Not drunk? Maybe, but did you see the gorilla?

Not drunk? Maybe, but did you see the gorilla?

People who imbibed only enough to reach half the legal limit for intoxication still were more than twice as likely as non-drinkers to miss spotting a person dressed up as a gorilla in a visual test.

The study is the first to show that visual errors caused by "inattentional blindness" are more likely to occur under the influence of alcohol.

This inability to see what's right in front of you occurs when important, though unexpected, objects appear in a person's visual field but are not detected while the person is focused on another task, according to Seema Clifasefi, a postdoctoral psychology researcher at the University of Washington who led the new study.

For the research, 46 adults, ages 21 to 35, were brought into a barlike setting. Half were given drinks containing enough booze to bring their blood-alcohol levels up to 0.04, or half the legal limit for intoxication in most states. The other half were served non-alcoholic drinks.

After the volunteers had blood-alcohol levels checked in a breath test, they were taken to a computer monitor and asked to watch a 25-second film clip. The clip showed people playing with a ball, and the volunteers were asked to count the number of times the ball was passed from one person to another.

In the middle of the clip, a person dressed in a gorilla suit appeared, walked among the players, beat its chest and left.

Afterward, each volunteer was asked if they saw the gorilla. Just 18 percent of the subjects who had been drinking said they noticed the ape, compared with 46 percent of the control group that hadn't been served alcohol.

Although the study, funded by the National Institute of Alcohol Research and Alcoholism, didn't directly test driving performance, it has serious implications for anyone driving after drinking even modest amounts of alcohol, the researchers noted.