Livewired. David Eagleman

A Horse in the River

       Making Invisible the Expected

       The Difference Between What You Thought Would Happen and What Actually Happened

       Going Toward the Light. Or Sugar. Or Data.

       Adjusting to Expect the Unexpected

       8 Balancing on the Edge of Change

       When Haiti Disappears

       How to Spread Drug Dealers Evenly

       How Neurons Expand Their Social Network

       The Benefits of a Good Death

       Is Cancer an Expression of Plasticity Gone Awry?

       Saving the Brain Forest

       9 Why Is It Harder to Teach Old Dogs New Tricks?

       Born as Many

       The Sensitive Period

       Doors Close at Different Rates

       Still Changing After All These Years

       10 Remember When

       Talking to Your Future Self

       The Enemy of Memory Is Not Time; It’s Other Memories

       Parts of the Brain Teach Other Parts

       Beyond Synapses

       Daisy-Chaining a Range of Timescales

       Many Kinds of Memory

       Modified by History

       11 The Wolf and the Mars Rover

       12 Finding Ötzi’s Long-Lost Love

       We Have Met the Shape-Shifters, and They Are Us

       Acknowledgments

       Notes

       Further Reading

       Index

      Every man is born as many men and dies as a single one.

      —MARTIN HEIDEGGER

       1

      THE DELICATE PINK MAGISTERIUM

      Imagine this: instead of sending a four-hundred-pound rover vehicle to Mars, we merely shoot over to the planet a single sphere, one that can fit on the end of a pin. Using energy from sources around it, the sphere divides itself into a diversified army of similar spheres. The spheres hang on to each other and sprout features: wheels, lenses, temperature sensors, and a full internal guidance system. You’d be gobsmacked to watch such a system discharge itself.

      But you only need to go to any nursery to see this unpacking in action. You’ll see wailing babies who began as a single, microscopic, fertilized egg and are now in the process of emancipating themselves into enormous humans, replete with photon detectors, multi-jointed appendages, pressure sensors, blood pumps, and machinery for metabolizing power from all around them.

      But this isn’t even the best part about humans; there’s something more astonishing. Our machinery isn’t fully preprogrammed, but instead shapes itself by interacting with the world. As we grow, we constantly rewrite our brain’s circuitry to tackle challenges, leverage opportunities, and understand the social structures around us.

      Our species has successfully taken over every corner of the globe because we represent the highest expression of a trick that Mother Nature discovered: don’t entirely pre-script the brain; instead, just set it up with the basic building blocks and get it into the world. The bawling baby eventually stops crying, looks around, and absorbs the world around it. It molds itself to the surroundings. It soaks up everything from local language to broader culture to global politics. It carries forward the beliefs and biases of those who raise it. Every fond memory it possesses, every lesson it learns, every drop of information it drinks—all these fashion its circuits to develop something that was never preplanned, but instead reflects the world around it.

      This book will show how our brains incessantly reconfigure their own wiring, and what that means for our lives and our futures. Along the way, we’ll find our story illuminated by many questions: Why did people in the 1980s (and only in the 1980s) see book pages as slightly red? Why is the world’s best archer armless? Why do we dream each night, and what does that have to do with the rotation of the planet? What does drug withdrawal have in common with a broken heart? Why is the enemy of memory not time but other memories? How can a blind person learn to see with her tongue or a deaf person learn to hear with his skin? Might we someday be able to read the rough details of someone’s life from the microscopic structure etched in their forest of brain cells?

THE CHILD WITH HALF A BRAIN

      While Valerie S. was getting ready for work, her three-year-old son, Matthew, collapsed on the floor.¹ He was unarousable. His lips turned blue.

      Valerie called her husband in a panic. “Why are you calling me?” he bellowed. “Call the doctor!”

      A trip to the emergency room was followed by a long aftermath of appointments. The pediatrician recommended Matthew have his heart checked. The cardiologist outfitted him with a heart monitor, which Matthew kept unplugging. All the visits surfaced nothing in particular. The scare was a one-off event.

      Or so they thought. A month later, while he was eating, Matthew’s face took on a strange expression. His eyes became intense, his right arm stiffened and straightened up above his head, and he remained unresponsive for about a minute. Again Valerie rushed him to the doctors; again there was no clear diagnosis.

      Then it happened again the next day.

      A neurologist hooked up Matthew with a cap of electrodes to measure his brain activity, and that’s when he found the telltale signs of epilepsy. Matthew was put on seizure medications.

      The medications helped, but not for long. Soon Matthew was having a series of intractable seizures, separated from one another first by an hour, then by forty-five minutes, then by thirty minutes—like the shortening durations between a woman’s contractions during labor. After a time he was suffering a seizure every two minutes. Valerie and her husband, Jim, hurried Matthew to the hospital each time such a series began, and he’d be housed there for days to weeks. After several stints of this routine, they would wait until his “contractions” had reached the twenty-minute mark and then call ahead to the hospital, climb in the car, and get Matthew something to eat at McDonald’s on the way there.

      Matthew, meanwhile, labored to enjoy life between seizures.

      The family checked into the hospital ten times each year.