Thursday, April 7, 2011
Setting his sights on the mystery of human uniqueness, V.S. Ramachandran reveals what baffling and extreme case studies can teach us about normal brain function and how it evolved.
In his new book, the neuroscientist takes us on a tour of some seemingly inexplicable behaviors of the brain. For instance, how can a totally blind person locate a spot of light on a wall? Or, a patient in coma wake up to answer the phone and then lapse back into a coma?
MAUREEN CAVANAUGH: In his new book, neuroscientist V.S. Ramachandran takes us on a tour of some seemingly inexplicable behaviors of the brain. For instance, how can a totally blind person locate a spot of light on a wall? It is in finding answers to these questions that Dr. Ramachandran opens up new ways of understanding consciousness.
Work the doctor did back in the 90s trying to cure phantom pain in amputees has recently been adopted by the US Department of Defense and involves the simple use of mirrors. Now, he believes another kind of mirror, a so-called mirror neuron in the brain, may provide a key to understanding the mystery of autism.
V.S. Ramachandran, distinguished professor in the Psychology and Neurosciences Department, UCSD, author of "The Tell-Tale Brain: A Neuroscientist's Quest For What Makes Us Human
CAVANAUGH: I'm Maureen Cavanaugh, and you're listening to These Days on KPBS. In his new book, neuroscience, V. S. Ramachandran, takes us on a tour of some seemingly inexplicable in the brain. For instance, how can a totally blind person locate a spot of light on a wall or a patient in a coma wake up on answer the phone and then lapse back into a coma? It is in finding answers to these questions that doctor Ramachandran opens up new ways of being consciousness. Work the doctor did pack in the 90s trying to cure phantom pain in amputees has recently been adopted by the U.S. Department of Defense and involves the simple use of mirrors. Now, he believes another kind of mirror, a so called mirror neuron in the brain, may provide a key to understanding the mystery of autism. V. S. Ramachandran is distinguished professor in the psychology and neurosciences department at UC San Diego. And he is author of the new back, the tell tale brain. Ape neuroscientist's quest for what makes us human. Good morning, doctor Ramachandran.
RAMACHANDRAN: Good morning.
CAVANAUGH: This is such a rich and varied topic. I'd like to start with the basics.
CAVANAUGH: What is it that neuroscientists like yourself are looking for? What do you hope to discover in your studies?
RAMACHANDRAN: Well, as an analogy, let's take the history of biology, especially molecular biology, there're all of these odd phenomena like pigs giving birth to pigs but not to donkeys, which every child wonders about, you how you breathe, how you pump blood with your heart, and that has to a large extent been answered, but similar questions arise about the functions in the brain, and what we especially cherish about ourselves is our minds, how we fall in love, how we construct a body image, how woe cant plate ourselves, our own existence, how we contemplate death, how we can think about the vastness of space, all of this happening in this lump of jelly, which you can hold in the palm of your hand, made up of one billion nerve cells instead of like liver cells or other cells in the body. They're highly specialized for exchange of information. So we want to know how the active it of these cells or patterns of activity give rise to mental phenomenon, so called simple phenomenon that like looking at a flower or very complex phenomena like free will. And we believe this can be achieved. It may take 50 years, it may take 400 years, but we're slowly getting there.
CAVANAUGH: Now you describe neuroscience as a young science, in spite of the fact that psychiatry and neurology have been around for decades. So what is new about neuroscience?
