THE passion is palpable in his bearing, in the onrush of words and his forceful gestures. The accomplished physician morphs into the adventurous neuroscientist, and yet again into the curious psychiatrist. His brinkmanship with science is breathtaking. The fame of Dr V.S. Ramachandran, Professor of Psychology and Neuroscience and Director of the Centre for Brain and Cognition at the University of California, San Diego, the author of the path-breaking work Phantoms in the Brain and its coda, The Emerging Mind (delivered initially as the Reith Lectures 2003), of the recipient of many academic honours and awards, sits lightly on him as he excitedly delves into the unknown:

How do you see the intrusion philosophy has made into neuroscience?

Inevitably, when you do neuroscience cognitive neuroscience or behavioural neurology it throws up all kinds of philosophical questions, such as what is mind, what is the relationship between qualia, sensations, the activity of neurons, what is the nature of the self, the question of personal identity. But, as we advance in science, this has enormous implications for philosophy. Some people could regard these as antithetical, but they really are not, because, obviously, quantum mechanics has profound implications for understanding causality, the meaning of causality. Some of the greatest philosophers like Kant and Ernst Mach also inspired Einstein. So its always a cross-fertilisation of ideas.

Would you say that as neuroscience continues to discover more and more of whats happening in the human mind or the brain, philosophy will recede and be painted into a corner?

I think with some philosophical questions, that will happen, they will be painted into a corner. But there will always be some fundamental issues of epistemology, such as: why do we exist? Why is there anything, rather than nothing? Science doesnt attempt to deal with these questions. On the other hand, the strange thing about consciousness is that we are not even sure whether it is a philosophical question or a scientific question.

Within the brain, certain areas seem to be more involved in what we call consciousness. And what we call consciousness also seems to be several processes which we are lumping together in one word. And its possible we can dissect these different processes and map them in different brain structures. That will enrich your understanding of consciousness. And then questions like, where is consciousness, or what is it, will recede into the background. Its a bit like when people ask: what is life? You know, living things are different, they have the vital spark. Now we know there is no vital spark, theres the DNA molecule, DNA replication, transcription, theres RNA, the Krebs cycle... once you understand all these processes nobody comes and says, yes, but you have to tell me what life is.

It would seem it is subjective consciousness that is the problematic area. What is called qualia, right?

You see, theres an analogous problem in physics where once Einstein came up with the idea of a space-time metaphor, the notion of what the present is. The whole idea of passage of time, it has been claimed, is an illusion, its not something that physics acknowledges. Yet we know that time passes. We are not even sure whether this is a philosophical problem or a scientific one.

Similarly, with consciousness and qualia, it is intimately linked to your sense of self. If you dont have a self, theres no question of qualia, right? The whole question of me experiencing red if there is no me, there is no question of experiencing red. So these are dual aspects of the same phenomenon, the sense of personhood, the sense of me. And the ability to know that you are aware of green, which I call a meta representation. So these are two sides of the coin. Now, thats proving to be the most elusive problem in all of neuroscience, all of biology.

But as scientists, what we are trying to do is to approach this problem indirectly, just as people understood heredity and DNA by looking at viruses. Are viruses half alive? We crystallise them, they behave like chemicals. But we also know that they replicate, and now we know that there are RNA molecules. So once we have understood DNA, nobody asks if the virus is really alive or not. Similarly, in consciousness, one day we may achieve a mature enough understanding of what it is.

You seem, in your [Reith] lecture, to assume that many brain functions are localised. For example, you talk of the fusiform gyrus for analysing colour information. Are many cognitive processes localised thus?

Some functions are localised fairly sharply in specific brain areas as well. Nobody would deny that the cough reflex, which is also a function of the brain, is a specific reflex that goes to the brain stem.

Now, whether these are localised or not is an empirical question. Some may turn out to have small sets of circuits involved, others may involve large chunks of neural tissue. But this should not be transformed into a philosophical question, like Fodor and others have tried to make it. Now, I welcome their contribution in that they try to clarify what you mean by localised, what you mean by not localised. But they dont take it any further. What I want to know is: which function is localised, where is it localised, to what extent is it localised?

Its a bit like the nature/nurture question. When I ask is it mainly genes, or is it environment, it turns out this is a meaningless question because theres always an interaction between the two.

You can take an ape and put it in a public school. Its not going to develop a proper public school accent. On the other hand, if a human is raised in a cave hes never going to be a scholar. This is obvious.

Its amazing how much acrimony goes into this without understanding that the only way to understand this is to do experiments. And some things, like the cough reflex, nobody would say you learnt it. Its completely genetic, or mostly genetic. But in something else, say language, learning is involved to a large extent, especially your lexicon, the words. Nobody would deny that.

How much credence would you give to the functionalist interpretation of neural states that some philosophers seem to promote?

We are not opposed to functionalism as a theory. But as a methodology, its seriously flawed. For example, with heredity, you can only get so far with functionalism. Its only when they did X-ray crystallography and understood the double helical structure that they saw the genetic code. If some philosopher had said, No, No, heredity is a function and needs functional analysis, wed still be stuck with Mendelian genetics; we wouldnt have understood DNA. I think the same is true of the brain.

Is your approach to cognitive science based on empirical studies or intuition?

