A NEUROLOGIST'S NOTEBOOK

THE MIND'S EYEWhat the blind see.

BY OLIVER SACKS

In his last letter, Goethe wrote, "The Ancientssaid that the animals are taught through theirorgans; let me add to this, so are men, but theyhave the advantage of teaching their organs inreturn." He wrote this in 1832, a time whenphrenology was at its height, and the brain wasseen as a mosaic of "little organs" subservingeverything from language to drawing ability toshyness. Each individual, it was believed, wasgiven a fixed measure of this faculty or that, ac-cording to the luck of his birth. Though we nolonger pay attention, as the phrenologists did, tothe "bumps" on the head (each of which, suppos-edly, indicated a brain-mind organ beneath), neu-rology and neuroscience have stayed close to theidea of brain fixity and localizationthe notion,in particular, that the highest part of the brain,the cerebral cortex, is effectively programmedfrom birth: this part to vision and visual proc-essing, that part to hearing, that to touch, and soon.This would seem to allow individuals littlepower of choice, of self-determination, let aloneof adaptation, in the event of a neurological orperceptual mishap.But to what extent are weour experiences,our reactionsshaped, predetermined, by ourbrains, and to what extent do we shape our ownbrains? Does the mind run the brain or the brainthe mindor, rather, to what extent does one runthe other? To what extent are we the authors, thecreators, of our own experiences? The effects ofa profound perceptual deprivation such as blind-ness can cast an unexpected light on this. Tobecome blind, especially later in life, presentsone with a huge, potentially overwhelming chal-lenge: to find a new way of living, of orderingones world, when the old way has been de-stroyed.A dozen years ago, I was sent an extraordinarybook called "Touching the Rock An Experience

of Blindness." The author, John Hull, was a pro-fessor of religious education who had grown upin Australia and then moved to England. Hullhad developed cataracts at the age of thirteen,and became completely blind in his left eye fouryears later. Vision in his right eye remained rea-sonable until he was thirty-five or so, and thenstarted to deteriorate. There followed a decade ofsteadily failing vision, in which Hull neededstronger and stronger magnifying glasses, andhad to write with thicker and thicker pens, until,in 1983, at the age of forty-eight, he becamecompletely blind."Touching the Rock" is the journal he dictatedin the three years that followed. It is full ofpiercing insights relating to Hulls life as a blindperson, but most striking for me is Hulls de-scription of how, in the years after his loss ofsight, he experienced a gradual attenuation ofvisual imagery and memory, and finally a virtualextinction of them (except in dreams)a statethat he calls "deep blindness."By this, Hull meant not only the loss of visualimages and memories but a loss of the very ideaof seeing, so that concepts like "here," "there,"and "facing" seemed to lose meaning for him,and even the sense of objects having "appear-ances," visible characteristics, vanished. At thispoint, for example, he could no longer imaginehow the numeral 3 looked, unless he traced it inthe air with his hand. He could construct a "mo-tor" image of a 3, but not a visual one.Hull, though at first greatly distressed about thefading of visual memories and imagesthe factthat he could no longer conjure up the faces ofhis wife or children, or of familiar and lovedlandscapes and placesthen came to accept itwith remarkable equanimity; indeed, to regard itas a natural response to a nonvisual world. Heseemed to regard this loss of visual imagery as aprerequisite for the full development, the height-

ening, of his other senses.Two years after becoming completely blind,Hull had apparently become so nonvisual as toresemble someone who had been blind frombirth. Hulls loss of visuality also reminded meof the sort of "cortical blindness" that can happenif the primary visual cortex is damaged, througha stroke or traumatic brain damagealthough inHulls case there was no direct damage to thevisual cortex but, rather, a cutting off from anyvisual stimulation or input.In a profoundly religious way, and in languagesometimes reminiscent of that of St. John of theCross, Hull enters into this state, surrenders him-self, with a sort of acquiescence and joy. Andsuch "deep" blindness he conceives as "anauthentic and autonomous world, a place of itsown. . . . Being a whole-body seer is to be in oneof the concentrated human conditions."Being a "whole-body seer," for Hull, meansshifting his attention, his center of gravity, to theother senses, and he writes again and again ofhow these have assumed a new richness andpower. Thus he speaks of how the sound of rain,never before accorded much attention, can nowdelineate a whole landscape for him, for itssound on the garden path is different from itssound as it drums on the lawn, or on the bushesin his garden, or on the fence dividing it from theroad. "Rain," he writes, "has a way of bringingout the contours of everything; it throws a col-oured blanket over previously invisible things;instead of an intermittent and thus fragmentedworld, the steadily falling rain creates continuityof acoustic experience . . . presents the fullnessof an entire situation all at once . . . gives a senseof perspective and of the actual relationships ofone part of the world to another."With his new intensity of auditory experience(or attention), along with the sharpening of hisother senses, Hull comes to feel a sense of inti-macy with nature, an intensity of being-in-the-world, beyond anything he knew when he wassighted. Blindness now becomes for him "a dark,paradoxical gift." This is not just "compensa-tion," he emphasizes, but a whole new order, anew mode of human being. With this he extri-cates himself from visual nostalgia, from thestrain, or falsity, of trying to pass as "normal,"and finds a new focus, a new freedom. Histeaching at the university expands, becomesmore fluent, his writing becomes stronger anddeeper; he becomes intellectually and spirituallybolder, more confident. He feels he is on solid

