The Phantom Neuroscientist

Cubist KingIn recent weeks, I have been devouring V.S. Ramachandran’s books and videos on what can be learned about the brain by studying patients with neurological damage.  To clarify my title, Ramachandran is not a phantom himself, but a doctor of phantoms – actually a ‘phantom-buster’.  He is famous for curing phantom-limb syndrome – an amputee’s stubborn, often debilitating, physical awareness of a limb that has been surgically removed – by an amazingly simple, low-tech trick with mirrors.

The ‘Phantom-Buster’ Mirror Trick

One of Ramachandran’s patients was desperate for relief from pain in his phantom arm, which he felt to be cramped and paralyzed.  As described in A Brief Tour of Human Consciousness:

We propped up a mirror vertically on a table…so that it was at right angles to his chest, and asked him to position his paralyzed phantom left arm on the left of the mirror and mimic its posture with his right hand, which was on the right side of the mirror.  We then asked him to look into the right-hand side of the mirror so that he saw the mirror reflection of his intact hand optically superimposed on the felt location of the phantom.  We then asked him to try to make symmetrical movements of both hands, such as clapping or conducting an orchestra, while looking in the mirror.  Imagine his amazement and ours when suddenly he not only saw the phantom move but felt it move as well.

The patient’s feeling of paralysis, and his pain, were instantly relieved.  A program of mirror therapy eventually resulted not only in permanent loss of pain in the phantom arm, but “loss” of the phantom itself – a dramatic change in the patient’s felt experience of his own body.

The sense of physical self – body-image – is part of our self-awareness.  The skin is an important boundary.  Tactile sensations start at the skin, and extend inwards.  Body-image includes the sense of proprioception – of where one’s body is in space – which is vital to our ability to navigate successfully through the world.

Phantom limb cases show that a person’s physical self-image can become greatly at odds with reality – the feeling of an arm survives both the loss of the arm itself, and the patient’s knowledge of its loss.  This is not denial, and is not the result of emotional longing for the lost arm.  The phantom may be paralyzed and acutely painful, a thing that the patient fervently desires to be without.  In these cases, body-image is stubborn and sticky, resisting correction to conform to the truth intellectually known by the patient.  These patients are of sound mind, suffering no delusions.

The other startling lesson of these examples is that physical self-image can be radically altered, without drugs, psychoanalysis, or high technology, by a simple ‘trick’ with mirrors.  No deception is used; the patient is fully aware that he is not seeing the phantom, but a reflection of his good arm in a mirror.  Qualification: he is consciously aware of the mirror.   At other levels of brain-function, ‘below’ consciousness, something very different must be going on.

The idea of self is stubborn and powerful.  We have definite ideas of who we are – of the future we can look forward to and the past that is ours.  We don’t think we can choose with whom to identify; we think there is a fact of the matter, which is beyond our direct control.  I am the person who will sit here tomorrow, typing on the same keyboard, continuing this narrative.  My son will be at university, taking his first economics class of the semester.  I am 61, and my knee has begun to hurt; he is 23, with years of youth ahead of him.  I cannot decide that his future will be mine.

Could there be a connection between the stubborn persistence of the amputee’s phantom limb against all evidence, and the stubbornness of my sense of continued existence through time?   And could there be some sort of ‘mirror trick’ which would radically change my deep-seated feelings of who I am?  That would, perhaps, allow me to regard my son’s future with a similar quality of emotion as I do my own?

Consciousness and “Blindsight”

There is much more in Ramachandran.  His material on consciousness is fascinating.  He drives a wedge between conscious awareness of sensory input and our ability to respond to it.  Through analysis, he attempts to identify the essential attributes of consciousness.

The word “blindsight” is strikingly oxymoronic.  Yet, in A Brief Tour of Human Consciousness, Ramachandran cites experimental studies showing that some blind patients can respond accurately to visual input without consciously seeing anything at all.

…a patient whose right visual cortex is damaged is completely blind to everything to the left of their nose when they are looking straight ahead (technically called the left visual field).  When examining such a patient, named GY, Weiskrantz noticed something very strange.  He showed the patient a little spot of light in the blind region and asked what he saw.  The patient said “nothing,” as would be expected.  But then he asked the patient to reach out and touch the light, even though he couldn’t see it.

