Overt activity during conditioned suppression: a search for punishment artifacts.

The team worked with pigeons that pecked a small disk for food.

A tone sounded before every mild electric shock. The birds never lost food for pecking.

The question: would the tone alone slow the birds’ key pecking, even though pecking itself was never punished?

The tone cut pecking to almost zero.

Because the response was never directly punished, the drop shows a learned emotional reaction, not a punishment effect.

Hearst et al. (1970) saw the same thing earlier: a brief shock warning stopped avoidance hopping. Together the studies prove the signal itself triggers fear, not the response cost.

Sanders et al. (1971) ran a near-copy of the setup but used lever presses instead of pecks. They still got suppression, showing the effect works across very different actions.

Wilkie et al. (1981) flipped the story: tones that meant “safe, no shock” kept rats pressing. This extends the 1971 finding by showing signals can either freeze or free behavior, depending on what they predict.

Bland et al. (2018) moved the idea into choice: a stimulus linked to no food also cut responding. Their work shows the same fear-based slowdown can come from extinction cues, not just shock cues.

You now know a stimulus can suppress behavior without any response-cost rule. When you see a sudden drop in a client’s rate, check what the cue predicts, not just what follows the response. Pairing a neutral sound with something scary may accidentally freeze useful skills.