Temporal factors influencing the pigeon's successive matching-to-sample performance: sample duration, intertrial interval, and retention interval.

Nelson et al. (1978) worked with pigeons in a lab.

They used successive matching-to-sample. The bird sees a color, waits, then pecks one key if the next color matches and another key if it does not.

The team changed three things: how long the first color stayed on, how long the bird waited between trials, and how long the bird waited before choosing.

Longer first colors gave better memory. Longer waits between trials also helped. Longer waits before choosing hurt memory.

The pattern fits the classic forgetting curve: more time equals more forgetting.

Shimp (1976) saw the same drop in memory when pigeons waited 2.5 to 6 seconds. Both papers show that time erodes memory in birds.

Madden et al. (2003) later built a math model of the same curve. They added reinforcer delay and still saw the same steep drop, proving the 1978 data still holds.

Wilkie et al. (1981) seems to disagree. They saw that extra visual stimuli during the wait hurt memory. R et al. never added extra lights, so their "longer wait" effect looks smaller. The clash disappears when you see that M et al. filled the wait with distractions, while R et al. left the wait empty.

Use successive matching when you need a go/no-go memory probe instead of a two-choice layout. Keep the sample long, keep the inter-trial break generous, and keep the retention interval short. If you must insert prompts or prompts during the wait, make them auditory, not visual, to protect the trace.