The effects of marijuana on brain perfusion and internal timing were assessed using [15O] water PET in occasional and chronic users. Twelve volunteers who smoked marijuana recreationally about once weekly, and 12 volunteers who smoked daily for a number of years performed a self-paced counting task during PET imaging, before and after smoking marijuana and placebo cigarettes. Smoking marijuana...
AbstractSubjects (16 men and 16 women) breathing 30 per cent nitrous oxide in oxygen, or 100 per cent oxygen, were tested to see if the effects of nitrous oxide on memory varied with different types of auditory stimuli and memory‐testing procedures. The drug produced substantial memory impairments. These impairments were milder in forced‐choice recognition than in yes/no recognition and for...