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If you’re interested in the brain, then you’re interested in the work of David Eagleman. Whether it’s his bestselling popular science books, his Emmy-nominated television series The Brain with David Eagleman, or his groundbreaking research published in journals like Science and Nature, there’s a good chance you’re already very familiar with what he does.
To celebrate the August 25 launch of Eagleman’s new book Livewired: The Inside Story of the Ever-Changing Brain, Digital Trends spoke with the adjunct professor at Stanford University and CEO of NeoSensory who has been called the “Malcolm Gladwell of brain science.”
Digital Trends: The title of your book is Livewired. A lot of people colloquially use the term “hardwired” when they discuss the brain. What do you mean by “livewired,” and why is the notion of hardwiring insufficient when we talk about the way that the brain works?
David Eagleman: Especially in this modern era, when we think about the brain, most people think in a computer metaphor. But fundamentally, the brain is very different from a digital computer. Just as an example, you cannot tear half the circuitry out of your cell phone and expect that it’s still going to work. And yet, with the brain, you can do what’s called a hemispherectomy, where you remove one half of the brain in the young child, and the child is just fine because the missing functions rewire themselves under the remaining real estate.
Instead of talking about the brain along the lines of hardware and software, we have to coin a new term for this — and so I coined livewire. We already have a concept called brain plasticity. That comes from the idea of plastic you can mold into any shape, and which then holds that shape. But what I realized is that the brain is doing more than that. It’s not a toy that you shape once and then holds that shape. It’s constantly changing every moment of your life till the day you die.
DT: You bring up the computational metaphor. What are your thoughts on artificial intelligence and, particularly, the pursuit of artificial general intelligence (AGI). Do you view such a thing as possible, and is modern A.I. research following along the right lines?
DE: Almost all of us in neuroscience suspect that it is possible to replicate the brain. It is a vastly sophisticated machine, but it is a machine in the end, with every cell in the system being driven by other cells. The question is whether A.I. as we currently practice it is capturing some principles about the brain. I think the answer is that modern A.I. was inspired by brain science, but has gone off in a very different direction. It can showcase superhuman performance in distinguishing pictures or playing chess or Go or things like that.
But that’s simply scratching the surface of what the brain is up to, and how the brain operates. Modern A.I. is based around the idea of “neurons” and “synapses,” and changing the strength of these connections. But inside biological neurons you have an entire cosmos going on. You have a redistribution of the channels that are in the membrane, you have changes in the biochemical cascades that are happening inside the neurons, all the way down to changes in the expression of genes inside the nucleus of the neuron.
Why do we not include any of that in A.I.? It’s because it’s very difficult, in 2020, to see any of that. We don’t have any good technology to measure it in real time. So what we do is simply concentrate on the neurons and the connections between the neurons. In this way, we’re like the drunk looking for his keys under the streetlight because the light is better there, even though that’s not where he lost his keys.
We’re leveraging the things we can measure and building models off of that. It’s very impressive, but modern A.I. cannot do what a three year old child can do. If you train a network to distinguish pictures of cats from dogs and then you ask it to distinguish camels from panda bears, it will fail catastrophically. It’s not particularly flexible.
DT: What advice do you have for people who want — and this is a terrible term — to get the most out of their brains? Are there lifestyle changes we should be making or things we should seek to learn to promote a sort of brain health?
DE: It turns out that the most important thing for the brain is to stay flexible. The job of the brain is to build an internal model of the world. What happens is that, as people get older and optimized in the world, they tend to learn less and less because there’s less need to change anything about the model. The one silver lining that I’ve seen to this coronavirus pandemic is that it’s kicked everyone off of our hamster wheels. We’re no longer just running our routines, but instead it’s forced us to rethink everything.
“The one silver lining that I’ve seen to this coronavirus pandemic is that it’s kicked everyone off of our hamster wheels.”
This turns out to be the best thing that you can do for the brain. I actually have a slight suspicion that there will be less dementia for those of us, decades from now, who enter our older years because we had this period in our life where we really challenged ourselves and thought hard about new ways of doing things. This is very important for brain health — and this has been shown by big studies run over decades. People who are constantly seeking novelty and facing new challenges have less incidence of dementia. It’s not that they don’t get, for example, Alzheimer’s disease. It’s simply that they don’t show the cognitive effects in the same way because they’re always making new roadways in the brain, even as part of these maps are deteriorating.
DT: You talked about coronavirus and, certainly, there are changes that are thrust upon us whether we like it or not. People might lose their jobs or careers and have to [develop new skills]. But what are some of the small things people might do proactively?
DE: The important part is to make sure that you’re doing things differently. Just as an example, I try to drive home from work a different route every day so I can see new things. Otherwise, you become an automatized zombie. You’ve probably noticed that time shrinks more and more as you become automatized in certain tasks.
