Impaired speed of visual information processing in marijuana intoxication

Abstract
A double-blind crossover study investigated the effects of marihuana on human visual information processing. A tachistoscopic paradigm was used and no marihuana effect was shown on the critical stimulus duration, a measure of stimulus intake. The visual backward masking data are compatible with a marihuana induced slowness of information processing from labile unconscious iconic memory to more permanent memory processes. Reports of marihuana''s effects on perception and early information processing are discussed.