EFFECTS OF CAFFEINE ON ALERTNESS IN SIMULATED AUTOMOBILE DRIVING

Thirty minutes after ingesting 200 milligrams of caffeine or a placebo, each of 24 male subjects drove an automobile simulator for 90 minutes. Immediately thereafter, the subject ingested a supplemental dose of the medication taken initially and then drove for another 90 minutes. The simulator provided a comprehensive and coherent set of stimulus inputs which produced a degree of realism not usually found in laboratory studies. Both the initial and the supplemental doses of caffeine significantly enhanced performance beyond that found with placebo, on each of four measures of alertness. /DOT/