ground at last.What Hull described seemed to mean as-tounding example of how an individual deprivedof one form of perception could totally reshapehimself to anew center, a new identity. It is said that those who see normally as in-fants but then become blind within the first twoyears of life retain no memories of seeing, haveno visual imagery and no visual elements in theirdreams (and, in this way, are comparable tothose born blind). It is similar with those wholose hearing before the age of two: they have nosense of having "lost" the world of sound, norany sense of "silence," as hearing people some-times imagine. For those who lose sight so early,the very concepts of "sight" or "blindness" sooncease to have meaning, and there is no sense oflosing the world of vision, only of living fully ina world constructed by the other senses. But it seemed extraordinary to me that such anannihilation of visual memory as Hull describescould happen equally to an adult, with decades,an entire lifetime, of rich and richly categorizedvisual experience to call upon. And yet I couldnot doubt the authenticity of Hulls account,which he relates with the most scrupulous careand lucidity.

Important studies of adaptation in the brain werebegun in the nineteen seventies by, among oth-ers, Helen Neville, a cognitive neuroscientistnow working in Oregon. She showed that inprelingually deaf people (that is, those who hadbeen born deaf or become deaf before the age oftwo or so) the auditory parts of the brain had notdegenerated or atrophied. These had remainedactive and functional, but with an activity and afunction that were new: they had been trans-formed, "reallocated," in Nevilles term, forprocessing visual language. Comparable studiesin those born blind, or early blinded, show thatthe visual areas of the cortex, similarly, may bereallocated in function, and used to processsound and touch.With the reallocation of the visual cortex totouch and other senses, these can take on a hy-peracuity that perhaps no sighted person canimagine. Bernard Morin, the blind mathemati-cian who in the nineteen-sixties had shown howa sphere could be turned inside out, felt that hisachievement required a special sort of spatialperception and imagination. And a similar sort ofspatial giftedness has been central to the work ofGeerat Vermeij, a blind biologist who has been

able to delineate many new species of mollusk,based on tiny variations in the shapes and con-tours of their shells.Faced with such findings and reports, neurolo-gists began to concede that there might be a cer-tain flexibility or plasticity in the brain, at leastin the early years of life. But when this criticalperiod was over, it was assumed, the brain be-came inflexible, and no further changes of aradical type could occur. The experiences thatHull so carefully recounts give the lie to this. It isclear that his perceptions, his brain, did finallychange, in a fundamental way. Indeed, AlvaroPascual-Leone and his colleagues in Boston haverecently shown that, even in adult sighted vol-unteers, as little as five days of being blindfoldedproduces marked shifts to nonvisual forms ofbehavior and cognition, and they have demon-strated the physiological changes in the brain thatgo along with this. And only last month, Italianresearchers published a study showing thatsighted volunteers kept in the dark for as little asninety minutes may show a striking enhancementof tactile-spatial sensitivity.The brain, clearly, is capable of changing evenin adulthood, and I assumed that Hulls experi-ence was typical of acquired blindnessthe re-sponse, sooner or later, of everyone whobecomes blind, even in adult life.So when I came to publish an essay on Hullsbook, in 1991, I was taken aback to receive anumber of letters from blind people, letters thatwere often somewhat puzzled, and occasionallyindignant, in tone. Many of my correspondents,it seemed, could not identify with Hulls experi-ence, and said that they themselves, even dec-ades after losing their sight, had never lost theirvisual images or memories. One correspondent,who had lost her sight at fifteen, wrote, "Eventhough I am totally blind . . . I consider myself avery visual person. I still see objects in front ofme. As I am typing now I can see my hands onthe keyboard. . . . I dont feel comfortable in anew environment until I have a mental picture ofits appearance. I need a mental map for my inde-pendent moving, too."Had I been wrong, or at least onesided, in ac-cepting Hulls experience as a typical response toblindness? Had I been guilty of emphasizing onemode of response too strongly, oblivious to thepossibilities of radically different responses?

This feeling came to a head in 1996, when I re-ceived a letter from an Australian psychologist

named Zoltan Torey. Torey wrote to me notabout blindness but about a book he had writtenon the brain-mind problem and the nature ofconsciousness. (The book was published by Ox-ford University Press as "The Crucible of Con-sciousness," in 1999.) In his letter Torey alsospoke of how he had been blinded in an accidentat the age of twenty-one, while working at achemical factory, and how, although "advised toswitch from a visual to an auditory mode of ad-justment," he had moved in the opposite direc-tion, and resolved to develop instead his "innereye," his powers of visual imagery, to theirgreatest possible extent.In this, it seemed, he had been extremely suc-cessful, developing a remarkable power of gen-erating, holding, and manipulating images in hismind, so much so that he had been able to con-struct an imagined visual world that seemed al-most as real and intense to him as the perceptualone he had lostand, indeed, sometimes morereal, more intense, a sort of controlled dream orhallucination. This imagery, moreover, enabledhim to do things that might have seemed scarcelypossible for a blind man. "I replaced the entireroof guttering of my multi-gabled home single-handed," he wrote, "and solely on the strength ofthe accurate and well-focused manipulation ofmy now totally pliable and responsive mentalspace." (Torey later expanded on this episode,mentioning the great alarm of his neighbors atseeing a blind man, alone, on the roof of hishouseand, even more terrifying to them, atnight, in pitch darkness.)And it enabled him to think in ways that hadnot been available to him before, to envisagesolutions, models, designs, to project himself tothe inside of machines and other systems, and,finally, to grasp by visual thought and simulation(complemented by all the data of neuroscience)the complexities of that ultimate system, the hu-man brain-mind.When I wrote back to Torey, I suggested thathe consider writing another book, a more per-sonal one, exploring how his life had been af-fected by blindness, and how he had respondedto this, in the most improbable and seeminglyparadoxical of ways. "Out of Darkness" is thememoir he has now written, and in it Torey de-scribes his early memories with great visual in-tensity and humor. Scenes are remembered orreconstructed in brief, poetic glimpses of hischildhood and youth in Hungary before the Sec-ond World War: the sky-blue buses of Budapest,

