Dr. Matt Walker

It may also be the reason, by the way, that coming back to proprioception, you can sometimes have that feeling of, some people will describe, my teeth are always falling out.

I always feel as though, it's a very common thing too, where you feel the absence of clothing on your body.

And you say, I walked out and I was going to this meeting and I realized I didn't have any pants on.

And you forget that proprioception is also about knowing that your clothes are on you and sensing those clothes.

You and I can now direct our attention and sense those clothes on us.

No, I often think that that may have been where that notion comes from.

Why would we not say that I am, sometimes people say I'm drifting off into sleep, or I'm about to enter sleep.

No, we say I'm falling asleep.

Now, some of that may be that I'm falling into a sort of a deeper and deeper state of a brain wave activity pattern, maybe.

But I actually think you're right.

Now, we don't know ultimately the origin of it, but I believe it's in part because people have this sense of falling, hence falling asleep.

There is a reason for it.

And we'll probably come on to this at some point when we speak about different methods for sleep optimization or the new wave of fascinating sleep enhancement tools has to do with temperature, we think.

that for you to be able to fall asleep and stay asleep, you have to drop your brain and body temperature by just a little less than about one degree Celsius, or probably two, two and a half degrees Fahrenheit.

And that's the reason, by the way, that you will always find it easier to fall asleep in a room that's too cold than too hot, because the room that's too cold is at least taking you in the right temperature direction for good sleep, whereas the room that's too hot, the opposite.

Turns out that the body's ability to dissipate heat, what we call thermoregulation here, and thermoregulation in one direction, which is the reduction in core body temperature, is superior when you are lying down versus when you are inclined versus when you are standing up.

And in part, it has to do with the distribution of blood throughout certain parts of the brain in the distal versus proximal regions, meaning sort of the regions that are closest to the core of your body versus the regions that are further away.

But your body's ability, if we largely take most items of clothes off you, and then we measure the core body temperature and the way that we do this, it's a delightful technique.

It's called a rectal probe.

And it's neither pleasant necessarily for the installation of the experiments doing it.