Cocaine versus food choice procedure in rats: environmental manipulations and effects of amphetamine.

Morgane et al. let rats pick between two levers. One lever gave cocaine. The other gave food pellets.

They changed three things: how much food was on the tray, how many presses each lever needed, and whether the rats got amphetamine shots. The team watched which lever the rats chose.

Bigger food piles and lower press counts made rats switch to the food lever. Small food piles and high press counts pushed them toward cocaine.

A single shot of amphetamine raised cocaine picks. Repeated amphetamine shots lowered them. The pattern looked like human clinic data.

Dykens et al. (1991) ran almost the same rat choice set-up twenty-two years earlier. They swapped cocaine for PCP and food for saccharin. Both studies show the same rule: when the drug costs more presses or the other treat gets better, drug use drops.

Cowie et al. (2016) later argued that cues, not the treats themselves, steer choice. Morgane’s work fits this view. The food tray light and lever colors likely told the rats which option was "safe" and "easy," guiding the shift.

Lucki et al. (1983) showed that amphetamine speeds up already-fast responding and slows already-slow responding. Morgane’s rats follow the same rate-dependency rule: baseline choice rate set by food size and effort predicts whether amphetamine will raise or lower cocaine picks.

You now have a quick lab model that copies human drug-choice patterns. Use it to test new medications or contingency plans before clinic trials. In practice, remember that both reinforcer size and effort matter: enrich the client’s nondrug environment and keep task effort low to tilt choice away from problem behavior.