Differences in reinforcers earned and unit price predictions: A comparative study of concurrent progressive schedules

LeComte et al. (2025) ran two levers side-by-side in a rat cage. One lever asked for more and more presses each time. The other asked for longer and longer holds. They wanted to see if the two schedules felt the same to the animal.

They measured how long the rat waited after each food pellet, how many pellets it earned, and the point where it quit. They kept everything else equal so only the requirement type changed.

Pause times after food were almost identical on both levers. The rat waited the same seconds whether the next task was more presses or a longer hold.

But the quitting point and the number of pellets earned jumped around more on the hold lever. The press lever gave steadier earnings and a clearer breakpoint.

Nasr et al. (2000) already showed that fixed-time parts sharpen choice and make behavior harder to disrupt. LeComte used fixed parts too, so their new data update that story by adding a progressive twist.

McSweeney et al. (1993) said pause length equals the last wait for food. LeComte’s pauses matched across levers, backing the linear-waiting rule even when the next task is duration-based.

Pilgrim et al. (2000) compared constant- versus variable-duration links and saw stronger preference for constant. LeComte kept duration constant while it grew, showing the preference edge holds even under progressive demands.

If you use progressive work in the clinic, know that ratio schedules give cleaner quit points and steadier reinforcer flow. Duration schedules may feel easier but produce jumpier data. When you fade demands, start with short holds to build tolerance, then switch to ratios for stable probes.