VS Ramachandran: Self-awareness, the Last Frontier

Posted on January 8, 2009 
Filed Under Brainfood

From The Edge:

qualia (QUAIL-yuh or QUAL-yuh singular: quale, QUAL-ee or -ay): Often referred to a “raw feels”, qualia are those subjective, qualitative properties of mental states such as sensations and emotions—the “what it is like” to see red, feel pain, be angry. Such mental states are thought to have intrinsic qualitative features by which we identify them through introspection.

Neuroscientist VS Ramachandran sheds light, by way of analogy and intriguing true cases, on self-awareness and a new term for me – qualia:

One of the last remaining problems in science is the riddle of consciousness. The human brain—a mere lump of jelly inside your cranial vault—can contemplate the vastness of interstellar space and grapple with concepts such as zero and infinity. Even more remarkably it can ask disquieting questions about the meaning of its own existence. “Who am I?” is arguably the most fundamental of all questions.

It really breaks down into two problems — the problem of qualia and the problem of the self. My colleagues, the late Francis Crick and Christof Koch have done a valuable service in pointing out that consciousness might be an empirical rather than philosophical problem, and have offered some ingenious suggestions.

But I would disagree with their position that the qualia problem is simpler and should be addressed first before we tackle the “Self.” I think the very opposite is true. I have every confidence that the problem of self will be solved within the lifetimes of most readers of this essay. But not qualia.

The qualia problem is well known. Assume I am an intellectually highly advanced, color-blind Martian. I study your brain and completely figure out down to every last detail what happens in your brain—all the physico-chemical events — when you see red light of wavelength 600 and say “red”. You know that my scientific description, although complete from my point of view, leaves out something ineffable and essentially non-communicable, namely your actual experience of redness.

There is no way you can communicate the ineffable quality of redness to me short of hooking up your brain directly to mine without air waves intervening (Bill Hirstein and I call this the qualia-cable; it will work only if my color blindness is caused by missing receptor pigments in my eye, with brain circuitry for color being intact.) We can define qualia as that aspect of your experience that is left out by me — the color-blind Martian. I believe this problem will never be solved or will turn out (from an empirical standpoint) to be a pseudo-problem. Qualia and so-called “purely physical” events may be like two sides of a Moebius strip that look utterly different from our ant-like perspective but are in reality a single surface.

So to understand qualia, we may need to transcend our ant-like view, as Einstein did in a different context. But how to go about it is anybody’s guess.

The problem of self, on the other hand, is an empirical one that can be solved — or at least explored to its very limit — by science. If and when we do it will be a turning point in the history of science. Neurological conditions have shown that the self is not the monolithic entity it believes itself to be. It seems to consist of many components each of which can be studied individually, and the notion of one unitary self may well be an illusion. (But if so we need to ask how the illusion arises; was it an adaptation acquired through natural selection?)

Consider the following disorders which illustrate different aspects of self.

Out of body experiences: patients with right fronto-parietal strokes report floating out into space watching their body down below — undoubtedly contributing to the myth of disembodied souls. Left hemisphere strokes result in the feeling of a mysterious presence — a phantom twin — hovering behind the patient’s left shoulder.

Apotemnophilia: An otherwise completely normal person develops an intense desire to have his arm or leg amputated. The right parietal (a part of it known as SPL) normally contains a complete internal image of the body. We showed recently that in these patients the part of the map corresponding to the affected limb is congenitally missing, leading to alienation of the limb.

The patients are sometimes sexually attracted to amputees. We postulate that in “normal” individuals there is a genetically specified homunculus in S2 that serves as a template acting on limbic and visual areas to determine aesthetic preference for ones own body type. Hence pigs are attracted to pigs not people. (Which is not to deny an additional role for olfactory and visual imprinting) But if the image in S2 is missing a limb this may translate into an aesthetic preference toward an amputee – mediated by reverse projections that are known to connect the (“emotional”) amygdala to every stage in the visual hierarchy.

Transsexuality: A woman claims that for as far back as she can remember she felt she was a man trapped in a woman’s body—even experiencing phantom penises and erections. Our ordinary notion of every person having a single sexual identity (or self) is called into question. It turns out there are at least four distinct aspects of sexuality; your external anatomy, your internal brain-based body image, your sexual orientation and your sexual identity—who you think others think of you as. Normally these are harmonized in fetal development but if they get uncoupled you become a transsexual person. (It is important to note there is nothing “abnormal” about them, any more than you would regard being gay as abnormal.)

A patient with a phantom arm simply watches a student volunteer’s arm being touched. Astonishingly the patient feels the touch in his phantom. The barrier between him and others has been dissolved.

