What If Dreams Are Protecting Your Brain? | David Eagleman

Added: 2026-06-02

[00:00:00]We live on this planet that rotates in the darkness for half the time.

[00:00:03]>> Mhm.

[00:00:04]>> And when you're in the dark, you can still hear and touch and taste and smell, but you can't see anymore. And obviously I'm talking about evolutionary time.

[00:00:10]>> Right.

[00:00:10]>> Before this last nanosecond of electrical light. Okay.

[00:00:13]Um and so it was really dark at night and the visual system was always disadvantaged for half the time. And so what we realized is the brain had to come up with this mechanism for defending the visual cortex against takeover.

[00:00:24]>> Oh.

[00:00:24]>> And and so every 90 minutes you've got these very ancient circuits, starting in your brainstem, every 90 minutes they just spit random activity into the visual cortex. That's all they do. And they're not hitting other parts of the brain, just the visual cortex.

[00:00:37]And as I mentioned, we are visual animals and so we interpret that as, "Oh, there's a story. There's stuff going on." But fundamentally it's just about defending the territory.

[00:00:47]>> I love it. It's like a war cuz that's kind of what the movie does is that it makes the consciousness there's a war >> right.

[00:00:52]>> in your conscious and your your subconscious. It's And that like all these projections are coming at you and that you're in you're in war with