WASHINGTON-A newly published study says talking on a cell phone while driving is risky business because the brain simultaneously cannot give complete attention to both the visual requirements of driving and the auditory task of listening, a finding consistent with previous university and government-sponsored research.
“Our research helps explain why talking on a cell phone can impair driving performance, even when the driver is using a hands-free device,” said Steven Yantis, a professor in the Department of Psychological and Brain Sciences in the Johns Hopkins’ Zanvyl Krieger School of Arts and Sciences.
“Directing attention to listening effectively `turns down the volume’ on input to the visual parts of the brain,” explained Yantis. “The evidence we have right now strongly suggests that attention is strictly limited-a zero-sum game. When attention is deployed to one modality-say, in this case, talking on a cell phone-it necessarily extracts a cost on another modality-in this case, the visual task of driving.”
Johns Hopkins said the study, published in a recent issue of The Journal of Neuroscience, reinforces earlier behavioral research on the danger of mixing mobile phones and motoring.
Research sponsored by the National Highway Traffic Safety Administration (new findings were announced two weeks ago) and the University of Utah have come to much the same conclusions as Yantis.
An interesting and potentially controversial aspect of the Johns Hopkins research is that Yantis and his colleagues did not directly study cell-phone use while behind the wheel. Rather, according to a Johns Hopkins press release, healthy young adults ages 19 to 35 were brought into a neuroimaging lab and asked to view computer displays while listening to voices over headphones. They watched a rapidly changing display of multiple letters and digits, while listening to three voices speaking letters and digits at the same time. The purpose, according to Johns Hopkins, was to simulate the cluttered visual and auditory input people deal with every day. Using functional magnetic resonance imaging, Yantis and his team recorded brain activity during each of these tasks. They found that when the subjects directed their attention to visual tasks, the auditory parts of their brain recorded decreased activity, and vice versa.
Still, Yantis insists his latest research can be applied to the real-world problem of drivers and their cell phones.
The National Institute on Drug Abuse funded the research.
The publication of the research comes as cities and states aggressively pursue legislation to ban hand-held cell-phone use by drivers, while allowing them to use hands-free devices to talk. New York, New Jersey and the District of Columbia have enacted hands-free laws. Connecticut is poised to become the next state to do so. Chicago’s ban on driver operation of hand-held phones kicks in July 8. Atlanta could be headed down the same road.
Other legislation passed by states this year forbids teenagers from talking on cell phones-even with hands-free gadgets-while driving.
