On the Move: A Life

by Oliver Sacks

  In 2011, Ralph died, far too young, from brain cancer, at the age of fifty-two. I miss him deeply, but like so many of my friends’ and mentors’ his voice has become an integral part of my thinking.

  —

  In 1953, while I was at Oxford, I read Watson and Crick’s famous “double helix” letter when it was published in Nature. I would like to say that I immediately saw its tremendous significance, but this was not the case for me, nor indeed for most people at the time.

  It was only in 1962, when Crick came to San Francisco and spoke at Mount Zion Hospital, that I started to realize the vast implications of the double helix. Crick’s talk was not on the configuration of DNA but on the work he had been doing with the molecular biologist Sydney Brenner to determine how the sequence of DNA bases could specify the amino acid sequence in proteins. They had just shown, after four years of intense work, that the translation involved a three-nucleotide code. This was itself a discovery no less momentous than the discovery of the double helix.

  But clearly Crick had already moved on to other things. There were, he intimated in his talk, two great enterprises whose exploration lay in the future: understanding the origin and nature of life, and understanding the relation of brain and mind—in particular, the biological basis of consciousness. Did he have any inkling, when he spoke to us in 1962, that these would be the very subjects he himself would address in the years to come, once he had “dealt with” molecular biology, or at least taken it to the stage where it could be delegated to others?

  In 1979, Crick published “Thinking About the Brain,” an article in Scientific American which, in a sense, legitimated the study of consciousness in neuroscientific terms; prior to this, the question of consciousness was felt to be irretrievably subjective, and therefore inaccessible to scientific investigation.

  A few years later, I met him at a 1986 conference in San Diego. There was a big crowd, full of neuroscientists, but when it was time for dinner, Crick singled me out, seized me by the shoulders, and sat me down next to him, saying, “Tell me stories!” In particular, he wanted stories of how vision might be altered by brain damage or disease.

  I have no memory of what we ate, or anything else about the dinner, only that I told him stories about many of my patients and that each one set off bursts of hypotheses and suggestions for further investigation in his mind. Writing to him a few days later, I said that the experience was “a little like sitting next to an intellectual nuclear reactor…. I never had a feeling of such incandescence.” He was fascinated when I told him about Mr. I. and also when I told him how a number of my patients had experienced, in the few minutes of a migraine aura, a flickering of static, “frozen” images in place of their normal, continuous visual perception. He asked me whether such “cinematic vision,” as I called it, was ever a permanent condition or one that could be elicited in a predictable way so that it could be investigated. (I said I did not know.)

  —

  During 1986, I spent a good deal of time with Mr. I., and in January of 1987 I wrote to Crick, “I have now written up a longish report on my patient…. Only in the actual writing did I come to see how color might indeed be a (cerebro-mental) construct.”

  I had spent most of my professional life wedded to notions of “naive realism,” regarding visual perceptions, for example, as mere transcriptions of retinal images; this “positivist” view was the dominant one in my Oxford days. But now, as I worked with Mr. I., this was giving way to a very different vision of the brain-mind, a vision of it as essentially constructive or creative. I added that I had now started to wonder whether all perceptual qualities, including the perception of motion, were similarly constructed by the brain.2

  I mentioned in my letter that I was working on Mr. I.’s case with my ophthalmologist friend Bob Wasserman and with Ralph Siegel, who had designed and conducted a variety of psychophysical experiments with our patient. I mentioned that Semir Zeki too had seen Mr. I. and tested him.

  At the end of October in 1987, I was able to send Crick “The Case of the Colorblind Painter,” a paper that Bob Wasserman and I had written for The New York Review of Books, and early in January of 1988 I got a response from Crick—an absolutely stunning letter: five pages of single-spaced typing, minutely argued and bursting with ideas and suggestions, some of which, he said, were “wild speculation.” He wrote:

  Thank you so much for sending me your fascinating article on the color-blind artist…. Even though, as you stress in your letter, it is not strictly a scientific article, nevertheless it has aroused much interest among my colleagues and my scientific and philosophical friends here. We have had a couple of group sessions on it and in addition I have had several further conversations with individuals.