My drive home from work is 20 minutes, but if I do the same drive home every day, it starts seeming like less and less time is passing. That’s because you’re running on autopilot. I’ll try to shave with my other hand, or brush my teeth with my other hand, or switch my watch to my other hand. These things are all simple, but they all cause the brain to rethink something that it’s already automatized. Let’s say someone has retired and they take up crossword puzzles, that’s great. But only do that until you get pretty good at it. Then drop it and pick up something new that you’re bad at.
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DT: Another topic you discuss in the book is this notion of neural redeployment. Could you explain what that refers to? It seems a fascinating phenomena.
DE: Typically, we think about the brain as having dedicated regions, like, “this part is the visual area, this part is for hearing, this part is for touch,” and so on. But, in fact, the whole system is extremely fluid. There’s a certain amount of real estate, and that real estate gets used by whatever is active. So when a child goes blind [they may well become better at processing sounds than sighted people]. This is true with hearing, touch, anything.
When we really look at the data, what we find is a very fluid system. As an analogy, I use the idea of continental plate drift where, if you look at the Earth, everything seems pinned into place. But, in fact, continents are floating around like lily pads over a certain timescale. That’s essentially what’s going on with the brain. You’ve got real changes going on there over time.
DT: What for you has been the most profound neuroscience development or study in recent years? What is the last discovery that really changed the way you think about the brain?
DE: One of the big surprises to me is just how rapidly areas of the brain start to encroach on other parts of the brain. If you blindfold a person and put them in a brain scanner, you start seeing things like touch and hearing make small activations in the visual system after about an hour. The system says: “Oh, I see. I’m not getting any vision anymore. That’s cool. That means that this territory is available for takeover.” That led me to propose an entirely new hypothesis about why we dream at night. For the entirety of human history, we’ve had dreams every night, but not understood why we’re dreaming.
My hypothesis, with a former student, is that dreaming is about fighting the takeover of the visual system at nighttime when the planet rotates into darkness. In other words, hearing and touch and everything else still work fine in the dark, and those systems try to take over your visual system. So what your brain evolved is this very sophisticated, very specific system that simply drives activity into the visual cortex. About every 90 minutes, it blasts the visual cortex with visual activity to defend it against takeover through the night. We experience that by having visual dreams.
DT: I wanted to ask you a bit about neurolaw, which I know is an area you’ve been involved with for a long time. Would you mind explaining what this means and why it’s an area worth focusing on?
DE: For about 14 years now, I’ve been running the Center for Science and Law. The issue, fundamentally, is that we assume that all brains are created equal. That’s a very charitable assumption, but it’s demonstrably false. Along any axis that you measure brains, you find they’re very different from one another. We also assume that brains have free will. Modern neuroscience suggests that neither of these assumptions are really true. The problem is that, as a result of this, we treat incarceration as a one-size-fits-all solution.
“Modern neuroscience has so much to say about what to do about mental illness, about drug addiction, traumatic brain injuries, and so on. That’s why it’s critical that we get neuroscience into the legal system.”
The estimates are that 30% of the prison population has mental illness of one sort or another. If you take somebody with schizophrenia and have them break rocks in the hot summer sun, that doesn’t fix their schizophrenia. Our prison population has gone up eight-fold in America ever since we declared the war on drugs. If you take somebody with a drug addiction and stick them in jail, that doesn’t fix their drug addiction. Modern neuroscience has so much to say about what to do about mental illness, about drug addiction, traumatic brain injuries, and so on. That’s why it’s critical that we get neuroscience into the legal system.
By the way, this doesn’t let anybody off the hook. People still get convicted exactly the same way, but it’s all about what you do from there. Instead of a backwards-looking system that says ‘this crime equals five years in prison,’ it’s a forward-looking system that says, ‘OK, you did this crime. Here’s how we can route you through the system so that there’s some rehabilitative strategy that we can maximize.’
DT: Finally, can you discuss the work that you’re doing at NeoSensory?
DE: Some years ago, my lab got very interested in the question of whether we could build sensory substitution systems for people who are deaf. That means taking sound but, instead of putting it into the ears as normally happens, we feed it to the brain through the skin. We’ve built devices that capture sound and turn them into spatial temporal patterns of vibration on the skin that people who are deaf can learn to understand.
Originally, we built this as a vest covered with vibratory motors. No,w we’ve gotten it down to a wristband that, as of about six months ago, has been on the market. It’s working beautifully. We get emails every day from people who say that they’ve picked up on sounds they didn’t even know were out there. They can respond to people who call their name or know when a machine is beeping. It’s been an absolutely lovely thing to take a very deep principle in neuroscience, and be able to spin a company out of my lab to build a device that directly affects people’s lives.
This interview has been edited for length and clarity.