A new study has shown that driving reduces one's ability to comprehend and use language.
The study led by researchers from University of Illinois has shown that driving impairs language skills.
"The previous findings made no sense to those of us who have studied language," said Gary Dell, a psycholinguist in the department of psychology at Illinois and corresponding author on the study.
"You might think that talking is an easy thing to do and that comprehending language is easy. But it's not.
"Speech production and speech comprehension are attention-demanding activities, and so they ought to compete with other tasks that require your attention - like driving," Dell added.
The new study was conducted in a driving simulator at the Beckman Institute for Advanced Science and Technology at Illinois.
The participants worked in pairs - one as a driver and the other as a conversation partner who was either in the simulator with the driver or talking with the driver via a hands-free cell phone from a remote location.
The findings revealed that a participant's ability to remember and retell a story declined significantly if he or she was also driving during the exercise.
The older subjects performed more poorly on these tasks to begin with, and their ability to retain and retell the stories worsened as much as that of their younger peers.
In contrast to their performance while sitting still, Dell said, "the drivers remembered 20 percent less of what was told to them when they were driving."
Declines in the accuracy of retelling the stories were most pronounced while drivers navigated through intersections or encountered more demanding traffic conditions.
"This study shows that various aspects of language go to hell when you're driving," said psychology professor Art Kramer, who collaborated on the study.
The findings appear in the journal Psychonomic Bulletin and Review.