Kim Carney / msnbc.com
By
msnbc.com contributor
updated 5/9/2007 9:09:56 AM ET 2007-05-09T13:09:56

The later Tim Harris stays up playing poker, the bolder — and more imprudent — he becomes. Hands that might have seemed hopeless early in the evening suddenly look like winners to the 56-year-old Bay Area grad student.

“I’ll think I have a better hand than I do and so I’ll tend to keep playing and pushing the hand when I probably should just fold,” Harris says. “At the end of the night, I’m broke and I realize I’ve made some bad decisions.”

As it turns out, it’s not just Harris choosing risky options when exhausted. Sleep experts point to disasters like the Exxon Valdez oil spill and Chernobyl as examples of what can happen when people don’t get enough sleep.

Gamblers, though, make really good lab rats for researchers who want to understand what happens to decision making when someone is sleep deprived. And the research goes a long way to explaining why a sleepy Harris might choose to keep betting when he’d otherwise toss in his cards.

Scientists set up experiments in which people have a choice between a high-risk gamble with the opportunity for a big payout and a low-risk option that offers the prospect of more moderate gain. They compared the decisions made by well-rested gamblers and those who’ve been up for hours on end.

Sure enough, the studies showed that when sleep is curtailed, people are drawn to risky, but high-paying, options.

And now, scientists think they understand why. Using brain scanners to peer into the heads of sleep-deprived gamblers, a group of Singapore researchers has shown why the mind may make poor choices when it’s tired.

When sleepy gamblers look at the high-risk, big-payout option, a region of the brain called the nucleus accumbens lights up much more than it would in well-rested people, says Dr. Michael Chee, co-author of the new research published in the journal Sleep.

“This is an area of the brain that activates in anticipation of receipt of reward,” explains Chee, a professor at the cognitive neuroscience laboratory at the Duke-National University of Singapore Graduate School of Medicine.

Double whammy
Making matters worse, lack of sleep seems to hinder a part of the brain that helps us learn from our mistakes.

“The orbitofrontal cortex is involved in emotional learning,” Chee says. “It comes into play when you get burned and you learn to avoid getting burned again.”

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This means you’ve got a double whammy, explains Matthew Walker, an assistant professor of psychology at the Harvard University School of Medicine.

It’s an incendiary situation in which the brain area that pulls you toward the high-payout gamble is revved up, while the region that might talk you out of it is turned down, Walker says.

None of this comes as a surprise to insomnia expert Michael L. Perlis, an associate professor and director of the sleep and neurophysiology laboratory at the University of Rochester. “We have an expression in my lab: It’s bad to be awake when reason sleeps,” he says, noting that insomniacs waking up in the middle of the night often have muddled thoughts because the rational parts of the brain are still sleeping.

It’s clear, Perlis says, that casino owners figured out the limitations of sleepy brains a long time ago.

“Think about it,” he explains. “There are no windows, no clocks — it’s essentially a time-free environment. You don’t known how long you’ve been there or what time of night it is. They’re trying to drive you to extended wakefulness.”

Although the sleep studies are being performed on gamblers, the results may have much broader implications.

Think about long-haul truck drivers who need to decide whether to stop and rest before continuing on their journeys, says Sean P.A. Drummond, an assistant professor in the department of psychiatry at the University of California, San Diego. “There’s a natural bias because traveling more miles means gaining money,” he adds.

Or, Drummond says, consider the sleep-deprived surgeon who needs to choose between an invasive procedure with the possibility of stunning results or one with a less miraculous impact, but with less probable peril.

Power of negative thinking
It’s not likely that people are going to change their sleep habits overnight, so is it possible to help the exhausted among us make better decisions?

Maybe, says Drummond, who just finished another study on groggy gamblers that will be published in the Journal of Sleep Research in June. His research suggests the way you frame the choice may make all the difference.

Teach people to focus on what might be lost — like a patient dying in a risky surgery — and they might be able to make better decisions even if they’re exhausted, he says.

Linda Carroll is a health and science writer living in New Jersey. Her work has appeared in The New York Times, Newsday, Health magazine and SmartMoney.

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