Everyone knows driving and texting is a bad idea, but many drivers think their instincts are so good—especially on familiar stretches of road, such as the route from home to work—that one little message might not hurt.
New research from the University of Houston and the Texas A & M Transportation Institute shows that texting has a unique effect on our ability to focus when behind the wheel. To measure the impact of common distractions while driving, the research team studied how drivers behaved when they were absent minded, emotionally distracted or engaged in texting.
For the study, 59 volunteers were asked to drive the same segment of highway four times, under normal driving conditions (avoiding adverse weather, for example). They were distracted by cognitively challenging questions, emotionally charged questions and trivial texts. The order of the question or text drive combinations was random to keep the study participants from anticipating the scenarios.
In all three situations, lead researchers Ioannis Pavlidis from UH and Robert Wunderlich of TTI, found that the driver’s hand movements became jittery—when compared with normal driving—when faced with a distraction. When absent-minded or emotional, however, the jittery hand movements resulted in “straighter trajectories with respect to a normal drive a safer driving,” according to the UH report.
When texting, the jittery hand movements resulted in significant lane deviations and unsafe driving. The researchers suggest that the texting-unsafe driving link is most likely the result of the change in eye movement required to text.
“A likely explanation for this paradox is the function performed by a part of the brain called the anterior cingulate cortex, or ACC,” Pavlidis said in a UH interview. “ACC is known to automatically intervene as an error corrector when there is conflict. In this case, the conflict comes from the cognitive, emotional and sensorimotor, or texting, stressors. This raises the levels of physiological stress, funneling ‘fight or flight’ energy to the driver’s arms, resulting in jittery handling of the steering wheel.”
What happens when the brain’s ACC automatically intervenes, Pavlidis said, is that it counterbalances any strong jitter to the left with an instant, equally strong jitter to the right and vice versa—a sort of sixth-sense safeguard. The effect of this forceful action is nullification of any veering to the left or the right of the lane and, thus, very straight driving.
For ACC to perform this corrective function, it needs support from the driver’s eye-hand coordination loop. If this loop breaks, which it does when the driver texts, then ACC fails and the jittery handling of the steering wheel is left unchecked, resulting in a significant lane deviation and possible accident.
“The driver’s mind can wander and his or her feelings may boil, but a sixth sense keeps a person safe at least in terms of veering off course,” Pavlidis said. “What makes texting so dangerous is that it wreaks havoc into this sixth sense. Self-driving cars may bypass this and other problems, but the moral of the story is that humans have their own auto systems that work wonders, until they break.”
The best practice, no doubt, is to keep your eyes on the road, not your smartphone, when behind the wheel. No matter what is in that text, your life and the lives of others on the road, is far more important.