Sign-tracking with an interfood clock.

Pigeons pecked a key while six color lights blinked in order between food deliveries.

The researcher compared two set-ups: one kept the same color order every cycle, the other shuffled the colors at random.

Both groups waited the same time for food; only the light order changed.

Birds in the fixed-order group kept pecking the key hard.

Birds in the random-order group soon stopped.

The result shows the birds were following the light sequence, not just watching for food.

Downing et al. (1976) saw the same thing earlier: pigeons worked harder when food and brief stimuli came in random order, not fixed.

Matson et al. (2013) later found fixed order helps humans too—four out of seven kids in a multielement FA showed clearer problem behavior when conditions ran ignore→attention→play→demand every cycle.

Miranda-Dukoski et al. (2014) extended the idea: when food odds kept changing, a quick color flash pulled the birds’ choices back on track, showing brief ordered cues can reboot control even in shifting schedules.

If you want steady responding between reinforcers, give a brief signal and keep its order the same.

Try running your brief stimulus in a fixed sequence during DRL, FI, or token boards before the big payoff.

You should see smoother, more predictable client behavior without extra edible rewards.