Human World

George Brainard tests blue light on astronauts’ body clocks

George Brainard is a neuroscientist working with the National Space Biomedical Research Institute. He’s testing how light affects astronauts working and sleeping in space.

George Brainard: An astronaut here on Earth experiences a 24 hour day/night cycle just like you and I. Now when they’re on the space station, they’re circling the planet every 90 minutes. So they’ve gone from a 24 hour day to a 90 minute day.

Your circadian rhythm is what tells you when it’s time to sleep and wake up. It’s tied to light – in particular, the blue-indigo region of the spectrum, according to Brainard.

George Brainard: And that’s the opportunity that we’re working on. Can you blue-enrich white-appearing light and get a strong circadian stimulus for the astronauts, and will this in fact help their sleep?

Dr. Brainard is also testing to see if a pure form of blue light will boost the waking performance of astronauts.

George Brainard: So for example, if an astronaut is wakened up out of sleep and there has to be a spacewalk for emergency purposes, you want that astronaut at their peak alertness.

Blue light’s earthly applications might include combating the effects of jet lag and shift work.

Special thanks today to the National Space Biomedical Research Institute – innovations for health in space and on Earth.

Our thanks to:
George Brainard
Professor of Neurology
Thomas Jefferson University
Philadelphia, PA

November 21, 2008
Human World

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