104. "A New Vision of the Mind" - Part 2

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In the mid-1950s, when I was in medical school, there seemed to be an unbridgeable gap between our neurophysiology and the actualities of how patients experienced neurological disorders. Neurology continued to follow the clinico-anatomical method set by Broca a century earlier, locating areas of damage in the brain and correlating these with symptoms; these speech disturbances were correlated with damage to Broca's speech area, paralysis with damage to motor areas, and so on. The brain was regarded as a collection or mosaic of little organs, each with specific functions but somehow interconnected. But there was little idea of how the brain worked as a whole. When I wrote The Man Who Mistook His Wife For a Hat in the early 1980s, my thinking was still grounded in this model, in which the nervous system was largely conceived as fixed and invariant, with "pre-dedicated" areas for every function.

p357 Such a model was useful, say, in locating the area of damage in someone with aphasia. But how could it explain learning and the effects of practice? How could it explain the reconstructions and revisions of memory we make throughout our lives? How could it explain consciousness -- its richness, its wholeness, its ever-changing stream, and its many disorders? How could it explain individuality or self?

Although huge advances were being made in the neuroscience of the 1970s and 1980s, there was, in effect, a conceptual crisis or vacuum. There was no general theory which could make sense of he rich data, the observations of a dozen different disciplines from neurology to child development, linguistics, and even psychoanalysis.

In 1986, I read a remarkable article by Israel Rosenfield in The New York Review of Books in which he discussed the revolutionary work and views of Gerald M. Edelman. Edelman was nothing if not bold. "We are at the beginning of the neuroscientific revolution," he wrote. "At its end, we shall know how the mind works, what governs our nature, and how we know the world."

It's not just the history of philosophy these people seem to be oblivious of, physics, especially quantum physics, had also been debating the ultimate nature of reality for some time. I suppose focusing on the more limited problem before them was reasonable enough, but you'd think there would be at least a hint of the other question.

...
p358 In 1987, Edelman published Neural Darwinism, a seminal volume and the first in a series of books presenting and exploring the ramifications of a very radical idea which he called the theory of neuronal group selection, or, more evocatively, neural Darwinism. I struggled with the book, finding the writing impenetrable at times, in part because of the novelty of Edelman's ideas and in part because of the book's abstractness and lack of concrete examples... 
...
p359 While Crick (and his co-workers) cracked the genetic code -- a set of instructions, in general terms, for building a body -- Edelman realized early that the genetic code could not specify or control the fate of every single cell in the body, that cellular development, especially in the nervous system, was subject to all sorts of contingencies -- nerve cells could die, could migrate (Edelman spoke of such migrants as "gypsies") , could connect up with each other in unpredictable ways -- so that even by the time of birth the fine neural circuitry is quite different even in the brains of identical twins; they are already different individuals who respond to experience in individual ways. 

Where do I bring in the problem of Atavism? 


Darwin, studying the morphology of barnacles a century before Crick or Edelman, observed that no two barnacles of the same species were ever exactly the same; biological populations consisted not of identical replicas but of different and distinct individuals. It was upon such a population of variants that natural selection could act, preserving some lineages for posterity, condemning others to extinction (Edelman liked to call natural selection "a huge death machine"). Edelman conceived, almost from the start of his career, that processes analogous to natural selection might be crucial for individual organisms -- especially higher animals -- in the course of their lives, with life experience serving to strengthen certain neuronal connections or constellations in the nervous system and to weaken or extinguish others.

Footnote 4. Edelman had originally pioneered a selectionist theory in relation to the immune system -- he was awarded a Nobel Prize for this work -- and then, in the mid-1970s, started to apply analogous concepts to the nervous system.

Edelman thought of the basic unit of selection and change as being not a single neuron but groups of fifty to a thousand interconnected neurons; thus he called his hypothesis the theory of neuronal group selection. He saw his own work as the completion of Darwin's task, adding selection at a cellular level within the life span of a single individual to that of natural selection over many generations.

Clearly there are some innate biases or dispositions as part of our genetic programming; otherwise an infant would have no tendencies whatever, would not be moved to do anything, seek anything, to stay alive. These basic biases (towards, for example, food, warmth, and contact with other people) direct a creature's first movements and strivings.

p361 And at an elementary physiological level, there are various sensory and motor givens, from the reflexes that automatically occur (for example, in response to pain) to certain innate mechanisms in the brain (for example, control of respiration and autonomic functions). 

I would add that fear of falling -- crawling onto a glass floor for example -- that even newborns have. 


