An analysis of altered attention in monkeys exposed to delta-9-tetrahydrocannabinol during development.

Monkey infants born to mothers treated chronically with 2.4 mg/kg delta-9-tetrahydrocannabinol (THC) showed an alteration in visual attention characterized by a failure to limit the duration of attention when looking at novel stimuli. Five off-spring of treated mothers were compared to nine controls in a standardized situation in which they could view slides through a small peephole. THC offspring looked longer at slides early in a session and during the first session in which a given slide was seen. The time of appearance of the peak duration in a series of attention episodes also differed between groups. These alterations in visual attention could have an influence on perceptual and cognitive processes.