Acceleration and suppression of rats' responding to avoid foot shock and tail shock.

The team placed eight rats in a cage with a wheel. Turning the wheel delayed electric shock.

A tone came on before every shock. For half the rats the shock hit the feet. For the other half it hit the tail. The researchers counted wheel turns to see how the warning tone changed work speed.

Foot-shock rats froze for a few seconds after the tone, then spun the wheel faster than before. Tail-shock rats slowed down and stayed slow.

Same sound, same upcoming pain, but body location flipped the result: brief stop-then-run versus steady stop.

Mosk et al. (1984) later kept the shock on the feet and only moved the intensity. They found a minimum level was needed; more juice did not speed the wheel. Hamilton et al. (1978) now shows that where the shock lands matters as much as how strong it is.

Garcia et al. (1973) saw pure suppression: a tone before lever shock simply cut pressing. The new study repeats that when the tail is targeted, but adds the foot-shock twist—first stop, then surge. The difference is body site, not species or task.

Davis et al. (1972) got more avoidance when they paired light with sound. Together these papers say stimulus extras—compound cues or shock locus—can push responding up or down. Pick your add-on carefully.

When you add a warning stimulus to an avoidance program, think about the client’s body focus. A pad that buzzes near the heel may energize stepping, while a waistband signal could shut it down. Test both sites, track brief pause versus lasting suppression, and adjust signals to keep the desired motion going.