There is much controversy concerning the use and abuse of illicit drugs such as marijuana. One of the main controversial issues surrounding this drug is whether or not its use hinders cognition. Authors Robert Block, L D Chait, Robert Mathias and Peter Fried, Barbara Watkinson, Deborah James, and Robert Gray have all conducted slightly differing studies on the cognitive effects of marijuana. Block, the author of, "The Effect of Chronic Marijuana Use on Human Cognition," studied the effects of long term marijuana use by comparing nonusers to light, intermediate and heavy users in several intellectual fields. Chait, who wrote "Subjective and Behavioral Effects of marijuana", Studied the effects of, marijuana the say aster using the drug. Peter Fried, Barbara Watkinson, Deborah James, and Robert Gray, coauthors of "Current and Former Marijuana Use: Preliminary Findings of a Longitudinal Study of effects on IQ in Young Adults", investigated the effects of heavy, intermediate, light and past users as well as nonusers on the effect of IQ. Finally Mathias, the writer of "Studies Show the Cognitive Impairment Lingers in Heavy Marijuana Users", studied the effects of heavy marijuana use on cognitive function as well as the learning of new information. …
