Study shows just listening to cell phones significantly impairs drivers

Mar 05, 2008

Carnegie Mellon University scientists have shown that just listening to a cell phone while driving is a significant distraction, and it causes drivers to commit some of the same types of driving errors that can occur under the influence of alcohol.

The use of cell phones, including dialing and texting, has long been a safety concern for drivers. But the Carnegie Mellon study, for the first time, used brain imaging to document that listening alone reduces by 37 percent the amount of brain activity associated with driving. This can cause drivers to weave out of their lane, based on the performance of subjects using a driving simulator.

The findings, to be reported in an upcoming issue of the journal Brain Research, show 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,” said neuroscientist Marcel Just, director of the Center for Cognitive Brain Imaging.

Other distractions, such as eating, listening to the radio or talking with a passenger, also can divert a driver. Though it is not known how these activities compare to cell phone use, Just said there are reasons to believe cell phones may be especially distracting. “Talking on a cell phone has a special social demand, such that not attending to the cell conversation can be interpreted as rude, insulting behavior,” he noted. A passenger, by contrast, is likely to recognize increased demands on the driver’s attention and stop talking.

The 29 study volunteers used a driving simulator while inside an MRI brain scanner. They steered a car along a virtual winding road at a fixed, challenging speed, either while they were undisturbed, or while they were deciding whether a sentence they heard was true or false. Just’s team used state-of-the-art functional magnetic resonance imaging (fMRI) methods to measure activity in 20,000 brain locations, each about the size of a peppercorn. Measurements were made every second.

The driving-while-listening condition produced a 37 percent decrease in activity of the brain’s parietal lobe, which is associated with driving. This portion of the brain integrates sensory information and is critical for spatial sense and navigation. Activity was also reduced in the occipital lobe, which processes visual information.

The other impact of driving-while-listening was a significant deterioration in the quality of driving. Subjects who were listening committed more lane maintenance errors, such as hitting a simulated guardrail, and deviating from the middle of the lane. Both kinds of influences decrease the brain’s capacity to drive well, and that decrease can be costly when the margin for error is small.

“The clear implication is that engaging in a demanding conversation could jeopardize judgment and reaction time if an atypical or unusual driving situation arose,” Just said. “Heavy traffic is no place for an involved personal or business discussion, let alone texting.”

Because driving and listening draw on two different brain networks, scientists had previously suspected that the networks could work independently on each task. But Just said this study demonstrates that there is only so much that the brain can do at one time, no matter how different the two tasks are.

The study emerges from the new field of neuroergonomics, which combines brain science with human-computer interaction studies that measure how well a technology matches human capabilities. Neuroergonomics is beginning to be applied to the operation of vehicles like aircraft, ships and cars in which drivers now have navigation systems, iPods and even DVD players at their disposal. Every additional input to a driver consumes some of his or her brain capacity, taking away some of the resources that monitor for other vehicles, lane markers, obstacles, and sudden changes in conditions.

“Drivers’ seats in many vehicles are becoming highly instrumented cockpits,” Just said, “and during difficult driving situations, they require the undivided attention of the driver’s brain.”

Source: Carnegie Mellon University

Explore further: 3-D printing offers innovative method to deliver medication

add to favorites email to friend print save as pdf

Related Stories

Intermediary neuron acts as synaptic cloaking device

Feb 26, 2015

Neuroscientists believe that the connectome, a map of each and every connection between the millions of neurons in the brain, will provide a blueprint that will allow them to link brain anatomy to brain function. ...

Neural 3-D compass discovered in mammalian brain

Dec 03, 2014

Pilots are trained to guard against vertigo: a sudden loss of the sense of vertical direction that renders them unable to tell "up" from "down" and sometimes even leads to crashes. Coming up out of a subway ...

Recommended for you

3-D printing offers innovative method to deliver medication

3 hours ago

3-D printing could become a powerful tool in customizing interventional radiology treatments to individual patient needs, with clinicians having the ability to construct devices to a specific size and shape. That's according ...

Mystery of the reverse-wired eyeball solved

Feb 27, 2015

From a practical standpoint, the wiring of the human eye - a product of our evolutionary baggage - doesn't make a lot of sense. In vertebrates, photoreceptors are located behind the neurons in the back of the eye - resulting ...

Neurons controlling appetite made from skin cells

Feb 27, 2015

Researchers have for the first time successfully converted adult human skin cells into neurons of the type that regulate appetite, providing a patient-specific model for studying the neurophysiology of weight ...

Quality control for adult stem cell treatment

Feb 27, 2015

A team of European researchers has devised a strategy to ensure that adult epidermal stem cells are safe before they are used as treatments for patients. The approach involves a clonal strategy where stem cells are collected ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

WolfAtTheDoor
not rated yet Mar 05, 2008
There are probably a hundred different things that could distract a driver. People (and researchers for that matter) like to pick on cell phones because cell phones are annoying.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.