Conditional discrimination performance by pigeons on a response-independent procedure.

Researchers worked with four pigeons in a small chamber. A red or green light came on for five seconds. After the light, grain arrived on one side no matter what the bird did.

The birds only got grain on the right if red had been on. They only got grain on the left if green had been on. This setup tests a conditional discrimination: "If color X, go side Y."

All birds soon pecked the correct side as soon as the color appeared. Pecking stayed accurate even when the team turned off the grain for many trials.

Next the team added a delay. The color went off, the chamber stayed dark up to ten seconds, then the side lights came on. Accuracy stayed high until the gap reached about ten seconds.

Bacon-Prue et al. (1980) later showed pigeons can remember short two-item lists, but control drops once the wait tops two seconds. The 1977 birds held a one-item rule for ten seconds, showing compound color-plus-side cues last longer than bare serial order.

Griffin et al. (1977), published the same year, also found pigeon memory fades as delays grow. Both labs agree: after about ten seconds stimulus control weakens.

McGonigle et al. (1982) showed a brief flash right after a response can keep pigeons working when reward is late. The 1977 study adds that the color cue itself can act like that flash, bridging the gap between signal and payoff.

When you teach a conditional rule such as "If the stop card is red, line up; if green, keep playing," chain the color with an extra cue like position or a brief word. The compound package will hold together even if praise or tokens are delayed a few seconds, helping learners stay accurate while you reach the reinforcer.