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16455Why Great Minds Can't Grasp Consciousness

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  • medit8ionsociety
    Dec 15, 2008
      From Livescience.com
      At a physics meeting last October, Nobel
      laureate David Gross outlined 25 questions
      in science that he thought physics might
      help answer. Nestled among queries about
      black holes and the nature of dark matter
      and dark energy were questions that wandered
      beyond the traditional bounds of physics
      to venture into areas typically associated
      with the life sciences.

      One of the Gross's questions involved human
      consciousness.

      He wondered whether scientists would ever
      be able to measure the onset consciousness
      in infants and speculated that consciousness
      might be similar to what physicists call a
      "phase transition," an abrupt and sudden
      large-scale transformation resulting from
      several microscopic changes. The emergence
      of superconductivity in certain metals when
      cooled below a critical temperature is an
      example of a phase transition.

      In a recent email interview, Gross said he
      figures there are probably many different
      levels of consciousness, but he believes
      that language is a crucial factor distinguishing
      the human variety from that of animals.

      Gross isn't the only physicist with ideas
      about consciousness.

      Beyond the mystics

      Roger Penrose, a mathematical physicist
      at Oxford University, believes that if a
      "theory of everything" is ever developed
      in physics to explain all the known phenomena
      in the universe, it should at least partially
      account for consciousness.

      Penrose also believes that quantum mechanics,
      the rules governing the physical world at
      the subatomic level, might play an important
      role in consciousness.

      It wasn't that long ago that the study of
      consciousness was considered to be too abstract,
      too subjective or too difficult to study
      scientifically. But in recent years, it has
      emerged as one of the hottest new fields in
      biology, similar to string theory in physics
      or the search for extraterrestrial life in astronomy.

      No longer the sole purview of philosophers
      and mystics, consciousness is now attracting
      the attention of scientists from across a
      variety of different fields, each, it seems,
      with their own theories about what consciousness
      is and how it arises from the brain.

      In many religions, consciousness is closely
      tied to the ancient notion of the soul,
      the idea that in each of us, there exists
      an immaterial essence that survives death
      and perhaps even predates birth. It was
      believed that the soul was what allowed
      us to think and feel, remember and reason.

      Our personality, our individuality and our
      humanity were all believed to originate
      from the soul.

      Nowadays, these things are generally attributed
      to physical processes in the brain, but
      exactly how chemical and electrical signals
      between trillions of brain cells called
      neurons are transformed into thoughts, emotions
      and a sense of self is still unknown.

      "Almost everyone agrees that there will be
      very strong correlations between what's in
      the brain and consciousness," says David
      Chalmers, a philosophy professor and Director
      of the Center for Consciousness at the
      Australian National University. "The question
      is what kind of explanation that will give you.
      We want more than correlation, we want
      explanation -- how and why do brain process
      give rise to consciousness? That's the big mystery."

      Just accept it

      Chalmers is best known for distinguishing between
      the 'easy' problems of consciousness and the 'hard' problem.

      The easy problems are those that deal with
      functions and behaviors associated with consciousness
      and include questions such as these: How
      does perception occur? How does the brain
      bind different kinds of sensory information
      together to produce the illusion of a seamless experience?

      "Those are what I call the easy problems, not because they're trivial,
      but because they fall within the standard methods of the cognitive
      sciences," Chalmers says.

      The hard problem for Chalmers is that of
      subjective experience.

      "You have a different kind of experience --
      a different quality of experience -- when you
      see red, when you see green, when you hear
      middle C, when you taste chocolate," Chalmers
      told LiveScience. "Whenever you're conscious,
      whenever you have a subjective experience,
      it feels like something."

      According to Chalmers, the subjective nature
      of consciousness prevents it from being
      explained in terms of simpler components,
      a method used to great success in other areas
      of science. He believes that unlike most of
      the physical world, which can be broken down
      into individual atoms, or organisms, which
      can be understood in terms of cells, consciousness
      is an irreducible aspect of the universe,
      like space and time and mass.

      "Those things in a way didn't need to evolve,
      " said Chalmers. "They were part of the
      fundamental furniture of the world all along."

      Instead of trying to reduce consciousness
      to something else, Chalmers believes consciousness
      should simply be taken for granted, the way
      that space and time and mass are in physics.
      According to this view, a theory of consciousness
      would not explain what consciousness is or
      how it arose; instead, it would try to explain
      the relationship between consciousness and
      everything else in the world.

      Not everyone is enthusiastic about this idea, however.

      'Not very helpful'

      "It's not very helpful," said Susan Greenfield,
      a professor of pharmacology at Oxford University.

      "You can't do very much with it," Greenfield
      points out. "It's the last resort, because
      what can you possibly do with that idea? You
      can't prove it or disprove it, and you can't
      test it. It doesn't offer an explanation, or
      any enlightenment, or any answers about why
      people feel the way they feel."

      Greenfield's own theory of consciousness
      is influenced by her experience working
      with drugs and mental diseases. Unlike some
      other scientists -- most notably the late
      Francis Crick, co-discoverer of the structure
      of DNA, and his colleague Christof Koch, a
      professor of computation and neural systems
      at Caltech -- who believed that different
      aspects of consciousness like visual awareness
      are encoded by specific neurons, Greenfield
      thinks that consciousness involves large groups
      of nonspecialized neurons scattered throughout the brain.

      Important for Greenfield's theory is a
      distinction between 'consciousness' and
      'mind,' terms that she says many of her
      colleagues use interchangeably, but which
      she believes are two entirely different concepts.

      "You talk about losing your mind or blowing
      your mind or being out of your mind, but
      those things don't necessarily entail a loss
      of consciousness," Greenfield said in a
      telephone interview. "Similarly, when you
      lose your consciousness, when you go to sleep
      at night or when you're anesthetized, you
      don't really think that you're really going
      to be losing your mind."

      Like the wetness of water

      According to Greenfield, the mind is made
      up of the physical connections between neurons.
      These connections evolve slowly and are
      influenced by our past experiences and therefore,
      everyone's brain is unique.

      But whereas the mind is rooted in the physical
      connections between neurons, Greenfield believes
      that consciousness is an emergent property
      of the brain, similar to the 'wetness' of water
      or the 'transparency' of glass, both of which
      are properties that are the result of -- that is,
      they emerge from -- the actions of individual molecules.

      For Greenfield, a conscious experience occurs
      when a stimulus -- either external, like a
      sensation, or internal, like a thought or a
      memory -- triggers a chain reaction within
      the brain. Like in an earthquake, each conscious
      experience has an epicenter, and ripples from
      that epicenter travels across the brain, recruiting
      neurons as they go.

      Mind and consciousness are connected in
      Greenfield's theory because the strength
      of a conscious experience is determined by
      the mind and the strength of its existing
      neuronal connections -- connections forged
      from past experiences.

      Part of the mystery and excitement about
      consciousness is that scientists don't know
      what form the final answer will take.

      "If I said to you I'd solved the hard problem,
      you wouldn't be able to guess whether it would
      be a formula, a model, a sensation, or a drug,"
      said Greenfield. "What would I be giving you?"

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