Effects of reinforcement magnitude on interval and ratio schedules.

Lowe et al. (1974) tested how the size of a milk reinforcer changes the way rats work.

They used three simple schedules: fixed-interval, fixed-ratio, and variable-interval.

Each rat got either a small drop or a big drop after completing the schedule.

Bigger milk drops always made the rats pause longer right after drinking.

On fixed-interval schedules the rats also ran faster once they started again.

On ratio schedules the running speed stayed the same even with the bigger reward.

Staddon (1970) saw the same longer pause when the milk lasted more seconds instead of being bigger, so the pause is driven by how good the reinforcer feels, not just size.

Reed (1991) later showed big rewards can actually slow responding on variable-interval but speed it up on variable-ratio, proving schedule type is the key driver.

Foltin (1997) looked like a contradiction: longer wheel-running rewards made rats press less, not more. The difference is that running also tires them out, so bigger is not always better when the reward itself takes effort.

When you pick a reinforcer, think about the schedule you are using. A bigger or longer reward will always stretch the post-reinforcement pause, but it will only boost the run rate on interval schedules. With ratio schedules you get the pause without the extra speed, so weigh the cost of lost time against the value of the larger reward.