Intuition is what gets you started; and then you need empirical studies. In every lab now in the United States, in every corner, theres an fMRI being done, an EEG being done. Now, there is so much of it being done that purely by accident some of it is going to be good. Technology often drives science just think of the telescope, the microscope and so obviously its a good thing overall. But the brain behind the microscope, the brain behind the telescope, is just as important, if not more important. Hundreds of children were using telescopes as toys, but Galileo had to come along and look at the stars. Likewise, brain-imaging technology often lulls you into a false sense of having understood whats going on.

Would you then care to speculate on the nature of consciousness?

The word consciousness, like life, is used in many different ways. Its a collection of different mechanisms. One is qualia. And then theres the notion of self awareness. I am aware that I am seeing red. Its debatable whether a cat is aware that it is seeing red no doubt it sees red and it reacts appropriately. Now, theres a tantalising question: if you are not aware that you are seeing red, are you even aware of red? In other words, without knowing that you know, the word know doesnt mean anything.

But the poet Rimbaud says you should no longer say I think. You should say, it thinks me.

Its interesting you should mention Rimbaud, because hes also synesthetic. Thats one of the phenomena weve been studying lately, where people get their senses muddled up. When they hear tones, they see colours. When they see numbers, they see colours. People used to think this was some kind of quirk. People even used to think it was bogus, that they were making it up. About seven or eight years ago, my student Ed Hubbard and I showed that this is a genuine sensory phenomenon, which parts of the brain are involved, and that it has deeper implications for understanding things like what is metaphor.

Now we have become very interested in this discovery of mirror neurons. These are neurons in the front of the brain. You record from them this has been done by Giaccamo and Rizzolatti in 1996 or 97, I believe and these neurons in the frontal lobes recorded from a monkey fire every time the monkey reaches for a peanut. So one neuron fires when the monkey reaches for the nut, another neuron fires when it pulls a lever, another when it pushes something, another neuron when the monkey picks up a nut and puts it in its mouth.

Now, what Rizzolatti found, to his amazement, was that some of these neurons would fire when the monkey watches another person performing that action. This was truly extraordinary.

I said that this was going to do for psychology what DNA did for biology help explain a host of hitherto mysterious mental capacities, like the early emergence of language, words, proto language, metaphor, your ability to transmit culture through imitation, through emulation, empathy, your ability to put yourself in another persons shoes, look at the world from his point of view.

The neurons are allowing you to put yourself in the other monkeys shoes, the other persons shoes. So I call them the empathy neurons, or the Dalai Lama neurons it fires in you when you hurt somebody else! This neuron is telling you that, in some sense, you are literally feeling his pain.

One of the things we have discovered in our lab is the cause of the cruel disorder called autism, which you see in children. The word autism literally means aloneness. Autistic children have grossly impoverished language and communication skills, no empathy for other people, and inability to adopt another persons point of view. And, as has been known, they have a huge problem with metaphor, the metaphoric use of sentences. A bulb flashed in my mind and I said: My God, whats gone wrong in autism are precisely the functions of mirror neurons. So maybe autism is caused by deficits of mirror neurons. If autistic children reach out and grab something, the neurons fire. But when they watch somebody, there is no activity.

When studying animal brains one can induce lesions, which may not be possible with human brains. So you are left with non-interventionist techniques for a good part, arent you?

Yes, but sometimes nature gives you an experiment, because you may have a patient with a very small lesion. If the stroke is sufficiently small, with the imaging techniques now available, you can pinpoint. You can find another patient with a lesion in a different location. And then you do the behavioural experiment and correlate. Even better than that, now youve got magnets which can temporarily inactivate a part of the brain. And then you see how does the behaviour change.

On the ethical dimensions of neuroscience experimentation.

Obviously, there are tremendous ethical issues here. But I would say no more than the problems of cloning, the problems of abortion, the problems of nuclear weapons they are ethical problems, but they are in a sense political as well. They have to be tackled politically.

Imagine five centuries from now I am a mad neuroscientist and I produce a brain in a vat. I take your brain and put it in a vat. I can give all the right patterns and make you think youre Bill Gates, Hugh Hefner, Mark Spitz, Crick... everybody you want to be but retaining your identity. In other words, your personal cherished memories of upbringing in Kerala I am not wiping off all that, but, as bonus, you also have the abilities of a Crick, of a Gates, and so on.

I give you the choice of that artificial brain or the real you continuing. Now, ninety per cent of people pick the real you.

Exactly. Because, logically, youre already a brain in a vat there is the cranial cavity and all that. I ask you which vat do you want and you prefer the crummy vat! But to create the simulations in the vat, you have to understand the brain enough to understand culture, for instance. And culture, by its very nature, depends on the contingencies of what happened.

Without understanding that, how can you programme it in the vat? So you could say that this Frankenstein scenario will never happen. You could argue both ways: that the time will come when all this will be understood; or that given the uniqueness of cultural trajectories, and without a peculiar concatenation of environmental and genetic circumstances, how can you create it?

The brain, with a trillion or so synapses, is such a fascinating field.

Yes, but before that you may think that this brain in the vat business is some science fiction stuff. Its not going to happen any time. And I agree its not going to happen soon. But we are approaching that.

Your blog, your i-way-, i-view, email, webmail we are all being already assimilated into the brahman of cyberspace. What is the individual, but a node in this huge Internet? We are approaching that stage where we are becoming like the brain in the vat.