Body sway and divided attention performance under the influence of alcohol: dose-response differences between males and females.

This study assessed women and men on a divided attention task, body sway, and subjective (self-report) estimates of impairment across different doses of alcohol. Twelve females and 12 males (mean age of 20.4 years) were given placebo, low, and high doses of alcohol in random order across sessions. Each subject was tested 3 times during each session. The study controlled for recent drinking history by restricting participation to light drinkers who were matched on age and education. Alcohol doses were adjusted for body fat and equivalent blood alcohol concentrations (BACs) were attained in the two gender groups. The results indicated that women and men did not differ in their extent of cognitive impairment at placebo and low alcohol doses. However, women showed significantly more cognitive impairment than their male counterparts at the high alcohol doses, even with equivalent BACs. The sway measure was influenced only by BAC and not by the gender of the subject. Sway observations were less sensitive and more variable than estimates of cognitive impairment. The subjective impairment data indicated that female subjects were less sensitive than males to the effects of alcohol at both the low and high doses. Implications for future research on cognitive impairment are discussed.