Positive contrast, negative induction, and inhibitory stimulus control in the rat.

The researchers worked with rats in a lab. They used two kinds of cues. One cue meant no food would come no matter what. The other cue meant food would drop on a timer, even if the rat did nothing.

The rats pressed a lever. The team watched which cue gave stronger stop signals. They wanted to know which cue would slow pressing more and also make later pressing jump higher.

The cue linked to no food won. It cut pressing more and later made the rats press faster when food came back. This is positive contrast.

The timer cue also cut pressing, but it never gave the later jump. Only the real extinction cue built strong stop control.

Neuringer (1973) saw the same thing four years earlier. Extinction dropped behavior faster than free food and was the only one to give contrast. The new study adds that extinction cues also gain stronger stop power.

Whalen et al. (1979) moved the effect to babies. Three-month-olds kicked more when one mobile stopped paying off. The rat finding holds across species and ages.

Sadowsky (1973) looked at pigeons given timeout or blackout instead of extinction. Only extinction gave clear contrast, matching the rat data. The papers agree: true non-reinforcement, not just darkness or free food, drives the effect.

When you set up discrimination programs, the way you signal no reinforcement matters. A clear extinction cue builds stronger stop control and can later boost correct responses. Skip vague cues like random praise or timer rewards. Use clear, extinction-based signals when you want behavior to drop fast and stay clean.