Social drinkers underestimate the additive impairing effects of alcohol and visual degradation on behavioral functioning.
BACKGROUND
Studies have shown that social drinkers are poor estimators of alcohol-induced impairment. Underestimates of blood alcohol concentration and other indices of intoxication are associated with decisions to perform risky behaviors, such as operating a motor vehicle. It is possible that self-evaluations of impaired functioning under alcohol might be particularly compromised in the presence of other sources of impairment. A common source of impairment that co-occurs with alcohol is visual degradation.


OBJECTIVE
The present study compared actual and self-evaluated impairment in response to four conditions (0.65 g/kg alcohol, degradation of task-relevant stimuli, alcohol plus visual degradation, and no-treatment control) to determine whether social drinkers would perceive an increase in impairment from the combined treatments.


METHODS
Actual psychomotor impairment was measured in 16 social drinkers (eight men) by a pursuit rotor task and their self-evaluations of this impairment were obtained on a rating scale.


RESULTS
Alcohol and visual degradation impaired participants' actual performance to a similar degree and, in combination, the impairing effects were additive. Participants' self-evaluation ratings showed that they underestimated the additive impairment produced by the combination of alcohol and visual degradation.


CONCLUSIONS
The findings suggest that social drinkers might be unable to appreciate an increase in behavioral impairment when alcohol is consumed in the context of another impairing influence.
Harrison
Emily L R
EL
Department of Psychology, University of Kentucky, Lexington, KY 40605-0044, USA.
Fillmore
Mark T
MT
D000328:Adult; D000428:Alcohol Drinking / Q000523:psychology*; D001519:Behavior / Q000187:drug effects*; D002492:Central Nervous System Depressants / Q000097:blood; D000431:Ethanol / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000187:drug effects*; D012649:Self Concept; D014796:Visual Perception / Q000187:drug effects*
D002492:Central Nervous System Depressants; D000431:Ethanol