When it comes to making calls from a moving vehicle, the hands-off technique of operating cell phones is just as distracting as the hands-on approach. Experiments conducted in a virtual reality suite at U of I's Beckman Institute for Advanced Science and Technology found that drivers-young and old alike-still struggled to see dangerous scenarios appearing in front of them even when both hands were on the steering wheel.
"What we found was that both young adults and older adults tended to show deficits in performance," said Arthur F. Kramer, LAS professor of psychology. "They made more errors in detecting important changes and they took longer to react to the changes."
For the experiment, 14 young, inexperienced licensed drivers (mean age 21.4), and 14 older, more experienced drivers (mean age 68.4) actively engaged in a casual hands-free phone conversation. As they chatted, they faced a large, flickering screen on which digitally manipulated images of Chicago traffic and architecture continually changed. Each flicker, which simulated eye movements, resulted in a change of scenery that might or might not be important to a driver-a child running into a driver's path, a simple change in a theater sign, or bright or subtle color changes.
Older adults' ability to detect important changes to a driver dipped significantly. "For the older adults, it was quite scary in that contextual restraints no longer drove their eye-scanning strategies," Kramer noted. "When they were in a conversation on a cell phone, they were no longer any faster or any more accurate in their ability to detect meaningful changes, such as a little girl running between cars in traffic, than they were able to detect changes that were not meaningful to driving safely."
Younger subjects did detect relevant changes more readily and with fewer errors than older adults, but their reaction times were slowed. "When you are driving, you often don't have extra seconds to react," Kramer said.
Interestingly, researchers found no significant negative impairments among participants who simply listened on hands-free phones. Kramer theorized that comprehending and not responding, requires fewer mental resources and, therefore, does not interfere with driving.
