Those who consume alcohol may easily overlook unexpected objects in their field of vision, even when their blood alcohol content is only half the legal limit for driving.
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| Alcohol narrows attention to a small area in a scene (Photo: painetworks) |
Dr. Seema Clifasefi from the University of Washington in Seattle, USA, explains that this phenomenon is known as “inattentional blindness,” which can sometimes occur in sober individuals.
Alcohol is already known to affect driving ability, reaction time, and visual attention, but no studies have yet investigated its impact on inattentional blindness.
To explore this, researchers had 47 volunteers watch a video of two teams of players passing a ball back and forth and asked them to count how many times the team in white passed the ball.
In the video, a woman dressed as a gorilla appeared among the players, standing in the middle of the screen, beating her chest, and then walking away.
Participants consumed a drink about 5 minutes before watching the video. After viewing, the research team asked if they had seen the gorilla.
Half of the participants were given a non-alcoholic drink, while the other half drank vodka and tonic, raising their blood alcohol content to half the legal driving limit.
Half of each group was informed that they had consumed alcohol, while the other half believed their drink was non-alcoholic.
Those who knew they had consumed alcohol reported feeling more intoxicated, even if they had the non-alcoholic drink. However, whether they were told they had consumed alcohol or not did not affect their ability to notice the gorilla.
Overall, one-third of the participants did not recognize the gorilla. Among sober participants, 46% noticed the animal, compared to only 18% in the intoxicated group.
“The results demonstrate that alcohol causes temporary blindness,” Clifasefi and her team concluded. “In our study, alcohol narrowed attention to a small area in a scene (counting volleyball passes), making other information in that scene (the gorilla) more likely to be overlooked,” they stated.
In this case, even just one strong drink could leave you blind, the team added.
M.T
