Cued and uncued terminal links in concurrent-chains schedules.

Smith et al. (1994) worked with pigeons in a lab. The birds chose between two keys in a concurrent-chains setup.

Each key led to a terminal link. One link had a light cue. The other link had no cue. The team watched how cues changed the birds' choices.

Without cues, birds paid more attention to the first part of the chain. With cues, they paid more attention to the last part.

The cue acted like a tiny sign that said, 'Good stuff ahead.' It pulled choices toward the signaled side even if that side took longer.

Dougherty et al. (1996) later showed that delay difference, not ratio size, steers choice. Both studies agree: terminal-link details matter more than simple numbers.

Alvarez et al. (1998) found local context cues beat global rates. Their 'context' is like B's light cue: a small nearby signal outweighs big-picture math.

Ladouceur et al. (1997) proved a stimulus keeps its own value. This supports B's result: the cue itself becomes a reinforcer, not just a marker.

When you set up reinforcement schedules, remember that signals can act as mini-reinforcers. A simple visual or verbal cue near the end of a task can shift a client's preference, even if the delay stays the same. Try adding a clear 'almost done' cue to the richer schedule and watch whether engagement moves with the signal.