the egg-yellow trams, the lighting of gas lamps,the funicular on the Buda side. He describes acarefree and privileged youth, roaming with hisfather in the wooded mountains above the Da-nube, playing games and pranks at school,growing up in a highly intellectual environmentof writers, actors, professionals of every sort.Toreys father was the head of a large motion-picture studio and would often give his sonscripts to read. "This," Torey writes, "gave methe opportunity to visualize stories, plots andcharacters, to work my imaginationa skill thatwas to become a lifeline and source of strengthin the years ahead."All of this came to a brutal end with the Nazioccupation, the siege of Buda, and then the So-viet occupation. Torey, now an adolescent, foundhimself passionately drawn to the big ques-tionsthe mystery of the universe, of life, andabove all the mystery of consciousness, of themind. In 1948, nineteen years old, and feelingthat he needed to immerse himself in biology,engineering, neuroscience, and psychology, butknowing that there was no chance of study, of anintellectual life, in Soviet Hungary, Torey madehis escape and eventually found his way to Aus-tralia, where, penniless and without connections,he did various manual jobs. In June of 1951,loosening the plug in a vat of acid at the chemi-cal factory where he worked, he had the accidentthat bisected his life. "The last thing I saw with complete claritywas a glint of light in the flood of acid that wasto engulf my face and change my life. It was anano-second of sparkle, framed by the black cir-cle of the drumface, less than a foot away. Thisas the final scene, the slender thread that ties meto my visual past." When it became clear that his corneas hadbeen hopelessly damaged and that he would haveto live his life as a blind man, he was advised torebuild his representation of the world on thebasis of hearing and touch and to "forget aboutsight and visualizing altogether. "But this wassomething that Torey could not or would not do.He had emphasized, in his first letter to me, theimportance of a most critical choice at this junc-ture: "I immediately resolved to find out how fara partially sense-deprived brain could go to re-build a life." Put this way, it sounds abstract, likean experiment. But in his book one senses thetremendous feelings underlying his resolu-tionthe horror of darkness, "the empty dark-ness," as Torey often calls it, "the grey fog that

was engulfing me," and the passionate desire tohold on to light and sight, to maintain, if only inmemory and imagination, a vivid and living vis-ual world. The very tide of his book says all this,and the note of defiance is sounded from thestart. Hull, who did not use his potential for im-agery in a deliberate way, lost it in two or threeyears, and became unable to remember whichway round a 3 went; Torey, on the other hand,soon became able to multiply four-figure num-bers by each other, as on a blackboard, visualiz-ing the whole operation in his mind, "painting"the suboperations in different colors.Well aware that the imagination (or the brain),unrestrained by the usual perceptual input, mayrun away with itself in a wildly associative orself-serving wayas may happen in deliria,hallucinations, or dreamsTorey maintained acautious and "scientific" attitude to his own vis-ual imagery, taking pains to check the accuracyof his images by every means available. "Ilearned," he writes, "to hold the image in a ten-tative way, conferring credibility and status on itonly when some information would tip the bal-ance in its favor." Indeed, he soon gained enoughconfidence in the reliability of his visual imageryto stake his life upon it, as when he undertookroof repairs by himself. And this confidence ex-tended to other, purely mental projects. He be-came able "to imagine, to visualize, for example,the inside of a differential gearbox in action as iffrom inside its casing. "I was able to watch thecogs bite, lock and revolve, distributing the spinas required. I began to play around with this in-ternal view in connection with mechanical andtechnical problems, visualizing how subcompo-nents relate in the atom, or in the living cell."This power of imagery was crucial, Toreythought, in enabling him to arrive at a solution ofthe brain-mind problem by visualizing the brain"as a perpetual juggling act of interacting rou-tines."In a famous study of creativity, the Frenchmathematician Jacques Hadamard asked manyscientists and mathematicians, including Ein-stein, about their thought processes. Einsteinreplied, "The physical entities which seem toserve as elements in thought are . . . more or lessclear images which can be voluntarily repro-duced and combined. [Some are] of visual andsome of muscular type. Conventional words orother signs have to be sought for laboriouslyonly in a secondary stage." Torey cites this, andadds, "Nor was Einstein unique in this respect.

Hadamard found that almost all scientists workthis way, and this was also the way my projectevolved."

