YOUR BRAIN IS EVOLVING

All the bene cial choices you make are ways to evolve your brain. At a certain level, this is slow going; it took hundreds of millions of years for the most primitive animal brains to grow and develop into the spectacularly sophisticated human brain. In Darwinian terms, there is no other kind of evolution except this one, which depends on random mutations of genes over aeons of time. But we will argue that since people’s choices create new neural pathways and synapses, along with new brain cells, human beings undergo a second kind of evolution that rests upon personal choice. Driven by what you want out of life, your personal growth works by reshaping your brain. If you choose to grow and develop, you are guiding your own evolution.

Super brain is the product of conscious evolution. Biology fuses with the mind. Up to the time you were around age twenty, nature took care of your physical development, which happened more or less automatically. You didn’t choose to lose your baby teeth or learn to focus your eyes. But much else depended on the meeting of mind and genes. At three years old, most children are not ready to read. (An exceptional few are: a condition known as hyperlexia can bring on the ability to read before age two.) By age four or five, children are eager to read, and their brains are ready. A child discovers that black specks on a page mean something. Learning foreign languages also has its optimal age, which peaks in late adolescence.

Back when neuroscientists believed that the brain was xed and stable, learning wasn’t considered the same as evolution. But if the brain is changing as you learn, the two are synonymous. There was a news story recently about Timothy Doner, age sixteen, a high school student in New York City who decided to learn modern Hebrew in 2009, soon after his bar mitzvah. A tutor was hired, and the lessons went well. Timothy was discussing Israeli politics with his tutor, which led him to think about learning Arabic (considered one of the ve hardest languages on earth), so he attended a college summer course on it.

The newspaper account continues: “It took him four days to learn the alphabet, he said, a week to read uidly. Then he dived into Russian, Italian, Persian, Swahili, Indonesian, Hindi, Ojibwa, Pashto, Turkish, Hausa, Kurdish, Yiddish, Dutch, Croatian, and German, teaching himself mostly from grammar books and ash card applications on his iPhone.” Timothy began posting videos online in other languages; he soon gained an international fan club. He discovered that he was a polyglot, someone who has mastered a number of foreign languages. Beyond this stage are hyperpolyglots, people obsessed with learning dozens of tongues. “Timothy was inspired by a video of Richard Simcott, a British hyperpolyglot, speaking 16 languages in succession.”

That the pre x hyper, or “excessive,” appears so often in this book (hyperthymesia for memory, hyperlexia for reading, hyperpolyglots for foreign language learners) attests to the low norms that we still set for the brain. But there is no reason to regard exceptional performance as excessive, a word that implies something freakish if not disordered. Our view is that we could be evolving into a new norm higher than ever before. Conscious evolution leads to super brain, which isn’t freakish, disordered, or abnormal in any way. Black specks on a page would have ba ed our remote ancestors, but the brains of those early Homo sapiens were already evolved enough to permit language and reading. What they needed was time and the rise of cultures that would nourish language. What amazing things will we be doing routinely in the future, with essentially the same brain? Today we already lead lives of inconceivable complexity compared with people two generations ago.

Whose Face Is That?

The fact that Timothy could learn the fundamentals of a new language in a month, and even acquire a decent accent in Hindi or German, shows that the brain, when trained at the optimal time, can take a quantum leap with a skill that is already built into it. But what exactly has been built in? Science nds the answers one piece at a time, almost always as the result of a medical problem.

A striking example is face blindness, or prosopagnosia. Some soldiers returning home from World War II who had su ered head wounds failed to recognize their families’ faces, or anyone else’s. They could describe each feature precisely hair color, eyes, the shape of the nose but when asked at the end, “So, do you know who this is?” they answered with a baffled shake of the head.

At rst, scientists connected face blindness to traumatic injuries; eighteenth- and nineteenth-century doctors had long noted queer mental de cits in their patients. But over the next ve decades it emerged that face blindness can be a predisposition just over 2 percent of the population seem to have it. In extreme cases, you cannot recognize even your own face. (The noted neurologist Oliver Sacks, who has written a book on the subject, has revealed that he has prosopagnosia. One time he apologized for bumping into someone, only to discover that he was apologizing to his own re ection in a mirror!)

Through injury or genetics, people with face blindness are defective in the fusiform gyrus, a part of the temporal lobe that is connected to recognizing not just faces but also body shape, colors, and words. Oddly, it can take years before someone discovers that they have this defect. Using an excuse like “I’m bad with faces,” the person relies upon sensory cues, such as the sound of a friend’s voice, or the way he dresses, in place of actually recognizing his face. One man reported that when his best friend at work changed her haircut, he walked right past her as if she were a stranger.

Prosopagnosia would seem to be a cut-and-dried diagnosis, traceable to a small, precisely located area of the brain. It’s a well-documented fact that our brains are wired to allow us to recognize faces. Five visual patches in the back of the brain register sights unconsciously. For us to see them consciously, these signals must be relayed to the cerebral cortex in the front. When this circuitry doesn’t work properly, recognition is absent. (Another speci c patch allows you to recognize locations. When people have a defect there, they can describe a house in every detail but not recognize that they are standing in front of their own house.) Animals already possess the basic adaptation. Evolution has given them some incredible recognition abilities: Antarctic penguins returning home with food for their young can walk into a tightly packed ock of millions of birds and proceed directly to their own chick. (The standard explanation is that the parent has imprinted on the cry of its young, but other senses could be involved.) But there is another side to face blindness. Some people display the opposite ability—they are “super recognizers,” an as-yet-little-studied phenomenon.

