Dr. Michael Grandner

And then in the 1930s, people looked at these squiggly lines on paper and put them into four buckets.

And then it became five and then it was back to four.

Um,

Just are you stage one, two, three, or REM based on the pattern of squiggly lines?

This is humans rating it.

Do they exist in nature?

No, we made them up.

You know, this is how humans categorize stuff based on patterns of brain activity on the outer layers of the cortex that are fluctuating during sleep.

The fact that you can look at heart rate fluctuations in combination with movement and get a really good estimate about which state of brainwave patterns you happen to be in at that moment, even though two humans can't always agree when looking at the same squiggly lines.

Is that stage one or stage two?

Is that REM?

Is that REM or did they drift into stage two or stage one at this point?

Eh, it looks kind of similar.

I'll call it REM.

Well, I'll call it stage two.

You see this all the time.

This is why we don't even use AI yet.

to rate these things because humans don't trust them because they can't even agree with each other.

There's no gold standard that you can even train a lot of these AIs against because even the humans can't agree.

So it's a moving target anyway.