Livewired: The Inside Story of the Ever-Changing Brain

The difference between predictions and outcomes is the key to understanding a strange property of learning: if you’re predicting perfectly, your brain doesn’t need to change further… Changes in the brain happen only when there’s a difference between what was expected and what actually happens.

So how does the massively complicated brain, with its eighty-six billion neurons, get built from such a small recipe book? The answer pivots on a clever strategy implemented by the genome: build incompletely and let world experience refine. Thus, for humans at birth, the brain is remarkably unfinished, and interaction with the world is necessary to complete it.

Dropping into the world with a half-baked brain has proven a winning strategy for humans. We have outcompeted every species on the planet: covering the landmass, conquering the seas, and bounding onto the moon. We have tripled our life spans. We compose symphonies, erect skyscrapers, and measure with ever-increasing precision the details of our own brains. None of those enterprises were genetically encoded. At least they weren't encoded directly. Instead, our genetics bring about a simple principle: don't build inflexible hardware; build a system that adapts to the world around it. Our DNA is not a fixed schematic for building an organism; rather, it sets up a dynamic system that continually rewrites it's circuitry to reflect the world around it and to optimize its efficacy within it.

The thrill of life is not about who we are but about who we are in the process of becoming.” “Dreams are the means by which the visual cortex prevents takeover.” Every man can, if he so desires, become the sculptor of his own brain. —SANTIAGO RAMÓN Y CAJAL (1852–1934), neuroscientist and Nobel laureate

Or that babies will mimic an adult sticking out her tongue, a feat requiring a sophisticated ability to translate vision into motor action.

If you’re missing the tool, create it.

the experiences and goals of a person are always reflected in the brain’s structure.

Brain circuitry comes to reflect what you do, and so the cortex of a highly trained musician morphs into something measurably different—in a way that you can see on brain imaging, even with an untrained eye. If you pay careful attention to a region of the motor cortex involved in hand movement, you’ll find something amazing: musicians have a puckering on their cortex where nonmusicians do not, shaped roughly like the Greek letter omega (Ω).4 The thousands of hours of practice on the instrument physically molds the brains of the musicians.

We’ve all heard of the Spidey sense: the tingling sensation by which Peter Parker detected trouble in the vicinity. Why not have a Tweety sense?

... So the basis of behavioral improvement is not simply the repeated performance of a task; it also requires neuromodulatory systems to encode relevance. Without acetylcholine, the ten thousand hours is wasted time.

The fact is that the future is hard to predict. Whatever the case, as we move toward the horizon, the only certainty is that we will increasingly choose our own plug-and-play peripheral devices. We are no longer a natural species who has to wait millions of years for Mother Nature's next sensory gift. Instead, like any good parent, Mother Nature has given us the cognitive capacity to go out and shape our own experience.

Several emerging companies, still in their infancy, hope to increase the speed of brain communication to the outside world by writing and reading neural data rapidly by means of direct plug-ins. The problem is not theoretical but practical. When an electrode is placed into the brain, the tissue slowly tries to push it out, in the same way that the skin of your finger pushes out a splinter. That's the small problem. The bigger one is that neurosurgeons don't want to perform the operations, because there is always the risk of infection or death on the operating table is the operating table. And beyond disease states (such as Parkinson's or severe depression), it's not clear that consumers will undergo an open-head surgery just for the joy of texting their friends more rapidly.

The answer is simply that you don’t know where the prosthetic leg is. Your good leg is streaming an enormous amount of data to the brain, telling about the position of your leg, how much the knee is bent, how much pressure is on the ankle, the tilt and twist of the foot, and so on. But with the prosthetic leg, there’s nothing but silence: the brain has no idea about the limb’s position.

especially as 87 percent of visually impaired people live in developing countries.