Soon after receiving Toreys manuscript, I re-ceived the proofs of yet another memoir by ablind person: Sabriye Tenberkens "My PathLeads to Tibet." While Hull and Torey are think-ers, preoccupied in their different ways by in-wardness, states of brain and mind, Tenberken isa doer; she has travelled, often alone, all overTibet, where for centuries blind people havebeen treated as less than human and denied edu-cation, work, respect, or a role in the community.Virtually single-handed, Tenberken has trans-formed their situation over the past half-dozenyears, devising a form of Tibetan Braille, estab-lishing schools for the blind, and integrating thegraduates of these schools into their communi-ties.Tenberken herself had impaired vision almostfrom birth but was able to make out faces andlandscapes until she was twelve. As a child inGermany, she had a particular predilection forcolors, and loved painting, and when she was nolonger able to decipher shapes and forms shecould still use colors to identify objects. Ten-berken has, indeed, an intense synesthesia. "Asfar back as I can remember," she writes, "num-bers and words have instantly triggered colors inme. . . . The number 4, for example, [is] gold.Five is light green. Nine is vermillion. . . . Daysof the week as well as months have their colors,too. I have them arranged in geometrical forma-tions, in circular sectors, a little like a pie. WhenI need to recall on which day a particular eventhappened, the first thing that pops up on my in-ner screen is the days color, then its position inthe pie." Her synesthesia has persisted and beenintensified, it seems, by her blindness.Though she has been totally blind for twentyyears now, Tenberken continues to use all herother senses, along with verbal descriptions, vis-ual memories, and a strong pictorial and synes-thetic sensibility, to construct "pictures" oflandscapes and rooms, of environments andscenespictures so lively and detailed as to as-tonish her listeners. These images may some-times be wildly or comically different fromreality, as she relates in one incident when sheand a companion drove to Nam Co, the great saltlake in Tibet. Turning eagerly toward the lake,Tenberken saw, in her minds eye, "a beach ofcrystallized salt shimmering like snow under an

evening sun, at the edge of a vast body of tur-quoise water. . . . And down below, on the deepgreen mountain flanks, a few nomads werewatching their yaks grazing." But it then turnsout that she has been facing in the wrong direc-tion, not "looking" at the lake at all, and that shehas been "staring" at rocks and a gray landscape.These disparities dont faze her in the leastsheis happy to have so vivid a visual imagination.Hers is essentially an artistic imagination, whichcan be impressionistic, romantic, not veridical atall, where Torey s imagination is that of an engi-neer, and has to be factual, accurate down to thelast detail.

I had now read three memoirs, strikingly differ-ent in their depictions of the visual experience ofblinded people: Hull with his acquiescent de-scent into imageless "deep blindness," Toreywith his "compulsive visualization" and meticu-lous construction of an internal visual world, andTenberken with her impulsive, almost novelistic,visual freedom, along with her remarkable andspecific gift of synesthesia. Was there any suchthing, I now wondered, as a "typical" blind expe-rience?I recently met two other people blinded in adultlife who shared their experiences with me.Dennis Shulman, a clinical psychologist andpsychoanalyst who lectures on Biblical topics, isan affable, stocky, bearded man in his fifties whogradually lost his sight in his teens, becomingcompletely blind by the time he entered college.He immediately confirmed that his experiencewas unlike Hulls: "I still live in a visual worldafter thirty-five years of blindness. I have veryvivid visual memories and images. My wife,whom I have never seenI think of her visually.My kids, too. I see myself visuallybut it is as Ilast saw myself, when I was thirteen, though I tryhard to update the image. I often give publiclectures, and my notes are in Braille; but when Igo over them in my mind, I see the Braille notesvisuallythey are visual images, not tactile."Arlene Gordon, a charming woman in her sev-enties, a former social worker, said that thingswere very similar for her: "If I move my armsback and forth in front of my eyes, I see them,even though I have been blind for more thanthirty years." It seemed that moving her armswas immediately translated for her into a visualimage. Listening to talking books, she added,made her eyes tire if she listened too long; sheseemed to herself to be reading at such times, the

sound of the spoken words being transformed tolines of print on a vividly visualized book infront of her. This involved a sort of cognitiveexertion (similar perhaps to translating one lan-guage into another), and sooner or later thiswould give her an eye ache.I was reminded of Amy, a colleague who hadbeen deafened by scarlet fever at the age of ninebut was so adept a lipreader that I often forgotshe was deaf. Once, when I absent-mindedlyturned away from her as I was speaking, she saidsharply, "I can no longer hear you.""You mean you can no longer see me," I said."You may call it seeing," she answered, "but Iexperience it as hearing."Amy, though totally deaf, still constructed thesound of speech in her mind. Both Dennis andArlene, similarly, spoke not only of a heighten-ing of visual imagery and imagination since los-ing their eyesight but also of what seemed to be amuch readier transference of information fromverbal descriptionor from their own sense oftouch, movement, hearing, or smellinto a vis-ual form. On the whole, their experiencesseemed quite similar to Toreys, even thoughthey had not systematically exercised their pow-ers of visual imagery in the way that he had, orconsciously tried to make an entire virtual worldof sight.There is increasing evidence from neurosci-ence for the extraordinarily rich interconnected-ness and interactions of the sensory areas of thebrain, and the difficulty, therefore, of saying thatanything is purely visual or purely auditory, orpurely anything. This is evident in the very tidesof some recent papersPascual-Leone and hiscolleagues at Harvard now write of "The Meta-modal Organization of the Brain," and ShinsukeShimojo and his group at Caltech, who are alsoexploring intersensory perceptual phenomena,recently published a paper called "What You SeeIs What You Hear," and stress that sensory mo-dalities can never be considered in isolation. Theworld of the blind, of the blinded, it seems, canbe especially rich in such inbetween statestheintersensory, the metamodalstates for whichwe have no common language.