Super recognizers remember almost every face they’ve ever encountered. They can go up to someone on the street to say, “Remember me? You sold me a pair of black shoes at Macy’s ten years ago.” Naturally, the person being accosted almost never remembers. So startling are such encounters that super recognizers have been accused of stalking— being followed is an easier explanation to accept. Nor does the passage of time fool super recognizers. When shown pictures of seven- or eight-year-olds who grew up to be Hollywood stars, a super recognizer will instantly know whose faces they are. When asked how she does it, one woman shrugged. “To me, a face growing old is just changing super cially, like going from brunette to blonde or getting a new hair style.” The deep wrinkles of an octogenarian don’t mask the similarities to the same person photographed for a school picture in third grade.

If face blindness is a brain defect, what is super recognition? To answer that, we would have to know how people recognize faces in the rst place. One thing we don’t do is use cues, the way people with face blindness do to compensate for their disorder. When you meet a woman of a certain age, you don’t go through a checklist of eyes, hair, nose, mouth, and then say, “Oh, it’s my mother.” You recognize her instantly an ability that goes back to the predisposition a baby has almost from birth. If mothers are special cases, that doesn’t make the mystery any easier. The brain forms complete pictures, known as gestalts, so biology underlies our ability to recognize faces all at once instead of one piece at a time.

The fact is that photons of light stimulating cells on the retina and signals being transmitted to the visual cortex carry no image. The optic nerve turns an image into a neural message that has no shape or luminosity. The information goes through at least ve or six steps of processing. Light and dark regions are sorted out, outlines are detected, patterns decoded, and so on. Recognition comes very near the end of the process. But when you say, “Oh, it’s my mother,” nobody has the slightest idea how your brain has recognized her. The six stages of processing don’t tell the story. Computer experts working in the eld of arti cial intelligence have tried to enable machines to recognize faces using various pattern cues. The results are rudimentary at best. If you see the photo of a familiar face that is slightly out of focus, you have no trouble knowing who it is, but even the smartest computer is stymied.

But if you take a photograph of a face and turn it upside down, you will lose the ability to recognize it, whether the face belongs to someone in your family, a celebrity, or even yourself. You can prove it to yourself by opening any celebrity magazine like

People and turning it upside down those famous faces will become indecipherable puzzles. But a computer built for facial recognition doesn’t care if the image is upside down or right side up. It can easily be programmed for either one. Why did evolution give us the potential for super recognition but not upside-down faces?

Our answer wouldn’t be brain speci c. We’d say that the mind doesn’t need upsidedown recognition of faces, so the brain never developed it. A Darwinian would consider such a statement absurd. In strict Darwinian terms, there is no mind, no guidance of evolution, no purpose nothing is inherited except through random mutations at the genetic level. It’s quixotic for Rudy, as a genetic researcher, to allow mind into the equation. But he is convinced that the brain grows and develops in accord with what the mind wants. As evidence, we point to the fast-changing picture of the mind-brain connection. If neuroplasticity proves that behavior and lifestyle choices can change the brain, it’s no great stretch to call this process evolutionary. As we evolve, variations slowly arise in our brains and genes.

At this stage of neuroscience, however, predisposition is a mixed picture with ba ing aspects. We no longer consider nature to be separate from nurture in human development. In some cases nature dominates—some music prodigies begin tapping out Bach fugues on the piano at age two. But music can also be learned, which is nurture. The camp that wants all predispositions to be genetic has only part of the truth on its side; the opposite camp, which demotes inborn talent, claiming that ten thousand hours of practice can duplicate the ability of a genius, also owns only half the truth.

Let’s go back to the polyglots who become xated on learning dozens of tongues. To learn language, human beings depend upon genes, along with such vaguely de ned traits as intelligence and attention; they also depend on nurture, which includes practice, necessary to train the brain in any new skill. But where do other necessary things fall, like patience, enthusiasm, passion, and even taking an interest? Must there be a gene for carving a cow out of butter for the Iowa state fair year after year? People develop very specific, even peculiar interests.

Far more mysterious is how a damaged or diseased brain can outperform a healthy one. That is the case with savant syndrome, now considered a form of autism but sometimes related to injury to the right temporal lobe. Those who su er from savant syndrome (they used to be called “idiot savants”) lack simple, everyday abilities but possess extraordinary ones. Musical savants, for example, can play on the piano any piece they’ve heard only once, including very complex classical music, even though they’ve never taken a piano lesson. Calendar savants can instantly tell you what day of the week any date falls on, including a date like January 23, 3323. There are language savants, too. One child su ering from this syndrome was unable to take care of himself or nd his way unaided on city streets. On his own, he had somehow managed to teach himself foreign languages from books, which wasn’t discovered until he got lost on a eld trip. His caregivers panicked but eventually located the boy, who was calmly translating for two strangers, one of whom spoke Chinese, the other Finnish. Like Arabic, these are two of the ve hardest languages on earth. Even more astonishing, the boy had learned Chinese with the textbook held upside down!

Spectacular examples like these can be daunting, but evolution is universal, open to all. The brain is unique among all bodily organs in being able to evolve personally, here and now. A ve-year-old learning to read is evolving, as viewed from the physiology of the brain; he is laying down new pathways to give physical reality to the words of a Mother Goose rhyme. The adult brain is evolving when a person learns to manage anger, y a jet, or develop compassion. The rich possibility of change demonstrates how evolution really works.