David Eagleman

And every 90 minutes just blasts random activity in there.

And so dreaming is the brain's way of defending the visual cortex against takeover.

It's essentially a screensaver.

So we published this and we studied 25 different species of primates and looked at how plastic they are.

In other words, humans are extraordinarily adaptable and plastic in their brains.

And that means they're at higher risk of the visual cortex getting taken over.

Whereas other...

primates like the gray mouse lemur it's called um happens to be very let's call it pre-programmed where it you know hits adolescence fast and learns how to walk fast and weans from its mother fast and all this stuff reproduces fast and um and and so we looked at how how much dreaming there is and it turns out humans have lots of dreaming to prevent take over the visual cortex whereas other you know less flexible animals um have less dreaming because they just don't need it as much

That's exactly right.

Yeah, it's just random activity.

What happens is, you know, the synapses, the connections that are hot during the day are the ones when you blast random activity in there, those, you know, tend to be the stories that get activated.

So, you know, if I'm thinking about my, you know, my boss who said this to me, or I'm thinking about this big thing that I have to do tomorrow, then it's likely that that's going to come up in my dreams.

But, you know, we all know dreams are just...

They're so weird in their plot lines.

And because the brain is a natural storyteller, we end up imposing narrative.

And by the way, when you wake up and you tell somebody else your dream, you're doing a whole nother layer of imposing narrative on it.

Because even just saying it out loud, you have to sort of make things make sense.

But truthfully, it's just random activity.

And it's kind of like a Rorschach blot.

If you just look at some random blob of ink