“But I can’t see it,” said the patient.  “How do you expect me to point to it?”  Weiskrantz said to try anyway; take a guess.  To the researcher’s surprise, the patient reached out and pointed accurately to the dot that he could not consciously perceive.  After hundreds of trials it became obvious that he could point with 99 percent accuracy, even though he claimed on each trial that he was just guessing and didn’t know if he was getting it right or not.  [BTHC p. 28]

Ramachandran puts forward a theory to explain this staggeringly counterintuitive result.  Neuroscience has identified pathways in the brain which carry information from the optic nerve.  Not just one pathway, but several.  The damage which left GY blind on the left side affected his visual cortex, an area of the brain where processing necessary for conscious vision takes place.  But there is another, more primitive pathway that carries visual information to an area at the top of the brain stem called the superior colliculus, and that pathway remained intact, allowing the brain

…to locate  the object in space.  The message is then relayed to higher brain centres in the parietal lobes that guide the hand movement accurately to point to the invisible object!

Defining Consciousness

Blindsight is striking because it makes us doubt that we know what consciousness is – even though we are immersed in consciousness every day.   So, what is consciousness?  Ramachandran makes a valiant attempt to put some definition on this venerable idea.

He introduces the term “qualia” to describe the conscious content of sensory experience.  I am not sure why this jargon term is needed, or how “qualia” differs from the good old word “sensations” in this context.   As used by philosophers, “qualia” seems to emphasize the subjectivity and privacy of conscious experience.

Ramachandran attempts to define qualia by listing their essential attributes.  The following list is paraphrased from Phantoms in the Brain.

  1. Irrevocability.  The mind cannot change qualia to something else.  By contrast, when we imagine something, as opposed to having sensations, we can change it at will.  I can turn my imagined purple cow turquoise.
  2. Flexibility of response.  There is always “flexibility” in how we respond to qualia.  I think Ramanchandran means that the actions we take in response to conscious experience are the sorts of actions that we consider to be at least partly under our conscious control.  “What you can do with the representation is open-ended.” By contrast, qualia are not required for the knee-jerk response, which is inflexible.  Paraplegics show a healthy knee-jerk, although they cannot feel the hammer tap.
  3. Endurance. “In order to make decisions on the basis of a qualia-laden representation, the representation needs to exist long enough for you to work with it.”  Qualia are accessible to short-term memory.

Elsewhere, Ramachandran writes about another characteristic of conscious experience not included in this list: the unity of consciousness.  All elements of consciousness – not only qualia or sensations, but emotions, thoughts, memories, intentions, etc. – are manifested in a shared arena where they can be contemplated and acted on together.  I cannot imagine being conscious of anything without being able to compare and contrast it to other conscious experiences.  The ability to relate sensations to one another in various ways, and to mediate our response to them by identifying the objects that give rise to them, placing those objects in a world model, and applying intention and planning in order to realize goals, seems fundamental to consciousness.  I would hazard that that is what consciousness is for.  It is the ability to relate the heterogeneous contents of consciousness to one another that makes possible the flexibility of response listed by Ramachandran.

Consciousness and Self

Ramachandran says consciousness and self are interdependent.  In Phantoms in the Brain, he writes, “Qualia and self are really two sides of the same coin; obviously there is no such thing as free-floating qualia not experienced by anyone and it’s hard to imagine a self devoid of all qualia.”  And in A Brief Tour of Human Consciousness:  “You can’t have free-floating sensations or qualia with no one to experience them, and you can’t have a self completely devoid of sensory experiences, memories or emotions.”

I agree that a self without conscious experiences is hard or impossible to imagine.  But does the existence of conscious experiences really require a self?

What if there were experiences not experienced by anyone?  Not ‘free-floating’, but unified in a ‘field’ of consciousness.  A field, but not somebody’s field.  Not a field experienced by someone.

The idea that experience does not require a subject goes back at least to the British empiricist Hume.  In attacking the philosophical view that perceptions must inhere in a substance, he concludes, “Nothing appears requisite to support the existence of a perception.” [A Treatise of Human Nature, “On the Immateriality of the Soul”]  He goes on to cast doubt on the concept of self.  “Self or person … is that to which our … impressions and ideas are supposed to have a reference.”  Hume searches introspectively for some empirical evidence of a self, but comes up empty.  “I can never catch myself at any time without a perception, and can never observe anything but the perception.”  He rejects as a metaphysical invention the concept of self as the subject of experience, and takes the position that a person is “nothing but a bundle of collection of different perceptions, which succeed each other with an inconceivable rapidity and are in a perpetual flux and movement.”  [THN, “Of Personal Identity”]

Common metaphors speak to what is essential to the concept of consciousness.  The “field” of consciousness is where sensations (from different sense-organs), short-term memory, thought, intention, emotion, and other elements of consciousness are brought together and interact.  The “field” of consciousness is its unity.  The “stream” of consciousness is a metaphor for changes in the contents of consciousness over time.  Sensations, thoughts, intentions, emotions enter the field of consciousness, endure for a while, and are replaced by other conscious elements.  The stream has a temporal dimension; the field is a time-slice of the stream.

