Livewired: The Inside Story of the Ever-Changing Brain left me feeling both awed and comforted by the astonishing capabilities of the human brain.
Consider this: Your brain can listen to music, learn to play the violin, read sheet music, translate abstract symbols into properly coordinated arm and finger movements, write a symphony, conduct eighty other musicians to play a symphony together, and then talk about the emotional impact of the music with your family and friends.
Yet at birth, we humans can barely feed ourselves.
How do we get from helpless infant to accomplished maestro?
Or this: The human brain has about 86 billion neurons and 200 trillion connections between them. Yet there are only 20 thousand genes in the human genome. How could all those neurons and all that complexity be coded in so few genes? More important, what exactly do our genes code for?
Livewired is a book about neuroplasticity, the capacity of the human brain to modify its structure and function in response to events and experiences. Except that the author, David Eagleman doesn’t like the term. He thinks it doesn’t adequately describe what our brains are capable of, what they actually do throughout our lives.
“The brain chronically adjusts itself to reflect its challenges and goals. It molds its resources to match the requirements of its circumstance. When it doesn’t possess what it needs, it sculpts it.” [p. 12]
Our brains are livewired.
David Eagleman is a neuroscientist at Stanford University and a best-selling author. He studies brain plasticity, sensory substitution, time perception and synesthesia. Livewired is his eighth book.
By David Eagleman
Vantage, New York, 2021
Livewired looks at how the brain develops from infancy and adapts to changing circumstances.
Eagleman takes us through case studies and scientific research about how the brain deals with changes in sensory perception. For example, if we lose our sight or hearing, the brain will reallocate its “real estate” to the remaining senses. Scientists are learning how to connect devices like cochlear implants to the brain to help blind and deaf people. Through sensory substitution the brain learns how to process the imperfect signals of our devices restoring, at least partially, the lost senses.
We are starting to be able to enhance our senses, for example, enabling people to see into the ultraviolet or infrared. And we can even create new senses. Eagleman describes the case of a man who implanted small magnets into his fingertips. He can now “feel” the magnetic fields around electric circuits.
But it’s not just inputs. The brain adapts its output to changing circumstances too. Eagleman describes how the brain learns to control bionic limb replacements. We can even learn to control additional limbs like a third arm, or connect tailor-made devices for specific industries or tasks to the brain. The idea of additional or custom limbs sounds like something out of science fiction, but we do this all the time even today.
For example, when I put on my rollerblades, which I plan to do after I finish writing this review, I am, in effect, putting on new, artificial feet. My center of gravity is a few centimeters higher. These new rolling feet have way less friction with the ground than my regular feet. I have to move in a completely different way. But with practice, I’ve learned – or rather my brain has learned – to do this effortlessly. And when I take off my skates my brain immediately switches back to controlling my feet and legs in the usual way.
I loved how Eagleman describes the brain as “locked in a crypt of silence and darkness inside your skull” connected to the outside world by electrochemical signals. And how the brain is “infotropic” constantly trying to maximize the amount of useful information it gets, filtering out static or irrelevant signals while staying on the alert for new and dynamic inputs, like a jaguar suddenly appearing out of the shadows.
Livewired left me in awe of the brain. We often compare the brain to a machine, but no human made machine, not even the most powerful computer, is worthy of being compared to the brain. Eagleman says it’s the wrong analogy anyway. The brain isn’t a machine. It’s more like a city, constantly adapting, growing new capabilities, occasionally tearing down old structures and replacing them with new, more useful ones.
Adaptability is what the brain is built for, that’s what our genes code for. To develop our brains, to learn to walk, talk, and think, to become a fully functioning person, we must interact with the world.
The book gave me hope and comfort too. The brain is so adaptable that it seems to be able to recover, at least partially, from serious injuries. And we’re learning how to help the brain along with new devices that can bypass or even replace damaged senses and limbs.
Who knows, we might even be able to adapt to some of the global challenges we face as a species.
Thanks for reading.
Can we create new senses for humans?
TED Talk by David Eagleman, March 2015