Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!
Conversations on Consciousness
Biology 202
2006 Book Commentaries
On Serendip
Conversations on Consciousness
Astra Bryant
The popular science book I choose to read, Conversations on Consciousness is a collection of short interviews that discuss the current state of the study of consciousness. Over the course of several years, Dr. Susan Blackmore (Senior Lecturer in Psychology at the University of the West of England) met privately with 21 neurobiologists and psychologists, and asked them all the same question: What is the problem of consciousness. Each interview is both an independent discussion of personal views on consciousness, and a survey of the multiple theories that have been proposed to explain human consciousness. Some of these theories are similar, many are contradictory, and a few are incredibly unique. The scientists interviewed, in alphabetical order were: Bernard Baars, Ned Block, David Chalmers, Patricia and Paul Churchland, Francis Crick, Daniel Dennett, Susan Greenfield, Richard Gregory, Stuart Hameroff, Christof Koch, Stephen LaBerge, Thomas Metzinger, Kevin O'Regan, Roger Penrose, V.S. Ramachandran, John Searle, Petra Stoerig, Francisco Varela, Max Velmans, and Daniel Wegner. With so many distinct interviews included, a complete listing of every topic mentioned in each interview would be far too lengthy to include - but such a list would include theories that describe consciousness as a spotlight in a crowded theater, a neurocomputational weapon, an expression of open-ended symbol manipulation occurring in the brain, a unified field modified by perception, a solution to the need to biologically distinguish self from non-self, and a quantum effect.(1)
With 21 interviews, each one introducing at least one new theory of
consciousness, Conversations on Consciousness is filled with many
fascinating topics that warrant discussion. However, during my reading,
two particular theories caught my attention. The first of these is not
so much a theory of consciousness, as a new way of looking at the
problem of consciousness. In 1994, David Chalmers clarified the
discussion of consciousness by offering a definition of what actually
needed to be explained. In his interview, Chalmers again explains and
elaborates on his definition of the problem of consciousness as being
comprised of an easy problem, and a hard problem.
Sue: You talked earlier about the 'easy problems' and the 'hard
problem', and this distinction is probably what you are most famous
for. In fact, everyone now seems to start any discussion of
consciousness with an account of the 'hard problem'. Can you tell me
how you came to categorize it that way?
Dave: I never thought of this as a terribly profound distinction to
make. I thought I was just stating the obvious. I gave a paper at the
first Tucson conference on consciousness, back in '94, and early in the
conference I got up and wanted to say some substantive things about
consciousness. So I thought, 'OK, I'll start by stating the obvious -
what need to be explained is behavior (those are the easy problems),
and subjective experience (that's the hard problem).' (2)
Before reading Conversations on Consciousness, I had no introduction to
the various theories of consciousness - every theory proposed in this
book was a brand new idea to me. During my introduction to
consciousness as a biological problem, I believe that Chalmers'
distinction was the most basically insightful theory I read. Although
in hindsight, the need for such a distinction is obvious, before
reading Chalmers' interview, the series of problems I thought could be
explained together included topics that are both easy and hard
problems. Chalmers' definition allowed me to clearly distinguish issues
that could be discussed without necessarily involving the complicated
issue of subjectivity. I think that when discussing consciousness, it
is crucial to strictly define the boundaries of your discussion -
without them, explanations can become too complex in an attempt to
cover al the symptoms of conscious behavior. Chalmers offers an
eloquent clarification of an intrinsically complicated subject. Like
most, if not all of the specific theories mentioned in Conversations on
Consciousness, our in-class discussions did not mention by name
Chalmers' easy/hard distinction. While discussing the grand scheme of
neurobiology, divisions were avoided - our class made deliberate
attempts towards formulating a united theory of the workings of the
nervous system (e.g. the box within a box series of diagrams). However,
discussions of the smaller components of the nervous system were
approached in a manner reminiscent of Chalmers' distinction. Much of
class time involved the explanation of specific biological behaviors
(e.g. movement, vision, and speech). But also discussed were harder
biological problems (e.g. sleepwalking and the I-function). But while
the I-function was discussed in depth, with careful distinctions made
between behaviors and the I-function (e.g. Christopher Reeve), we never
discussed the biology behind the presence of the I-fuction - or the
presence of the subjective experiences we happily defined (e.g. vision,
hearing). Many times we skirted these discussions, but we never openly
entered into a discussion.
