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T**R
Where'd those clubbed fingers go?
On page 7, talking about lung cancer and clubbing of the fingers, Ramachandran/Blakeslee say "Remarkably, this telltale sign disappears instantly on the operating table as the surgeon removes the cancer." I know this not to be true, but I was already very impressed with the book. This kept bothering me until by page 100 or so, I decided to check out the author a little. He appeared to have exemplary credentials. Then that very afternoon the new issue of Discover Magazine arrived and I found him mentioned twice, one of those times in a short feature.In the preface, he says, "When writing a popular book, professional scientists always have to walk a tightrope between making the book intelligible to the general reader, on the one hand, and avoiding oversimplification, on the other, so that experts are not annoyed." Maybe the instantly cured clubbed fingers fit into this category. He also says, "Some of the cases I describe are really composites of several patients, including classics in the medical literature." Perhaps this explains it.Possibly it was the journalist, Blakeslee, who decided to make the situation somewhat more interesting, but then one has to consider that other conclusions may be a little enhanced.Be that as it may, this book presents remarkable data. It reads like a detective story and describes an empathetic doctor who has lots of rapport with his patients as he tries to help them deal with their unique problems. The book gives an excellent review of brain anatomy and function. The first 20 pages summarizes aspects of the scientific method so well, I was enthralled. As I kept reading, I found out that someone with a keen mind using curiosity, simple observations, and prop-like equipment could still uncover new scientific data.Other reviewers have eloquently described the contents, and I urge you to read them. Despite my criticism, this book deserves a "5", and should add to anyone's knowledge about consciousness and how the mind works.
D**D
About neurology
Interesting stories about the brain and how things can go wrong with its working.
O**H
The Fascinating Struggles of the Brain to Understand Itself!
Below are key excerpts from the book that I found particularly insightful:1- "I mention this episode to emphasize that a single medical student or resident whose mind is open to new ideas and who works without sophisticated equipment can revolutionize the practice of medicine. It is in this spirit that we should all undertake our work, because one never knows what nature is hiding. I'd also like to say a word about speculation, a term that has acquired a pejorative connotation among some scientists. Describing someone's idea as "mere speculation" is often considered insulting. This is unfortunate. As the English biologist Peter Medawar has noted, "An imaginative conception of what might be true is the starting point of all great discoveries in science." Ironically, this is sometimes true even when the speculation turns out to be wrong...Every scientist knows that the best research emerges from a dialectic between speculation and healthy skepticism. Ideally the two should coexist in the same brain, but they don't have to. Since there are people who represent both extremes, all ideas eventually get tested ruthlessly. "2-"The famous saying "May you live in interesting times" has a special meaning now for those of us who study the brain and human behavior. On the one hand, despite two hundred years of research, the most basic questions about the human mind—How do we recognize faces? Why do we cry? Why do we laugh? Why do we dream? and Why do we enjoy music and art?—remain unanswered, as does the really big question: What is consciousness? On the other hand, the advent of novel experimental approaches and imaging techniques is sure to transform our understanding of the human brain. What a unique privilege it will be for our generation—and our children's—to witness what I believe will be the greatest revolution in the history of the human race: understanding ourselves. The prospect of doing so is at once both exhilarating and disquieting. There is something distinctly odd about a hairless neotenous primate that has evolved into a species that can look back over its own shoulder and ask questions about its origins. And odder still, the brain can not only discover how other brains work but also ask questions about its own existence: Who am I? What happens after death? Does my mind arise exclusively from neurons in my brain? And if so, what scope is there for free will? It is the peculiar recursive quality of these questions—as the brain struggles to understand itself—that makes neurology fascinating."3- "But before we begin, I think it's important for you to understand my personal approach to science and why I am drawn to curious cases. When I give talks to lay audiences around the country, one question comes up again and again: "When are you brain scientists ever going to come up with a unified theory for how the mind works? There's Einstein's general theory of relativity and Newton's universal law of gravitation in physics. Why not one for the brain?" My answer is that we are not yet at the stage where we can formulate grand unified theories of mind and brain. Every science has to go through an initial "experiment" or