Control of concurrent avoidance and appetitive behaviors by an indicator of shock proximity.

Dardano (1971) worked with monkeys in a lab cage. A 20-light bar sat on the wall. Each light meant shock was one step closer.

The monkeys could press a lever. Each press moved the light back and also gave a bit of banana. The animals had to keep both shock away and snacks coming at the same time.

The team then removed key lights so the bar looked shorter. They wanted to see if the monkeys still avoided shock without those cues.

When the full 20-light bar worked, the monkeys pressed just enough to stay safe and still earn food. They used the lights like a ruler.

Once the middle lights were taken out, pressing fell apart. Shock came more often even though the lever still worked. The monkeys lost the picture of how close danger was.

Bacon-Prue et al. (1980) saw the same idea in pigeons. Birds pecked less as the time to shock grew. Both studies show animals watch the clock and pace themselves.

McIntire et al. (1987) looked one step wider. They ran pure avoidance sessions before daily appetitive work. Just having the aversive block nearby later cut the rats' food-time responding. F's within-session drop and D's across-day drop fit together: avoidance poisons appetitive control in both small and big windows.

FIELPREMACK et al. (1963) tried multiple warning cues earlier. They found sound beats light for control. F moved the idea to a visual ladder and still got strong stimulus control until rungs were yanked out. The two papers show the form of the cue matters less than its reliability.

For BCBAs the lesson is simple: keep the roadmap in view. If you thin a visual timer, remove check marks, or fade a warning card too fast, the learner may stop using the safety response even though the skill was 'mastered'. Check that every critical cue is still obvious before you call an avoidance or DRL program stable.