ad info

CNN.com
 MAIN PAGE
 WORLD
 ASIANOW
 U.S.
 LOCAL
 POLITICS
 WEATHER
 BUSINESS
 SPORTS
 TECHNOLOGY
   computing
   personal technology
   space
 NATURE
 ENTERTAINMENT
 BOOKS
 TRAVEL
 FOOD
 HEALTH
 STYLE
 IN-DEPTH

 custom news
 Headline News brief
 daily almanac
 CNN networks
 CNN programs
 on-air transcripts
 news quiz

  CNN WEB SITES:
CNN Websites
 TIME INC. SITES:
 MORE SERVICES:
 video on demand
 video archive
 audio on demand
 news email services
 free email accounts
 desktop headlines
 pointcast
 pagenet

 DISCUSSION:
 message boards
 chat
 feedback

 SITE GUIDES:
 help
 contents
 search

 FASTER ACCESS:
 europe
 japan

 WEB SERVICES:
Tech

Birds sleep with one eye open, half awake, study finds

graphic

February 3, 1999
Web posted at: 9:38 p.m. EST (0238 GMT)

LONDON (Reuters) -- Apart from flying, birds have another enviable ability -- they can sleep with one eye open and half of their brain awake, researchers said Wednesday.

It's called unihemispheric slow-wave sleep (USWS), and it allows birds to detect approaching predators while still getting a bit of shut-eye.

"They are able to make behavioral decisions about whether they keep one half of the brain awake or allow both halves of it to sleep," Niles Rattenborg said in a telephone interview.

The behavioral neurophysiologist at Indiana State University in Terre Haute and his colleagues believe their research, published in the science journal Nature, is the first evidence that an animal can control sleep and wakefulness simultaneously in different parts of the brain.

Dolphins, seals and manatees also have USWS, which lets them sleep and swim to the surface to breathe, but Rattenborg said birds seem to be able to use it at will.

"What was unique is that they are able to control it. They can also sleep with both halves of the brain. When they are sleeping under more risky situations, they increase the proportion of their sleep with one eye open and half their brain awake," he added.

Rattenborg thinks the research could have some implications for humans. Some sleep disorders, such as sleepwalking, are thought to occur when parts of the brain wake up while other parts are still sleeping.

"If birds can do it, humans might be able to do it in some form or another," he said.

There are even anecdotal accounts of war veterans who claimed that under extreme stress they were able to sleep with one eye open. But researchers have been unable to demonstrate it scientifically because it would involve putting a person under extreme stress. "We can't do that," said Rattenborg.

Copyright 1999 Reuters Limited. All rights reserved.


RELATED SITES:
Nature
Indiana State University
Note: Pages will open in a new browser window
External sites are not endorsed by CNN Interactive.
 LATEST HEADLINES:
SEARCH CNN.com
Enter keyword(s)   go    help

Back to the top   © 2001 Cable News Network. All Rights Reserved.
Terms under which this service is provided to you.
Read our privacy guidelines.