[extropy-chat] Fwd: What is consciousness?
jef at jefallbright.net
Tue Dec 12 17:15:59 UTC 2006
I don't normally forward such lengthy material to the list, but I think
this isn't generally available on-line. It's relevant to much of the
discussion on this list and the best brief exposition of these ideas
that I've seen.
> Paul Broks: What is consciousness?
> New Scientist tackles eight of the deepest challenges faced by
> science - from reality and consciousness, to free will and death,
> in The Big Questions special features.
> On this special day, my 121st birthday, it is good to be surrounded
> by those I love. There's no denying I feel old, but in body, not
> spirit. Oh dear, there I go, slipping into the old ways of
> thinking: mind and body, spirit and substance. There's no excuse.
> The ghost in the machine was exorcised long ago - and here's
> Celeste, my sweet, uploaded daughter: the living proof.
> She kisses my aged forehead. Chronologically, Celeste is 90 years
> old. Physically she's a genetically re-engineered woman of 30.
> Psychologically, well, these days you have to keep an open mind
> about psychological ways of being. But one never stops worrying
> about one's children, and the uploading - the transfer of
> information from old brain to new - was, I confess, a little
> troubling. I have always felt some responsibility for the current
> popularity of mind transposition. I helped create a climate of
> acceptance. Forgive me if I reminisce.
> WHAT was that I wrote? "The laser beams of cognitive neuroscience
> are beginning to penetrate the philosophical fog of centuries"?
> Tosh! The real philosophical fog was just beginning to roll in. But
> that wasn't how it felt at the time. Mind science was coming of
> age. Traditional methods of correlating brain damage and behaviour
> combined with neuroimaging and computational science to produce
> ever more refined models of the working brain and, by 2012, the
> microarchitectures of cognitive function were rapidly unfolding.
> Writing in 2005, the inventor and futurist Ray Kurzweil had
> predicted that the brain would be fully "reverse engineered" by the
> mid-2020s, with hardware and software available for the
> implementation of human intelligence in a non-biological substrate.
> He was not far wrong, and "consciousness" went the way of
> phlogiston, the theoretical substance that scientists once used to
> explain fire. Strange we ever thought the problem hard.
> But as our post-millennial neuroscientists marvelled at the
> sparkling, dare I say spectral, patterns cascading from their
> high-resolution brain scanners, they were nagged by a mischievous
> question: who's running the show? How does the brain, with its
> diverse and distributed functions, come to arrive at a unified
> sense of identity? "Soul" doesn't figure in the lexicon of
> neuroscience, but what about the soul's secular cousin, "self"?
> Could we speak of a person's brain without, ultimately, speaking of
> the person? Was the self merely the sum of its cerebral parts? The
> illusion of the ghost in the machine was compelling - the natural
> intuition that somewhere in the shadows of the brain there lurks an
> observing "I", an experiencer of experiences, thinker of thoughts
> and controller of actions.
> This was hard to reconcile with the material facts (the vacant
> machinery that actually packs the skull) and it was plain to see
> that the mental operations underlying our sense of self - feelings,
> thoughts, memories - were dispersed throughout the brain. There was
> no homuncular assembly point where a little soul-pilot sat watching
> the dials of experience and pulling the levers of action. We were,
> neuropsychologically speaking, all over the place. And anyway, who
> did we think was pulling the levers in the little soul-pilot's
> head? If we found a ghost in the machine we'd have to start looking
> for the machine in the ghost.
> Belief in an inner essence, or central core, of personhood, was
> called "ego theory". The alternative, "bundle theory", made more
> neurological sense but offended our deepest intuitions. Too bad, I
> thought. We should learn to face facts. The philosopher Derek
> Parfit put it starkly: we are not what we believe ourselves to be.
