And they will study whether it is involving in controlling sleep quantity alone, or also what scientists call the "wakefulness-behavioral drive."

VOA: special.2009.08.26

And then you do twenty-plus miles the next day,you sleep in a tent, you gotta wake up and you got to do it again.

VOA: special.2009.11.02

I moved it slowly,very slowly, so that I might not interfere with the old man's sleep.

VOA: special.2009.05.16

He says he realized it was time to find a separate space where the poets could gather and he could still get some sleep.

VOA: special.2009.04.27

It might also interfere with sleep, he says, and that could have an influence.

VOA: special.2009.03.10

It might also interfere with sleep,he says, and that could have an influence.

VOA: special.2009.02.11

It said they were getting far less sleep than they should.

VOA: special.2009.06.02

People can sleep in it for a few days.

VOA: special.2010.02.02

It was too cold for them to sleep much.

VOA: special.2009.07.22

and by the time they figure out why, it may be too late as,one by one, the specter kills them in their sleep.

VOA: standard.2010.05.04

You can sleep on it.If you still feel like going in the morning, - I'll take you to the airport.- No. I want to drive.

VOA: standard.other