Arlene, like Dennis, still identifies herself inmany ways as a visual person. "I have a verystrong sense of color," she said. "I pick out myown clothes. I think, Oh, that will go with this orthat, once I have been told the colors." Indeed,she was dressed very smartly, and took obvious

pride in her appearance."I love travelling," she continued. "I sawVenice when I was there." She explained howher travelling companions would describe places,and she would then construct a visual imagefrom these details, her reading, and her own vis-ual memories. "Sighted people enjoy travellingwith me," she said. "I ask them questions, thenthey look, and see things they wouldnt other-wise. Too often people with sight dont see any-thing! Its a reciprocal processwe enrich eachothers worlds."If we are sighted, we build our own images,using our eyes, our visual information, so in-stantly and seamlessly that it seems to us we areexperiencing "reality" itself. One may need tosee people who are color-blind, or motion-blind,who have lost certain visual capacities fromcerebral injury, to realize the enormous act ofanalysis and synthesis, the dozens of subsystemsinvolved in the subjectively simple act of seeing.But can a visual image be built using nonvisualinformationinformation conveyed by the othersenses, by memory, or by verbal description?There have, of course, been many blind poetsand writers, from Homer on. Most of these wereborn with normal vision and lost their sight inboyhood or adulthood (like Milton). I lovedreading Prescotts "Conquest of Mexico" and"Conquest of Peru" as a boy, and feel that I firstsaw these lands through his intensely visual, al-most hallucinogenic descriptions, and I wasamazed to discover, years later, that Prescott notonly had never visited Mexico or Peru but hadbeen virtually blind since the age of eighteen.Did he, like Torey, compensate for his blindnessby developing such powers of visual imagerythat he could experience a "virtual reality" ofsight? Or were his brilliant visual descriptions ina sense simulated, made possible by the evoca-tive and pictorial powers of language? To whatextent can language, a picturing in words, pro-vide a substitute for actual seeing, and for thevisual, pictorial imagination? Blind children, ithas often been noted, tend to be precocious ver-bally, and may develop such fluency in the ver-bal description of faces and places as to leaveothers(and perhaps themselves) uncertain as towhether they are actually blind. Helen Kellerswriting, to give a famous example, startles onewith its brilliantly visual quality.

When I asked Dennis and Arlene whether theyhad read John Hulls book, Arlene said, "I was

stunned when I read it. His experiences are sounlike mine." Perhaps, she added, Hull had "re-nounced" his inner vision. Dennis agreed, butsaid, "We are only two individuals. You are go-ing to have to talk to dozens of people. . . . But inthe meanwhile you should read JacquesLusseyrans memoir." Lusseyran was a French Resistance fighterwhose memoir, "And There Was Light," dealsmostly with his experiences fighting the Nazisand later in Buchenwald but includes manybeautiful descriptions of his early adaptations toblindness. He was blinded in an accident whenhe was not quite eight years old, an age that hecame to feel was "ideal" for such an eventuality,for, while he already had a rich visual experienceto call on, "the habits of a boy of eight are notyet formed, either in body or in mind. His bodyis infinitely supple." And suppleness, agility,indeed came to characterize his response toblindness.Many of his initial responses were of loss, bothof imagery and of interests:

A very short time after I went blind I forgot thefaces of my mother and father and the faces ofmost of the people I loved. . . . I stopped caringwhether people were dark or fair, with blue eyesor green. I felt that sighted people spent toomuch time observing these empty things. . . . I nolonger even thought about them. People nolonger seemed to possess them. Sometimes inmy mind men and women appeared withoutheads or fingers.

This is similar to Hull, who writes, "Increas-ingly, I am no longer even trying to imaginewhat people look like. . . . I am finding it moreand more difficult to realize that people look likeanything, to put any meaning into the idea thatthey have an appearance." But then, while relinquishing the actual visualworld and many of its values and categories,Lusseyran starts to construct and to use animaginary visual world more like Toreys. This started as a sensation of light, a formless,flooding, streaming radiance. Neurological termsare bound to sound reductive in this almost mys-tical context. Yet one might venture to interpretthis as a "release" phenomenon, a spontaneous,almost eruptive arousal of the visual cortex, nowdeprived of its normal visual input. This is aphenomenon analogous, perhaps, to tinnitus orphantom limbs, though endowed here, by a de-