But in Edelman's view, very little else is programmed or built in. A baby turtle, on hatching, is ready to go. A human baby is not ready to go; it must create all sorts of perceptual and other categorizations and use them to make sense of the world -- to make an individual, personal world of its own, and to find out how to make its way in that world. Experience and experiment are crucially important here -- neural Darwinism is essentially experiential selection.

This is where I have to come back to Atavism (and by "Atavism" I mean the way the term was used earlier in the book by Abba Eben to describe the characteristics he and Oliver Sacks shared with their common grandfather, who Sacks hadn't known). I'm very intrigued by neural Darwinism. I think this is mostly correct, but it is also going to have to explain how personalities are passed on from generation to generation -- often skipping a generation -- and how individuals seem to often be born with a characteristic disposition. 

Neural Darwinism is on the opposite end of the spectrum from "classical" notions of reincarnation (the Tibetan view, for example). I have problems with both extremes while acknowledging reasons to also believe both. I'm not sure it will be possible to find a middle ground that is open to both views.

Also, there's that business of people who have a clearly delineated genetic propensity to either understand or to not understand fundamental mathematical concepts. If you can predict that one cousin will be able to grasp calculus while another cousin won't, then this strongly suggests that their brains are hardwired from conception to some extent. 

Also, I have to note that Darwin's Origin was published in 1859. About 30 years after Faust; and roughly 20 years before The Birth of Tragedy and The Brothers K.


The real functional "machinery" of the brain, for Edelman, consists of millions of neuronal groups, organized into larger units or "maps." These maps, continually conversing in ever-changing, unimaginably complex, but always meaningful patterns, may change in minutes or seconds. One is reminded of C. S. Sherrington's poetic evocation of the brain as "an enchanted loom," where "millions of flashing shuttles weave a dissolving pattern, always a meaningful pattern though never an abiding one; a shifting harmony of subpatterns."

The creation of maps that respond selectively to certain elemental categories -- for example, to movement or color in the visual world -- may involve the synchronization of thousands of neuronal groups. Some mappings take place in discrete and anatomically fixed, pre-dedicated parts of the cerebral cortex, as is the case with color: color is constructed predominantly in the area called V4. But much of the cortex is plastic, pluripotent "real estate" that can serve (within limits) whatever function is needed; thus what would be auditory cortex in hearing people may be reallocated for visual purposes in congenitally deaf people... [and vice versa.]

p362 Ralph Siegel... pioneered a very original optical "meso" method that allowed him to look at dozens or hundreds of neurons as they interacted and synchronized with one another in real time. One of his findings -- unexpected and baffling at first -- was that neuronal constellations or maps could change in a matter of second as the animal learned or adapted to different sensory inputs. [This use of "constellation" forces me to mention a connection with Adrian in Doctor Faustus that has been at the back of my mind for a paragraph or two. You could re-write the passage about how his brain was being augmented by his little syphilitic friends to match this scientific theory.] This was very much in accordance with Edelman's theory of neuronal group selection, and Ralph and I spent many hours discussing the implications of his theory with each other and with Edelman himself, who, like Crick, was fascinated by Ralph's work.


Maybe Siegel is even more like Rosalind Franklin than Sacks is.

Where perception of objects is concerned, Edelman likes to say, the world is not "labeled"; it does not come "already parsed into object." We must make our perceptions through our own categorizations. "Every perception is an act of creation," as Edelman says. As we move about, our sense organs take samplings of the world, and from these, maps are created in the brain. There then occurs with experience a selective strengthening of those mappings that correspond to successful perceptions -- successful in that they prove the most useful and powerful for the building of "reality."

I have a problem with the use of "reality" here. Success is based on survival, as with Darwin. Reality in any profound sense has little to do with it. The "reality" we perceive is that reality which increases our chances of passing on our genes. 

Here's a crude example, but we are talking about crude biology here. If I find fertile females of my species strangely attractive, it -- in theory -- aids my chances of passing on my genes. If fertile females seem particularly attractive to me when they are ovulating (experiments have demonstrated this to be true), my chances are even better. But this also suggests that my perception of the world, at least when it comes to the appearance of females of my species, is manipulated by my brain at a sub-conscious level. What I see is what it is useful for me to see, not "reality" in any underlying sense. It is certainly not Kant's "thing in itself" that I'm perceiving. 


p363 Edelman speaks here of a further, integrative activity peculiar to more complex nervous systems; this he calls "reentrant signaling." In his terms, the perception of a chair, for example, [Plato's chair makes its inevitable appearance at last] depends first on the synchronization of activated neuronal groups to form a "map," then a further synchronization of a number of scattered mappings throughout the visual cortex -- mappings relating to many different perceptual aspects of the chair (its size, its shape, its color, its "leggedness," its relation to other sorts of chairs -- armchairs, rocking chairs, baby chairs, etc.). In this way, a rich and flexible percept of "chairhood" is achieved, which allows the instant recognition of innumerable sorts of chairs as chairs. This perceptual generalization is dynamic, so it can be continually updated, and it depends on the active and incessant orchestration of countless details.

