Kris Oser, 37, of Hastings-on-Hudson, N.Y., is an email fiend. A single mother and director of communications for a market research company, she has to be immediately accessible to executives and the news media.
That means Oser is often on the phone and messaging several people at the same time -- and that can lead to trouble. In one recent gaffe, she mistakenly emailed a reporter at The Wall Street Journal instead of her best friend, asking her to pick up Oser’s daughter from school.
Alison Zollars Arthur knows better. As the owner of a skin and body wellness center, the 44-year-old Houston resident regularly counsels her clients about the importance of a healthy diet. But too often, she pigs out on fast food, salty snacks, and wine.
"If I have one glass of wine, I will have more," she says. "The voice saying, 'You really shouldn't,' shuts down, and I can do anything I want to."
That "voice" is the dorsolateral prefrontal cortex, an area of the brain that handles planning,...
“Speed is the modern, natural high,” says psychiatrist Edward Hallowell, MD, director of the Hallowell Center for Cognitive and Emotional Health in Sudbury, Mass. But he insists that true multitasking is a myth. We may feel we’re doing two -- or more -- things at once, but it’s an illusion. Instead, we’re quickly switching our focus back and forth.
That’s because the cerebral cortex can pay attention to only one thing at a time, says Hallowell. “What people really do is shift their attention from one task to the next in rapid succession. That reduces the quality of the work on any one task, because you’re ignoring it for milliseconds at a time.”
The cortex handles “executive control” -- that is, allocating the mind’s resources and prioritizing between tasks. However, there’s a lag of up to several tenths of a second each time it handles a switch, according to a University of Michigan study completed for the Federal Aviation Administration. This tiny bit of time can add up to big inefficiencies, the study shows.
Multitaskers Are Distracted
Distraction can also be dangerous. David Strayer, a professor of psychology at the University of Utah in Salt Lake City and an expert on driver distraction, has found that a motorist talking on a cell phone is every bit as impaired as someone who’s legally drunk. And there are health costs: Stress, including the self-imposed kind, means more cortisol into the bloodstream. Chronically elevated levels of cortisol can damage the heart, cause high blood pressure, suppress the immune system, and make you susceptible to type 2 diabetes.