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On the Move
As promised (in 86) here is yet another random book to consider. Though this time it's just a chapter plus a bit more. On the Move was Oliver Sacks' autobiography published the spring before he died. Does that ring a bell? The final part of Faust, The Private Papers of Henry Ryecroft, and The Brothers K. were also published just before their author's died. I don't know what this means.
p340 Mr I. had become colorblind after sixty-five years of seeing colors normally -- totally colorblind, as if "viewing a black and white television screen." The suddenness of the event was incompatible with any of the slow deteriorations that can befall the retinal cone cells and suggested instead a mishap at a much higher level, in those parts of the brain specialized for the perception of color.
I already have a problem with this, after reading Dawkins. He's actually talking about the parts of the brain specialized for displaying as color certain ranges of electromagnetic radiation. Since I have a fondness for b&w photography and video, I think I would have mixed feelings about this happening to me. It would be dangerous as a great deal of information -- about skin infection and the age of food products, for example -- is brought to our attention by color, but I can also think of some advantages. I would love to know to what extent, if any, Mr I. became more adept at deriving information from his grey-scale vision that we usually derive from color.
Moreover, it became apparent that Mr I. had lost not only the ability to see color but the ability to imagine it. He now dreamed in black and white, and even his migraine auras were drained of color.
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[Semir] Zeki had been making a neurophysiological investigation of color perception by recording from electrodes inserted into the visual cortex of monkeys, and he had shown that a single area (V4) was responsible for the construction of color. He thought there was probably an analogous area in the human brain. I was fascinated by Zeki's talk, especially by his use of the word "construction" in relation to color perception.
A whole new way of thinking seemed to ray our from Zeki's work, [this would have been around 1985] and it set me thinking of the possible neural basis for consciousness in a way I had never considered before -- and to realize that with our new powers of imaging the brain and our newly developed abilities to record the activity of individual neurons in living and conscious brains, we might be able to plot how and where all sorts of experiences are "constructed." This was an exhilarating thought. I realized the vast leap which neurophysiology had made since my own student days in the early 1950s, when it was beyond our power, almost beyond imagination, to record from individual nerve cells in the brain while an animal was conscious, perceiving, and acting.
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p341 Ralph [Siegel, a neurophysiologist and protege of Francis Crick at the Salk Institute who Sacks has run into at a concert] was curious -- what had I been writing about through the entire concert? Had I been wholly unconscious of the music? No, I said, I was conscious of the music, and not just as background. I quoted Nietzsche, who used to write at concerts, too; he loved Bizet and once wrote, "Bizet makes me a better philosopher."
I'm including this in part to show that Sacks is familiar with Nietzsche though not, apparently, with the issues of phenomenology. Also, considering that Siegel was apparently distracted by the concert goer in front of him scribbling away throughout the concert, Nietzsche had no choice but to write at concerts to get his Bizet boost. Sacks had the option of putting on a record instead of attending concerts.
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[Talking about Mr I,] He outlined half a dozen simple but crucial tests that could help pinpoint at what stage the construction of color had broken down in the painter's brain.
p343 Ralph thought always in deep physiological terms, while neurologists, myself included, often content ourselves with the phenomenology of brain disease or damage, with little thought of the precise mechanisms involved and no thought at all of the ultimate questions of how experience and consciousness emerged from brain activity. [This still seems to be more the brain/mind question and not the philosophical question of the underlying nature of reality.] For Ralph, all the questions he explored in the monkey brain, the insights he so patiently collected one by one, always pointed to that ultimate question -- the relationship of brain and mind.
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p343 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.
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p344 ...There were, he [Crick] intimated in his talk [at Mount Zion Hospital in 1962], 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...
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... 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.
This puts Sacks into the Rosalind Franklin role, bringing experimental data to the theoretician. (I looked that Scientific American article up on a hunch. I'm pretty sure I read it at the time.)
...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," [the way a motion picture is actually composed of a sequence of still images] 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.)
p345 During 1986, I spent a good deal of time with Mr I., and in January of 1987 I wrote to Francis, "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."
How is this possible?! How can he tell stories about Nietzsche I've never heard and then be ignorant of one of the most fundamental subjects of philosophy over the past several centuries? What do they do at Oxford? And he's still just talking about the "construction" of the image in our heads, not its relation to external reality.
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.
Footnote 2. A few days later, I got a reply in which Crick sought more detail about the difference between my migraine patients and a remarkable patient described in a 1983 paper by Josef Zihl and his colleagues. Zihl's patient, for example, could not pour a cup of tea; she saw a motionless "glacier" of tea hanging from the spout. Some of my migraine patients had experienced such "stills" in rapid succession, whereas for Zihl's patient, who had acquired motion blindness following a stroke, the stills apparently lasted much longer, perhaps several seconds each. In particular, Crick wanted to know whether successive stills in my migraine patients occurred within the interval between successive eye movements or only between such intervals. "I would very much like to discuss these topics with you," he wrote, "including your remarks about color as a cerebro-mental construct."...
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p348 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 "Toward a Neurobiological Theory of Consciousness," one of the first synaptic 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.
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p349 In June 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 of 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 [opthomologist] and Knut Norby, 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... I also told him... how Knut and I tried to imagine what changes might have occurred in his brain in response to his achromatopsia [Knut's not seeing color]. 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.
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p350 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 [this is May 2003], 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" sequence of stills described to be 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 skau in Micronesia.)
p351 When I mention 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."
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[Francis wrote to Sacks] "I have enjoyed reading the account [in Uncle Tungsten] of your early years... Like you I was very impressed by the Periodic Table and by ideas about the structure 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.
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p353 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...
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p355 [At lunch at Crick's home in La Jolla] ...Ralph was eager to tell Francis about his latest work -- a new form of optical imaging which could show structures almost down to the cellular level in the living brain... it was on this "meso" scale that both Crick and Gerald Edelman, whatever their differences, now located the functional structures of the brain.
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...Francis spoke with great pride... of Christof's forthcoming book, The Quest for Consciousness... He outlines the dozens of investigations, years of work, which lay ahead -- work especially stemming from the convergence of molecular biology with systems neuroscience... Francis, I felt, had no fear of death, but his acceptance of it was tinged with sadness that he would not be alive to see the wonderful, almost unimaginable, scientific achievements of the twenty-first century. The central problem of consciousness and its neurobiological basis, he was convinced, would be fully understood, "solved," by 2030. "You will see it," he often said to Ralph, and you may, Oliver, if you live to my age."
p356 In January of 2004, I received the last letter I would get from Francis. He had read "In the River of Consciousness." "It reads very well," he wrote, "though I think a better title would have been 'Is Consciousness a River?' since the main thrust of the piece is that it may well not be." (I agreed with him.)
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