  He added that he had sent a copy of the article and his letter to David Hubel, who, with Torsten Wiesel, had done pioneering work on the cortical mechanisms of visual perception. I was very excited to think that Crick was opening our paper, our “case,” for discussion in this way. It gave me a deeper sense of science as a communal enterprise, of scientists as a fraternal, international community, sharing and thinking on each other’s work, and of Crick himself as a sort of hub, in touch with everyone in this neuroscientific world.

  “Of course the most interesting feature,” Crick wrote:

  is Mr. I.’s loss of the subjective sense of color, together with its absence in his eidetic imagination and in his dreams. This clearly suggests that a crucial part of the apparatus needed for these latter two phenomena is also needed for color perception. At the same time, his memory for color names and color associations remained completely intact.

  He went on to carefully summarize a number of papers by Margaret Livingstone and David Hubel outlining their theory of three stages in early visual processing and speculated that Mr. I. had sustained damage at one of these levels (the “blob system” in V1), where cells would be particularly sensitive to lack of oxygen (perhaps caused by a small stroke or even carbon monoxide poisoning).

  “Do please excuse the length of this letter,” he concluded. “We might talk about it over the phone, after you’ve had time to digest it all.”

  Bob, Ralph, and I were all mesmerized by Crick’s letter. It seemed to get deeper and more suggestive every time we read it, and we got the sense that it would need a decade or more of work to follow up on the torrent of suggestions Crick had made.

  Contacting me again a few weeks later, Crick mentioned two of Antonio Damasio’s cases: in one of these, the patient had lost color imagery but still dreamed in color. (She later regained her color vision.)

  And he wrote:

  So glad to…learn that you plan more work on Mr. I. All the things you mention are important, especially the scans…. There is no consensus yet among my friends about what the damage might be in such cases of cerebral achromatopsia. I have (very tentatively) suggested the V1 blobs plus some subsequent degeneration at higher levels, but this really depends on seeing little in the scans (if most of V4 is knocked out you should see something). David Hubel tells me that he favors damage to V4, though this opinion is preliminary. David van Essen tells me that he suspects some area further upstream.

  “I think the moral of all this,” Crick concluded, “is that only careful and extensive psychophysics on [such] a patient plus accurate localization of the damage will help us. (So far, we cannot see how to study visual imagery and dreams in a monkey.)”

  —

  In August of 1989, Crick wrote to me, “At the moment I am trying to come to grips with visual awareness, but so far it remains as baffling as ever.” He enclosed the manuscript of a paper called “Towards a Neurobiological Theory of Consciousness,” one of the first synoptic articles to come out of his collaboration with Christof Koch at Caltech. I felt very privileged to see this manuscript, in particular their carefully laid-out argument that an ideal way of entering this seemingly inaccessible subject would be through exploring disorders of visual perception.

  Crick a
nd Koch’s paper was aimed at neuroscientists and covered a vast range in a few pages; it was sometimes dense and highly technical. But I knew that Crick could also write in a very accessible and witty and personable way; this was especially evident in his two earlier books, Life Itself and Of Molecules and Men. So I now entertained hopes that he might give a more popular and accessible form to his neurobiological theory of consciousness, enriched with clinical and everyday examples. (He did this in his 1994 book, The Astonishing Hypothesis.)

  —

  In June of 1994, Ralph and I met Crick for dinner in New York. The talk ranged in all directions. Ralph talked about his current work with visual perception in monkeys and his thoughts on the fundamental role of chaos at the neuronal level; Francis spoke about his expanding work with Christof Koch and their latest theories about the neural correlates of consciousness; and I spoke about my upcoming visit to Pingelap, with its scores of people—nearly 10 percent of the population—born completely colorblind. I planned to travel there with Bob Wasserman and Knut Nordby, a Norwegian perceptual psychologist who, like the Pingelapese, had been born without color receptors in his retinas.