phenomena-driven stage—in which its practitioners are still discovering the basic laws—before it reaches a more sophisticated theory-driven stage...My point is simply that neuroscience today is in the Faraday stage, not in the Maxwell stage, and there is no point in trying to jump ahead. I would love to be proved wrong, of course, and there is certainly no harm in trying to construct formal theories about the brain, even if one fails (and there is no shortage of people who are trying). But for me, the best research strategy might be characterized as "tinkering." Whenever I use this word, many people look rather shocked, as if one couldn't possibly do sophisticated science by just playing around with ideas and without an overarching: theory to guide one's hunches. But that's exactly what I mean (although these hunches are far from random; they are always guided by intuition."4- "First and foremost, they suggest that brain maps can change, sometimes with astonishing rapidity. This finding flatly contradicts one of the most widely accepted dogmas in neurology— the fixed nature of connections in the adult human brain. It had always been assumed that once this circuitry, including the Penfield map, has been laid down in fetal life or in early infancy, there is very little one can do to modify it in adulthood. Indeed, this presumed absence of plasticity in the adult brain is often invoked to explain why there is so little recovery of function after brain injury and why neurological ailments are so notoriously difficult to treat. But the evidence from Tom shows— contrary to what is taught in textbooks—that new, highly precise and functionally effective pathways can emerge in the adult brain as early as four weeks after injury. It certainly doesn't follow that revolutionary new treatments for neurological syndromes will emerge from this discovery right away, but it does provide some grounds for optimism."5- "When we experience pain, special pathways are activated simultaneously both to carry the sensation and to amplify it or dampen it down as needed. Such "volume control" (sometimes called gate control) is what allows us to modulate our responses to pain effectively in response to changing demands (which might explain why acupuncture works or why women in some cultures don't experience pain during labor). Among amputees, it's entirely possible that these volume control mechanisms have gone awry as a result of remapping—resulting in an echo-like "wha wha" reverberation and amplification of pain. Second, remapping is inherently a pathological or abnormal process, at least when it occurs on a large-scale, as after the loss of a limb. It's possible that the touch synapses are not quite correctly rewired and their activity could be chaotic. Higher brain centers would then interpret the abnormal pattern of input as junk, which is perceived as pain. In truth, we really don't know how the brain translates patterns of nerve activity into conscious experience, be it pain, pleasure or color."6- "This simple experiment not only shows how malleable your body image is but also illustrates the single most important principle underlying all of perception—that the mechanisms of perception are mainly involved in extracting statistical correlations from the world to create a model that is temporarily useful."7- "For your entire life, you've been walking around assuming that your "self is anchored to a single body that remains stable and permanent at least until death. Indeed, the "loyalty" of yourself to your own body is so axiomatic that you never have to pause to think about it, let alone question it. Yet these experiments suggest the exact opposite—that your body image, despite all its appearance of durability, is an entirely transitory internal construct that can be profoundly modified with just a few simple tricks. It is merely a shell that you've temporarily created for successfully passing on your genes to your offspring."8- "So the first step in understanding perception is to get rid of the idea of images in the brain and to begin thinking about symbolic descriptions of objects and events in the external world. A good example of a symbolic description is a written paragraph like the ones on this page. If you had to convey to a friend in China what your apartment looks like, you wouldn't have to tele-transport it to China. All you'd have to do would be to write a letter describing your apartment. Yet the actual squiggles of ink—the words and paragraphs in the letter—bear no physical resemblance to your bedroom. The letter is a symbolic description of your bedroom."9- "In making these judgments, the brain takes advantage of the fact that the world we live in is not chaotic and amorphous; it has stable physical properties. During evolution—and partly during childhood as a result of learning—these stable properties became incorporated into the visual areas of the brain as certain "assumptions" or hidden knowledge about the world that can be used to eliminate ambiguity in perception."10- "Bear in mind that the filling in is not just some odd quirk of the visual system that has evolved for the sole purpose of dealing with the blind spot. Rather, it appears to be a manifestation of a very general ability to construct surfaces and bridge gaps that might be otherwise distracting in an image—the same ability, in fact, that allows