What The Pandemic Is Doing To The Wiring In Our Brains

Speaker 1: 00:00 This is KPBS midday edition. I'm Mark Sauer with Maureen Kavanaugh. If only the brain were smart enough to figure out how the brain works. There is so much that we do not know yet. Brain research has greatly expanded in recent years, including advanced knowledge of how it's wired as our next guest will explain. David Eagleman is a neuroscientist professor at Stanford and author of the new book live wired. The inside story of the ever-changing brain. Welcome to midair. Speaker 2: 00:27 Hi, great to be here, Mark. Speaker 1: 00:28 Start with how the brain is wired. Unlike the hard drive on my computer here, our brains don't come entirely preprogrammed, right? Speaker 2: 00:35 That's right. It turns out that DNA is only, let's say half the secretive life and the other half is everything around you. All of the experiences that you absorb, this is what causes the brain to wire up in the particular ways that it does. We are essentially like sponges human brains in particular, we drop into the world half baked. And then from there, we, um, we absorb everything around us to finish that way. Speaker 1: 01:03 And you write that the brain's wiring changes one day to the next often in subtle ways, sometimes dramatically explain how that works. Speaker 2: 01:10 You know, you've got 86 billion neurons. These are the main brain cells. And each one of these has about 10,000 connections to its neighbors. So you've got, you know, like 0.2 quadrillion connections in the brain. And these things are changing all the time. You know, when, when you learned that my name is David, there's a change in your brain, such that if in a week from now, you say, Oh, I talked with that guy, David, that's represented by a physical change in your brain. That's what it means to remember something. And so we are a constantly changing dynamic system. And, um, and I think this is the really important way to think about and to understand the brain is not as a collection of pieces and parts that you draw on a map, but instead to understand it as a living dynamic electric fabric, Speaker 1: 01:58 What happens when suddenly nothing is normal, such as in a pandemic, when we all suddenly become like shut-ins, I'm thinking of kids, not in school because of the pandemic, it's a problem, vexing societies everywhere now, and fears over not just the lack of learning, but the disconnect from socializing and how does the brain adapt to such dramatic life changes or does it ever really adapt? Speaker 2: 02:20 Yeah. Well, I tell you, that's the thing we are so adaptable and strangely, I think that this whole issue about brain plasticity is the single silver lining to 2020. And here's what I mean by that. Um, you know, normally what the brain is trying to do is establish an internal model of the world so that we can operate in it effectively. And that's essentially what we've spent our whole lives doing is figuring out, okay, look, I get this, I know how to, how to optimize my performance in this world. And then suddenly 2020 comes along and all of us are kicked off the hamster wheel and the things that we thought we knew exactly how to do in situations, how to function in and so on, we suddenly are off that path of least resistance and we have to rethink things afresh. And that's actually what brain plasticity is really good at doing is figuring out, okay, whoops, this model doesn't work anymore. Let's generate a different model. Let's think of new things. And so despite how lousy this year has been for everyone, it's been an extremely creative time. Also everything from individuals to businesses have been figuring out new ways of doing things that they wouldn't have thought of even recently, of course, Speaker 1: 03:38 We're all individuals with individual brains. I'm wondering what happens in people where the wire wiring just fails to adjust Speaker 2: 03:45 That's right. I mean, people have a different capacities to deal with anxiety and stress. And so this is a really lousy time in terms of, you know, everything from alcoholism and drug addiction to suicide. Um, this is a really tough time on people. As I said, from the point of view of brain plasticity. The reason this matters is because we know from decades long studies, that the most important thing is to challenge the brain is to have it facing novel challenges and circumstances all the time. And where we see this, especially is when people retire. Often people will retire and their lives will shrink and they'll end up sitting on the couch, watching Jerry Springer and that's all they do. But you can contrast that with, um, with groups of people that have been studied, who have stayed cognitively active to their last days. And it turns out some of those people have Alzheimer's disease physically in their brain. And yet nobody knew it. They didn't show the cognitive deficits that are typical of Alzheimer's. And the reason is even as their brain was physically degenerating, they were making new roadways between a and B and C and D. They were constantly making new things happen in their brains specifically because they were being challenged with novel circumstances. Okay. Speaker 1: 05:06 Thinking, stay busy as the message there. I wanted to shift gears a little bit. Yeah. Lots of us dream where we remember dream sometimes interpret dreams, but what do we know really about dreams and their function in the brain wiring involved? Speaker 2: 05:18 Yes. So in this book, in Livewired, I propose a completely new hypothesis about dreams and, and I think this is correct actually. Um, essentially it has to do with how rapidly parts of the brain takeover other parts. So for example, when a person goes blind, other areas like touch and hearing ended up taking over the real estate that used to belong to vision. But one of the surprises in neuroscience has been how rapidly this sort of encroachment happens. So it turns out that if you blindfold somebody to be tightly and put them in the scanner, um, you start seeing touch and hearing have some influenced in the visual area of the brain after about an hour. And so when I saw that data a few years ago, I realized, ah, the issue is every night when we go to sleep because of the rotation of the planet, we're cast into darkness 12 hours of the night, um, when it's dark, you know, your hearing and your touch and all that still works, but your vision does not work. What I realized with a student of mine, Don Vaughn, is that we need to have some self defense system built in to keep the visual cortex, uh, to keep it having its territory during the night. And that's what dreams are. You have this very specific circuitry that looks at how much activity is in the visual cortex, and then essentially just slams it with activity every 90 minutes. And our hypothesis is that this is simply to keep it defended against takeover from the other senses. Speaker 1: 06:52 I've been speaking with neuroscientist, David Eagleman whose new book live wired. The inside story of the ever changing brain is published this week. Thanks for joining us today. Speaker 2: 07:02 Great. Thanks so much.