Why Great Minds Can't Grasp Consciousness
By Ker Than, LiveScience Staff Writer
http://www.livescience.com/health/050808_human_consciousness.html
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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FROM: Over the hills and far away. . .
The way to do is be. Lao Tzu
OldWomansZenChronicles.blogspot.com
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