Neurology


Seeing with Your Tongue

The New Yorker

The climbers at Earth Treks gym, in Golden, Colorado, were warming up: stretching, strapping themselves into harnesses, and chalking their hands as they prepared to scale walls stippled with multicolored plastic holds. Seated off to one side, with a slim gray plastic band wrapped around his brow, Erik Weihenmayer was warming up, too--by reading flash cards. "I see an'E' at the end," he said, sweeping his head over the top card, from side to side and up and down. Weihenmayer moved triumphantly on to the next card. Erik Weihenmayer is the only blind person to have climbed Mt. He was born with juvenile retinoschisis, an inherited condition that caused his retinas to disintegrate completely by his freshman year of high school. Unable to play the ball games at which his father and his brothers excelled, he took to climbing after being introduced to it at a summer camp for the blind. He learned to pat the rock face with his hands or tap it with an ice axe to find his next hold, following the sound of a small bell worn by a guide, who also described the terrain ahead. With this technique, he has summited the tallest peaks on all seven continents.


Silicon Valley's Quest to Live Forever

The New Yorker

On a velvety March evening in Mandeville Canyon, high above the rest of Los Angeles, Norman Lear's living room was jammed with powerful people eager to learn the secrets of longevity. When the symposium's first speaker asked how many people there wanted to live to two hundred, if they could remain healthy, almost every hand went up. The venture capitalists were keeping slim to maintain their imposing vitality, the scientists were keeping slim because they'd read--and in some cases done--the research on caloric restriction, and the Hollywood stars were keeping slim because of course. When Liz Blackburn, who won a Nobel Prize for her work in genetics, took questions, Goldie Hawn, regal on a comfy sofa, purred, "I have a question about the mitochondria. I've been told about a molecule called glutathione that helps the health of the cell?" Glutathione is a powerful antioxidant that protects cells and their mitochondria, which provide energy; some in Hollywood call it "the God molecule." But taken in excess it can muffle a number of bodily repair mechanisms, leading to liver and kidney problems or even the rapid and potentially fatal sloughing of your skin. Blackburn gently suggested that a varied, healthy diet was best, and that no single molecule was the answer to the puzzle of aging. Yet the premise of the evening was that answers, and maybe even an encompassing solution, were just around the corner. The party was the kickoff event for the National Academy of Medicine's Grand Challenge in Healthy Longevity, which will award at least twenty-five million dollars for breakthroughs in the field. Victor Dzau, the academy's president, stood to acknowledge several of the scientists in the room. He praised their work with enzymes that help regulate aging; with teasing out genes that control life span in various dog breeds; and with a technique by which an old mouse is surgically connected to a young mouse, shares its blood, and within weeks becomes younger. Joon Yun, a doctor who runs a health-care hedge fund, announced that he and his wife had given the first two million dollars toward funding the challenge. "I have the idea that aging is plastic, that it's encoded," he said. "If something is encoded, you can crack the code." To growing applause, he went on, "If you can crack the code, you can hack the code!" It's a big ask: more than a hundred and fifty thousand people die every day, the majority of aging-related diseases. Yet Yun believes, he told me, that if we hack the code correctly, "thermodynamically, there should be no reason we can't defer entropy indefinitely. We can end aging forever." Nicole Shanahan, the founder of a patent-management business, announced that her company would oversee longevity-related patents that Yun had pledged to the cause.


Daniel Dennett's Science of the Soul

The New Yorker

Four billion years ago, Earth was a lifeless place. Nothing struggled, thought, or wanted. Seawater leached chemicals from rocks; near thermal vents, those chemicals jostled and combined. Some hit upon the trick of making copies of themselves that, in turn, made more copies. The replicating chains were caught in oily bubbles, which protected them and made replication easier; eventually, they began to venture out into the open sea. A new level of order had been achieved on Earth. The tree of life grew, its branches stretching toward complexity. Organisms developed systems, subsystems, and sub-subsystems, layered in ever-deepening regression. They used these systems to anticipate their future and to change it. When they looked within, some found that they had selves--constellations of memories, ideas, and purposes that emerged from the systems inside. They experienced being alive and had thoughts about that experience. They developed language and used it to know themselves; they began to ask how they had been made. This, to a first approximation, is the secular story of our creation. It has no single author; it's been written collaboratively by scientists over the past few centuries. If, however, it could be said to belong to any single person, that person might be Daniel Dennett, a seventy-four-year-old philosopher who teaches at Tufts. In the course of forty years, and more than a dozen books, Dennett has endeavored to explain how a soulless world could have given rise to a soulful one. His special focus is the creation of the human mind.


For the Golden State Warriors, Brain-Zapping Could Provide an Edge

The New Yorker

Though you couldn't tell from the picture, these particular headphones incorporated a miniature fakir's bed of soft plastic spikes above each ear, pressing gently into the skull and delivering pulses of electric current to the brain. Made by a Silicon Valley startup called Halo Neuroscience, the headphones promise to "accelerate gains in strength, explosiveness, and dexterity" through a proprietary technique called neuropriming. "Thanks to @HaloNeuro for letting me and my teammates try these out!" McAdoo tweeted. On Thursday night, McAdoo and his teammates will seek the eighty-ninth and final win of their record-breaking season, as they defend their National Basketball Association title in Game 6 of the final series against LeBron James's Cleveland Cavaliers. The headphones' apparent results, in other words, have been impressive.


The Mistrust of Science

The New Yorker

The following was delivered as the commencement address at the California Institute of Technology, on Friday, June 10th. If this place has done its job--and I suspect it has--you're all scientists now. Sorry, English and history graduates, even you are, too. Science is not a major or a career. It is a commitment to a systematic way of thinking, an allegiance to a way of building knowledge and explaining the universe through testing and factual observation.


Feel Me

The New Yorker

On a bitter, soul-shivering, damp, biting gray February day in Cleveland--that is to say, on a February day in Cleveland--a handless man is handling a nonexistent ball. Igor Spetic lost his right hand when his forearm was pulped in an industrial accident six years ago and had to be amputated. In an operation four years ago, a team of surgeons implanted a set of small translucent "interfaces" into the neural circuits of his upper arm. This afternoon, in a basement lab at a Veterans Administration hospital, the wires are hooked up directly to a prosthetic hand--plastic, flesh-colored, five-fingered, and articulated--that is affixed to what remains of his arm. The hand has more than a dozen pressure sensors within it, and their signals can be transformed by a computer into electric waves like those natural to the nervous system. Since, from the brain's point of view, his hand is still there, it needs only to be recalled to life. With the "stimulation" turned on--the electronic feed coursing from the sensors--Spetic feels nineteen distinct sensations in his artificial hand. Above all, he can feel pressure as he would with a living hand. "We don't appreciate how much of our behavior is governed by our intense sensitivity to pressure," Dustin Tyler, the fresh-faced principal investigator on the Cleveland project, says, observing Spetic closely. "We think of hot and cold, or of textures, silk and cotton. But some of the most important sensing we do with our fingers is to register incredibly minute differences in pressure, of the kinds that are necessary to perform tasks, which we grasp in a microsecond from the feel of the outer shell of the thing. We know instantly, just by touching, whether to gently squeeze the toothpaste or crush the can." With the new prosthesis, Spetic can sense the surface of a cherry in a way that allows him to stem it effortlessly and precisely, guided by what he feels, rather than by what he sees. Prosthetic hands like Spetic's tend to be super-strong, capable of forty pounds of pressure, so the risk of crushing an egg is real. The stimulation sensors make delicate tasks easy. Spetic comes into the lab every other week; the rest of the time he is busy pursuing a degree in engineering, which he has taken up while on disability.