Pigeons' spatial memory: factors affecting delayed matching of key location.
Delayed matching stays sharp when samples are long, delays brief, and options limited.
01Research in Context
What this study did
Researchers tested pigeon memory for key location. Birds saw a lit key, then had to peck the same spot after a wait.
They changed three things: how long the sample stayed on, how long the wait lasted, and how many keys lit up later.
The goal was to see which conditions hurt memory most.
What they found
Accuracy dropped when the sample blinked off fast. Long waits also hurt.
Adding more comparison keys or placing them in a broken row made errors rise.
In short, pigeons forgot faster with short cues, long delays, or cluttered arrays.
How this fits with other research
Haemmerlie (1983) ran the same task next year and added flashing distractors during the wait. Spatial distractors that pointed to wrong keys made accuracy fall even more.
Northup et al. (1991) later showed the drop can be flipped. They gave birds a non-rewarded extra key during training. That simple change pushed memory to 24 hours—far beyond the few seconds seen here.
Together the three papers draw a clear line: without help, pigeon spatial memory is fragile; with the right training tweaks, it can last all day.
Why it matters
You probably do not train pigeons, but the rules still apply. Keep teaching cues long, delays short, and choices few. If you must stretch the delay, add discrimination practice first. These tweaks cut errors in any delayed matching lesson, from sight words to money skills.
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02At a glance
03Original abstract
The delayed-matching-to-sample procedure was modified to study pigeons' spatial memory. Nine pecking keys, arranged as a three-by-three matrix, served as the spatial cues. Trials began with a brief "ready" stimulus (dimming of the houselight). Then a randomly chosen key was lit briefly as a sample. After a short delay the sample key was lit again along with one of the other eight keys. A peck at the key that had served as the sample produced grain reinforcement, where as a peck to the other key produced only the intertrial interval. After delayed matching of key location was learned, the effects of sample and delay duration, number of keys illuminated as sample and comparisons, and organization of three-key samples were studied. Matching accuracy decreased as sample duration decreased, delay increased, the number of locations serving as samples increased, the number and proximity of comparisons increased, and when the three-key samples were "discontinuous" rather than "lines".
Journal of the experimental analysis of behavior, 1982 · doi:10.1901/jeab.1982.37-45