Cotards syndrome: the patient claims he is dead and rejects all evidence to the contrary.

Capgras delusion: the patient claims that his mother looks like his mother but is in fact an impostor. Other patients claim that they inhabit a house that’s a duplicate of their real house. Bill Hirstein and I (and Haydn Ellis and Andrew Young) have shown that this highly specific delusion arises because the visual area in the brain is disconnected from emotional areas. So when our patient David sees his mother he recognizes her — along with the penumbra of memories linked to her. But no emotions and no jolt of familiarity is evoked so he rationalizes away his curious predicament saying she is an impostor. It is important to note that these patients are usually intelligent and mentally stable in most other respects. It is the selective nature of the delusion that makes it surprising and worth studying.

David also had difficulty abstracting across successive encounters of a new person seen in different contexts to create an enduring identity for that person. Without the flash of recognition he ought to have experienced in the second, third or n’th exposure, he couldn’t bind the experiences together into a single person. Even more remarkably David sometimes duplicated his own self! He would often refer to “The other David who is on vacation.” It was as if even successive episodes of his own self were not bound together the way they are in you and me.

This is not to be confused with MPD (“multiple personality disorder”) seen in psychiatric contexts. MPD is often a dubious diagnosis made for medico-legal and insurance purposes and tends to fluctuate from moment to moment. (I have often been tempted to send two bills to an MPD patient to see if he pays both.) Patients like David, on the other hand, may give us genuine insight into the neural basis of selfhood.

• In another disorder the patient, with damage to the anterior cingulate develops “akinetic mutism”. He lies in bed fully awake and alert but cannot talk or walk — indeed doesn’t interact in any way with people or things around him. Sometimes such patients wake up (when given certain drugs) and will say “I knew what was going on around me but I simply had no desire to do anything”. It was if he had selective loss of one major attribute of the self — free will.

• Even odder is a phenomenon called “The telephone syndrome”. The patient (I’ll call him John) will display akinetic mutism — no visual consciousness — when seeing his (say) father in person. But if he receives a phone call from his father he suddenly becomes conscious and starts conversing with him normally. (S. Sriram and Orrin Devinsky, personal communication.) It’s as if there are two Johns — the visual John who is only partially conscious and the auditory John (with his own self) who talks over the phone. This implies a degree of segregation of selves — all the way from sensory areas to motor output — that no one would have suspected…

The purported “unity” or internal consistency of self is also a myth. Most patients with left arm paralysis caused by right hemisphere stroke complain about it as, indeed, they should. But a subset of patients who have additional damage to the “body image” representation in the right SPL (and possibly insula) claim that their paralyzed left arm doesn’t belong to them.

The patient may assert that it belongs to his father or spouse. (As if he had a selective “Capgras” for his arm). Such syndromes challenge even basic assumptions such as “I am anchored in this body” or “This is my arm”. They suggest that “belongingness” is a primal brain function hardwired through natural selection because of its obvious selective advantage to our hominoid ancestors. It makes one wonder if someone with this disorder would deny ownership of (or damage to) the left fender of his car and ascribe it to his mother’s car.

There appears to be almost no limit to this. An intelligent and lucid patient I saw recently claimed that her own left arm was not paralyzed and that the lifeless left arm on her lap belonged to her father who was “hiding under the table”. Yet when I asked her to touch her nose with her left hand she used her intact right hand to grab and raise the paralyzed hand—using the latter as a “tool” to touch her nose!

Clearly somebody in there knew that her left arm was paralyzed and that the arm on her lap was her own, but “she” — the person I was talking to — didn’t know. I then lifted her “father’s hand” up toward her, drawing attention to the fact that it was attached to her shoulder. She agreed and yet continued to assert it belonged to her father. The contradiction didn’t bother her.

Her ability to hold mutually inconsistent beliefs seems bizarre to us but in fact we all do this from time to time. I have known many an eminent theoretical physicist who prays to a personal God; an old guy watching him from somewhere up there in the sky. I might mention that I have long known that prayer was a placebo; but upon learning recently of a study that showed that a drug works even when you know it is a placebo, I immediately started praying. There are two Ramachandrans — one an arch skeptic and the other a devout believer. Fortunately I enjoy this ambiguous state of mind, unlike Darwin who was tormented by it. It is not unlike my enjoyment of an Escher engraving…

MORE.

VS Ramachandran at TED talks on YouTube.

Comments

One Response to “VS Ramachandran: Self-awareness, the Last Frontier”

  1. Joe on January 29th, 2009 6:33 pm

    Cool piece.
    I can’t begin to imagine what it’s like to think my arm belongs to someone else. And to truly believe it despite obvious evidence otherwise.

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