Conditioned suppression with extinction as the signalled stimulus.

The team worked with pigeons that pecked a key for food. A red light came on for 30 seconds. Right after the light, the food stopped for five minutes.

They wanted to see if the birds would learn to stop pecking as soon as the warning light appeared.

The pigeons almost quit pecking during the red light. Their response rate dropped to near zero.

The short warning worked like a stop sign. It created strong conditioned suppression.

Hoffman et al. (1966) showed that shock-linked tones can suppress pigeons for years. Henton (1972) proves that extinction, not just shock, can do the same job.

Morse et al. (1966) found that extinction can make birds attack each other. Henton (1972) shows the opposite: a signal before extinction can cut responding without any aggression.

Sadowsky (1973) used extinction as a "bad" condition to create behavioral contrast. Henton (1972) treats extinction the same way, but asks what happens when the bird gets a heads-up.

You can use a brief warning stimulus to soften the blow of extinction. Tell your client, "In two minutes the iPad goes off," then show a timer or card. The signal becomes a conditioned suppressor, so problem behavior drops before the reinforcer is removed. Start with short warnings and thin them slowly to keep the effect strong.