Why do I have the feeling these guys are reinventing Platonic Idealism starting with the brain rather than the mind? Surely that can't be the case. 


Such correlation and synchronization of neuronal firing in widely separated areas of the brain is made possible by very rich connections between the brain's maps -- connections which are reciprocal and may contain millions of fibers. Stimuli from, say, touching a chair may affect one set of maps; stimuli from seeing it may affect another set. Reentrant signaling takes place between these sets of maps as part of the process of perceiving a chair. 

Categorization is the central task of the brain, and reentrant signaling allows the brain to categorize its own categorizations, then recategorize these, and so on. Such a process is the beginning of an enormous upward path enabling ever higher levels of thought and consciousness.

p364 Reentrant signaling might be likened to a sort of neural United Nations, in which dozens of voices are talking together, while including in their conversations a variety of constantly inflowing reports from the outside world, bringing them together into a larger picture as new information is correlated and new insights emerge.

Edelman, who once planned to be a concert violinist, uses musical metaphors as well. In a BBC radio interview, he said:

Think: if you had a hundred thousand wires randomly connecting four string quartet players and that, even though they weren't speaking words, signals were going back and forth in all kinds of hidden ways {as you usually get them by the subtle nonverbal interactions between the players} that make the whole set of sounds a unified ensemble. That's how the maps of the brain work by reentry. 


The players are connected. Each player, interpreting the music individually, constantly modulates and is modulated by the others. There is no final or "master" interpretation; the music is collectively created, and every performance is unique. This is Edelman's picture of the brain, as an orchestra, an ensemble, but without a conductor, an orchestra which makes its own music.

I found Edelman's metaphor puzzling until Sacks elaborated on it. This is why Sacks is Sacks. That he is useful to us has been clear since his early books, what I hadn't realized was his value to people like Edelman and Crick. He's a very interesting middleman serving audiences both above and below. And I can't help mentioning that he seems to play somewhat the same role that Feynman played in physics. Feynman makes quantum mechanics as understandable as possible to the average person, but his Feynman diagrams even provided the cognoscenti with a tool for understanding quantum reality that they would have said they didn't need. 


When I walked back to my hotel after dinner with Gerry that evening, I found myself in a sort of rapture... I had the feeling of having been liberated from decades of epistemological despair -- from a world of shallow, irrelevant computer analogies into one full of rich biological meaning, one which corresponded with the reality of brain and mind. Edelman's theory was the first truly global theory of mind and consciousness, the first biological theory of individuality and autonomy.

This sounds so much like he's talking about free will vs determinism. About the philosophical questions that lead to nihilism and existentialism. The problems that Foucault and the rest felt Sartre had tried to paper over. Yet I still have the feeling these two, almost mirror, conversations are going on in alternate -- or at least disconnected universes. 

I do like the phrase "epistemological despair." That would actually be a good title for a book about philosophy since the 18th century.


p365 I thought, "Thank God I have lived to hear this theory." I felt as I imagined many people must have felt in 1859 when the Origin came out. The idea of natural selection was astounding but, once one thought about it, obvious. Similarly, when I grasped what Edelman was about that evening, I thought, "How extremely stupid of me not to have thought of this myself!" just as Huxley had said after reading the Origin. It all seemed so clear suddenly.

Interestingly, the theory of Glaciation is my favorite example of a theory that, once you hear it, instantly confirms itself and changes your view of the natural world. All you have to do is sit in Yosemite Valley or on half the hills in Scotland for the landscape at your feet to confirm beyond a shadow of a doubt the theory.

And yet, it is my understanding that Darwin himself rejected the theory of Glaciation when it was first presented because there was no way it could have occurred on a biblical timescale. This is one of the saddest things I've ever read. 


A few weeks after my return from Florence, I had another epiphany, of a rather improbable and comic sort. I was driving up to Lake Jefferson... when I saw -- a cow! But a cow transfigured by my new Edelmanian view of animal life, a cow whose brain was constantly mapping all its perceptions and movements, a cow whose inner being consisted of categorizations and mappings, neuronal groups flashing and conversing at great speed, an Edelmanian cow suffused by the miracle of primary consciousness. "What a wonderful animal!" I thought to myself. "Never have I seen a cow in this light before."

