Drivers Have Poor Judgment When It Comes to Their Sobriety after Drinking
A new study finds that the perception of feeling sober after drinking alcohol may be entirely subjective. Researchers have studied how cognitive functions are affected during the rising and falling blood alcohol concentrations (BAC) of an intoxicated state and compared these BAC levels against self-perceived levels of sobriety. The subjective feeling of sobriety is premature in comparison to a drinker’s reasoning and problem-solving abilities’ recovery from impairment.
Lead researcher Dr. Peter Snyder from The Warren Alpert Medical School of Brown University and colleagues conducted a 2-day experiment measuring the participants’ rising and declining BAC levels during intoxication and the impacts on their executive cognitive functions. Previously, similar alcohol studies had only measured the impact of alcohol on basic functions such as motor speed and information processing speed, yet Snyder’s study became the first to consider executive functions. In the study, 20 participating college students consumed alcoholic beverages over an 8-hour period in order to bring their BAC near 0.10 percent and then down to normal levels.
During their varying rising and falling BAC levels, participants were required to complete on-screen computer maze learning exams. For sober, healthy young adults (whom served as the placebo group), the hidden maze exam was completed with few errors. However, the participants displayed progressively higher rates of error while following simple directions during the exam with increasing BAC levels. Regardless of their self-reported feelings of sobriety, the participants’ likelihood to commit errors did not decline as progressively as their subjective feeling of drunkenness. The researchers conclude that the participants’ executive functions were not recovering as quickly as the participants believed, but were instead more closely related to their actual BAC levels, putting them at greater risk of committing error.
While basic functions are able to recover in a shorter time span following drunkenness, executive functions—the cognitive functioning involved in driving skills and making judgments regarding traveling through intersections or changing lanes—are not able to recover as quickly. According to the study, the perception of recovery from drunkenness progressed more rapidly than the drinker’s actual cognitive recovery, which may explain why many drunk drivers make the erroneous conclusion that they are fit to drive.
With an average of 17,000 deaths caused by alcohol-impaired vehicular accidents every year in the U.S., too many drunk drivers get behind the wheel believing they are more sober than they really are. Sixteen to 20-year-old male drivers face a twofold chance of a vehicular accident after raising their BAC by 0.02 percent; even further, their risk increases 52 times when their BAC becomes 0.08–0.10 percent. The researchers hope that their findings will influence alcohol education programs for college-aged adults to help better inform these drivers of the risks involving drinking and driving.
The study is published in the August 2010 issue of Experimental and Clinical Psychopharmacology, a publication of the American Psychological Association.