vout and precociously imaginative little boy,with some element of the supernal. But then, itbecomes clear, he does find himself in posses-sion of great powers of visual imagery, and notjust a formless luminosity.The visual cortex, the inner eye, having nowbeen activated, Lusseyrans mind constructed a"screen" upon which whatever he thought ordesired was projected and, if need be, manipu-lated, as on a computer screen. "This screen wasnot like a blackboard, rectangular or square,which so quickly reaches the edge of its frame,"he writes. "My screen was always as big as Ineeded it to be. Be cause it was nowhere in spaceit was everywhere at the same time. . . . Names,figures and objects in general did not appear onmy screen without shape, nor just in black andwhite, but in all the colors of the rainbow.Nothing entered my mind without being bathedin a certain amount of light. . . . In a few monthsmy personal world had turned into a paintersstudio." Great powers of visualization were crucial tothe young Lusseyran, even in something as non-visual (one would think) as learning Braille (hevisualizes the Braille dots, as Dennis does), andin his brilliant successes at school. They were noless crucial in the real, outside world. He de-scribes walks with his sighted friend Jean, andhow, as they were climbing together up the sideof a hill above the Seine Valley, he could say:

"Just look! This time were on top. . . . Youllsee the whole bend of the river, unless the sungets in your eyes!" Jean was startled, opened hiseyes wide and cried: "Youre right." This littlescene was often repeated between us, in a thou-sand forms.

"Every time someone mentioned an event,"Lusseyran relates, "the event immediately pro-jected itself in its place on the screen, which wasa kind of inner canvas. . . . Comparing my worldwith his, [Jean] found that his held fewer picturesand not nearly as many colors. This made himalmost angry. When it comes to that, he used tosay, which one of us two is blind?" It was his supernormal powers of visualizationand visual manipulationvisualizing peoplesposition and movement, the topography of anyspace, visualizing strategies for defense and at-tackcoupled with his charismatic personality(and seemingly infallible "nose" or "ear" for de-tecting falsehood, possible traitors), which later

made Lusseyran an icon in the French Resis-tance. Dennis, earlier, had spoken of how the height-ening of his other senses had increased his sensi-tivity to moods in other people, and to the mostdelicate nuances in their speech and self-presentation. He could now recognize many ofhis patients by smell, he said, and he could oftenpick up states of tension or anxiety which theymight not even be aware of. He felt that he hadbecome far more sensitive to others emotionalstates since losing his sight, for he was no longertaken in by visual appearances, which most peo-ple learn to camouflage. Voices and smells, bycontrast, he felt, could reveal peoples depths. Hehad come to think of most sighted people, hejoked, as "visually dependent." In a subsequent essay, Lusseyran inveighsagainst the "despotism," the "idol worship" ofsight, and sees the "task" of blindness as re-minding us of our other, deeper modes of per-ception and their mutuality. "A blind person hasa better sense of feeling, of taste, of touch," hewrites, and speaks of these as "the gifts of theblind." And all of these, Lusseyran feels, blendinto a single fundamental sense, a deep atten-tiveness, a slow, almost prehensile attention, asensuous, intimate being at one with the worldwhich sight, with its quick, flicking, facile qual-ity, continually distracts us from. This is veryclose to Hulls concept of "deep blindness" asinfinitely more than mere compensation but aunique form of perception, a precious and specialmode of being.

What happens when the visual cortex is nolonger limited, or constrained, by any visual in-put? The simple answer is that, isolated from theoutside, the visual cortex becomes hypersensitiveto internal stimuli of all sorts: its own autono-mous activity; signals from other brain ar-easauditory, tactile, and verbal areas; and thethoughts and emotions of the blinded individual.Sometimes, as sight deteriorates, hallucinationsoccurof geometrical patterns, or occasionallyof silent, moving figures or scenes that appearand disappear spontaneously, without any rela-tion to the contents of consciousness, or inten-tion, or context. Something perhaps akin to this is described byHull as occurring almost convulsively as he waslosing the last of his sight. "About a year after Iwas registered blind," he writes, "I began to havesuch strong images of what peoples faces

looked like that they were almost like hallucina-tions."These imperious images were so engrossing asto preempt consciousness: "Sometimes," Hulladds, "I would become so absorbed in gazingupon these images, which seemed to come andgo without any intention on my part, that I wouldentirely lose the thread of what was being said tome. I would come back with a shock . . . and Iwould feel as if I had dropped off to sleep for afew minutes in front of the wireless." Thoughrelated to the context of speaking with people,these visions came and went in their own way,without any reference to his intentions, conjuredup not by him but by his brain.The fact that Hull is the only one of the fourauthors to describe this sort of release phenome-non is perhaps an indication that his visual cortexwas starting to escape from his control. One hasto wonder whether this signalled its impendingdemise, at least as an organ of useful visual im-agery and memory. Why this should have oc-curred with him, and how common such a courseis, is something one can only speculate on.Torey, unlike Hull, clearly played a very activerole in building up his visual imagery, took con-trol of it the moment the bandages were takenoff, and never apparently experienced, or al-lowed, the sort of involuntary imagery Hull de-scribes. Perhaps this was because he was alreadyvery at home with visual imagery, and used tomanipulating it in his own way. We know thatTorey was very visually inclined before his acci-dent, and skilled from boyhood in creating visualnarratives based on the film scripts his fathergave him. We have no such information aboutHull, for his journal entries start only when hehas become blind.For Lusseyran and Tenberken, there is anadded physiological factor: both were attractedto painting, in love with colors, and strongly sy-nestheticprone to visualizing numbers, letters,words, music, etc., as shapes and colorsbeforebecoming blind. They already had an overcon-nectedness, a "cross talk" between the visualcortex and other parts of the brain primarily con-cerned with language, sound, and music. Givensuch a neurological situation (synesthesia is con-genital, often familial), the persistence of visualimagery and synesthesia, or its heightening,might be almost inevitable in the event of blind-ness.Torey required months of intense cognitivediscipline dedicated to improving his visual im-

