[Paleopsych] Live Science: Why great minds can't grasp consciousness
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Sat Sep 3 01:31:54 UTC 2005
Why great minds can't grasp consciousness
Subject no longer just for philosophers and mystics, but remains a mystery
Aug. 8, 2005 By Ker Than
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
Penrose also believes that quantum mechanics, the rules governing the
physical world at the subatomic level, might play an important role in
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,"
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 David 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
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
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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