Vilayanur S. Ramachandran explains what brain damage can reveal about the connection between celebral tissue and the mind, using three startling delusions as examples.
Vilayanur Subramanian “Rama” Ramachandran is a neurologist best known for his work in the fields of behavioral neurology and psychophysics. He is currently the Director of the Center for Brain and Cognition, Professor in the Psychology Department and Neurosciences Program at the University of California, San Diego, and Adjunct Professor of Biology at the Salk Institute for Biological Studies.
Ramachandran initially obtained an M.D. at Stanley Medical College in Madras, India, and subsequently obtained a Ph.D. from Trinity College at the University of Cambridge. Ramachandran’s early work was on visual perception but he is best known for his experiments in behavioral neurology which, despite their apparent simplicity, have had a profound impact on the way we think about the brain.
Ramachandran has been elected to fellowships at All Souls College, Oxford, and the Royal Institution, London (which also awarded him the Henry Dale Medal). He gave the 2003 BBC Reith Lectures and was conferred the title of Padma Bhushan by the President of India in 2007. He has been called “The Marco Polo of neuroscience” by Richard Dawkins and “the modern Paul Broca” by Eric Kandel. Newsweek magazine named him a member of “The Century Club”, one of the “hundred most prominent people to watch” in the 21st century.
Vilayanur Ramachandran‘s partial transcript: I study the human brain — the functions and structure of the human brain. And I just want you to think for a minute about what this entails. Here is this mass of jelly — three pound mass of jelly you can hold in the palm of your hand, and it can contemplate the vastness of interstellar space. It can contemplate the meaning of infinity and it can contemplate itself contemplating on the meaning of infinity. And this peculiar recursive quality that we call self-awareness, which I think is the Holy Grail of neuroscience, of neurology, and hopefully, someday, we’ll understand how that happens.
OK, so how do you study this mysterious organ? I mean you have 100 billion nerve cells, little wisps of protoplasm, interacting with each other, and from this activity emerges the whole spectrum of abilities that we call human nature and human consciousness. How does this happen? Well, there are many ways of approaching the functions of the human brain. One approach, the one we use mainly, is to look at patients with sustained damage to a small region of the brain, where there’s been a genetic change in a small region of the brain. What then happens is not an across-the-board reduction in all your mental capacities, a sort of blunting of your cognitive ability. What you get is a highly selective loss of one function with other functions being preserved intact, and this gives you some confidence in asserting that that part of the brain is somehow involved in mediating that function. So you can then map function onto structure, and then find out what the circuitry’s doing to generate that particular function. So that’s what we’re trying to do.
So let me give you a few striking examples of this. In fact, I’m giving you three examples, six minutes each, during this talk. The first example is an extraordinary syndrome called Capgras syndrome. If you look at the first slide there, that’s the temporal lobes, frontal lobes, parietal lobes, OK — the lobes that constitute the brain. And if you look, tucked away inside the inner surface of the temporal lobes — you can’t see it there — is a little structure called the fusiform gyrus. And that’s been called the face area in the brain because when it’s damaged, you can no longer recognize people’s faces. You can still recognize them from their voice and say, oh yeah, that’s Joe, but you can’t look at their face and know who it is, right? You can’t even recognize yourself in the mirror. I mean, you know it’s you because you wink and it winks, and you know it’s a mirror, but you don’t really recognize yourself as yourself.
OK. Now that syndrome is well known as caused by damage to the fusiform gyrus. But there’s another rare syndrome, so rare, in fact, that very few physicians have heard about it, not even neurologists. This is called the Capgras delusion, and that is a patient who’s otherwise completely normal has had a head injury, comes out of coma, otherwise completely normal, he looks at his mother and says, “This looks exactly like my mother, this woman, but she’s an impostor — she’s some other woman pretending to be my mother.” Now, why does this happen? Why would somebody — and this person is perfectly lucid and intelligent in all other respects, but when he sees his mother, his delusion kicks in and says it’s not mother.
Now, the most common interpretation of this, which you find in all the psychiatry text books, is a Freudian view, and that is that this chap — and the same argument applies to women by the way, but I’ll just talk about guys — when you’re a little baby, a young baby, you had a strong sexual attraction to your mother. This is the so-called Oedipus complex of Freud. I’m not saying I believe this, but this is the standard Freudian view. And then as you grow up, the cortex develops, and inhibits these latent sexual urges towards your mother. Thank God, or you would all be sexually aroused when you saw your mother. And then what happens is, there’s a blow to your head, damaging the cortex, allowing these latent sexual urges to emerge, flaming to the surface, and suddenly and inexplicably you find yourself being sexually aroused by your mother. And you say, “My God, if this is my mom, how come I’m being sexually turned on? She’s some other woman. She’s an impostor.” It’s the only interpretation that makes sense to your damaged brain.