RAMACHANDRAN: Well, I think that we're at the same stage in neuroscience as physics was in the 19th century, where people were just looking at the lay of the land and just discovering the basics. Exploring the basic phenomena of nature. Or the time of chemistry, earlier days of chemistry, when people were looking at elements, and looking at chemical compounds, and looking at their compounds, and noticing that some elements cluster together. Then they came up with a [CHECK AUDIO] taxonomy sort of thing, so what I'm getting at is, we're at the same stage in psychology and neuroscience, and we're discovering the lay of the land, and basically tinker, finding interesting phenomena, discovering their relationships, seeing if there's anything lawful, and coming up with lots of fascinating things to study. So in a sense, it's the best time to be in the field, when it's still in its infancy where you're doing Farraday style experiment, or Galileo, what did he do? He took a cardboard tube, I'm talking about Galileo, two lenses, aimed it at the sky, and discovered the sky, discovered the milky way is made up of stars, discovered the moons of Jupiter, these little specs were Jupiter were moving around Jupiter, so the earth can't be the center of is the universe. Because here are moons spinning around Jupiter. And all of that he discovered using a tube with two lenses so much we're at that stage in neuroscience and psychologist. It's very immature, and at the same time exhilarating the progress.
CAVANAUGH: I'm speaking with V. S Ramachandran, he is author of the new book, the tell tale brain, a neuroscientist's quest for what makes us human. Now, the way you go back trying to study the brain and what makes us human is very interesting. Because what you -- you learn an awful lots from extreme cases, one might even say bizarre behaviors in people's brains. What is that connection between damage or this extreme behavior and what he woo can learn about the way the brain functions?
RAMACHANDRAN: Well, the sort of thing my colleagues and I do in behavioral neurology, I think illustrates well, the magic of science. And speaking of magic, I think major has a great deal in common with science, where you take something completely incomprehensible and bizarre, but once it's explained, you have this feeling, ah ha! Why didn't I think of that before? When somebody else explains it, or you explain it, my god, why didn't I see it earlier? So that -- that's what makes science an exciting enterprise. And it has this check Sherlock homes like quality to it, where little odd clues can give you the key to the Treasury of insights into that area you're studying. This is not the only way to do since science, but it is one way to do science. And what I look at is patients with strange syndromes of usually we call these anomalies, so Thomas Kuhn spoke of paradigms in science, the reigning paradigm in science, [CHECK AUDIO] and continues doing science using those axioms that govern that science. Every now and then, some observation comes up which threatens to [CHECK AUDIO] and typical reaction, especially among my colleagues is to brush it under the carpet and gaze in a sort of mass denial. And this is not silly because a lot of times anomalies are false alarms and you can't just waste your time following them. But if you have a nose, if you have the intuition to lead you to the right ones, it can lead you to a gold mine.
CAVANAUGH: I want to interrupt you just a moment to tell everybody I'm speaking with doctor V. S Ramachandran, he's the author of the tell tale brain, a neuroscientist's quest for what makes us human. Now, doctor Ramachandran you've just been telling us about how anomalies and mutations can inform and actually advance the study of the brain, and of many other sciences as well. I'm wondering, at this point you're studying autism. And you're studying autism specifically the inability of autistic children to imitate the behavior of others. Tell us how you have basically focused in on that and why you think that's important.
RAMACHANDRAN: Well, going back to structure function correlation, that's groups of neurons in the front of the brain that send motor commands to control your muscles so if go and pick up a peanut with your arm, there's a neuron in the front of your brain, in the prenatal cortex that's firing, orchestrating the precise sequence of muscles you need to go and grab that peanut of that's just going along the spinal cord, out through the [[CHECK]] to the muscles. There are different nourishes for different actions like one neuron for putting something in your mouth, another one for pulling something, another one for make threading something through something. Now, that's been known for ages, miles an hour 50 years, they're called motor command nourishes but a subset of these, maybe 10, 15 percent, up to 20 percent, the peanut grabbing command neuron in your brain will fire when you watch somebody else grabbing a peanut. I'm sorry, grabbing a peanut I should say.
