Acute and chronic effects of cocaine on the spontaneous behavior of pigeons.
Cocaine makes pigeons move more over time, and the extra motion can last weeks after the last dose.
01Research in Context
What this study did
Researchers gave pigeons a shot of cocaine every day. They used three doses: low, medium, and high.
Each bird lived in a small chamber with a floor that sensed every step. Computers counted how much the birds moved before and after each dose.
What they found
Day by day the birds walked more after the shot. This growth in movement is called sensitization.
Even after a month without cocaine, half of the birds still showed extra movement. The drug left a long footprint.
How this fits with other research
Gardner et al. (1976) and Dykens et al. (1991) saw very different pictures in monkeys. Those older studies found that steady cocaine blunted behavior, not boosted it. The key gap is the task: the monkeys had to press levers for food, while the pigeons merely roamed free.
Bromley et al. (1998) also worked with monkeys, but they measured how hard the animals would work for cocaine. Their data line up with the pigeon study: cocaine can drive higher output, yet the measure was lever presses, not steps.
Together the papers show one drug, two stories. When work is required, tolerance and pauses appear. When movement is free, sensitization and lingering activity win.
Why it matters
You probably will not dose clients with cocaine, yet the lesson is clear: the same stimulus can excite or suppress depending on what the client must do. When you see a medication or reinforcer lose punch, check the schedule. A simple shift from free play to structured work could flip the effect.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Watch if a client’s free-time hyperactivity differs from their table-time focus; the same biology may look opposite under work demands.
02At a glance
03Original abstract
The present experiment examined the effects of acute and daily cocaine on spontaneous behavior patterns of pigeons. After determining the acute effects of a range of doses, 9 pigeons were divided into three groups that received one of three doses of cocaine daily, either 1.0, 3.0, or 10.0 mg/kg cocaine. Measures were taken of spontaneous locomotion, pecking, preening, and emesis. Under daily administration, cocaine induced consistent and substantial enhancements of its locomotor effects in all 9 pigeons, consistent with the phenomenon of locomotor sensitization. The maximum locomotor output did not differ according to the size of the daily dose. Locomotion was not elevated following tests of the saline vehicle, suggesting the effect was due to cocaine, not to a change in baseline or reactivity to the injection procedure. Cocaine dose-dependently decreased preening when given acutely, and those effects were not altered by repeated cocaine administration. Pecking occurred at very low rates and was unresponsive to cocaine treatment. Cocaine-induced emesis showed a dose-dependent increase under initial tests with cocaine, and those effects were attenuated following daily exposure. In a final condition, cocaine was replaced with daily saline for 30 days to assess the persistence cocaine-related increases in locomotion. Approximately half of the pigeons continued to show enhanced effects even after 30 days without cocaine, so although persistence was obtained, it showed marked intersubject variability. The data indicate that the effects of repeated cocaine administration on the behavior of pigeons shows parallels with many effects commonly reported with rodents (i.e., increased locomotion following repeated treatment, decrease in preening or grooming, persistence following drug withdrawal).
Journal of the experimental analysis of behavior, 2010 · doi:10.1901/jeab.2010.94-25