Cell-phone study cites 'inattention blindness'

By Jane E. Allen
Los Angeles Times

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Being driven to distraction Number of cellular telephone subscribers in the United States (as of late January): 137,458,902 Estimated number of cell-phone owners who use their phones while driving: 85 percent Estimated cell-phone use while behind the wheel: 60 percent Estimated number of drivers using a cell phone during any daytime moment: 500,000 Increased likelihood of getting into an accident while driving and using a cell phone: 400 percent

Now researchers are finding out exactly why. The brain can do only so much at any one time, they say. As a result, it can't fully process visual signals while carrying on a conversation.

With visual and auditory signals competing, a driver's ability to see and react to what's ahead — even when gazing directly at a car, sign or pedestrian — is diminished. This phenomenon of "inattention blindness," in which the brain doesn't fully process what the eyes are taking in, helps explain how cell-phone conversations distract drivers and contribute to an increasing number of accidents. There are more than 137 million U.S. cellular subscribers, and studies show that the vast majority of them use their phones behind the wheel.

"Looking and seeing aren't one and the same," said University of Utah psychologist David Strayer, who has spent five years studying how cellular-phone use affects driving. "Just because your eyes are directed at something doesn't mean you're processing it. Seeing means paying attention. When you're not attending to driving, you're more of a hazard."

Strayer and his colleagues previously found that motorists talking on phones were more likely to react sluggishly to traffic signals or to simply miss them. With a conversation diverting their attention, drivers are likelier to be tripped up by sudden events such as a child darting into their path or another car slamming on its brakes, Strayer said.

Many states have considered restricting cell-phone use while driving. New York banned the use of handheld phones by drivers in 2001, but Strayer and his colleagues have found that the impairment occurs equally with hand-held or hands-free models. That suggests the problem lies with the distraction of the conversation, not of holding the phone.

The research appears in the March issue of the American Psychological Association's Journal of Experimental Psychology: Applied. Some of the findings also appear in the February/March issue of Injury Insights, published by the nonprofit National Safety Council.

In one experiment, researchers used video cameras and sophisticated instruments to track the students' eye movements during virtual drives. Even when the instruments confirmed that the participants were looking directly at objects along the simulated road, those talking on the phone were less likely to remember the objects.