Too Little Sleep: The New Performance Killer

Last Updated Feb 9, 2011 11:04 AM EST

As we all work longer and longer hours, take less vacation and work through the weekend, we may assume we're being heroic, or virtuous.

The truth is we're not; new research shows we're stupid.

Quite literally.

Missing just one night's sleep has a noticeable impact on the brain's ability to function as Dardo Tomasi and his colleagues at the Brookhaven National Laboratory discovered when they took 14 healthy, non-smoking right-handed men and made half of them stay awake through the night. In the morning, both rested and groggy subjects were put through a serious of tests that involved tracking ten balls on a screen. As they completed the tests, an MRI scanner took pictures of their brains, to see how the rested brain differed from the one that was deprived of sleep. They found that the sleepier the subjects, the lower their accuracy in the tests.

The Smartest Thinking is First to Go

Most telling of all, the higher order brain activity - in the parietal and occipital lobes - was the first thing to go. But while the parietal and occipital lobes were less active, the thalamus was very busy. Scientists hypothesize that it works extra hard to stay alert. So all the energy you want to concentrate on solving a hard problem just goes on staying awake.

What these and other studies indicate is that, yes, we can stay awake for long periods of time with little sleep - but what we lose, progressively, is the ability to think. "A tired worker tends to perform like an unskilled worker." Or you could say: a smart worker starts to work like a mindless one. I was reminded of this when interviewing former Countrywide mortgage dealers, so many of whom talked about their sweatshop hours.

An adult should get 6-8 hours of sleep a night. Less than that, and sleep deprivation starts to starve the brain. There is why we crave comfort food - donuts, candy - when we're tired: our brains want sugar. After 24 hours of sleep deprivation, there is an overall reduction of 6 percent in glucose reaching the brain. But the loss isn't shared equally; the parietal lobe and the prefrontal cortex lose 12 to 14 percent of their glucose. And those are the areas we need most for thinking: for distinguishing between ideas, for social control and to be able to tell the difference between good and bad.

"Sleepless Machismo" Culture Rampant in Corporate America

To Charles Czeisler, Professor of Sleep Medicine at Harvard Business School, encouraging a culture of sleepless machismo is downright dangerous. He calls it "the performance killer" and is amazed by today's work cultures that glorify sleeplessness, the way the age of Mad Men once glorified people who could hold their drink.

"We now know," says Czeisler, "that 24 hours without sleep or a week of sleeping four or five hours a night induces an impairment equivalent to a blood alcohol level of 0.1%. We would never say 'This person is a great worker! He's drunk all the time!' yet we continue to celebrate people who sacrifice sleep."

A blood alcohol level of 0.1% is above all legal limits for alcohol while driving. The US and UK limits are 0.08%. At 0.1%, you are liable to be prone to mood swings, emotionally over-expressive, loss of peripheral vision, depth perception and distance acuity and poor reasoning.

Hospital interns scheduled to work for 24 hours increase their chances of stabbing themselves with a needle or scalpel by 61 percent, their risk of crashing a car by 168 percent and their risk of a near miss by 460 percent. Twenty percent of car crashes are attributed to nothing more complex than lack of sleep, yet still executives take the red eye, jump into the rental car and drive off. When this is so well-established, why do we remain willfully blind to it? When most companies vigorously prosecute alcohol policies, why don't they have corporate sleep policies?

Photo courtesy of starfish 5112 C.C.2.0


  • Margaret Heffernan On Twitter»

    Margaret Heffernan has been CEO of five businesses in the United States and United Kingdom. A speaker and writer, her most recent book Willful Blindness was shortlisted for the Financial Times Best Business Book 2011. Visit her on www.MHeffernan.com.

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