Livewired The inside story of the ever-changing brain

Review by Booklist Review

Neuroscientist Eagleman extols the dynamic nature of the human brain, describing it as "a cryptic kind of computational material, a living three-dimensional textile that shifts, reacts, and adjusts itself." At birth, human brains possess a limited number of built-in abilities but an immense amount of flexibility. During growth, people effectively "rewrite" brain circuitry as they adapt to their body, their experiences, and the outside world. Eagleman dubs this brain-modeling power and proficiency "livewired." He explores dreams, memory, illusions, and synesthesia. At times, his discussion intersects with philosophy: "The enemy of memory is not time, it's other memories." The bionic retinal chip (to treat blindness), the cochlear implant (for deafness), and how the brain decodes sensory data from the environment are reviewed. The resiliency of an adept armless archer and a child with only half a brain are spotlighted, while Eagleman enjoys pop-culture allusions such as Star Trek's Borg, Spider-Man villain Doc Ock, and the film Memento. Weighing in at about 3 pounds, the human brain, Eagleman avers, is a biological dynamo that remains, in many ways, a magnificent mystery.

From Booklist, Copyright (c) American Library Association. Used with permission.

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Review by Publisher's Weekly Review

Neuroscientist Eagleman (The Brain) delivers an intellectually exhilarating look at neuroplasticity. In his view, the brain's ability to reconfigure connections between its different areas in response to feedback is "quite possibly the most gorgeous phenomenon in biology," and also holds exciting practical applications. Eagleman explains how the brain's "maps" of the body are not genetically precoded, but arrive "remarkably unfinished" at birth and are then molded by experience, and walks readers through the concept of cortical redeployment, in which the function of different brain areas is reallocated according to need--for instance, in blind people, the visual cortex doesn't go unused, but is adapted for other purposes. Optimistically proposing that humanity can use neuroplasticity to its advantage, Eagleman describes the therapeutic field devoted to substituting one sense for another, and the potential for augmentation of existing senses (as has occurred with some cornea transplantees who found themselves suddenly able to see ultraviolet light). Finally, Eagleman addresses the implications for future tech innovations, observing that AI systems, despite their now "mindblowingly impressive" state, lack the brain's essential plasticity. Eagleman's skill as teacher, bold vision, and command of current research will make this superb work a curious reader's delight. (Aug.)

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Review by Library Journal Review

Recent developments in brain imaging, along with more sophisticated techniques for neural integration with digital systems, have ushered in a new age of experimental neuroscience that is beginning to unlock the mysteries and potentials of the brain in sensing, manipulating, and even thinking about the world. On the forefront of this, neuroscientist and educator Eagleman (The Brain: The Story of You) here tackles the burgeoning topic of neuroplasticity (a popular term he finds somewhat limiting and misleading). Arguing that the human brain has been evolutionarily shaped in a way that makes it particularly adaptable, he first offers examples of ways in which the brains of individuals with damage or deficits in their sensory apparatus have "rewired" themselves to compensate. These modifications, which have in the past happened organically (blind individuals who learn Braille have demonstrable changes in their ocular cortex), or, more recently, as a result of external intervention (deaf individuals show changes to their auditory cortex after a cochlear implant) are now observable through improved imaging techniques. Having thus grounded his argument, he then becomes increasingly speculative, exploring ways in which the adaptable nature of brain functioning might be harnessed through indirect and, ultimately, direct inputs to sense, control, and communicate with our environment. VERDICT A fascinating and ultimately very hopeful work narrated with clarity and enthusiasm by the author.--Forrest Link, The Coll. of New Jersey Lib., Ewing, NJ

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Review by Kirkus Book Review

A masterful update on how the brain operates. At the beginning, neuroscientist Eagleman notes how DNA gets all the credit for being the basis of life but deserves only half. Every animal today possesses DNA identical to that of 30,000 years ago, and its behavior is also indistinguishable. A caveman with identical DNA might look like us, but their actions and thoughts would be utterly foreign. Credit goes to the human brain, entirely the creation of DNA at birth but unfinished. "For humans at birth," writes the author, "the brain is remarkably unfinished, and interaction with the world is nec-essary to complete it." Unlike an arm or stomach, the brain is a dynamic system, a general-purpose computing device that changes in response to experience. With this introduction, Eagleman is off and running. In the first of many delightful educational jolts, he notes that the mature brain contains regions with specific functions, but under magnification, its billions of nerve cells, which form trillions of connections, look the same. What's happening? The brain does not think or hear or touch anything. "All it ever sees are electrochemical signals that stream in along different data cables," writes the author, but it works brilliantly to extract patterns from this input. As we age, our brain figures out a set of rules, which the author lays out in his conclusion. At birth it possesses enormous flexibility because it must literally learn how to function. Children can learn several languages fluently, but after age 10, new languages come with an accent. If a child is kept in the dark and silence for several years after birth, they will never see or talk. Neurons compete as fiercely as they cooperate. If one area stops functioning, others take over. Thus, when the vision region falls silent from blindness or even a few hours in a blindfold, input from hearing or touch moves in. To fend off this intrusion during sleep, Eagleman theorizes, our vision area continues to operate by generating dreams. Outstanding popular science. Copyright (c) Kirkus Reviews, used with permission.

Copyright (c) Kirkus Reviews, used with permission.

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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. 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. This routine continued for three years. Valerie and Jim began to mourn the loss of their healthy child--not because he was going to die, but because he was no longer going to live a normal life. They went through anger and denial. Their normal changed. Finally, during a three-week hospital stay, the neurologists had to allow that this problem was bigger than they knew how to handle at the local hospital. So the family took an air ambulance flight from their home in Albuquerque, New Mexico, to Johns Hopkins hospital in Baltimore. It was here, in the pediatric intensive care unit, that they came to understand that Matthew had Rasmussen's encephalitis, a rare, chronic inflammatory disease. The problem with the disease is that it affects not just a small bit of the brain but an entire half. Valerie and Jim explored their options and were alarmed to learn there was only one known treatment for Matthew's condition: a hemispherectomy, or the surgical removal of an entire half of the brain. "I can't tell you anything the doctors said after that," Valerie told me. "One just shuts down, like everyone's talking a foreign language." Valerie and Jim tried other approaches, but they proved fruitless. When Valerie called Johns Hopkins hospital to schedule the hemispherectomy some months later, the doctor asked her, "Are you sure?" "Yes," she said. "Can you look in the mirror every day and know you've chosen what you've needed to do?" Valerie and Jim couldn't sleep beneath the crushing anxiety. Could Matthew survive the surgery? Was it even possible to live with half of the brain missing? And even if so, would the removal of one hemisphere be so debilitating as to offer Matthew a life on terms not worth taking? But there were no more options. A normal life couldn't be lived in the shadow of multiple seizures each day. They found themselves weighing Matthew's assured disadvantages against an uncertain surgical outcome. Matthew's parents flew him to the hospital in Baltimore. Under a small child-sized mask, Matthew drifted away into the anesthesia. A blade carefully opened a slit in his shaved scalp. A bone drill cut a circular burr hole in his skull. Working patiently over the course of several hours, the surgeon removed half of the delicate pink material that underpinned Matthew's intellect, emotion, language, sense of humor, fears, and loves. The extracted brain tissue, useless outside its biological milieu, was banked in small containers. The empty half of Matthew's skull slowly filled up with cerebrospinal fluid, appearing in neuroimaging as a black void. In the recovery room, his parents drank hospital coffee and waited for Matthew to open his eyes. What would their son be like now? Who would he be with only half a brain? Excerpted from Livewired: The Inside Story of the Ever-Changing Brain by David Eagleman All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.

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