The relationship between alcohol dosage and performance decrement in humans.

Abstract

The effects of alcohol on perceptual, motor and cognitive performance were studied in 12 university students (6 women), all social drinkers, aged between 18 and 28. The subjects were tested 40, 100 and 160 min after they were given a placebo or 0.54, 0.75 and 1.00 g of alcohol/kg of body wt in a 4 .times. 4 crossover design. The alcohol was given as a 20% (vol/vol) solution in a sugar-free orange drink, consumed within 20 min. Mean blood alcohol concentrations at 40 min after 0.54, 0.75 and 1.00 g of alcohol/kg wt were 69, 92 and 101 mg/100 ml; at 100 min, 57, 84 and 113 mg/100 ml; and at 160 min, 44, 64 and 91 mg/100 ml. The subjects completed a battery of tests assessing standing steadiness, simple and complex reaction time, manual dexterity and numerical reasoning. In general, after alcohol there was a dose-dependent decrease in performance on all tests. Standing steadiness was the most sensitive to the effects of alcohol, perceptual speed the least. The tests and procedure would be suitable for the investigation of the effects of alcohol-drug interactions.