agery, making it more tenacious, more stable,more malleable, whereas Lusseyran seemed todo this almost effortlessly from the start. Perhapsthis was aided by the fact that Lusseyran was notyet eight when blinded (while Torey was twenty-one), and his brain was, accordingly, more plas-tic, more able to adapt to a new and drastic con-tingency.But adaptability does not end with youth. It isclear that Arlene, becoming blind in her forties,was able to adapt in quite radical ways, too, de-veloping not exactly synesthesia but somethingmore flexible and useful: the ability to "see" herhands moving before her, to "see" the words ofbooks read to her, to construct detailed visualimages from verbal descriptions. Did she adapt,or did her brain do so? One has a sense that To-reys adaptation was largely shaped by consciousmotive, will, and purpose; that Lusseyrans wasshaped by overwhelming physiological disposi-tion; and that Arlenes lies somewhere in be-tween. Hulls, meanwhile, remains enigmatic. There has been much recent work on the neu-ral bases of visual imagerythis can be investi-gated by brain imaging of various types (PETscanning, functional MRIs, etc.)and it is nowgenerally accepted that visual imagery activatesthe cortex in a similar way, and with almost thesame intensity, as visual perception itself. Andyet studies on the effects of blindness on the hu-man cortex have shown that functional changesmay start to occur in a few days, and can becomeprofound as the days stretch into months oryears.Torey, who is well aware of all this research,attributes Hulls loss of visual imagery andmemory to the fact that he did not struggle tomaintain it, to heighten and systematize and useit, as Torey himself did. (Indeed, Torey ex-presses horror at what he regards as Hulls pas-sivity, at his letting himself slide into deepblindness.) Perhaps Torey was able to stave offan otherwise inevitable loss of neuronal functionin the visual cortex; but perhaps, again, suchneural degeneration is quite variable, irrespectiveof whether or not there is conscious visualiza-tion. And, of course, Hull had been losing visiongradually for many years, whereas for Toreyblindness was instantaneous and total. It wouldbe of great interest to know the results of brainimaging in the two men, and indeed to look at alarge number of people with acquired blindness,to see what correlations, what predictions couldbe made.

But what if their differences reflect an underly-ing predisposition independent of blindness?What of visual imagery in the sighted? I first became conscious that there could behuge variations in visual imagery and visualmemory when I was fourteen or so. My motherwas a surgeon and comparative anatomist, and Ihad brought her a lizards skeleton from school.She gazed at this intently for a minute, turning itround in her hands, then put it down and withoutlooking at it again did a number of drawings ofit, rotating it mentally by thirty degrees eachtime, so that she produced a series, the lastdrawing exactly the same as the first. I could notimagine how she had done this, and when shesaid that she could "see" the skeleton in her mindjust as clearly and vividly as if she were lookingat it, and that she simply rotated the imagethrough a twelfth of a circle each time, I felt be-wildered, and very stupid. I could hardly seeanything with my minds eyeat most, faint,evanescent images over which I had no control.I did have vivid images as I was falling asleep,and in dreams, and once when I had a high fe-verbut otherwise I saw nothing, or almostnothing, when I tried to visualize, and had greatdifficulty picturing anybody or anything. Coinci-dentally or not, I could not draw for toffee.My mother had hoped I would follow in herfootsteps and become a surgeon, but when sherealized how lacking in visual powers I was (andhow clumsy, lacking in mechanical skill, too)she resigned herself to the idea that I would haveto specialize in something else.I was, however, to get a vivid idea of whatmental imagery could be like when, during thenineteen-sixties, I had a period of experimentingwith large doses of amphetamines. These canproduce striking perceptual changes, includingdramatic enhancements of visual imagery andmemory (as well as heightenings of the othersenses, as I describe in "The Dog Beneath theSkin," a story in "The Man Who Mistook HisWife for a Hat"). For a period of two weeks orso, I found that I could do the most accurateanatomical drawings. I had only to look at apicture or an anatomical specimen, and its imagewould remain both vivid and stable, and I couldeasily hold it in my mind for hours. I couldmentally project the image onto the paper beforemeit was as clear and distinct as if projectedby a camera lucidaand trace its outlines with apencil. My drawings were not elegant, but they

were, everyone agreed, very detailed and accu-rate, and could bear comparison with some of thedrawings in our neuroanatomy textbook. Thisheightening of imagery attached to everythingIhad only to think of a face, a place, a picture, aparagraph in a book to see it vividly in my mind.But when the amphetamine-induced state faded,after a couple of weeks, I could no longer visu-alize, no longer project images, no longerdrawnor have I been able to do so in the dec-ades since.

