On Looking: Eleven Walks With Expert Eyes (25 page)

This is the principle of plasticity of the brain: especially when we are young, our brains change depending upon what we are exposed to. Even in adults, the brain is always changing: the simple fact of learning something means that neural changes have occurred—if not as radically as in youth. A child who, in his first years of life, is unfortunate enough to lose an entire cerebral hemisphere, a half of a brain, due to tumor or other problem, will develop relatively
normally
. The other hemisphere simply takes over all the responsibilities of the lost one. By adulthood, though, a sudden loss of half a brain would mean the loss of impossibly many critical abilities, knowledge, and experience—and would be devastating. If it were the left hemisphere, for instance, the ability to understand language, use words, or write would likely be entirely wiped out, and the other hemisphere could not muster the forces to re-create them.

The baby born blind is (relatively) lucky: her brain will reorganize. With adults, the process is less dramatic. But even those who lose their vision as adults often pick up a heightened sensory ability or two. After he became blind as an adult, James Thurber continued to draw his famous long-faced hound dog, moving the pencil in a characteristic way between his fingers that let him trace its head without seeing what he was producing. He also had visual hallucinations: his visual system continued to think it was seeing something (including a blue Hoover vacuum, dancing brown spots and melting purple spots, and a couple of eight balls). All these images could well have informed his own whimsical writing and drawing.

Some blind people notice smells more vividly. Sacks writes of a doctor who became hyper-sensitive to the odors that we carry around with us. That would include body odor, certainly, but also the fragrances of the lotions or soaps or detergents that cling to us; and, for this doctor, even the odor we emit when anxious or
unhappy. The doctor felt that through smell he perceived others’ emotions more clearly than he had as a seeing person. This perceptual acuity is not just the realm of olfactory prodigies: with training, or simply attention, even the sighted can detect these smells. Might Gordon smell the lotion I spread on my face or the shampoo I lathered into my hair? Would people be olfactory curiosities or olfactorily offensive?

If she was vexed by the varieties of cosmetic scents we encountered in the elevator, Gordon did not let on. In fact, she told me she was sure she had
not
developed superhuman sensory powers with her blindness. Instead, she said, she simply used her senses better than she had before. But she belied this in the next breath. “. . . And a number of years later I also realized how much kinesthetic memory meant.”

We were heading outside. I hesitated on the stairs, trying to step out of the way of other residents in the entryway while staying close to Gordon, but she moved with confidence, freed of this visual clutter. Gordon was using a cane, and it promotes and expands a kinesthetic image of the world. Kinesthesia is one of our senses—one that works within our bodies, mapping where our limbs are in space. Sensory receptors on muscles and joints give feedback to the brain, mostly without our thinking about it. Kinesthetic memory is, thus, muscle memory. It is what was at work for me when I got on a bike after a dozen years of not being on bikes, or when my fingers roughly knew their way around that Chopin waltz I long ago could play on the piano. Though you often are not consciously aware of your kinesthetic ability, it is always with you. Should you find it easier to show someone where an object is, or demonstrate how to do something, rather than tell him, your kinesthetic ability is trumping even your linguistic ability.

At Gordon’s previous home, she explained, she navigated
the kitchen while cooking—or found a coordinated outfit in her well-organized closet—using this sense, her body’s sense of how it should move within the space of the kitchen or closet. Thus the reliability of everything being in the same place was crucial to her. After her kitchen was remodeled, shifting the placement of appliances and commonly used items, Gordon spent years reaching for the dish towel in the place where it used to hang. Her magnificent new top-of-the-line oven was functionally useless to Gordon: its interior was so cavernous that she would lose track of where the casserole was inside. In the old oven, it fit perfectly, and she knew the width and depth of that warm dark space.

When a compressed nerve led to some loss of feeling in her left hand, she became more aware, too, of how she used touch in her closet, “to feel the fabric, to know whether I was hitting a knit, or a silk, or a cotton.” Nonetheless, despite a reduced sense of touch, on the day we met, her clothes were impeccably coordinated. Even the color of her cane matched her outfit.

The cane was a long fiberglass number with a single colored stripe and a round ball at its tip. Gordon tentatively tapped the ground about two steps in front of her. She held my arm lightly and lingered a half step behind me. That way, “if we get to the edge of a cliff,” she suggested, “you’ll fall—but I won’t.” I accepted this deal.

As we progressed, I noticed that Gordon angled her head ever-so-slightly to the side, her ear leading her as much as her eyes. She was listening—for the cane, where it touched the world a step ahead of her. Cane work, as using a cane for navigation is called, is still a common skill taught to the visually impaired or blind. Though seeing-eye dogs get all the press, the “long cane” remains the most popular companion of the blind. Typically, users move the cane so that it traces a low arc in front of the body, touching down before the foot that is next to step forward. Approaching
more troublesome spots—doorways, curbs—the cane might be swept lightly across the ground. Variant techniques, learned through much practice, are employed for ascending stairs, descending stairs, and walking along a continuous wall.

As we slowly made our way down the street together, I saw how much holding a cane serves as a signal for others: it fairly shouts out that this person is to be navigated around. With my relatively inconspicuous injury temporarily hobbling me, I appreciated the usefulness of the neon sign signaling that this person must be treated differently. (I can imagine not wanting different treatment, too, but on a city sidewalk it seems salutary.) For the most part, pedestrians walking toward us abandoned the sidewalk jockeying game wherein two approaching people try to yield as little as possible to each other.

