EXTEROCEPTIVE CONTROL OF RESPONSE UNDER DELAYED REINFORCEMENT.

MOORHEARSKELLEHER et al. (1964) worked with rats in a small lab box. The rats pressed a lever for food, but the food always came 1 to 20 seconds late.

The team then turned the lights off during the wait. They wanted to see if this simple dark cue could keep the rats pressing smoothly.

Without the dark cue, response rates wobbled. When darkness filled the delay, pressing became steady and faster for every rat.

The external cue acted like a bridge, letting the rat link the press to the later food.

Okouchi (2009) later showed the same idea works with people. College students learned a two-button sequence even when praise came up to 30 seconds late, proving the delayed-reinforcement effect crosses species.

Baer et al. (1984) moved the idea into preschool. Kids kept their words and actions in sync even when the teacher's praise was delayed, again showing the cue can be social, not just darkness.

Berler et al. (1982) looked at the flip side: they used a 20-second cue that only signaled upcoming free food. Lever pressing rose during the cue, much like darkness boosted pressing in the 1964 study. Both papers show that inserting any clear external event can override schedule-induced pauses.

If you run DRA, DRL, or any procedure where reinforcement can't be immediate, add a salient cue during the wait. Turn the room lights off, ring a chime, or point to a colored card. One quick change can keep responding steady and reduce the drop-off you see with pure delay.