Stanford Neuroscientist: Can’t Remember Your Dreams? Your Brain May Be Warning You!

Steven Bartlett (0:00)

After many, many decades of people debating this, you might have figured out the reason why we dream.

David Eagleman (0:04)

Yes, and it's a simple answer. So if you go blind, the visual cortex in the back of the brain gets taken over by hearing and by touch and by other things. In fact, our colleagues at Harvard did an experiment where they blindfolded normally sighted people, and you could start seeing that takeover happening after 60 minutes. And that's when we realized, wow, the purpose of dreaming is to defend the visual territory from takeover from the other senses. But what fascinates me about brain plasticity, and what I've devoted my career to is figuring out the way that we can be the sculptors of our own brains, and how it gives us an opportunity to become the kind of person we would like to be.

Steven Bartlett (0:40)

I'm coming, dude.

David Eagleman (0:41)

Yes, here's the thing. Your brain peaked at the age of two.

Okay, so at the beginning, you've got fluid intelligence, meaning you could learn anything. But now that you have grown up in this world, you've got crystallized intelligence, meaning you know how to drive a car, you know how to operate a cell phone, you know how to run a business. And so your brain doesn't require as much change, which means that the structure of the brain is always degenerating.

Steven Bartlett (1:05)

So what are the set of actions that will fundamentally change my brain and make me that type of person who's motivated in disciplines and who has high agency and attacks the world?

David Eagleman (1:13)

So this is something I've studied in my lab for decades now. And the key is that...

Steven Bartlett (1:18)

And what about AI and the social media debate as it relates to brain development?

David Eagleman (1:22)

Well, I happen to be a cyber optimist for young people. I think it's gonna make them much smarter than the generation that came before. And here's why.

Steven Bartlett (1:31)

Interesting. Guys, I've got a favor to ask before this episode begins. It's the algorithm, if you follow a show, will deliver you the best episodes from that show very prominently in your feed. So when we have our best episodes on this show, the most shared episodes, the most rated episodes, I would love you to know. And the simple way for you to know that is to hit that follow button. But also, it's the simple, easy, free thing that you can do to help us make this show better. And I would be hugely grateful if you could take a minute on the app you're listening to this on right now and hit that follow button. Thank you so, so, so much.

Dr. David Eagleman, what made you so fascinated about the brain, and why should everybody listening be fascinated about the brain as well?

David Eagleman (2:17)

Here's what I think it is. When I was eight years old, I fell off of the roof of the house that was under construction, and I fell 12 feet and broke my nose on the floor below.

But the whole thing seemed to take a long time. I did the calculation and figured out that it only took 0.6 of a second to get from the top to the bottom. And I couldn't figure out why it seemed to have taken so long. So I think that got me really interested in perception and the machinery by which we view the world and taken in and what is actually real versus what's a construction of the brain. And that's what I've devoted my career to is figuring out how the brain, which is locked inside the skull, it's about three pounds, how it constructs this model of the world and which things we can take as reality and which things we shouldn't.

Steven Bartlett (3:06)

I think most people don't even know that there's a brain there almost. It sounds like a strange thing to say, but most of us haven't really seen our own brains at all. We've never been able to touch our own brains at all. So it's easy to fall into the trap of thinking that everything I experience is true and is reality. So I'm wondering how a deeper understanding of all this stuff can help me live a better life.

David Eagleman (3:27)

Yeah, one of the things that I started writing about years ago is that I think we're not, I think we often think of ourselves as individuals, meaning not divisible into other things. But really, you are a team of rivals. You've got all these neural networks that have different drives making different suggestions to you.