Researchers from the University of Warwick and Harvard Medical School have proved what anyone who has tried to close a deal from behind the wheel already know: Intense conversations are a dangerous distraction for drivers.
Warwick's Dr. Melina Kunar (above) and Harvard's Dr. Todd Horowitz examined the response times of test subjects engaged in conversations and found that they made significantly more errors and were markedly slower than those who were focused on the task at hand. The problem wasn't the phone itself, but the fact that the subjects were distracted by their conversations.
"Our research shows that simply using phones hands-free is not enough to eliminate significant impacts on a driver’s visual attention," Kunar said, because for all our love of Bluetooth headsets and speaker phones, we humans simply aren't biologically advanced enough to drive and talk simultaneously. "Generating responses for a conversation competes for the brain’s resources with other activities which simply cannot run in parallel.
This leads to a cognitive 'bottleneck' developing in the brain."
That's the same kind of bottleneck that forms behind you on the highway after you rear-end a car while yammering away on your hands-free.
To test their theory, Kunar and Horowitz measured the reaction times of test subjects who pressed a button in response to prompts on a computer screen. Those who were engrossed in conversations about their hobbies over a speakerphone made 83 percent more errors and responded with a delay of 212 milliseconds compared with their less-conversant counterparts.
That may not sound like much, but a car going 60 mph travels 18.7 feet in 212 milliseconds. That's enough to mean the difference between stopping safely and stopping to call your insurance agent.
The worst results came from the subjects tasked with listening to a list of words and then speaking new words that began with the same letters as each word on the list. Those "drivers" had a 480 millisecond delay, which at 60 miles per hour would mean 42.3 additional feet traveled before applying the brakes. Lesson: Don't try to solve the NPR Sunday Puzzle until you park your Volvo.
Why then, you ask, can drivers listen to the radio without the same level of distraction? Drs. Kunar and Horowitz anticipated that argument and tested for it. Study participants who listened to a chapter of a book in anticipation of being tested for listening comprehension had no significant impairment in their "driving" skills. Also relatively safe were mundane conversations. Yet another group listened to and repeated to a list of words — the research equivalent of occasionally responding "uh huh" during an obligatory phone call to a very talkative Aunt Ethel — to no measurable distraction.
Lesson: Take the conference call in the Lex, but save negotiations for the desk.
Photo: University of Warwick
