actually decreased both social interaction (Galanter et al., 1974) and empathic communications (Janowsky et al., 1979). Despite this, marijuana smokers have reported an enhanced effect on sensory-perceptual abilities (Tinklenberg and Darley, 1976) and improved insight into others (Green et al., 2003) after using the drug. In one of the few studies designed to examine the direct influence of marijuana on the ability to perceive emotions, Clopton and colleagues (1979) administered the Affect Sensitivity Test (AS) both before and after subjects smoked either a marijuana cigarette (containing 6 mg of THC) or a placebo cigarette. Designed to measure the ability to perceive emotions in others, results from the scale indicated a decrease in test scores in the active but not the placebo subjects, suggesting that intoxication resulted in difficulty with emotional perception. These results provide the first evidence that affective processing is affected by marijuana use, and may in fact be altered in individuals who smoke marijuana.