Natural selection could show me how cows in general had come to be, but neural Darwinism was necessary to apprehend what it was like to be this particular cow. Becoming this particular cow was made possible by experience selecting particular neuronal groups in its brain and amplifying their activities. 

p366 Mammals, birds, and some reptiles, Edelman speculated, have "primary consciousness," the ability to create mental scenes to help them adapt to complex and changing environments. This achievement, for Edelman, depended on the emergence of a new type of neuronal circuit at some "transcendent moment" in evolution -- a circuit allowing massive, parallel, reciprocal connections between neuronal maps, as well as among the ongoing global mappings that integrate new experiences and recategorize categories.

Yet another example of where I want to know exactly what the author intends us to get from his use of "transcendent." Is this intended to suggest Kant, or not? I'm guessing not. 


At some second transcendent moment in evolution, Edelman proposed, the development of "higher-order consciousness" was made possible in humans (and perhaps a few other species including apes and dolphins) by a higher level of reentrant signaling. Higher-order consciousness brings an unprecedented power of generalization and reflection, of recognizing past and future, so that finally self-consciousness, the awareness of being a self in the world, is achieved.

He just throws "recognizing past and future" out there. Surely it must have occurred to him that recognizing past and future could be analogous to distinguishing color from monotone. That "color" is a convention of perception, not something that "exists" in the world; and that past and future could be similar. And I guess recognizing "good and evil" would be the result of an even higher level of reentrant signaling.

...
...I often encounter situations in day-to-day neurological practice which completely defeat classical neurological explanations and cry out for explanations of a radically different kind, but many such phenomena can be explained, in Edelmanian terms, as breakdowns in local or higher-order mapping consequent upon nerve damage or disease.

p367 ...classical neurology had nothing to say about how, if the flow of neural information is impaired, [his example is when he badly injured his leg in an accident involving a bull] a limb may be lost to consciousness and to self, "disowned," and how there may then be a rapid remapping of the rest of the body which excludes that limb.

If the right hemisphere of the brain is badly damaged in its sensory (parietal) areas, patients may show an "anosognosia," an unawareness that anything is the matter, even though the left side of the body is senseless or paralyzed. Sometimes they may insist that their left side belongs to "someone else." For such patients, subjectively, their space and world are entire, even though they are living in a hemi-world. For many years, anosognosia was misinterpreted as a bizarre neurotic symptom, since it was unintelligible in terms of classical neurology. But Edelman sees such a condition as a "disease of consciousness," a total breakdown of high-level reentrant signaling and mapping in one hemisphere and a radical reorganization of consciousness in consequence.

Sometimes following a neurological lesion, a dissociation occurs between memory and consciousness, leaving only implicit knowledge or memory. Thus my patient Jimmie, the amnesic mariner, had no explicit memory of Kenndy's assassination, and when I asked him whether any president had been assassinated in the twentieth century, he would say, "No, not that I know of." But if I asked him, "Hypothetically, then, if a presidential assassination had somehow occurred without your knowledge, where might you guess it occurred: New York, Chicago, Dallas, New Orleans, or San Francisco?" he would invariably "guess" correctly, Dallas.

p368 Similarly, patients with total cortical blindness due to massive damage to the primary visual areas of the brain will assert that they can see nothing, but they may also mysteriously "guess" correctly what lies before them -- so-called blindsight. In all these cases, perception and perceptual categorization have been preserved but have been divorced from higher-order consciousness.

Individuality is deeply imbued in us from the very start, at the neuronal level. Even at a motor level, researchers have shown, an infant does not follow a set pattern of learning to walk or how to reach for something. Each baby experiments with different ways of reaching for objects and over the course of several months discovers or selects his own motor solutions. When we try to envision the neural basis of such individual learning, we might imagine a "population" of movements (and their neural correlates) being strengthened or pruned away by experience.

Similar considerations arise with regard to recovery and rehabilitation after strokes and other injuries. There are no rules; there is no prescribed path of recovery; every patient must discover or create his own motor and perceptual patterns, his own solutions to the challenges that face him; and it is the function of a sensitive therapist to help him in this.

p369 And in its broadest sense, neural Darwinism implies that we are destined, whether we wish it or not, to a life of particularity and self-development, to make our own individual paths through life. 

With possible Atavistic limitations. 


