August 1, 2005 A study showed that the part of the brain that controls vision becomes less active when people focus on something visually while having a conversation -- underscoring the hazards of talking on your cell phone while driving. Human factors experts say hands-free phones do not lower risk. Drivers on the phone are four times more likely to have accidents.
LAWRENCE, Kan.--Sealing a business deal, talking with your friends, making plans, checking messages ... Just how dangerous is driving and talking on a cell phone? New research that proves driving and dialing don't mix.
Everywhere you look -- to your right, your left, at a light and speeding down the highway -- everyone's chatting on a cell phone. And if you're like Chris Rowe, you'll admit you sometimes concentrate more on the conversation than what's happening in front of you. "It distracts me from paying attention to other cars on the road," he admits.
Mixing mobile phones and motoring is a dangerous combination. But why can't we safely talk and drive at the same time? New research shows the reason is inside our brain.
"When we do talk and do some other task, it's very clear to us that your brain is not fully doing both processes at the same time," Paul Atchley, a cognitive psychologist at University of Kansas in Lawrence, tells DBIS.
Psychologists at the University of Kansas found the part of the brain that controls vision becomes less active when people focus on something visually while having a conversation.
Dr. Atchley says, "Even though their eyes are open, they're missing things that are in the visual world that might be critical for them, for example a car coming into an intersection."
The Insurance Institute for Highway Safety reports drivers on the phone are four-times more likely to have an accident.
"Really what you need to do is just not drive and talk on the cell phone at the same time," Dr. Atchley says -- advice some drivers would rather not hear.
A hands-free phone is not the answer, either. Human factors experts say that doesn't lower your risk.
BACKGROUND: Backing up studies that show that drivers who use cell phones are more likely to have accidents, recent experiments by scientists at the University of Kansas show that observers engaged in a verbal task have a limited spatial attention window. The reason? They're less aware of incoming visual "cues."
WHAT THEY FOUND: Participants in the experiments were able to perform a simple task quite easily. But when half the group was asked to take on an additional verbal task, their ability to perform the first task was hindered. This indicates that even with the wide availability of hands-free devices for cell phone use in the car, there is still a significant risk involved when driving and talking on the phone at the same time.
THE PROBLEM: In the U.S., more than 190 million people used cell phones as of June 2005, compared to only 4.3 million in 1990. Studies have shown that motorists who use cell phones while driving are four times as likely to get into serious accidents. This happens in part because (a) people must take their eyes off the road momentarily while dialing, and (b) they become so absorbed in their conversations that it reduces their ability to concentrate on driving.
SPEECH AND THE BRAIN: Speech is a very complex function. There are two primary areas of the brain associated with speech: "Broca's area," located in the left frontal cortex, and "Wernicke's area," located further back and lower in the left temporal lobe. But scientists suspect other parts of the brain are involved as well. When we speak, we select words according to what we think the person we're talking to will understand. We activate the sounds for each word, and put them together in a sentence. We also choose which words to emphasize and how to pronounce them. All this information is processed by the brain and translated into movements of the mouth, jaw, tongue, palate, and voice box, among other areas.
The Human Factors and Ergonomics Society contributed to the information contained in the TV portion of this report.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.