Dialing, texting and otherwise using a cell phone is a distraction for drivers and is causing many legislatures to consider laws restricting cell phone use in cars.
In fact, U.S. Transportation Secretary Ray LaHood will host a two-day summit later this month where lawmakers and experts will discuss driving distractions like text messaging — and whether banning or limiting cell phones while driving is necessary.
According to Carnegie Mellon neuroscientist Marcel Just, simply listening to someone speak on the other end of a cell phone is enough to impair driving. Just and his colleagues used functional magnetic resonance imaging (fMRI) to study volunteers using a driver simulator. When they were listening to a sentence, they were more likely to weave in their lane.
Furthermore, the fMRI scans showed that listening to someone speak while they were driving reduced by 37 percent the amount of brain activity associated with driving, compared to driving alone.
Believe it or not, this decrease in available brain resources can cause drivers to commit the same types of driving errors that can occur under the influence of alcohol.
Another study from Just's laboratory showed that subjects could not willfully ignore someone speaking to them; the processing of a spoken message was so automatic that it could not be gated out, and continued to affect the brain activation associated with a second concurrent task.
Just's research shows that making cell phones hands-free or voice-activated is not sufficient in eliminating distractions to drivers.
"Drivers need to keep not only their hands on the wheel; they also have to keep their brains on the road," Just said. "The clear implication of our work is that engaging in a conversation could jeopardize the judgment and reaction time if an atypical or unusual driving situation arose."
He added, "Driving in quick-moving traffic is no place for an involved personal or business discussion, let alone texting."
Just is a pioneer in using brain imaging to discover how humans perform mental tasks and has testified in front of the Pennsylvania General.