Drug effects in squirrel monkeys trained on a multiple schedule with a punishment contingency.

Researchers gave squirrel monkeys a two-part task.

One part paid them food for pressing a lever.

The other part paid food but also shocked them for pressing.

Then the team gave the monkeys different drugs.

They watched how each drug changed pressing in both parts.

Sedatives made the monkeys press more in both parts.

Stimulants and anticholinergics cut pressing where food was paid.

But these same drugs raised pressing where no food was given.

Antipsychotics mainly lowered pressing for food.

The same drug acted very different across the two parts.

Kelly (1973) showed that changing how often you pay for certain response times shifts the whole pattern.

Schneider et al. (1967) now shows drugs can mimic or block those same shifts.

Together they prove schedule design, not just the drug, drives what you see.

Castelloe et al. (1993) found small timeout changes barely moved accuracy.

Schneider et al. (1967) shows drugs can create big swings, so timeout studies may miss drug-level effects.

If a client on meds suddenly stops working, check the task first.

The same pill can boost, cut, or flip behavior based on the pay-off.

Adjust the schedule before you blame the drug.