But how we finally answer the question whether there can be consciousness without the self depends on how we define “self”.  Ramachandran emphasizes that the concept of self is somewhat open-ended.  “Like ‘love’ or ‘happiness’, we use one word, ‘self,’ to lump together many different phenomena.”  [BTHC, p. 97]  If “self” is defined narrowly as a unifying principle for the elements of one person’s consciousness – a container of mentality, and nothing more – then, yes, consciousness implies self (trivially).  If, on the other hand, the concept of self is broader, including other essential attributes (such as duration, agency, awareness of self, perhaps even awareness of others), then the existence of consciousness does not logically imply the existence of a self, and an additional argument is required.

Towards a Definition of Self

In Phantoms in the Brain, Ramachandran offers a list of seven “characteristics that define the self”, a list later reorganized and pruned to five [BTHC, pp. 96-7]:

  1. Continuity.  “A sense of an unbroken thread running through the whole fabric of our experience with the accompanying feeling of past, present and future.”
  2. Unity, or coherence of self.   “In spite of the diversity of sensory experiences, memories, beliefs and thoughts, we each experience ourselves as one person, as a unity.
  3. Embodiment, or ownership.  “We feel ourselves anchored to our bodies.”
  4. Agency.  “What we call free will, [a sense of] being in charge of our own actions and destinies.”
  5. Reflection.  “The self, almost by its very nature, is capable of reflection – of being aware of itself.  A self that’s unaware of itself is an oxymoron.”

If what Ramachandran means by “self” includes all five of these characteristics, then logic does not dictate that wherever there is consciousness, there is a self.  If it’s true that there cannot be conscious experience without all of the above, an argument is needed.  But either Ramachandran’s argument was omitted, or I haven’t succeeded in following it.

Argument or no, I feel grateful to Ramachandran for this careful list of characteristics of the self.  It helps to know what we are talking about.  And there are a sixth and a seventh characteristic, emphasized in his earlier book, that also strike me as important.

6.  Emotional affect.  In a paragraph entitled, “The passionate self”, Ramachandran writes:

It is difficult to imagine the self without emotions…. If you don’t see the meaning or significance of something – if you cannot apprehend all its implications – in what sense are you really aware of it consciously?

“Meaning” and “significance” here have the sense of emotional salience, not the relationship between linguistic tokens and their referents favoured by linguists and philosophers.  Can there be conscious experience which has no emotional salience?  Could all of a person’s conscious experience have the same, flat, neutral emotional colouring?

Although I’m not sure Ramachandran would agree, the answer may be “yes” – again on evidence cited by Ramachandran. This passage is from a Ramachandran essay on the on-line forum, Edge:

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”.

The patient is described as lacking all emotional affect.  “Awake and alert” implies consciousness; and the patient’s self-report does also. 

The condition of akinetic mutism makes me doubt that emotion is necessary for consciousness.  But it may be necessary to the sense of self.  Emotional affect – broadly understood to include all appetites and aversions – seems essential to intentional action.  Our likes and dislikes motivate us.  If all my experience were emotionally neutral – a mid-grey on the agony-ecstasy scale – would I have a life?

As every Republican knows, the concept of self plays a powerful role in motivating action.   If I know that I will otherwise go hungry, I am strongly motivated to get off my butt and find a job; I’m much less likely to do it for you.  Without emotion, there would be no motivation at all.  If there were not, would the concept of self still make sense?  Maybe it would, but it wouldn’t feel like the same concept.

We seem to lack a common word for the attitude we bear towards ourselves, which carries with it a heightened emotional response.  If I hear about someone’s fate, I may picture it with indifference or mild interest, or even deep sympathy; but when I learn that it is my fate, my interest in the story quickens dramatically. The term “self-regard” is the best I can come up with for the attitude that colours everything that I consider myself with such vivid emotional affect.

