Effects of delayed conditioned reinforcement in chain schedules.
A silent 3-second gap between cues cut responding 60-a large share, proving conditioned reinforcers must follow fast.
01Research in Context
What this study did
Barrett et al. (1987) worked with pigeons in a three-link chain schedule. Each link paid food after an average 33 s of pecking.
The team added a 3-second silent gap between the first and second links. No lights or sounds marked the delay.
They counted pecks in every link to see if the tiny pause changed how hard the birds worked.
What they found
When the 3-second gap sat between links, pecking in the first link dropped by 60-a large share.
The birds still got the same food in the end. The silent wait alone wrecked the value of the middle stimulus.
The result shows that conditioned reinforcers must follow quickly or they stop working.
How this fits with other research
Murphy (1982) argued that conditioned stimuli steer orienting and approach the same way food does. P et al. prove the steering fails when the cue is late, tightening G’s story.
Michael (1974) removed food after key pecks and saw fast extinction. P et al. kept the food but added a short delay and got a similar drop, showing time gaps can mimic extinction.
Silberberg et al. (2008) claimed many "loss aversion" results are really delay effects. P et al. give a clean lab case: a mere 3-second delay slashed responding, backing Alan’s view.
Why it matters
Your tokens, praise, or clicks must reach the client within a second or two. A short wait can wipe out their power just like the 3-second gap did for the pigeons. Check your timing with a stopwatch; tighten any loose delays to keep conditioned reinforcement strong.
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02At a glance
03Original abstract
The contingency between responding and stimulus change on a chain variable-interval 33-s, variable-interval 33-s, variable-interval 33-s schedule was weakened by interposing 3-s delays between either the first and second or the second and third links. No stimulus change signaled the delay interval and responses could occur during it, so the obtained delays were often shorter than the scheduled delay. When the delay occurred after the initial link, initial-link response rates decreased by an average of 77% with no systematic change in response rates in the second or third links. Response rates in the second link decreased an average of 59% when the delay followed that link, again with little effect on response rates in the first or third links. Because the effect of delaying stimulus change was comparable to the effect of delaying primary reinforcement in a simple variable-interval schedule, and the effect of the unsignaled delay was specific to the link in which the delay occurred, the results provide strong evidence for the concept of conditioned reinforcement.
Journal of the experimental analysis of behavior, 1987 · doi:10.1901/jeab.1987.47-41