Andrew Huberman· PhD
And you can see if you knock here or here, depending on where exactly you knock, you get these up and down states. And if they last for, let's say, 200, 300, 400 milliseconds, and they occur at different places, you can formally compute what's called 'brain complexity' using Lempel-Ziv complexity. And you can show when everyone who's either awake like us, or we're asleep in a dream state, or we're on ketamine, where we're dissociated... In all those cases, the brain complexity's high. It's above a threshold. However, when you're in a non-REM sleep, when you're in a state of deep sleep, or you're anesthetized, or, of course, in the most extreme case, you're brain dead, then the brain complexity is very low.