> Actions and experiences are interconnected but ownerless. A human
> life consists of a long series - or bundle - of enmeshed mental
> states rolling like tumbleweed down the days and years, but with no
> one (no thing) at the centre. An embodied brain acts, thinks, has
> certain experiences, and that's all. There is no deeper fact about
> being a person. The enchanted loom of the brain does not require a
> Parfit devised a famous thought experiment. Imagine being
> teleported. A special scanner records the state of every cell in
> your brain and body and digitally encodes the information for radio
> transmission. Your body is destroyed in the process but
> reconstructed as soon as the signals are received and decoded at
> your destination. You "arrive" in precisely the same condition that
> you "left", identical in body, brain and patterns of mental
> activity. Your memories, beliefs, plans, skills and emotions are
> perfectly intact and you go about your business feeling and
> believing that nothing about you has changed in the slightest. It's
> just like waking from a dreamless sleep and getting on with the
> If you are comfortable with this scenario then you should be
> comfortable with bundle theory. You appreciate that the observing
> "I" is no more than patterns of energy and information, which can
> be disrupted and reconstituted without destroying the self -
> because there is no self to destroy. The patterns are all. If, on
> the other hand, you believe that some essential "you" would be lost
> in the process then you are an irredeemable ego theorist. You
> believe that the reconstituted body is not "you" but a mere
> replica. Although the replica will know in its bones that it is the
> very person who stepped into the scanner at the start of the
> journey, and friends and loved ones will agree, you insist it could
> not be you because your body and brain would have been destroyed.
> Incidentally, we see here a neat inversion of conventional
> thinking. Those who believe in an essence, or soul, suddenly become
> materialists, dreading the loss of the "original" body. But those
> of us who don't hold such beliefs are prepared to countenance a
> life after bodily death.
> The philosophical speculations were intriguing, but the science of
> selfhood also had more practical concerns. This was the dawn of a
> new age in neuropsychiatry. The idea that certain forms of insanity
> were "disorders of the self" had been around for two centuries and
> more, but now the concept was being refined. The core deficits of
> autism and schizophrenia, for example, were revealed as faults in
> the brain circuits underlying personal awareness. This
> confederation of networks - frontal, limbic, temporal and
> cerebellar - orchestrated social cognition, from the analysis of
> gaze direction and facial expression to the deciphering of beliefs,
> attitudes, and intentions. In the process, it gave definition to
> that fundamental unit of social intercourse: the person. Just as
> the brain had evolved systems for guiding interaction with the
> physical world so, we rather belatedly realised, it had also
> evolved specialised mechanisms for enabling the interaction of
> "self" and "other".
> The discovery of "mirror neurons" in the 1990s was a breakthrough
> in this regard. According to Vilayanur S. Ramachandran, one of the
> leading neuroscientists of the era, it was a discovery as
> significant in its way as Crick and Watson's decoding of the
> structure of DNA. Mirror neurons were activated not only in
> response to self-generated behaviour (reaching for an object, say)
> but also in response to actions performed by other individuals.
> Pain and emotional behaviour were similarly mirrored. The
> implication - that minds were neurologically "bridged" - was
> far-reaching, and mirror neurons rapidly took their place in
> theories of developmental psychology and moral behaviour.
> The self had entered the neurobiological laboratory. Around this
> time it also became evident that, rather than being a single "ghost
> in the machine", we were a composite of two phantoms. The self of
> the present moment - the so-called "minimal" or "core" self - was,
> in the words of the neuroscientist Antonio Damasio, "a transient
> entity, recreated for each and every object with which the brain
> interacts". It was bound to brain systems involved in mapping and
> regulating body states. The other phantom was the "extended" self:
> a unified, continuous being journeying from a remembered past to an
> anticipated future, with a repertoire of skills, stores of
> knowledge and dispositions to act in certain ways. This
> "autobiographical" self emerged from language and long-term memory
> networks. Michael Gazzaniga, one of the great pioneers of cognitive
> neuroscience, pointed to a specialised left-hemisphere system - he
> called it "the Interpreter" - whose function was to wind disparate
> strands of brain function into a single thread of subjective
> experience. It worked by identifying patterns of activity across
> different brain modules and correlating these with events in the
> external world: it was a teller of tales.
> The minimal self gave us our sense of location and boundary, and
> our intuitions of agency - the feeling that we exercise control
> over our actions. But these fundamentals of self-awareness were
> rather fragile constructs. Disturbances of temporal and parietal
> lobe function could cause profound dislocations of perception such
> as out-of-body experiences and autoscopic hallucinations (seeing
> one's body in extrapersonal space). Damage to the frontal lobes
> could disturb the sense of agency, with limbs developing a
> recalcitrant will of their own.
> The extended self, too, was neurologically fragile. It could be
> gradually dismantled by dementia, or shattered by a sudden viral
> attack, the story of the self dissolved with the dissolution of
> memory. In contrast, a deep-brain stroke or injury to the frontal
> lobes could leave memory unaffected but recalibrate the machineries
> of emotion and temperament. The story continued, but the central
> character had changed beyond recognition. Sometimes the brain's
> story-telling mechanism itself broke down, resulting in the
> confabulation of fictional, often fantastical, autobiographical
> distortions. As science writer John McCrone put it, we are all just
> a stumble or burst blood vessel away from being someone else.