RAMACHANDRAN: So these are called mirror neurons because what is going in your brain, those cells in your brain, which is now called mirror neurons are constructing a virtual reality simulation looking at the world, in particular reach think out and grabbing the peanut from the other person's point of view, almost reading that person's intentions, reading that person's mind, so they have been called mind reading neurons or mirror neurons and we know they also almost certainly exist in humans, they have been discovered in monkeys, and through functional imaging, there are strong hunts that they exist in human. Now you do need other neurons for stimulating other minds, and to think of other people as people so you can empathize with. So you need of them for empathy. And other have suggested they're involved the emergence of language, and they may be involved things like pretend play, so you temporarily adopt the role of the toy, the superman, which children do all the time. And emotional empathy, and these are precisely the things that are missing in autism, so if you make a list of deficits in autism, lack of pretend play, difficulty in imitation and make a list of what mirror neurons are expected to do, it's almost a precise match. So this is what led us to study, suggest, ten years ago, that mirror are neuron dysfunction may be one of many causes that leads to autism. And even to this day, I should point out, the evidence for this is compelling but not conclusively. More work needs to be done. Maybe it's not the mirror neurons themselves that are affected with you1 the neurons that [CHECK AUDIO] but something connected with mirror neurons is messed up in their brain is my view.
CAVANAUGH: Doctor Ramachandran, one area in which your research and your experiments have now actually resulted in a new therapy for U.S. war veterans. Is your work with amputees and phantom limbs. You tell us about a patient named Victor who lost his arm, and you constructed a device that really sort of removed the phantom pain that he was having in that arm.
RAMACHANDRAN: Whys. Had, are people with amputations often have -- 99 percent of them zoo a phantom. If you amputate the arm, they have a phantom arm, if you amputate the leg, they have a phantom leg. And this is very common. And the majority of them, maybe two thirds of them, have intense pain in the phantom. It's called a phantom pain. And they'll say things like my arm is clenched into a fist, my phantom, and the nails are digging into the palm. And it's excruciatingly painful. And it has been notoriously difficult to treat. I mean, chronic pain in a real limb is hard enough to treat. And by the way, it turns out you can use mirrors to treat human chronic pain in an in tact limb, not just in phantoms. Even more astonishing. But with a phantom, being clenched, and the guy says I'm trying to open it, and it's painful, and it's clenched, and it's awkward and so on and so forth. We don't know why this happens, but it's as though the discrepancy, of trying to move it, the motor command go to the arm, the phantom arm, but then it fails to go to the [CHECK AUDIO] partly to the pain so much we said what if you restore the loop so that you get the visual illusion that the phantom is actually obeying your command? How do you do that? You can't do that because you can't see your phantom. So we devised a trick of putting the mirror on the table in front of the patient. Propped up vertically with a couple of brick or put the mirror in a cardboard box. So that the mirror is parallel to your nose so to speak. Then you can look in -- let's say your left arm -- you are the patient, your left arm is a phantom. You put the left arm on the left side of the mirror, the phantom on the left side of the mirror, and it's clenched and in an awkward position and it's very painful, then you put your right arm on the right side of the mirror, and mimic the clenching so it has the same posture as the felt position of the phantom. Then you look at the reflection of the normal arm in the mirror, it looks like the phantom has come back. You create the visual illusion of having resurrected the phantom. Now, if you send commands to both hands, your right hand, of course, will open and close or move left and right, and you send the [CHECK AUDIO] so it looks like you create the visual illusion that not only has the phantom left arm been resurrected but it's obeying your command to clench or unclench and recheck check and this restores the loop, and seems astonishingly to open the hand, mobilize the hand and animates the hand, and this seems to relieve the phantom pain in about half the patients we've seen. And subsequently, elaborate clinical trials have been done by people like Walter reed, and shown that in fact in large scales, medical trials, it works. But it was the first time anybody had shown that visual input, coming from vision and where are eye walls can go into the brain ask can feed all the way back to pain centers in the brain and powerfully modulate pain and