Effects of alcohol on psychomotor performance and perceived impairment in heavy binge social drinkers

Abstract

Alcohol intoxication often results in negative consequences; however, specific behavioral and subjective effects vary as a function of individual differences. The present study utilized an alcohol challenge paradigm to examine whether heavy binge social drinkers (HD; n=77), compared to light social drinkers (LD; n=55), exhibit: (1) greater tolerance in psychomotor task performance under the influence of alcohol, and (2) differential perceptions of the impairing effects of alcohol. The study included three test sessions in which participants consumed either a low (0.4 g/kg) or a high (0.8 g/kg) dose of ethanol or a placebo beverage administered in random order and counterbalanced within group. Participants completed the Digit-Symbol Substitution Task (DSST) and the Grooved Pegboard at pre-drink baseline and at multiple time points after beverage consumption. They also completed a scale of perceived impairment at several intervals after beverage consumption. Ethanol impaired performance at the high dose, but not at the low dose (ps<.001). The groups exhibited similar alcohol-induced impairment. However, HD reported lower self-perceived impairment compared to LD, particularly during the early portion of the blood alcohol curve when actual impairment was most pronounced (p<.001). Thus, this study extends prior research in that habitual binge social drinking does not appear to be associated with tolerance to alcohol's impairing effects on select psychomotor skills. Further, results may have implications for alcohol-related harm as binge social drinkers regularly consume intoxicating doses of alcohol but may not be aware of the physical and cognitive impairments produced by alcohol.

Figure 1

Mean scores for Pegboard (time to complete task, top row) & DSST (number correct, bottom row) (± SEM) for LD and HD at baseline and all post-beverage consumption time points during each of the three doses separately. Alcohol impaired performance at the high alcohol dose but not the low dose. There were no differences between the groups.

Figure 2

Mean scores of self-rated impairment items (± SEM) for LD and HD groups at each dose. X-axes indicate time since the completion beverage. **p<.001; *p<.01; ^a p = .06; Indicate HD reported significantly less impairment than LD.