> Selfhood is malleable. That was the message.
> The neurological diseases that were then still prevalent tended to
> carve human nature at its joints in such ways, and one occasionally
> saw what appeared to be clear dissociations of the two "selves". I
> remember an epileptic patient telling me of her intermittent loss
> of identity, a condition known as transient epileptic amnesia. Her
> surroundings would suddenly feel unfamiliar, and then she would
> begin to feel unfamiliar to herself. Soon she had no idea who she
> was, where she was or what she was doing. She was stripped to the
> minimal self: a floating point of subjective awareness untethered
> by identity.
> In other, rare, cases I saw the opposite: the minimal self
> dissolving, leaving only the story of the extended self. One
> patient had a strong sense of identity and autobiography but
> believed that she had ceased to exist. "Am I dead?" she asked. This
> condition, Cotard's syndrome, was due to a neurological decoupling
> of feelings and thoughts. Thinking that one exists was not enough:
> the notion had also to be felt - "I feel I think, therefore I am."
> Another Cotard's patient believed that her voice was all that was
> left of her. She was "just a voice, and if that goes, I won't be
> anything". We all have an inner voice, a stream of sub-vocal
> speech. It keeps the story going and helps sustain the illusion
> there's "someone home". One man, recovering from a stroke that had
> virtually abolished his capacity for speech, including self-talk,
> described the condition of total wordlessness as being like
> confinement to a continuous present.
> But these words you are now reading, whose are they? Yours or mine?
> The point of writing is to take charge of the voice in someone
> else's head. This is what I am doing. My words have taken
> possession of the language circuits of your brain. I have become,
> if only transiently, your inner voice. Doesn't that mean, in a
> certain sense, that I have become you (or you me)? It's a serious
> question. Written text is a primitive but powerful form of virtual
> reality. In the beginning was the word.
> And in the end? A liberating truth. There are no souls, only
> stories. I have witnessed a Copernican revolution of the self; a
> historical shift from the age of solipsism, when we were all at the
> centre of the universe - self-loving, self-loathing, self-absorbed
> - to an era of self-dispersion when ego is deemed constrictive. I
> saw the science of selfhood figure increasingly in the great social
> and moral debates of the century, from age-old wrangles about
> euthanasia and free will to disputes over brain enhancement,
> cyberethics, and the fusion, fission and transposition of minds.
> But if once we worried about euthanasia, now it was the rights of
> intelligent, self-aware machines that came to exercise the minds of
> the politicians and ethicists. The golden rule - treat others as
> you want to be treated - had been almost universally endorsed as a
> moral Polaris, but depended on a fixed understanding of the terms
> "you" and "other". Now it is not so clear where one person ends and
> another begins. Neural implants, followed by nanobot
> brain-extension technologies, have increased the
> information-processing capacity of the human brain a billionfold.
> Biological modes of empathy (dear old mirror neurons) have long
> been superseded. It is now possible to share the experiences of
> others directly; to be someone else. Reliance on the biological
> brain is discouraged, of course. Who wants to die?
> And so Celeste, my sweet, uploaded daughter, takes my hand and
> leads me to the chamber where my gift awaits. I see my
> re-engineered body, which sits motionless: the limp corpse of a
> young man prepared for resurrection. Its carbon nanotube brain
> circuitry lies dormant, but will soon be infused with my digital
> ghost. Like Celeste, I chose 30. That was a good age. Unlike her, I
> resisted the temptation to tinker with cosmetic details. Take me or
> leave me. And I'm opting for a conservative, level 1 transposition:
> my new brain will run, like the old one, as a stand-alone unit with
> unenhanced software. Celeste is level 3 - enhanced and hive-mind
> compatible. She is fully immersible - and these days mostly
> immersed - in the web of awareness, a.k.a. the hive.
> "What's it like?" I ask her.
> "Inconceivable," she says, her eyes mocking my nostalgia for puny
> individualism. Then she tells me that the time has come. I sit in
> the chair adjacent to the corpse, wishing that it didn't have to be
> quite so ceremonial.
> "When did I realise I was God?" says the psychotic aristocrat in
> the old film The Ruling Class. "Well, I was praying and I suddenly
> realised I was talking to myself." My epiphany was less grandiose.
> It was quite the opposite. I realised I was talking to myself, but
> no one was listening.
> "Happy birthday, Dad."
> Goodbye, Celeste.
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