When I read Neural Darwinism, I wondered if it would change the face of neuroscience as Darwin's theory had changed the face of biology. The short, but inadequate, answer is that it has not, although there are now countless scientists who take for granted many of Edelman's ideas without acknowledging, or perhaps even knowing, that they are Edelman's. In this sense, his thinking, though not explicitly acknowledged, has been shifting the very grounds of neuroscience. 

Sacks is doing something clever with "explicit" and "implicit" knowledge in these paragraphs. 


In the 1980s, Edelman's theory was so novel that it could not easily be fitted into any of the existing models, the paradigms, of neuroscience, and it was this, I think, which prevented its wide acceptance -- coupled with Edelman's at times dense and difficult writing. Edelman's theory was "premature," so ahead of its time, so complex and demanding of new ways of thinking, that it was resisted, or ignored, in the 1980s, but in the next twenty or thirty years, with new technologies, we will be in a good position to verify (or disprove) its ultimate tenets. It remains, for me, the most powerful and elegant explanation of how we humans and our brains construct our very individual selves and worlds. 

This last paragraph about how an idea can be too far ahead of its time, reminds me of one of my favorite ideas from Proust. The notion that the artist, or in this case the scientist, sometimes has to educate a new generation to appreciate some new way of viewing the world. Proust was thinking of painting -- but the idea applies just as well to music. 20th century physics is full of such paradigm shifting ideas (relativity and quantum mechanics leap to mind), but there were experiments to confirm and to fairly quickly bring people around. The basic working of the brain is still on the edge of experimental science and therefore of proof. 


The last chapter
p380 [Writing about the time, in his mid-70s,when  he was recovering from extremely painful back problems and had just met someone he loved] There was an intense emotionality at this time: music I loved, or the long golden sunlight of late afternoon, would set me weeping. I was not sure what I was weeping for, but I would feel an intense sense of love, death, and transience, inseparably mixed. 

He was also taking heavy duty pain killers. 

...
p381 In the last week of December, the nerve pain had started to grow less. Was this because the postoperative edema was settling? Or was it -- a hypothesis I could not help entertaining -- because the joy of being in love was a match for the pain of the neuralgia and could alleviate it almost as well as Dilaudid or fentanyl? Did being in love itself flood the body with opiods, or cannabinoids, or whatever?
...
It has sometimes seemed to me that I have lived at a certain distance from life. This changed when Billy and I fell in love... 

Deep, almost geological changes had to occur; in my case, the habits of a lifetime's solitude, and a sort of implicit selfishness and self-absorption, had to change...
...
...It was a new experience for me to lie quietly in someone's arms and talk, or listen to music, or be silent, together....

The parallel with the cancer non-survivor in Anne Lamott's "The Last Waltz", and with Zossima's dying brother, would be more dramatic if he wasn't on so many opiates, but still, I think we see at least a hint of the same phenomena.

Unfortunately, this portion of his life is described in almost no detail. Perhaps he ran out of time and was more interested in getting the book out before he died than in wrapping up his story. It would be nice to know how his (age and illness related?) ego revision in his final years affected his thinking and writing. He doesn't reveal this in the book. 

However, I suspect he wrote that last chapter -- and in fact his last three books -- after his life changed, so that is a good sign. 

That penultimate chapter I liked so much, doesn't really seem to belong in this book. I would guess that Sacks realized he wasn't going to get around to writing yet another book on that subject, so decided to include it here. What we lose by that is any detail on the later years of his life. His autobiographical life is an interesting story until he moves to NYC at which point it becomes a mix of occasional personal anecdotes and a gloss of his published works.

For your convenience, I'm including a passage from my After Ryecroft blog that I think relates to this "mind" material -- especially the question of color perception:

Here's a fascinating passage from The God Delusion that Richard Dawkins really should contemplate some more:

What we see of the real world is not the unvarnished real world but a model of the real world, regulated and adjusted by sense data -- a model that is constructed so that it is useful for dealing with the real world. The nature of that model depends on the kind of animal we are. A flying animal needs a different kind of world model from a walking, a climbing or a swimming animal... I've speculated, in The Blind Watchmaker and elsewhere, that bats may 'see' colour with their ears. The world-model that a bat needs, in order to navigate through three dimensions catching insects, must surely be similar to the model that a swallow needs in order to perform much the same task... Once again, the perceptions that we call colours are tools used by our brains to label important distinctions in the outside world. Perceived hues -- what philosophers call qualia -- have no intrinsic connection with lights of particular wavelengths. They are internal labels that are available to the brain, when it constructs its model of external reality...

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