Think your Bluetooth or other hands-free technology makes it safer to use your cell phone while driving? Think again.
The use of handheld devices while driving is rejected because it limits a driver’s ability to operate a vehicle properly, and recent research shows that having your hands free isn’t the only thing that matters for safety. It’s equally important to have your mind free of distractions while driving. A study published by the University of Sussex in England found that talking on the phone, even with a hands-free device, requires much of the same brain processing resources needed for driving. Doing both at the same time caused participants in the study to detect fewer hazards, respond to hazards more slowly and fail to register seeing things that were right in front of them.
Cell phone use is just one of many culprits that lead to distracted driving, but in recent years, it has contributed to a growing number of crashes. That’s largely because of the limitations of the human brain: Our brains simply aren’t able to do everything we may expect of them at the same time.
Are You Paying Attention?
If you’ve ever been irritated by a family member who appears to tune out your voice while he is reading the newspaper or trying to attend to a crying grandchild, you may be surprised to learn that he may not be ignoring you purposefully. Instead, his brain may be simply unable to pay attention to what you’re saying while focused on the newspaper or a small child’s whines.
Through extensive study, researchers have found that attention is a limited resource. Each person only has a certain amount of attention available, and when focusing his or her attention on one thing, he or she is unable to focus on others. Nobody is able to attend to everything at once, so when we apply our attention resources to one thing, we are always doing so at the expense of other things. That’s why, as you attend to the crying toddler, you may miss hearing what your spouse is trying to tell you.
Each of our senses has some attention resources, but they can also interfere with each other. For instance, if you’re looking at something (paying attention to a visual task), you may be able to listen to something else (paying attention to an auditory task) more easily than you could focus on looking at something else. That’s why you may feel like you can pay attention to the road in front of you while talking on a cell phone, but not while looking at your navigation system. However, attention to one sense, such as hearing, can impair attention to another, such as vision, says Marc Green, Ph.D., attention researcher.
Your Brain on a Cell Phone
The human brain has a limited capacity to process visual images simultaneously. Although talking on the phone may seem like it would only require auditory resources—the sense of hearing—it actually uses up a lot more of the brain’s visual processing abilities than was previously understood, psychology researchers at the University of Sussex found.
That’s because in many cases, when you’re in a conversation, your brain is visualizing what you’re talking about. For instance, someone on the other end of the phone line may ask, “Where did you put the green folder?” Such a question leads you to visually imagine the room where you put the folder and try to remember where you put it.
Research shows that when your brain uses its visual processing capabilities for even imaginary imaging, there is not enough processing ability left over to properly keep track of what’s right in front of your eyes. For instance, you may see the trash receptacle in your lane, but because your brain is focused on your phone conversation, you may not actually register the receptacle until you’re too close to avoid it—or you’ve already hit it. Even worse, your brain could be busy processing your phone conversation and cause you to miss the vehicle pulling out into your lane or the child running into the street from your right.
“Conversations are more visual than we might expect, leading drivers to ignore parts of the outside world in favor of their inner visual world, with concerning implications for road safety,” says Graham Hole, a senior lecturer in psychology at the University of Sussex and one of the study’s authors.
By tracking eye movements, the Sussex study also found that drivers who were distracted suffered from “visual tunneling,” which means they tended to focus their eyes on a small, central region directly ahead of them. Such tunneling led participants to miss hazards in their peripheral vision.
These findings signify dangerous consequences for drivers who use their cell phones, even those that are hands-free. “The only safe phone in a car is one that’s switched off,” Hole says.
Are You Breaking the Law?
When you use your cell phone behind the wheel, you’re not just endangering yourself, your passengers and others; you may also be breaking the law. That means you could risk getting a ticket or worse, a criminal charge in the case of an accident.
A number of states have passed legislation banning some types of cell phone use. Fourteen states and the District of Columbia ban handheld cell phone use while driving. No state bans all cell phone use while driving, but 38 states and D.C. do ban all cell phone use by novice drivers, such as those under a certain age or newly licensed. Twenty states also ban all cell phone use for school bus drivers. Texting while driving is almost universally banned: 46 states and D.C. prohibit text messaging for all drivers.
According to the National Safety Council, there are three basic requirements for staying safe while driving: Keep your eyes on the road, hands on the wheel and your mind on driving.
When using a cell phone, whether hands-free or handheld, it’s almost impossible to abide by those three requirements. You can help keep yourself, your passengers and others safe by waiting to use your device until you’ve stopped the car.
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