What Keeps a Neuroscientist Up at Night | Good Night with Ben Gleib (Ep 2)

[00:00:00]What is the thing about the brain that keeps you up most of the night?

[00:00:04]>> Well, um the question of consciousness is a really big one. I mean, that's a biggie.

[00:00:11]Nowadays, the question of intelligence, what is intelligence, how do we define intelligence, is AI actually intelligent or is it just a statistical parrot? Um and uh you know, these are questions that keep me up at night. A question that used to keep me up at night is dreaming.

[00:00:27]>> Yeah, you talk about you think you've may may have figured out why we dream.

[00:00:30]>> Yeah.

[00:00:30]>> Please tell me.

[00:00:31]>> It's this. You mentioned earlier that if for example, if a person goes blind, the what we call the visual cortex gets taken over by other senses cuz nothing lies fallow in the brain.

[00:00:40]>> senses now.

[00:00:41]>> Yeah, exactly. You've got better hearing, better touch, and so on because all that cortical real estate >> your partner blindfolds you, everything is next level.

[00:00:49]>> Exactly, right.

[00:00:50]Yes.

[00:00:51]So, this ties into this actually because what my colleagues at Harvard figured out is that um >> I also have colleagues at Harvard, by the way.

[00:00:59]>> Okay, great.

[00:01:00]I'm [laughter] glad.

[00:01:01]>> People don't know that about me, but anyway.

[00:01:03]>> Um they blindfolded people and put them in a scanner. They were doing something else, but they they blindfolded these people and what they noticed is that after an hour, you started seeing little little bits of activity in the visual cortex when they touched a person or made a sound. And so, what that indicated was that the the takeover of the visual cortex was starting after just an hour of being blindfolded, which was really surprising. What I immediately realized, my student and I realized that there's a big deal here, which is that the planet rotates into darkness and we spend half our time in the dark, and that means the visual system is at a disadvantage cuz you can still hear and taste and touch and smell in the dark, but you can't see. Obviously, I'm talking about evolutionary time where it's really dark at night. Okay. So, what we realized is that's why we have dreams is to defend that territory during the nighttime. So, it turns out every 90 minutes, you got these very ancient circuits in the brain stem that just blast activity just into the primary visual cortex, nowhere else.

[00:02:03]Just every 90 minutes blasts this random activity. And And because we're visual creatures and storytellers, we see and we put together stories around >> system for your brain. It's like a screen saver.

[00:02:13]>> Wow.

[00:02:14]>> [laughter] >> And it's all And like the little that perfect dream is when the screen saver hits the corner.

[00:02:19]>> That's perfectly. [laughter] >> And it feels so satisfying.