Canada

The Canadian Press - ONLINE EDITION

Brain drain: Talking on cell while turning left may be risky, neuroimaging shows

By: Sheryl Ubelacker, The Canadian Press

Posted: 02/28/2013 1:02 AM | Comments: 0 | Last Modified: 02/28/2013 9:19 AM

An man works his phone as he drives through traffic in Dallas, Tuesday, Feb. 26, 2013. A study shows the most dangerous manoeuvre a driver can ever perform is make a left turn while chatting on a cellphone. THE CANADIAN PRESS/AP/LM Otero

TORONTO - Drivers who talk on a cellphone — even one that's hands-free — while executing a left-hand turn at an intersection could be putting themselves at serious risk, say neuroscientists who imaged the brain to see how it copes with competing tasks.

Making a left turn and phone-chatting at the same time "could be the most dangerous thing they ever do on the road," said Tom Schweizer, director of neuroscience research at St. Michael's Hospital in Toronto.

Schweizer and his research team wanted to see how the brain deals with the often complex task of making a left turn at a busy intersection — where most serious traffic accidents occur — when coupled with a common distraction like conversing by cellphone.

The team set up a driving simulator, which includes a steering wheel, brake and accelerator pedals, and a simulated traffic scenario on a monitor, inside a functional MRI. The high-tech machine captures real-time images of the brain while a person performs a task or reacts to stimuli.

Sixteen participants (seven females and nine males), aged 20 to 30, who had been driving an average of seven years, were put through simulated driving tests while in the MRI. For consistency in the study, all were right-handed.

They were asked to execute a number of normal driving manoeuvres, including a left turn, said Schweizer, explaining that their field of vision is filled with the traffic-scenario image, which is similar to looking through a vehicle's windshield.

As a subject performed the various tasks, researchers watched another screen showing what areas of their brain were activated.

"What you see when they're doing a left-hand turn at a busy intersection, the entire brain lights up, which is far different from what brain areas are used when just doing straight driving or making a right-hand turn," he said.

"You have to look at oncoming traffic, pedestrians and lights, and co-ordinate all that," he said. "It requires a significant amount of co-ordinated brain areas to pull that off."

The researchers then added a distraction to the task of making a left turn, in this case by asking true-false questions that were stand-ins for talking on a hands-free cellphone.

One question was: A triangle has four sides. True or false?

"Everybody knows the answer to those questions, but you're forced to listen to the speaker and process that information and come up with a true or false response," Schweizer said.

"When we did that, what we found was quite striking," he said.

The visual processing part of the brain started to shut down, so resources could be allocated to the prefrontal cortex, which controls decision-making.

"What was really striking, though, was how much of the visual cortex started to shut down. It was almost a 50 per cent drop ... So that was quite a dramatic shift," he said.

Schweizer said simultaneously trying to juggle a left turn and a verbal distraction — even a passenger speaking or a radio talk show — could make the traffic move that much more risky.

"I think it's still fairly dangerous to still be talking on a hands-free device, even though there's some thinking that it's so much better for us and will lead to far fewer accidents" than holding a phone to the ear, he said.

"We think that that's so much worse, but the reality is that hands-free is not brain-free."

The study was published online Thursday in the journal Frontiers in Human Neuroscience.

Future research will involve a larger number of participants of various ages, including older drivers and those with brain injury or neurological disorders such as dementia.

Fact Check

Have you found an error, or know of something we’ve missed in one of our stories? Please use the form below and let us know.

* Required

In which story did you find the error? *
Please post the headline of the story or the title of the video with the error.
What was the error? *
Please post exactly what was wrong with the story.
What should we have written?
Please indicate your source for the correct information.
Who else should we interview to improve this story?
Please include any contact information you may have.
Can we contact you in the future for advice on stories about this topic?
Yes

No
First Name: *
Last Name: *
E–mail Address: *
This will only be used to contact you if we have a question about your submission, it will not be used to identify you or be published.
Phone: *
This will only be used to contact you if we have a question about your submission, it will not be used to identify you or be published.
Colour:
Are you blue? If you can see this, leave it blank and get some CSS support.
Enter the words that you see: * This is to prevent our forms from being filled out automatically.
You have failed to correctly identify the words in the box above. Please try again.

More Canada

Undock

You can comment on most stories on winnipegfreepress.com. You can also agree or disagree with other comments. All you need to do is register and/or login and you can join the conversation and give your feedback.

Have Your Say

New to commenting? Check out our Frequently Asked Questions.

The Winnipeg Free Press does not necessarily endorse any of the views posted. By submitting your comment, you agree to our Terms and Conditions. These terms were revised effective April 16, 2010.