2:03pm

Tue April 19, 2011
Humans

Just Power Through The Late Shift? Dream On

News that air traffic controllers had fallen asleep at their posts has brought a chorus of outrage. But if you think it's easy for humans to stay awake and vigilant when working in the middle of the night, think again. The truth is, there's no one-size-fits-all answer for making sure nodding off never occurs.

The problem is humans aren't nocturnal, but modern society demands some people work at night. So is there anything people can do to be certain they stay awake during the graveyard shift?

"I usually say no when I get that question," says Torbjorn Akerstedt, a sleep researcher at the Karolinska Institute in Stockholm. "Night work is unphysiological. You can never make it as good as day work."

What Akerstedt means by "unphysiological" is our bodies have an internal clock that's designed to keep us alert during the day and asleep at night. That clock is set by the time the sun rises and sets.

So any kind of night work is tough, but "there are several varieties of night work that are worse than other types — for example, if you have very short rest periods between shifts," says Akerstedt.

That's because getting enough sleep before a night shift starts is important for staying up. But there's a problem. "If I give you 12 hours of sleep by day, you're still going to be impaired at 2 in the morning because your clock doesn't adjust," says Tom Roth, a sleep researcher at the Henry Ford Hospital in Detroit.

A Quick Nap?

So what can you do at 2 a.m. when your internal clock is telling you to sleep? Roth says a nap during your shift might help.

But Secretary of Transportation Ray LaHood has apparently ruled that out. "On my watch, controllers will not be paid to take naps," LaHood said on Fox News Sunday. He says the government's plan is to give controllers an extra hour off between shifts.

Roth thinks that's a mistake. "I would rather see that hour of extra sleep from 2 to 4 in the morning, when that person is really impaired in that tower," he says.

Roth says anyone who's experienced jet lag knows what it feels like when your body is tugging you to fall asleep. The difference is, when you fly half way around the globe, the light changes with you and the light of the local daytime helps you shift your internal clock. You can shift your internal clock artificially, with bright lights at night and dark curtains during the day, but it's tough and hard to maintain.

It's also true that some people can handle jet lag or night shift work more easily than others.

"You have people that are short sleepers, people who are long sleepers," says Maurice Ohayon, a sleep researcher at Stanford University. Not only do people vary on the amount of sleep they need, there are also differences in when they need their sleep. Larks tend to like to go to sleep early and get up early; for night owls, it's the opposite.

But Ohayon says everyone will experience times when they get sleepy in the middle of the night.

"Here is the biggest problem. We know that sleepiness is something that is taking you by surprise. You don't know when you are passing from sleepiness to sleep," he says. "You are always at risk to have a big period of excessive sleepiness. The sleep can come at any moment. The danger is there."

Ohayon says it's basically luck that prevents more accidents caused by drowsy shift workers from occurring. That's not a particularly comforting thought, and it implies it will take more than threats from angry politicians to keep people awake and vigilant in the middle of the night. Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.