you to see a rabbit behind a picket fence as a complete rabbit, not a sliced-up one. In our natural blind spot we have an especially obvious example of filling in—one that provides us with a valuable experimental opportunity to examine the "laws" that govern the process."11- "An important distinction must be made between perceptual and conceptual completion. To understand the difference, just think of the space behind your head now as you are sitting on your chair reading this book. You can let your mind wander, thinking about the kinds of objects that might be behind your head or body. Is there a window? A Martian? A gaggle of geese? With your imagination, you can "fill in" this missing space with just about anything, but since you can change your mind about the content, I call this process conceptual filling in. Perceptual filling in is very different. When you fill in your blind spot with a carpet design, you don't have such choices about what fills that spot; you can't change your mind about it. Perceptual filling in is carried out by visual neurons. Their decisions, once made, are irreversible: Once they signal to higher brain centers "Yes, this is a repetitive texture" or yes, this is a straight line." what you perceive is irrevocable."12- "If I'm right, all these bizarre visual hallucinations are simply an exaggerated version of the processes that occur in your brain and mine every time we let our imagination run free. Somewhere in the confused welter of interconnecting forward and backward pathways is the interface between vision and imagination We don't have clear ideas yet about where this interface is or how it works (or even whether there is a single interface), but these patients provide some tantalizing clues about what might be going on. The evidence from them suggests that what we call perception is really the end result of a dynamic interplay between sensory signals and high-level stored information about visual images from the past. Each time any one of us encounters an object, the visual system begins a constant questioning process. Fragmentary evidence comes in and the higher centers say, "Hmmmmm, maybe this is an animal." Our brains then pose a series of visual questions: as in a twenty-questions game. Is it a mammal? A cat? What kind of cat? Tame? Wild? Big? Small? Black or white or tabby? The higher visual centers then project partial "best fit" answers back to lower visual areas including the primary visual "best fit" answers back to lower visual areas including the primary visual cortex. In this manner, the impoverished image is progressively worked on and refined (with bits "filled in," when appropriate). I think that these massive feed forward and feedback projections are in the business of conducting successive iterations that enable us to home in on the closest approximation to the truth. To overstate the argument deliberately, perhaps we are hallucinating all the time and what we call perception is arrived at by simply determining which hallucination best conforms to the current sensory input. But if, as happens in Charles Bonnet syndrome, the brain does not receive confirming visual stimuli. it is free simply to make up its own reality. And, as James Thurber was well aware, there is apparently no limit to its creativity."13- "The idea that the right hemisphere is a left-wing revolutionary that generates paradigm shifts, whereas the left hemisphere is a die-hard conservative that clings to the status quo, is almost certainly a gross oversimplification, but, even if it turns out to be wrong, it does suggest new ways of doing experiments and goads us into asking novel questions about the denial syndrome."14- "One can make a list of the many kinds of self-deception that Sigmund and Anna Freud described and see clear-cut, amplified examples of each of them in our patients. It was seeing this list that convinced me for the first time of the reality of psychological defenses and the central role that they play in human nature. Denial...Repression...Reaction formation...Rationalization...Humor...Projection."15- "His Story offers insights into how each of us constructs narratives about our life and the people who inhabit it. In a sense your life—your autobiography—is a long sequence of highly personal episodic memories about your first kiss, prom night, wedding, birth of a child, fishing trips and so on. But it is also much more than that. Clearly, there is a personal identity, a sense of a unified "self" that runs like a golden thread through the whole fabric of our existence. The Scottish philosopher David Hume drew an analogy between the human personality and a river—the water in the river is ever-changing and yet the river itself remains constant. What would happen, he asked, if a person were to dip his foot into a river and then dip it in again after half an hour—would it be the same river or a different one? If you think this is a silly semantic riddle, you're right, for the answer depends on your definition of "same" and "river.""16- "There are some questions about the brain that are so mysterious, so deeply enigmatic, that most serious scientists simply shy away from them, as if to say, "That would be premature to study" and "I'd be a fool if I embarked on such a quest." And yet these are the very issues that fascinate us most of all. The most obvious one, of course, is religion, a