It beat its swords into plowshares. It altered its machinery to match the demands of the present.
Tokyo did what brains do.
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.
Why is that a good strategy for the brain? After all, human-built technology has been very successful, and we use an entirely different strategy there. We build fixed hardware devices with software programs to neatly accomplish what we need. What would be the advantage of melting the distinction between those layers so that the machinery is constantly redesigned by the running of the programs?
The first advantage is speed.6 You type rapidly on your laptop because you don’t have to think about the details of your fingers’ positions, aims, and goals. It all just proceeds on its own, seemingly magically, because typing has become part of your circuitry. By reconfiguring the neural wiring, tasks like this become automatized, allowing fast decisions and actions. Millions of years of evolution didn’t presage the arrival of written language, much less a keyboard, and yet our brains have no trouble taking advantage of the innovations.
Compare this with hitting the correct keys on a musical instrument you’ve never played before. For these sorts of untrained tasks, you rely on conscious thinking, and that is comparably quite slow. This speed difference between amateurism and expertise is why a leisure soccer player constantly has the ball stolen. In contrast, the experienced player reads the signals of his opponents, capers with fancy footwork, and shoots the ball with high precision. Unconscious actions are more rapid than conscious deliberation. Plows farm faster than swords.
The second advantage of specializing the machinery for important tasks is energy efficiency. The newbie soccer player simply doesn’t understand how all the movement of the field fits together, while the pro can manipulate the game play in multiple ways to score a goal. Whose brain is more active? You might guess it’s the high-scoring expert—because he understands the structure of the game and is zipping through possibilities, decisions, and intricate moves. But that would be the wrong guess. The expert’s brain has developed neural circuitry specific to soccer, allowing him to make his moves with surprisingly little brain activity. In a sense, the expert has made himself one with the game. In contrast, the amateur’s brain is on fire with activity. He’s trying to figure out which movements matter. He’s entertaining multiple interpretations of the situation and trying to determine which, if any, are correct.
As a result of burning soccer into the circuitry, the pro’s performance is both fast and efficient. He’s optimized his internal wiring for that which is important in his outside world.
AN EVER-CHANGING SYSTEM
The concept of a system that can be changed by external events—and keep its new shape—led the American psychologist William James to coin the term “plasticity.” A plastic object is one that can be shaped, and it can hold that shape. This is how the material we call plastic gets its name: we mold bowls, toys, and phones with it, and the material doesn’t melt uselessly back to its original form. And so it is with the brain: experience changes it, and it retains the change.
“Brain plasticity” (also called neuroplasticity) is the term we use in neuroscience. But I’ll use that term only sparingly in this book, because it sometimes risks missing the target. Whether intentionally or not, “plasticity” suggests that the key idea is to mold something once and keep it that way forever: to shape the plastic toy and never change it again. But that’s not what the brain does. It carries on remolding itself throughout your life.
Think of a developing city, and note the way it grows, optimizes, and responds to the world around it. Observe where the city builds its truck stops, how it crafts its immigration policies, how it modifies its education and legal systems. A city is always in flux. A city is not designed by urban planners and then immobilized like a plastic ornament. It incessantly develops.
Just like cities, brains never reach an end point. We spend our lives blossoming toward something, even as the target moves. Consider the feeling of stumbling on a diary entry that you wrote many years ago. It represents the thinking, opinions, and viewpoint of someone who was a bit different from who you are now, and that previous person can sometimes border on the unrecognizable. Despite having the same name and the same early history, in the years between inscription and interpretation the narrator has altered.
The word “plastic” can be stretched to fit this notion of ongoing change, and to keep ties to the existing literature I’ll use the term occasionally.7 But the days of being impressed by plastic molding may be past us. Our goal here is to understand how this living system operates, and for that I’ll coin a term that better captures the point: “livewired.” As we’ll see, it becomes impossible to think about the brain as divisible into layers of hardware and software. Instead, we’ll need the concept of liveware to grasp this dynamic, adaptable, information-seeking system.
To appreciate the power of a self-configuring organ, let’s return to Matthew’s story. After the removal of an entire hemisphere of his brain, he was incontinent, couldn’t walk, and couldn’t speak. His parents’ worst fears had materialized.
But with daily physical therapy and language therapy, he was slowly able to relearn language. His acquisition followed the same stages as an infant: first one word, then two, then small phrases.
Three months later, he was developmentally appropriate—right back where he was supposed to be.
Now, many years later, Matthew cannot use his right hand well, and he walks with a slight limp.8 But he otherwise lives a normal life with little indication that he’s been through such an extraordinary adventure. His long-term memory is excellent. He went to college for three semesters, but because of difficulty taking notes with his right hand, he quit to work at a restaurant. There he answers phones, takes care of customer service, serves dishes, and covers just about any job that needs to be done. People who meet him have no suspicion that he is missing half of his brain. As Valerie puts it, “If they didn’t know, they wouldn’t know.”
How could such a major neural obliteration go unnoticed?
Here’s how: the remainder of Matthew’s brain dynamically rewired to take over the missing functions. The blueprints of his nervous system adjusted themselves to occupy a smaller piece of real estate—encompassing the fullness of life with half the machinery. You couldn’t slice out half the electronics from your smartphone and hope to still make a call, because hardware is fragile. Liveware endures.
In 1596, the Flemish cartographer Abraham Ortelius pored over a map of the earth and had a revelation: the Americas and Africa looked as if they could fit together like puzzle pieces. The match seemed clear, but he had no good idea about what had “torn them apart.” By 1912, the German geophysicist Alfred Wegener conjectured the notion of continental drift: although the continents had previously been assumed to be immutable in their locations, perhaps they were floating around like mammoth lily pads. The drift is slow (continents waft at the same rate your fingernails grow), but a million-year movie of the globe would reveal the landmasses as part of a dynamic, flowing system, redistributing according to rules of heat and pressure.
Like the globe, the brain is a dynamic, flowing system, but what are its rules? The number of scientific papers on brain plasticity has bloomed into the hundreds of thousands. But even today, as we stare at this strange pink self-configuring material, there is no overarching
