Key pecking in pigeons produced by pairing keylight with inaccessible grain.
Autoshaping can create key pecks without instant food, but bright or extra stimuli can suppress the response.
01Research in Context
What this study did
Scientists paired a small keylight with grain the pigeons could see but not eat.
They wanted to know if the birds would still peck the key even without instant food.
Some birds first saw the light and grain together, others saw them separately.
What they found
The pigeons started pecking the key when light and unreachable grain went together.
A very bright keylight stopped the pecking; the birds looked around instead.
Birds that first saw light and grain apart took longer to learn the peck.
How this fits with other research
Redd (1969) showed autoshaping works with shock reduction instead of food.
Tracey et al. (1974) also saw less pecking when extra feeder lights came on, matching the bright-light drop seen here.
Christophersen et al. (1972) found a lit key can block new learning; the same kind of overshadowing may explain why the bright keylight cut pecking in this study.
Why it matters
You can start a new response without giving the reinforcer right away—just pair the signal with future food. Keep the signal small; too much brightness can pull attention away from the response. If a client has a history of mixed signals, expect slower acquisition and plan extra pairing trials.
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02At a glance
03Original abstract
In Experiment I, keylight was paired with inaccessible grain delivery (under two conditions of keylight intensity) to determine if autoshaping would occur in the absence of primary reinforcement. In Experiment II, the procedure was repeated with accessible grain, for comparison. In Experiment III, the procedures were repeated with explicitly unpaired presentations of keylight and either inaccessible or accessible grain. The results indicated that key pecking occurred as quickly in the presence of keylight pairings with inaccessible grain as with accessible grain, though (except for one bird) key pecking was not maintained with inaccessible grain. Furthermore, compared to the dim keylight, the bright keylight greatly suppressed key pecking when paired with inaccessible grain, and reduced the rate of key pecking when paired with accessible grain. Little key pecking occurred in groups exposed to explicitly unpaired presentations of keylight (whether bright or dim) and grain (whether accessible or inaccessible). When the birds in Experiment III were retested with explicitly paired presentations of keylight and grain, little key pecking was observed, suggesting suppressive effects of prior explicitly unpaired presentations. It is suggested that the effects of key-brightness manipulation were produced by the association of grain with cues other than the response key, or by distraction produced by partial illumination of the grain hopper.
Journal of the experimental analysis of behavior, 1975 · doi:10.1901/jeab.1975.23-199