Preference for signaled over unsignaled shock schedules: Ruling out asymmetry and response fixation as factors.

Rats chose between two chambers. One chamber gave mild shocks on a fixed schedule. A tone always sounded five seconds before each shock. The other chamber gave the same shocks, but with no warning tone.

The twist: the signaled side sometimes delivered twice as many shocks. The experimenters also balanced which side was left or right to rule out position habits. They wanted to see if rats still picked the warning tone even when it meant more shocks.

Every rat stayed on the signaled side most of the time. They accepted double the shock rate just to get the five-second tone. The preference stayed strong even when the chambers swapped places.

The result copied earlier work and showed the effect was not due to rats getting stuck on one side or liking one response lever.

Liberman et al. (1973) already saw the same choice: rats took signaled shocks that were up to eight times denser. Green et al. (1984) tightened the controls and still got the same answer, so the preference is real.

Hymowitz (1981) looks like a contradiction. In that study, signaled shock did not always reduce suppression of lever pressing. The difference is the task: N measured how hard rats worked for food while shocks occasionally arrived; B et al. let rats freely pick their world. Choice reveals preference; suppression measures disruption.

Hearst et al. (1970) also seems opposite. A warning tone hurt avoidance responding and raised total shocks. Again, the setup differs—continuous avoidance versus discrete choice. When animals can simply walk away, they walk toward the signal.

Predictability beats rate, intensity, and position. For clients who must face aversive events—medical procedures, loud alarms, timeout—give a clear, dependable cue that marks both the event and its absence. A five-second warning can outweigh twice the discomfort, so invest in good signals before trying to cut the dose.