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Increased susceptibility to memory intrusions and the Stroop interference effect during acute marijuana intoxication.

W D Hooker, R T Jones

Psychopharmacology 1987 DOI: 10.1007/bf00690920 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Double-blind, crossover experiment Peer reviewed
Sample size 12
Population Adult males who smoked marijuana cigarettes
Intervention cannabinoid-exhausted marijuana (placebo)
Dose 1.2% delta-9-tetrahydrocannabinol (THC)
Duration 2 days 1-3 weeks apart
Measures Paced Auditory Serial Addition Test, Stroop Color and Word Test, Randt Memory Battery, Controlled Oral Word Association Test
Topics Cannabis
Key findings Marijuana smoking significantly increased short story omissions and intrusions in delayed free recall and significantly increased the Stroop interference effect, while leaving immediate and sustained attention, semantic memory retrieval, and color reading and naming speed unaffected. The authors propose that marijuana may compromise associative control, a cognitive process they suggest is inherent in memory function.

Abstract

The marijuana-induced acute memory impairment was assessed in a double-blind, crossover experiment. Twelve males smoked NIDA-supplied cigarettes containing 1.2% delta-9-tetrahydrocannabinol (THC) or cannabinoid-exhausted marijuana (placebo) in counterbalanced order on 2 days 1-3 weeks apart. Practice, pre- and postsmoking test sessions were conducted with the Paced Auditory Serial Addition Test, Stroop Color and Word Test, and alternate forms of the Randt Memory Battery and the Controlled Oral Word Association Test. A significantly greater number of short story omissions and intrusions occurred in delayed free recall after marijuana. Immediate and sustained attention, controlled retrieval from semantic memory, and speed of reading and naming colors were not affected. The Stroop interference effect was significantly greater following marijuana. Subjects appeared to experience parallel difficulties in inhibiting associations to the new material and inhibiting the overlearned response of reading in a new learning task. Marijuana may compromise associative control, presumably a cognitive process inherent in memory function.