04/25/2010 05:12 am ET | Updated May 25, 2011

Caution: Multitasking Can Be Dangerous to Your Health

"I'm listening to you," the gamer says, as his thumbs manipulate the controller with music playing on his computer in the background. Really? How much focus could he devote to a conversation with several other stimuli taking his attention?

As a physician, educator, researcher and administrator, I'm no stranger to having a lot of balls in the air and multiple people needing my attention at the same time. But research shows that although it may seem that we can address several things at once, as various stimuli compete for attention, they must line up to gain access to our "concentrational resources," and we can only truly concentrate on one thing at a time. So, when there are competing tasks, we end up shifting from one task to another. We do this shifting in milliseconds, but this shifting actually decreases our efficiency in dealing with any one topic. And since concentration isn't unlimited, every ring tone, beep, bell and pixel flash can splinter attention the way the trunk of even the most solid oak tree can get splintered by lightening. With enough flashing text messages, traffic lights, upsetting news and tiny keyboards to contend with, even a strong base of concentration can get splintered into a toothpick.

If the woman in the car ahead of you is texting, it's not enough to keep a couple of car lengths between you and her bumper; steer clear altogether. Texting involves all three types of distraction: visual, manual and cognitive. The person's eyes are off the road, her hands are off the wheel and her mind is off driving. Texting while driving is as impairing as drunk driving, similar to having a blood alcohol level at the legal limit of .08 percent, and, as such, it increases the risk of an accident by 50 percent.

Even with hands-free devices, the "Splintered Toothpick Principle" still applies. Using a cell phone reduces the amount of brain activity associated with driving by 37 percent, as elegantly shown by a group of scientists at the Center for Cognitive Brain Imaging at the Carnegie Mellon University in Pittsburgh. The researchers used a technology know as functional magnetic resonance imaging to visualize the parts of the brain that were working during simulated driving with or without listening to somebody speaking. No wonder a "cell phone driver" is four times as likely to get into a crash serious enough to become injured. Whether it is because of talking, texting, dialing or e-mailing, it is the secondary task that contributes to more than 22 percent of all crashes and near crashes. Angelenos remember the tragic, needless loss of life in the Metrolink crash in Chatsworth on Sept. 12, 2008 that was caused by the engineer texting rather than paying attention to driving the train.

Besides the logistical liabilities of multitasking, the "instant" aspect of new technologies can have an effect on developmental health. For adults, decreasing response times may be disconcerting, but children who regard the immediacy of texting as a normal time frame for acquiring or retrieving information can develop learning issues. Professor Michael Abramson, an Epidemiologist at Monash University in Australia, did research with children aged 11 to 14 that showed that kids who used text messaging the most were more likely to give faster, but less accurate responses to IQ tests. This is unsettling news for Type A parents who have already made preemptive donations to Harvard.

Another neuroscientist at Monash, Susan Greenfield, is concerned that texting, Twittering and other forms of instant communication could lead to a rise in attention deficit disorders, especially in children under 10, whose brains are still developing. Her concern is that if children keep using their phones at the expense of all other forms of expression, there could be a resulting imbalance in their development. Studies also have demonstrated that multitasking results in decreased sleep for adolescents, a group that could use more sleep rather than less.

Societal demands to do more in the same amount of time and to be connected 24/7 have made "multitasking" seem like a positive thing, when in reality it often can be quite detrimental. Perhaps if we called it "multi-splintering" instead, it might help remind us that our concentration isn't unlimited, and that certain tasks need and require our full, undivided attention. The good news is that with focused and directed effort, we are able to improve our concentration, instead of letting it get splintered away and fall apart.