  In February of 1995, I sent Francis a copy of An Anthropologist on Mars, which had just been published and contained an expanded version of “The Case of the Colorblind Painter,” much amplified, in part, through my discussions with him on the case. I also told him something of my experiences in Pingelap and how Knut and I tried to imagine what changes might have occurred in his brain in response to his achromatopsia. In the absence of any color receptors in his retinas, would the color-constructing centers in his brain have atrophied? Would they have been reallocated for other visual functions? Or were they, perhaps, still awaiting an input, an input that might be provided by direct electrical or magnetic stimulation? And if this could be done, would he, for the first time in his life, see color? Would he know it was color, or would this visual experience be too novel, too confounding, to categorize? Questions like these, I knew, would fascinate Francis too.

  Francis and I continued to correspond on various subjects. I wrote to him at length about the patient whom I called Virgil, whose sight was restored after a lifetime of blindness, and I wrote to him with thoughts about sign language and the reallocation of auditory cortex in deaf signers. And I often carried on a sort of mental dialogue with him whenever puzzling problems came up with regard to visual perception or awareness. What, I would wonder, would Francis think of this—how would he attempt to explain it? How would he investigate it?

  —

  Francis’s nonstop creativity—the incandescence that struck me when I first met him in 1986, allied to the way in which he always looked forward, saw years or decades of work ahead for himself and others—made one think of him as immortal. Indeed, well into his eighties, he continued to pour out a stream of brilliant and provocative papers, showing none of the fatigue, or fallings off, or repetitions of old age. It was in some ways a shock, therefore, early in 2003, to learn that he had run into serious medical problems. Perhaps this was in the back of my mind when I wrote to him in May of 2003, but it was not the main reason why I wanted to make contact with him again.

  I had found myself thinking of time—time and perception, time and consciousness, time and memory, time and music, time and movement. I had returned, in particular, to the question of whether the apparently continuous passage of time and movement given to us by our eyes was an illusion—whether in fact our visual experience consisted of a series of timeless “moments” which were then welded together by some higher mechanism in the brain. I found myself referring again to the “cinematographic” sequences of stills described to me by migraine patients and which I myself had on occasion experienced. (I had also experienced it very strikingly with other perceptual disorders when I got intoxicated by sakau in Micronesia.)

  When I mentioned to Ralph that I had started writing about all this, he said, “You have to read Crick and Koch’s latest paper. They propose in it that visual awareness really consists of a sequence of ‘snapshots’—you are all thinking along the same lines.”

  I wrote to Francis, enclosing a draft of my article on time. I threw in, for good measure, a copy of my latest book, Uncle Tungsten, and some recent articles dealing with our favorite topic of vision. On June 5, 2003, Francis sent me a long letter, full of intellectual fire and cheerfulness and with no hint of his illness. He wrote:

  I have enjoyed reading the account of your early years. I also was helped by an uncle to do some elementary chemistry and glass blowing, though I never had your fascination with metals. Like you I was very impressed by the Periodic Table and by ideas about the structures of the atom. In fact, in my last year at Mill Hill [his school] I gave a talk on how the “Bohr atom,” plus quantum mechanics, explained the Periodic Table, though I’m not sure how much of all that I really understood.

  I was intrigued by Francis’s reactions to Uncle Tungsten and wrote back to ask him how much “continuity” he saw between that teenager at Mill Hill who talked about the Bohr atom, the physicist he had become, his later “double helix”self, and his present self. I quoted a letter that Freud had written to Karl Abraham in 1924—Freud was sixty-eight then—in which he had said, “It is making severe demands on the unity of the personality to try and make me identify myself with the author of the paper on the spinal ganglia of the Petromyzon. Nevertheless it does seem to be the case.”

