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Consciousness conference - if interested in cog. anthr., etc.
John O'Brien (JOBRIEN@UCS.INDIANA.EDU)
Fri, 6 May 1994 19:52:52 EST
---------- Forwarded message ----------
Date: Fri, 22 Apr 1994 15:32:48 +1000
From: Kevin Korb <korb@bruce.cs.monash.edu.au>
To: Multiple recipients of list PSYCHE-D <PSYCHE-D%NKI.BITNET@uga.cc.uga.edu>
Subject: Toward a Scientific Basis for Consciousness
>From: spotter@druggist.gg.caltech.edu (Steve Potter)
Last week (April 12-17, 1994) I attended the following conference in
Tucson, AZ:
TOWARD A SCIENTIFIC BASIS FOR CONSCIOUSNESS
Here I will present a short review of this exciting meeting, along with
some opinions on some of the ideas presented.
The overall mood at the conference, about 300 attending, was unusually
enthusiastic, due to the fact that this was really the first conference of
its type, bringing together researchers from many fields to talk about what
has been for the major part of this century a taboo subject in scientific
circles. Recent advances in a number of neuroscience methods have made
possible the objective, independently verifiable observation of a number of
phenomena associated with conscious thought. Furthermore, new modeling
paradigms associated with distributed processing in neural networks, chaos,
and emergent phenomena have resulted in simulations displaying many of the
qualities of conscious entities. These forces, and the fact that
consciousness is something we all (hopefully!) have and care about, brought
us together and will most likely result in the expansion of this and
related conferences in the years to come.
Attending were researchers from very diverse fields, including biological
neuroscientists, computational neuroscientists, philosophers,
anesthesiologists, physicists, mathematicians, psychologists,
neurosurgeons, 'chaoticians' (a la Malcolm, in Jurassic Park), cognitive
scientists, and a fairly large contingent of 'researchers' of the
paranormal (ESP, shamanistic rituals, meditation). I was a little
disappointed that the organizers did not weed out a few of the more flaky
posters and talks, but the diversity was fun. The majority of the posters
and all but a couple of the talks were in the non-flaky category, i.e.,
relating to testable hypotheses and the scientific method currently
accepted in the academic world.
There were no parallel sessions, and the auditorium (at the U. of A.
Medical Center) was packed, making coffee breaks in the small lobby fairly
claustrophobic. A table was set up for anyone to display a book or paper
they were pushing, for people to look at. I learned about a number of
exciting books that I must go out and get ASAP this way, and think this
ought to be done at more conferences.
Abstracts for all of the talks and posters were provided along with the
program, in a nice binder. It was announced that the complete papers will
be published in a book, but I will not hold my breath, as the presenters
are not even required to submit them for a month or so. A fairly complete
list of those attending was also provided by the end of the conference.
There were a number of field trips arranged that were too pricey for my
taste. I brought my bike and arranged my own field trips for free.
For official info about the conference or proceedings, dont ask me, ask the
organizers:
Alfred Kaszniak kaszniak@ccit.arizona.edu
Stuart Hameroff srh@ccit.arizona.edu
Jim Laukes jlaukes@ccit.arizona.edu
Okay, here are some observations and opinions about the talks (and
posters).
A lot of folks gave whole talks on or at least paid lip service to the
notion of quantum mechanics having something fundamental to do with
consciousness. David Chalmers, in his excellent wrap-up put my opinion of
this issue cleverly: "Consciousness is mysterious. Quantum mechanics is
mysterious. By the 'Law of Minimization of Mystery', if you find two
mysteries, maybe they are the same." I feel like QM may be a useful
metaphor for some aspects of consciousness, but we know _way_ too little
about either to apply QM literally as a basis for consciousness. Let's be
careful not to mix up our metaphors and theories.
Relating to this issue was something I had not heard about before
(surprising, considering I was a brain biochemist as a grad student) and
was quite interesting, was the possibility that microtubules could be
computational or information-transmitting elements. Microtubules (MTs) are
the major cytoskeletal elements of neurons, and basically all cells.
