Vanderbilt Register: Researchers find neural ‘bottleneck’ thwarts multitasking

"Many people think they can safely drive while talking on their cell
phone. Vanderbilt neuroscientists Paul E. Dux and René Marois have
found that when it comes to handling two things at once, your brain,
while fast, isn’t that fast." …

http://www.vanderbilt.edu/register/articles?id=31525