A few months ago, at a medical conference inBoston, I spoke of Toreys and Hulls experi-ences of blindness, and of how "enabled" Toreyseemed to be by the powers of visualization hehad developed, and how "disabled" Hull wasinsome ways, at leastby the loss of his powers ofvisual imagery and memory. After my talk, aman in the audience came up to me and askedhow well, in my estimation, sighted people couldfunction if they had no visual imagery. He wenton to say that he had no visual imagery what-ever, at least none that he could deliberatelyevoke, and mat no one in his family had any,either. Indeed, he had assumed this was the casewith everyone, until he came to participate insome psychological tests at Harvard and realizedthat he apparently lacked a mental power that allthe other students, in varying degrees, had."And what do you do?" I asked him, wonder-ing what this poor man could do."I am a surgeon," he replied. "A vascular sur-geon. An anatomist, too. And I design solar pan-els."But how, I asked him, did he recognize whathe was seeing?"Its not a problem," he answered. "I guessthere must be representations or models in thebrain that get matched up with what I am seeingand doing. But they are not conscious. I cannotevoke them."This seemed to be at odds with my mothersexperienceshe, clearly, did have extremelyvivid and readily manipulable visual imagery,though (it now seemed) this may have been abonus, a luxury, and not a prerequisite for hercareer as a surgeon.Is this also the case with Torey? Is his greatlydeveloped visual imagery, though dearly asource of much pleasure, not as indispensable ashe takes it to be? Might he, in fact, have doneeverything he did, from carpentry to roof repairto making a model of the mind, without any con-

scious imagery at all? He himself raises thisquestion.

The role of mental imagery in thinking was ex-plored by Francis Galton, Darwins irrepressiblecousin, who wrote on subjects as various as fin-gerprints, eugenics, dog whistles, criminality,twins, visionaries, psychometric measures, andhereditary genius. His inquiry into visual im-agery took the form of a questionnaire, with suchquestions as "Can you recall with distinctness thefeatures of all near relations and many other per-sons? Can you at will cause your mental image .. . to sit, stand, or turn slowly around? Can you . .. see it with enough distinctness to enable you tosketch it leisurely (supposing yourself able todraw)?" The vascular surgeon would have beenhopeless on such testsindeed, it was questionssuch as these which had floored him when hewas a student at Harvard. And yet, finally, howmuch had it mattered?As to the significance of such imagery, Galtonis ambiguous and guarded. He suggests, in onebreath, that "scientific men, as a class, have fee-ble powers of visual representation" and, in an-other, that "a vivid visualizing faculty is of muchimportance in connection with the higher proc-esses of generalized thoughts." He feels that "it isundoubtedly the fact that mechanicians, engi-neers and architects usually possess the facultyof seeing mental images with remarkable clear-ness and precision," but goes on to say, "I am,however, bound to say, that the missing facultyseems to be replaced so serviceably by othermodes of conception . . . that men who declarethemselves entirely deficient in the power ofseeing mental pictures can nevertheless givelifelike descriptions of what they have seen, andcan otherwise express themselves as if they weregifted with a vivid visual imagination. They canalso become painters of the rank of Royal Aca-demicians." I have a cousin, a professional ar-chitect, who maintains that he cannot visualizeanything whatever. "How do you think?" I onceasked him. He shook his head and said, "I dontknow." Do any of us, finally, know how wethink?When I talk to people, blind or sighted, orwhen I try to think of my own internal represen-tations, I find myself uncertain whether words,symbols, and images of various types are theprimary tools of thought or whether there areforms of thought antecedent to all of these, formsof thought essentially amodal. Psychologists

have sometimes spoken of "interlingua" or"mentalese," which they conceive to be thebrains own language, and Lev Vygotsky, thegreat Russian psychologist, used to speak of"thinking in pure meanings." I cannot decidewhether this is nonsense or profound truthit isthis sort of reef I end up on when I think aboutthinking.

Galtons seemingly contradictory statementsabout imageryis it antithetical to abstractthinking, or integral to it?may stem from hisfailure to distinguish between fundamentallydifferent levels of imagery. Simple visual im-agery such as he describes may suffice for thedesign of a screw, an engine, or a surgical opera-tion, and it may be relatively easy to model theseessentially reproductive forms of imagery or tosimulate them by constructing video games orvirtual realities of various sorts. Such powersmay be invaluable, but there is something pas-sive and mechanical and impersonal about them,which makes them utterly different from thehigher and more personal powers of the imagi-nation, where there is a continual struggle forconcepts and form and meaning, a calling uponall the powers of the self. Imagination dissolves

and transforms, unifies and creates, while draw-ing upon the "lower" powers of memory andassociation. It is by such imagination, such "vi-sion," that we create or construct our individualworlds.At this level, one can no longer say of onesmental landscapes what is visual, what is audi-tory, what is image, what is language, what isintellectual, what is emotionalthey are allfused together and imbued with our own indi-vidual perspectives and values. Such a unifiedvision shines out from Hulls memoir no lessthan from Toreys, despite the fact that one hasbecome "non-visual" and the other "hyper-visual." What seems at first to be so decisive adifference between the two men is not, finally, aradical one, so far as personal development andsensibility go. Even though the paths they havefollowed might seem irreconcilable, both menhave "used" blindness (if one can employ such aterm for processes which are deeply mysterious,and far below, or above, the level of conscious-ness and voluntary control) to release their owncreative capacities and emotional selves, andboth have achieved a rich and full realization oftheir own individual worlds.

48-59THE NEW YORKER, JULY 28, 2003