Really if it's an hour or two after you've fallen asleep because you're in such a deep sleep at that point.

Sleep paralysis is something that is actually very common. Many people have it, I've had it myself. And what happens is, when you're in that REM stage of sleep, your brain is very active. You're dreaming your most during that stage, you're mind, your eyes are moving, there's a lot going on. It's like fireworks going on in your brain.

So we go through in the beginning of the night, we go into the really deep stages of sleep and we actually cycle through. So, when you go down to the deep stage, then you go back up and you actually come into something called REM sleep, which is after about 90 minutes.

Decrements in attention and concentration, being able to learn more efficiently, that's just not as good. Also, there are motor vehicle accidents, workplace accidents, we see that a lot.

Well, the actual function of the brain, not so sure yet. There's a lot of different theories about it, but when you talk about psychologically in your brain, a lot of people with insomnia, though not all, report that they can't turn their minds off.

Workplace accidents with people who are sleep deprived or people who work shifts and they don't get the right amount of sleep during the day or at night.

We haven't really - it's harder for us to set those rhythms. So it's really important to keep a steady bedtime and wake time to really lock in those rhythms.