The disruption of autoshaped key pecking in the pigeon by food-tray illumination.

Two experiments investigated the effect of food-tray illumination on pecking a lighted key that signalled food presentation. Pigeons key pecked less when both feeder and key stimuli preceded grain delivery than when the keylight alone signalled food. This detractive influence of grain-tray illumination did not result after prior pairings of the keylight with food. The involvement of associative and physical variables in autoshaping the pigeon's key peck is considered in light of these findings.