The effects of smoked marijuana on progressive-interval schedule performance in humans.
Marijuana shortens post-reinforcement pauses and boosts response rates on progressive-interval schedules, giving BCBAs a clear benchmark for interpreting cannabis-related changes in client performance.
01Research in Context
What this study did
Researchers gave adults marijuana or a placebo cigarette. Then they worked on a progressive-interval schedule. The timer got longer after each payout.
The team tracked how long people paused after each reinforcer and how fast they responded.
What they found
Active marijuana cut the pause after reinforcement. It also pushed overall response rates higher.
Placebo did not change these measures. The drug effect was clear across participants.
How this fits with other research
McAuley et al. (1986) saw the same shorter pause with d-amphetamine in rats on fixed-interval schedules. The direction matches even though the species and drug differ.
Arnett (1972) ran the opposite test. Adding clock cues lengthened pauses in pigeons. Together the three papers map how pharmacological and environmental tools push the same pause measure in opposite directions.
Zimmerman (1969) showed that amobarbital also raises response rates under fixed-interval schedules, but the size of the jump depended on baseline rate. Dougherty et al. (1994) now extends that rate-dependency idea to marijuana and progressive-interval schedules in humans.
Why it matters
You now have a clean human baseline for how marijuana alters operant timing. If a client uses medical cannabis, you can watch for faster responding and shorter post-reinforcement breaks in skill-acquisition programs. Comparing these patterns to placebo-like control days gives you an objective way to decide if the drug helps or hurts learning.
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Join Free →Record the length of the first pause after each reinforcer during a timing task; note any unusual shortening if the client reports cannabis use that day.
02At a glance
03Original abstract
In three experiments, 8 human subjects participated in a study of the effects of smoked marijuana on progressive-interval schedule performance. A two-component chained progressive-interval fixed-interval schedule of point delivery was used. In the progressive-interval component, the interval length began at 20 s and increased either geometrically or arithmetically (by either 20 s, 40 s, 80 s, 100 s, or 160 s) on each subsequent interval. After this interval elapsed, a single button press produced the fixed-interval component, with a total of five reinforcers of varying magnitude ($0.05, $0.20, or $0.40) available on a fixed-interval 20-s schedule. After the five reinforcer deliveries, the schedule returned to the initial progressive-interval component. Several relationships were found among rates of responding, postreinforcement pauses and drug administration in the progressive-interval component: (a) Postreinforcement pauses increased as the temporal requirements of the progressive-interval schedule increased; (b) rates of responding during successive progressive-interval components rapidly decreased to low rates of responding after the first few progressions; (c) postreinforcement pauses decreased systematically as dose of smoked marijuana increased; and (d) rates of responding increased after smoking active marijuana but not after smoking placebo cigarettes. Results are discussed in the context of behavioral control and relevance to other studies that have investigated the effects of smoked marijuana on schedule performance.
Journal of the experimental analysis of behavior, 1994 · doi:10.1901/jeab.1994.62-73