eliminate chronic pain in many instances. Now, you can do this to some extent with intense imagery too. People have shown that. But to a much smaller extent, and this is because imagery taps into the same circuits. And what you're doing with the mirror is target into those circuits in a very precise manner in a very simple -- using a five dollar mirror with a bunch of bricks which alleviates the pain in many cases. Now I mentioned real pain in a real arm. But even more exciting you can have a condition called complex regional pain syndrome, which is caused by a tiny little fracture or? Other source of injury in a finger, say, and normally, the finger is instantly immobilized by a reflex to protect it from further diagonal. Then what happens, it becomes swelled up, it becomes warm, it becomes painful but in some patients, as many as ten percent or 5 percent of patients, the finger becomes more swollen, more enflamed instead of subsiding, and the inflammation and pain spread to the entire arm. And you're stuck with this for life, the arm is paralyzed, painful, swollen forever. The astonishing thing is if you put a mirror, and look at the other hand, the reflection, and start moving it, so it looks like your paralyzed arms is moving with impunity, there's no pain, the brain is satisfied, so to speak that it can move that quote unquote painful arm, and get away did it. So you then start moving it, and the astonishing thing is it starts moving, and the pain subsides hymn instantly in many cases, if you do it for a few weeks, it subsides permanently, and the majority of patients going down from excruciating pain [CHECK AUDIO] mind body interactions, and it harks back to what I said 10, 15 years ago, that visual input can be used to powerfully modulate chronic pain and be clinically useful for patients.
CAVANAUGH: I just want to reiterate the fact that in army and military hospitals across the nation, this mirror technique to alleviate phantom pain in amputee system being used as a standard treatment now, and it comes from the research that you have done on this, I am struck, however, in the way that you're talking about this, in another thing that you have in your book about your tendency to really like simple methods. Simple methods to test your ideas about the way the brain operates. Talk to us a little bit about that.
RAMACHANDRAN: Well, I think it's true in any science. As I was saying earlier about Faraday or Galileo, often the answers are staring you in the face, and very simple experiments can reveal very important truth it is. There's no relation to the amount of work and effort you put into solving a problem, and how important the problem is. Sometimes there's a very -- what appears to be a very complicated problem, there's a simple, elegant solution to it. I think tattoo not something people learn, it's a style of research people can learn. Many of my students now adopt this method. And if you think about it, it's sort of obvious. And upon more training in medicine, in the early days in India, I think we relied off on clinical intuition, we relied on just simple hunches. And that, and also you had to be resourceful, given the absence of equipment, you had to be resourceful, I guess that's what I'm trying to say.
CAVANAUGH: I see.
RAMACHANDRAN: This forces you to be -- I don't want to say ingenious. It forces you to be resourceful, and that spills over into your research.
CAVANAUGH: And imaginative.
RAMACHANDRAN: And imaginative you might say, yes.
CAVANAUGH: Yes. Let me ask you, what are you most excited about in the field of neurosciences today.
RAMACHANDRAN: Well, you know, in science it's very hard to say because it's almost like most people don't like to hear this, it's like a fishing expedition. Suddenly you see a new -- you're going along one path, and suddenly you see a new clearing and a new path, and go off in a new direction. [CHECK AUDIO] even with phantom limbs, we found some astonishing new things, for example, a patient with a phantom limb, if he simply watches another person touching himself, his normal arm, the patient with the phantom limb then experiences it in his phantom. And phantoms have been known for over a hundred years, two hundred years, no observed this, and this happens almost certainly because of mirror neurons, the mirror neurons, fire when this other person is being touched but ordinarily you don't feel that because your skin is telling you, no, never mind, don't worry, you're not being touched. So you experience or know what he's feeling, empathize with what he's feeling but don't literally feel it, because otherwise you would get confused. But when you activate the arm, that null signal is missing, so you literally feel it in your arm.
CAVANAUGH: When you speak about mirror neurons, in fact they're pretty much all over your book, the tell tale brain, because you feel that these -- these neurons that help us empathize with other people, not only affect the way our bodies feel, but also affect the way we communicate with each other.
