Delayed reinforcement of fixed-ratio performance without mediating exteroceptive conditioned reinforcement.

Kendall et al. (1978) asked pigeons to peck a key on a fixed-ratio schedule. After the last peck, the birds waited in darkness before food arrived.

The delay lasted several seconds. No lights or sounds bridged the gap. The birds still had to trust that the peck-food link held.

The pigeons kept pecking fast even with the timeout. Their rate stayed far above birds that got food no matter how much they pecked.

The pause after food grew longer, but the run of pecks stayed quick. The response-reinforcer bond held without instant payoff.

Dunham (1972) saw a different picture in rats. Long delays also stretched the post-food pause, yet the next burst of lever presses slowed. Same schedule, different species, mixed result.

Halpern et al. (1966) showed that bigger ratios alone make pauses longer. B et al. added a twist: keep the ratio, insert a delay, and the pause still grows while response rate holds.

Together the papers show pause length is a sensitive clock. It grows with ratio size, with delay, or both, but the speed of the run can stay high if the dependency is clear.

You can trust response-reinforcer links even when payoffs are slow. Use clear, consistent contingencies and the learner will keep working through wait times. Skip extra bridging stimuli if the history is solid; the dependency itself can do the job.