quintessentially human trait, but it is only one unsolved mystery of human nature. What about Other uniquely human traits—such as our capacity for music, math, humor and poetry? What allowed Mozart to compose an entire symphony in his head or mathematicians like Fermat or Ramanujan to "discover" flawless conjectures and theorems without ever going through step-by-step formal proofs? And what goes on in the brain of a person like Dylan Thomas that allowed him to write such evocative poetry? Is the creative spark simply an expression of the divine spark that exists in all of us? Ironically clues come from a bizarre condition called "idiot savant syndrome" (or, to use the more politically correct phrase, the savant syndrome). These individuals (retarded and yet highly talented) can give us valuable insights about the evolution of human nature—a topic that became an obsession for some of the greatest scientific minds of the last century."17- "According to Wallace, as the human brain evolved, it encountered a new and equally powerful force called culture. Once culture. language and writing emerged, he argued, human evolution became Lamarckian—that is, you could pass on the accumulated wisdom of a lifetime to your offspring. These progeny will be much wiser than the offspring of illiterates not because your genes have changed but simply because this knowledge—in the form of culture—has been transferred from your brain to your child's brain. In this way, the brain is symbiotic with culture; the two are as interdependent as the naked hermit crab and with culture; the two are as interdependent as the naked hermit crab and its shell or the nucleated cell and its mitochondria. For Wallace, culture propels human evolution, making us absolutely unique in the animal kingdom. Isn't it extraordinary, he said, that we are the only animal in which the mind is vastly more important than any bodily organ, assuming a tremendous significance because of what we call "culture." Moreover, our brain actually helps us avoid the need for further specialization. Most organisms evolve to become more and more specialized as they take up new environmental niches, be it a longer neck for the giraffe or sonar for the bat. Humans, on the other hand, have evolved an organ, a brain, that gives us the capacity to evade specialization. We can colonize the Arctic without evolving a fur coat over millions of years like the polar bear because we can go kill one, take its coat and drape it on ourselves. And then we can give it to our children and grandchildren."18- "The moral of all this is not that we should have blind faith in the "wisdom of the East" but that there are sure to be many nuggets of insight in these ancient practices. However, unless we conduct systematic "Western-Style" experiments, we'll never know which ones really work (hypnosis and meditation) and which ones don't (crystal healing). Several laboratories throughout the world are poised to launch such experiments, and the first half of the next century will, in my view, be remembered as a golden age of neurology and mind-body medicine. It will be a time of great euphoria and celebration for novice researchers entering the field."19- "I won't pretend to have solved these mysteries, but I do think there's a new way to study consciousness by treating it not as a philosophical. logical or conceptual issue, but rather as an empirical problem."20- "It seems somehow disconcerting to be told that your life, all your hopes, triumphs and aspirations simply arise from the activity of neurons in your brain. But far from being humiliating, this idea is ennobling. I think. Science— cosmology, evolution and especially the brain sciences—is telling l us that we have no privileged position in the universe and that our sense of having a private non-material soul "watching the world" is really an illusion (as has long been emphasized by Eastern mystical traditions like Hinduism and Zen Buddhism). Once you realize that far from being a spectator, you are in fact part of the eternal ebb and flow of events in the cosmos, this realization is very liberating. Ultimately this idea also allows you to cultivate a certain humility—the essence of all authentic religious experience."21- "Paul Davies, who said: ..."This can be no trivial detail, no minor by-product of mindless, purposeless forces. We are truly meant to be here." Are we? I don't think brain science alone, despite all its triumphs, will ever answer that question. But that we can ask the question at all is, to me, the most puzzling aspect of our existence."
B**L
Enjoying it so far
I'm about half way through the book so far. A few things are very clear at this point. First, the author is a good writer. These are some dense/heavy topics. He makes them approachable and explains well how they add to his general theory of cognition and neurology. Second, the cases are really fascinating, and the author approaches them like a detective. This makes for a more involving and engaging reading experience. Third, the print is really small. I just started wearing glasses, and even with them, it's a bit physically uncomfortable to read the text. Regardless of this last point, I am thoroughly enjoying the book and have learned a lot from it.
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2 months ago
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