Is the absence of a common word evidence that this attitude does not exist – that I am spinning words about nothing?  I don’t think so – the experience is too vivid, the effect on action too pronounced.  Rather, it may indicate that this is something we do not understand clearly.  And things that are emotionally charged, but which we don’t understand, are dangerous.  If we do not understand our feelings, they control us; understanding allows us to choose how to respond.

Is emotional significance an essential characteristic of self?  I suspect it is – the salience of self-regard seems powerfully and centrally related to my sense of who I am.  Supporting evidence may be found in the condition called Cotard’s syndrome.  Ramachandran suggests that in Cotard’s patients, “perhaps all the sensory areas are disconnected from the limbic system, leading to a complete lack of emotional contact with the world” [PITB, p. 167].  The behavioural symptoms to which this deficit gives rise are most striking:  the patient insists that he is dead.

The delusion of Cotard’s is notoriously resistant to intellectual correction.  For example, a man will agree that dead people cannot bleed; then, if pricked with a needle, he will express amazement and conclude that the dead do bleed after all, instead of giving up his delusion and inferring that he is alive.  [BTHC, p. 91]

Without the accustomed emotional quickening towards himself, the patient concludes that he does not exist.  When presented with an anomaly – lo and behold, he bleeds! – the patient decides that, contrary to his previous belief, the dead can bleed.  Note that the patient remains logical!  Evidence requires a revision of his belief-system, and he makes it.  The astonishing thing is that he finds it more probable that dead people bleed (and move around, talk, etc.) than that he himself is alive!  Such is the central role of emotion in our sense of who we are – if this account is correct.

I have lots of unanswered questions about these neurological disorders and the lessons we can draw from them. What is the difference between akinetic mutism and Cotard’s, and why don’t the victims of the former deny that they’re alive?  (Or do they?)

7.  The social self.  In Phantoms in the Brain, Ramachandran writes:

… another important function [of the self-representation system] may be to support the sort of created or narrative self that the philosopher Dan Dennett talks about – that we present ourselves as unified in order to achieve social goals and to be understandable to others.  We also present ourselves as acknowledging our past and future identity, in order to be seen as part of society.  Acknowledging and taking credit or blame for things we did in the past help society (usually kin who share our genes) incorporate us effectively in its plans, thereby ensuring the survival and perpetuation of our genes.

The social self is a huge topic in itself, to which I hope to return another time.

Conclusions of this Post

Ramachandran’s discussion of Cotard’s syndrome convinces me more strongly that emotion – the special gestalt of emotions that fit under the umbrella-term “self-regard” – is essential to the concept of self.  The cases of akinetic mutism, although sketchily described, provide reason to doubt that emotional content is necessary to consciousness, reinforcing my intuitive doubt on that score.  If I’m right on both points – that emotion is essential to self, but consciousness can exist without emotional content – then having conscious experience does not depend on having a concept of self.  On that point I seem to part company with Ramachandran.  But I’m not sure.  In more than one place, Ramachandran indicates that our ideas of consciousness and self are due for a Kuhnian paradigm shift – radical reorganization into a new theory.

…maybe the solution to the problem of the self is not a straightforward empirical one.  It may instead require a radical shift in perspective, the sort of thing that Einstein did when he rejected the assumption that things can move at arbitrarily high velocities.  When we finally achieve such a shift in perspective, we may be in for a big surprise and find that the answer was staring at us all along.  I don’t want to sound like a New Age guru, but there are curious parallels between this idea and the Hindu philosophical (albeit somewhat nebulous) view that there is no difference between self and others, or that the self is an illusion. [BTHC p. 98]

If the work of Ramachandran and other neuroscientists is indeed a precursor to a scientific revolution, it should come as no surprise that it contains tensions and the odd seeming inconsistency.  That goes with the territory, and in no way undermines the immense value of their contributions.

References

THN: Hume, A Treatise of Human Nature, 1739

PITB: Ramachandran and Blakeslee, Phantoms in the Brain, 1998

BTHC: Ramachandran, A Brief Tour of Human Consciousness, 2004

2 Responses to “The Phantom Neuroscientist”

  1. This article is very interesing, and I shall take it to bed with me tonight to peruse more fully. Thank you. Clancette

  2. […] it is not is that nobody knows how to do this (yet). The BIID and transsexual equivalents of the ‘mirror trick’ discovered by Ramachandran, that effectively relieves pain and paralysis in the phantom limbs of […]

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