RAMACHANDRAN: Yes. To one of the points I make, and this has been made by other people too, it's kind of obvious. Is that they're involved in imitation learning so sophisticated learning through imitation is something that's fairly unique to humans. Monkeys can do it to a very limited extent. Despite the fact you use the phrase aping somebody, apes are not actually very good at it, orangutans are not bad. But nothing like humans, where you can watch somebody light a match and pretty much in a couple of trails or make a tool or light a fire or build a shelter or hunt a polar bear. And that's very important, all of these skills are transmitted very quickly. And that's very important in evolution because it transformed for the first time in the history of life on this planet, it transformed Darwinian evolution, which appears to be a painful laborious process of natural selection, weeding out from the genome genes that are not favorable for survival. So if you want a bear wants to evolve a coat, a fur coat, you 92 Ed to go through a thousand generations. Through natural selection. Each generation of bear has a slightly furrier coat, and it survives more and leaves more genes, and they get transmitted. But in a headquarter, an early homo erectus, or homo sapiens wanted to wear a fur coat, all they do is watch mom slay a bear, chase a bear, hunt down a bear, slay a bear, skin a bear and put it on, and can learn this in one issue maybe 3 or 4 tries so what took a thousand generations or a hundred thousand years, maybe, I'm just using numbers from the top of my head here, happens in just one generation. So as soon as the skill is acquired, it's transmitted to one generation to your offspring and on to your neighborhood neighbors, and it spreads very quickly if it's a useful innovation. So in a sense you could say evolution became Lamarckian instead of Darwinian. By which I mean, it became cultural. So the cultural evolution began. And then of course the language came into the picture, and it then became even faster, the transmission of knowledge through language. Then you of course have writing, the printing press, and then now of course the Internet. But the very first of these, the first worldwide web was little mirror neuron system.
CAVANAUGH: Let me ask you in closing, doctor Ramachandran, and this may be an unfair question, but I wonder if you have an answer for it. Of all the bizarre brain behaviors that you have witnessed, is there any one that really stumps you and sets you back and makes you just rethink everything?
RAMACHANDRAN: Well, I would say that my two favorite disorders are phantom limb syndrome because we've learned so much about so many different areas of research from just this one research. But what we're currently stumped by, and part of the problem is a disorder called [CHECK AUDIO] where the patient wants his arm removed. And there are aspects of this which is still puzzling. And people used to think it was just a psychological syndrome, and they want attention and things like that, which is all nonsense. What we found was that these people who are otherwise completely normal, in fact they even regard what they have, to have an arm amputated, as not necessarily abnormal, and many of them go and get it amputated. But as a scientist, I want to know what's going on in the brain. And it turns out that your parietal lobule, which is where you represent your body, where your body imagine is, that region of the brain fails to be represented. My students, Paul McGill and David Brian and I showed this some years ago. That this map is completes in all of us, of course, it's where you have a body image. It's missing this arm. But the input from the arm still goes to the brain, and doesn't have a place to go. And this produces an acute anxiety, it generates discomfort, which is sensed by the brain, and the brain then starts saying, abhorring the arm, saying, I want it removed, it's intrusive. And they get it removed. But there are still many aspects of the disorder which are [CHECK AUDIO] and why that would happen in our theory is hard to explain. So -- and there's another disorder called [CHECK AUDIO] syndrome that a person thinks he's dead, he claims with a perfectly straight face, even though he's intelligent and articulate and not [CHECK AUDIO] very often they're depressed, and very often they're not depressed, and they'll say I don't exist. How can a person say I don't exist, but his very denial implies he exists? So you get these interesting paradoxes in neurology, which is what makes this so challenging and intriguing, and sometimes you're lucky and you solve the paradox am.
CAVANAUGH: Well, I want to thank you so much for speaking with us today. Thank you so much.
RAMACHANDRAN: Thank you.
CAVANAUGH: I've been speaking with doctor V. V ram Ramachandran, [CHECK AUDIO] he is author of the tell tale brain a neuroscientist's quest for what makes us human. You've been listening to These Days on KPBS.