Preference for signaled versus unsignaled reinforcement delay in concurrent-chain schedules.

Researchers placed pigeons in a chamber with two keys. Pecking one key led to a signaled delay before grain arrived. Pecking the other key led to an equal but unsignaled delay.

The team measured which key the birds chose and how steadily they pecked during the wait.

Every pigeon picked the signaled delay side more often. They also pecked faster and with fewer breaks when the upcoming grain was cued.

The signal acted like a promise, keeping the birds engaged even though the wait time never changed.

Gomes‐Ng et al. (2023) later showed that adding a cue also shifts how people split attention between two stimulus features. Both studies say the same thing: a simple signal can rewire control by reinforcement.

Lincoln et al. (1988) and Jones et al. (1992) moved the idea into classrooms. They used constant time delay to teach kids with autism. The delay still helps, but now it is part of a prompt, not a choice between two keys.

Together the papers form a bridge: from pigeons picking keys, to humans picking answers, to teachers picking prompts.

If your learner stalls or wanders before reinforcement, add a clear cue that marks the wait. A short beep, a colored card, or a countdown can turn dead time into engaged time. Start with two-second delays and pair the cue with every reinforcer. Watch responding tighten within one session.