  In Crick’s case, the seeming discontinuity was even greater, for Freud was a biologist from the beginning, even though his first interests were in the anatomy of primitive nervous systems. Francis, in contrast, had taken his undergraduate degree in physics, worked on magnetic mines during the war, and went on to do his doctoral work in physical chemistry. Only then, in his thirties—at an age when most researchers are already stuck in what they are doing—did he have a transformation, a “rebirth,” as he was later to call it, and turn to biology. In his autobiography, What Mad Pursuit, he speaks of the difference between physics and biology:

  Natural selection almost always builds on what went before…. It is the resulting complexity that makes biological organisms so hard to unscramble. The basic laws of physics can usually be expressed in simple mathematical form, and they are probably the same throughout the universe. The laws of biology, by contrast, are often only broad generalizations, since they describe rather elaborate (chemical) mechanisms that natural selection has evolved over millions of years…. I myself knew very little biology, except in a rather general way, till I was over thirty…my first degree was in physics. It took me a little time to adjust to the rather different way of thinking necessary in biology. It was almost as if one had to be born again.

  By the middle of 2003, Francis’s illness was beginning to take its toll, and I began to receive letters from Christof Koch, who by that time was spending several days a week with him. They had become so close, it seemed, that many of their thoughts were dialogic, emerging in the interaction between them, and what Christof wrote to me would condense the thoughts of both. Many of his sentences would start, “Francis and I do have a few more questions about your own experience…. Francis thinks this…. Myself, I am not sure,” and so on.

  In response to my paper on time (a version of which was later in The New York Review of Books as “In the River of Consciousness”), Crick quizzed me minutely on the rate of visual flicker experienced in migraine auras. These were matters we had discussed when we first met fifteen years earlier, but this, apparently, we had both forgotten; certainly neither of us made any reference to our earlier letters. It was as if no resolution could be reached in 1986, and both of us, in our different ways, had shelved the matter, “forgotten” it, and put it into our unconscious, where it would incubate for another decade and a half before reemerging. Francis and I were converging on a problem which had defeated us before; we were now getting closer to an answer. My feeling of this was so intense in August of 2003 that I felt I had to make a visit to see Francis in La
Jolla.

  I stayed in La Jolla for a week and made frequent visits to Ralph, who was again working at the Salk. There was a very sweet, noncompetitive air there (or so it seemed to me, as an outsider, in my brief visit), an atmosphere which had delighted Francis when he first arrived at the Salk in the mid-1970s and which had deepened, with his continued presence, ever since. He was still, despite his age, a very central figure there. Ralph pointed out his car to me, its license plate bearing just four letters, A T G C—the four nucleotides of DNA—and I was happy to see his tall figure one day going into the lab, still very erect, though walking slowly, with the aid of a cane.

  I made an afternoon presentation one day, and just as I started, I saw Francis enter and take a seat quietly at the back. I noticed that his eyes were closed much of the time and thought he had fallen asleep, but when I finished, he asked a number of questions so piercing that I realized he had not missed a single word. His closed-eye appearances had deceived many visitors, I was told, but they might then find, to their cost, that these closed eyes veiled the sharpest attention, the clearest and deepest mind, they were ever likely to encounter.

  On my last day in La Jolla, when Christof was visiting from Pasadena, we were all invited to come up to the Crick house for lunch with Francis and his wife, Odile. “Coming up” was no idle term; Ralph and I, driving, seemed to ascend continually, around one hairpin bend after another, until we reached the Crick house. It was a brilliantly sunny California day, and we all settled down at a table in front of the swimming pool (a pool where the water was violently blue—not, Francis said, because of the way the pool was painted, or the sky above it, but because the local water contained minute particles which, like dust, diffracted the light). Odile brought us various delicacies—salmon and shrimp, asparagus—and some special dishes which Francis, now on chemotherapy, was limited to eating. Though she did not join the conversation, I knew how closely Odile, an artist, followed all of Francis’s work, if only from the fact that it was she who had drawn the double helix in the famous 1953 paper and, fifty years later, a frozen runner to illustrate the snapshot hypothesis in the 2003 paper that had so excited me.