Use of an ambiguous-sample procedure to establish a cue to forget in pigeons.
A quick, neutral stimulus can be trained to work like a delete key for bad stimulus control.
01Research in Context
What this study did
Pigeons saw two colors in a row. The second color was tricky: it matched both choices.
After the tricky color, a short horizontal line flashed. This line was meant to tell the bird, “Forget what you just saw.”
Researchers wanted to know if the line could become a real “cue to forget” and cut errors.
What they found
The birds learned the trick. When the line followed the tricky color, they picked the correct choice more often.
The line acted like a delete key for the bad sample, clearing the way for better matching.
How this fits with other research
Griffin et al. (1977) showed pigeons can boost short-term memory with extra pecks. The 1989 study flips that idea: instead of helping memory, a cue can erase it.
Skrtic et al. (1982) found memory falls apart as delays grow. The forget cue in 1989 gives a way to speed up that fall on purpose, a handy tool when old cues get in the way.
Bacon-Prue et al. (1980) kept sequences short to keep control tight. The 1989 paper adds a new layer: you can weaken control after the fact, not just before.
Why it matters
You can weaken stubborn stimulus control without waiting for extinction. Place a brief, neutral cue right after the problem prompt. Over a few sessions, that cue can teach the learner to drop the old response and wait for new instructions. Try it when a client keeps echoing the wrong answer or when staff give mixed prompts.
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02At a glance
03Original abstract
Pigeons were trained on a variation of the matching-to-sample task in which on double-sample trials two samples, one associated with each of the comparison stimuli, were presented successively. Responding to the comparison associated with the first sample was reinforced on half the double-sample trials, and responding to the comparison associated with the second sample was reinforced on the remaining half. One of two postsample stimuli was presented following the termination of each colored sample. A vertical line was presented after a correct or target sample, and a horizontal line was presented after an incorrect or interfering sample. With extended training, each bird demonstrated above-chance accuracy on double-sample trials, providing prima facie evidence that one or both of the postsample stimuli exerted control over matching behavior. Experiment 2 provided evidence that the horizontal line functioned as a cue to forget the code activated by the preceding sample stimulus. It was concluded that a condition sufficient to establish a postsample stimulus as a cue to forget is that the postsample immediately follow presentation of a sample that, if it were to control test responding, would lead to nonreinforcement.
Journal of the experimental analysis of behavior, 1989 · doi:10.1901/jeab.1989.52-325