape pausing.
Segal (1962) first proved external clocks control fixed-interval timing; L et al. extend that idea into the messy VI world.
Why it matters
You can now use brief visual or auditory cues to set wait times in VI-based programs. Pair a short tone with short intervals and a long tone with long intervals. Clients will pause longer after reinforcement when the signal says the next reward is far away, smoothing out response bursts and building better temporal regulation.
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Join Free →Pick one VI activity, add a 3-s light for short intervals and a 9-s light for long intervals, then measure post-reinforcement pause.
02At a glance
03Original abstract
Rats' lever pressing produced sucrose reinforcers on a variable-interval schedule where, in different conditions, the duration of a stimulus presented immediately after reinforcement was either correlated or uncorrelated with the duration of the current interreinforcement interval. Under the baseline schedule, in which no stimulus was presented, the minimum interreinforcement interval was 8 s and the mean postreinforcement pause of each subject approximated this value. Response rates increased slowly over the first 10 to 15 s and then remained roughly constant throughout the remainder of the interval. In both the correlated and uncorrelated conditions, the added stimulus resulted in the postreinforcement pauses lengthening to values in excess of the duration of the preceding stimulus. This resulted in a poststimulus pause which was, in most cases, roughly constant irrespective of the duration of the preceding stimulus, or of the reinforcement contingencies prevailing immediately after stimulus offset. Local response-rate patterns in the uncorrelated conditions were similar to those obtained under the baseline schedule in which no stimulus was presented. However, in the correlated condition local response rates increased across the remainder of the interreinforcer interval. Further, the rate of acceleration was inversely related to the duration of the preceding stimulus. These results show that a correlation between stimulus duration and the ensuing time to reinforcement can control behavior-a type of temporal control not previously reported.
Journal of the experimental analysis of behavior, 1984 · doi:10.1901/jeab.1984.42-267