Several talks (somewhat redundantly) described how tubulin, the monomer
protein of which MTs are made, can switch between its two conformational
states based on the conformational state of neighboring monomers. Anyone
who knows jack about cellular autonoma will recognize certain similarities
here, and they actually did simulations to show waves of conformational
change propagating along the MTs. (Or along organized clusters of water
molecules next to or inside the MTs.) As far as I could tell, this was all
rampant speculation, yet to be borne out by experimental studies on real
MTs, but had a number of testable predictions. Hameroff mentioned that the
lowly single-celled paramecium has quite a complex repertoire of behavior
(not quite on the level with human consciousness, I would argue!) and yet
no nervous system. He proposes that its complex web of MTs may be its
'nervous system'.
Being fairly well-read in the neural nets literature, I am struck by how
much has been accomplished with models using fairly simplistic 'neurons',
and certainly nothing as sophisticated as _sub_cellular nervous systems
within them. This leads me to believe that, whether MT processors exist or
not, we dont need to invoke such theories to explain consciousness. I must
not slight the boatloads of research that has shown that rearrangement of
MTs and other cytoskeletal elements is important in learning and memory,
but changing the cell's shape is a different issue than what these folks
were proposing.
Just about every single speaker had a quote from or mentioned the work of
William James, who seems to have figured all this out around the turn of
the century. I am _not_ well read in psychology, but am inspired to track
down his writings, considering how progressive many of his ideas on
consciousness were. For instance, he was well aware of the associational
nature of all concepts, i.e., nothing has any meaning except in relation to
other things. I enjoy taking this concept all the way down to the neural
level, where the associations are between activated ensembles and such.
I was very pleased to learn of the substantial work of Eric Harth on the
importance of feedback connections in the brain in perception. These
massive tracts, sometimes bigger than the feed-forward ones, are far too
often ignored by neuroscientists, leading them to believe that the brain is
stimulus-driven. Well, of course it is, but I feel (and Harth backed my
feelings) that most of what we see, feel, hear, etc. emanates from our
brain, the environment merely getting the thoughts started.
One of my heroes, Walter Freeman, described how a stimulus makes the brain
(the smell-centers, specifically) go from a chaotic state to a state of
aperiodic oscillation, a basin of attraction probably corresponding to the
conscious feeling of recognizing the odor. I bet the feedback connections
play a major role in sending the system into its basins. (Perhaps he has
knows this already, I am not sure.)
I was disappointed that several other prominent Thinkers on Thinking did
not attend the conference--were they invited? Notably, Douglas Hofstadter,
Daniel Dennett, John Searle, Ray Jackendoff, Stephen LaBerge, the
Churchlands, Robert Ornstein, Francis Crick, Geoffrey Edelman, Martha
Farah, and Marvin Minsky, come to my mind. Perhaps next year!
The conference was mostly synthesis, proposals and speculations, so no
great answers about how consciousness happens yet. The best real data
presented, IMHO, was from Bruce McNaughton, who records from up to 150
neurons at a time in the hippocampus of a freely behaving rat for weeks at
a time. Beside the fact that this is an extremely impressive technical
feat (I know because I am trying to do very similar things with cultured
neurons, that dont run around all night), it was a real window into the
thought processes (consciousness?) of a rat. He recorded the neurons'
activity while the rat was foraging around a box, and during naps before
and after the foraging. He found 'place cells' that fire only when the rat
is in a specific part of the box. He was able to use the place cell 'map'
to accurately predict the rat's trajectory, based on the neural signals.
He also showed the effect of subsequent learning on previously established
maps. But even cooler was the observation that neurons that had correlated
firing during the foraging and not before (implying that they are learning
preferences to nearby places), also were highly correlated during the
post-forage nap. Thus, the rat may have been dreaming of snippets of its
box experience, reinforcing or consolidating the important associations.
Neat stuff.
I look toward functional MRI to come up with similar experiments on humans
in the near future. Keep your eye on this amazing new technology: I
predict that it will oust PET studies in a year or two, due to its far
greater spatial and temporal resolution, and the fact that it does not
require the poor subject to dose up on radioactivity.
An excellent conference overall, with many speakers referring to other's
talks in their talks.
Subscribe to Psyche-D if you are into this type of thing and want to chat
with like minded individuals who obviously have way more free time than I
do.
Steve Potter, Ph.D.
Division of Biology 156-29
California Institute of Technology
Pasadena, CA 91125
spotter@druggist.gg.caltech.edu
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