But the real utility of the cane is in what it conveys to its holder about the space she is approaching. It carries tactile information about the surface underfoot, whether grass or concrete, smooth or rocky. It locates holes, gradients, obstructions, even errant distracted texters (although rarely fast enough to avoid collision). But more than that, it conveys information via sound. The cane is the fiberglass version of an echolocating little brown bat: it sends out a sound—a tap—which then bounces around the environment. Listening, Gordon, with her ear trained to the bounced sound, could discriminate the sounds of the space not just underfoot, but above her head and to her side.

Dolphins and bats naturally echolocate, sending out high-frequency sounds and listening for the sounds to bounce back at them. The frequency of the reflected sound paints a picture of the objects in their environment. Amazingly, these animals do this in real time, using it to make their way with the speed of, well, dolphins and bats: incredibly fast. Humans, sighted or not, also have some ability to learn to do a kind of rudimentary echolocation,
using mechanical clickers, but we do not spend a lot of time flexing that muscle. Often, blind persons do. In some, this sensitivity is accompanied by an ability to hear the echoes of clicking sounds they produce themselves. With this skill, some can fluidly ride bikes and skateboard.

I became aware of Gordon’s auditory acuity as we walked along her street. A classic Upper West Side street in New York City, it houses various towering apartment buildings. One barely notices the difference among them from street level: the bottom floors are often lined with a similar limestone. Any characteristic brickwork, cornice, or grotesques on the building face needed distance to be appreciated. Along this stony monolith to our side, Gordon suddenly spoke up:

“Are we under an awning?”

We were not. Each of the buildings we were passing had an awning projecting over the sidewalk. It is in its shade that the building’s residents can wait for a taxi when it rains, or simply relax in the quasi-private transition from the city streets to home. But Gordon and I were not under an awning. We were, however, fast closing in on one.

“We’re about two feet from it,” I said, a little disappointed that she had gotten it wrong.

A moment later, we moved under it. With the warmth of the sun blocked temporarily from grilling our skin, even I, sighted and unobservant, could notice the change. The shade spoke relief for my arms and head.

“I sensed it,” Gordon said with satisfaction. “There was a big difference in the sound.”

Oh.
Oh!
The sound. The clap of her tapping cane bounced off and hit the underside of the awning, coming back at us muted, clipped. I could suddenly feel the closeness of the awning overhead, the way it broadened the sounds of our footfalls. A doorman
chatting with a tenant in a low tone was perfectly intelligible. This public space felt private, protected from the sounds of the city.

Three short steps later, we were out from under the awning’s shading reach, and noises again flew away into the open air. I asked Gordon if she could tell we had emerged. She took another step.

“
Now
we’re out.”

The awning Gordon perceived, I realized, was wider on either side than the awning I could see. This “sound” awning projected a good two or three feet more on both left and right: that was where the sound from the cane tap began to change. Gordon could see the awning. Hers was just a broader umbrella.

A professor of religion named John Hull, who lost vision in one of his eyes during his teens and in the other eye in his midlife, describes in his memoir how rain colors the landscape for him. With its “tapping” on everything in sight, it “throws a coloured blanket over previously invisible things,” Hull writes. “Instead of an intermittent and thus fragmented world, the steadily falling rain . . . presents the fullness of an entire situation all at once.” The lawn, the hill, the fence, the path, the bush are articulated by the pitter-patter of rain. Distances, variation, height, material, and curves all appear in splashes and drips.

This is how the cane does its canely magic. Gordon described
to me what she was hearing of the landscape from its echo off her cane tap. She heard when an alleyway appeared between buildings lining our route. She heard the height of buildings and noticed when we had arrived in front of a school (quieted in summertime) set back more deeply from the street. Inside her building, she told me, she uses the sound of the floors that present themselves when the elevator doors open to identify whether she has arrived at the basement gym or the penthouse. “In a carpeted room,” she added, “I’ll sometimes get lost. Because I can’t hear sounds.” A tap on the carpet bounces exactly nowhere.

In Gordon’s case, using the cane has changed her brain. Beyond “personal space,” the space around us that we discourage most other bodies from entering into, our brains are also alert to “peripersonal space,” the bubble of space outlined by and directly surrounding our bodies. The bubble extends to right about where our limbs can extend—so it is larger for people with longer arms, piano-player fingers, or legs up to there. Neuroscientists discovered cells in the brains of monkeys and humans that are specialized to fire to sounds, touch, and sights in this near space. Even with normal fingers and limbs, if you have ever sensed someone sneaking up behind you as you sat engaged in a book or a meal, you were experiencing your own peripersonal space. For even the sneakiest of persons creates small noises of movement and breath, emits ample odor, warms the air, and, with his body, changes the way sounds bounce around your head. We can feel his presence.

Wonderfully, our brain extends that bubble when we extend ourselves. Wear a top hat for a day and you will soon stop knocking it on low doorway lintels; after using chopsticks regularly, the brain begins to consider them extensions of your fingers. The brain of a baseball player experiences his bat as a continuation of his hands; the trumpeter’s trumpet is an adjunct of herself. And a
blind person experienced with using a cane has the athletes’ and musicians’ skill with it.

Your top-hat or chopstick bubble, though, lasts only as long as you wear the hat or eat your meal. The brain is plastic, and can creatively adapt to a new situation, but it changes right back when it no longer needs to be creative. In one study, researchers who blindfolded willing subjects for five days used fMRIs to show that the subjects’ visual centers (their occipital cortices) had begun to fire at non-visual stimulation, such as when feeling the bumps of Braille. A day after removing the blindfolds, their brains morphed back into their ordinary, non-Braille-reading shapes. The authors speculate that connections in the brain that already exist but lie dormant are simply unmasked with visual deprivation. In blind people, they suggest, these connections are what are exploited, temporarily and then indefinitely, to help them take advantage of that visual real estate.