Researchers warn that texting is the worst of all driving distractions because it disables your "sixth sense."
According to an extensive, new study conducted by researchers from the Texas A&M Transportation Institute and the University of Houston, drivers have a sixth sense that keeps them safe and on track even if they're emotional or absent-minded while driving.
In fact, the emotional and cognitive distractions actually made study participants drive safer and in a straighter line.
That sixth sense, however, is not present when texting and driving. Because texting breaks the driver's eye-hand coordination, the sixth sense doesn't kick in.
"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," says Ioannis Pavlidis, director of the Computational Physiology Laboratory at the University of Houston. Pavlidis led the study, which involved 59 participants.
The 59 volunteers had to drive four times along the same section of highway, each time under different conditions. Under "normal" conditions, they had no distractions, meaning they only had to focus on driving and nothing else. Other conditions involved driving while being distracted by questions that posed a mental challenge, or questions with an emotional charge. Researchers also observed the participants' driving performance while texting. The driving conditions were randomly selected to lower the chances of bias.
As opposed to driving under conditions deemed "normal" or with no distractions, the emotional, absent-minded and texting conditions made the drivers more "jittery" in handling the steering wheel. This resulted in significant deviations in trajectory only where texting was involved, while the other two distracting conditions prompted a straighter trajectory and safer driving compared to normal driving.
As Pavlidis explains, a part of the brain automatically kicks in when there's a conflict. In this study, the emotional, distracted or texting stages caused the conflict. The part of the brain that made distracted or emotional subjects drive better than they did under normal circumstances is called the anterior cingulate cortex, or ACC.
The conflict stressors raised the levels of participants' physiological stress, "funneling fight or flight" energy to the driver's arms. This caused the jittery response, when the ACC automatically intervened and counterbalanced the motion.
"The end effect of this forceful action is nullification of any veering to the left or the right of the lane and, thus, very straight driving," adds Pavlidis.
ACC, however, is highly dependent on the hand-eye coordination loop, which is broken when texting and driving. With the loop broken, ACC no longer intervenes to offset the jittery handling of the steering wheel and drivers end up steering off-course.
In light of these findings, researchers concluded that texting is the most dangerous driving distraction. The study is published in the journal Nature.