The other topic that caught my attention, I must mention simply because
of its controversial nature: the quantum theory of consciousness. Roger
Penrose originally proposed this theory in a book entitled The
Emperor's New Mind. The theory states that consciousness is
intrinsically a non-computational phenomenon - that the ability to have
conscious understanding requires more than mere computations mechanics
(no matter how complex the computations are). While this argument could
lead towards dualism, Penrose instead concluded that the ingredient
missing from our largely computational vision of how the nervous system
works, involves quantum mechanics. During his interview, Penrose
explain how he arrived at quantum mechanics for the solution to
consciousness.
Roger: I'm saying that the Gödel argument tells us that we are not
simply computational entities; that out understanding is something
outside computation. It doesn't tell us it's something unphysical, but
there's a crucial thing that's missing, which has to do with quantum
mechanics. Mine is a version of the Sherlock Holmes argument, which I
admit is a weak argument - that to say once you've eliminated
everything else, then what remains must be the truth, no matter how
improbably. Quantum mechanics is the most obvious place where we don't
know enough about physics. Where do you see non-computability in
physics? You don't seem to see it anywhere else. So this, therefore, is
presumably where it is. (2)
Also interviewed was Stuart Hameroff, who has collaborated with Penrose
on the quantum theory. Hameroff took Penrose's idea, and located the
quantum events within the microtubules of the brain's neurons.
Stuart: ... I had been studying the computational capabilities of
protein structures called microtubules which make up the internal
scaffolding within nerve cells. It seemed that microtubules were
excellent candidates for quantum computation, that quantum computing
might be happening inside nerve cells where they could be isolated. I
also knew from my study on anesthesia that the molecular mechanisms by
which anesthetic gas molecules erase consciousness involves only
quantum mechanical interactions with certain proteins in the brain. So
it was reasonable to believe that consciousness involved quantum
processes and that microtubules might be quantum computers. (2)
In my opinion, this theory surpasses even the theories involving
first-person reported lucid dreaming in its use of creative biological
reasoning. In Conversations on Consciousness, many scientists broached
the idea that consciousness is a fundamental principle of the universe
(a theory that I am quite partial to, provided that sufficient evidence
can be provided). But their ideas depend on measuring consciousness
(e.g. humans have more consciousness than squirrels - just as humans
have more mass - and theoretically we can measure this). And, as these
scientists admit, there is currently no soundly quantifiable way to
measure consciousness - a problem which a few scientists are working
towards solving. But the quantum theory of consciousness embraces
science's current inability to quantify consciousness. The proposal
that our inability to solve this one problem directly connects to our
inability to solve another problem is extraordinary, and somewhat
audacious, as is the reclassification of microtubules from cellular
support to quantum computers. After reading Hameroff's interview, I
became fascinated with this theory, simply because of its outrageous
logical progression. I was therefore thrilled when, several interviews
later, Penrose also discussed this extraordinary theory. The quantum
consciousness theory, with its current lack of supporting evidence,
remains the outlandish companion to more conventional theories (e.g.
emergence). But because of its sheer variety, and distinct
dissimilarity to any topic discussed in class, this theory was the most
memorable, and enjoyable, topic in Conversations on Consciousness.
Many other topics were discussed during the interviews, including
several on dream states and the first-person method that I found too
unquantifiable for my tastes. However, all these topics served as a
thorough introduction to the many methods currently being used in the
examination of consciousness. Conversations on Consciousness is not a
typical popular science book – its topic is less specific than many of
its fellows', and it is not interested in popularizing the science for
the reader's benefit. The topics of most popular science books require
thorough background knowledge of biology. But because these books are
written to make the science accessible for a general audience, the
author must teach his audience the background science they need, before
he is able to make his point. Given the vast complexity of biology,
these explanations may last chapters, and are frequently tediously
long. But Conversations on Consciousness does not have an 'Introductory
Biology for the Masses' section. As a collection of interviews, it is
not one scientist's lecture to the general public. It is a series of
private conversations on which the public is allowed to eavesdrop. The
interviewee does not need to spend an hour explaining how neurons
function – as a holder of degrees is psychology, physiology and
parapsychology, Susan Blackmore (the interviewer) already knows the
basic biology, and no explanations are added for the benefit of the
reader. This might make the book less comprehensible for the person who
knows nothing of neurobiology - without grounding in anatomical
structures, the topic of consciousness can easily become a purely
philosophical discussion. But I was grateful to be reading a book that
did not pander to a lower denominator. Conversations on Consciousness
assumes you are an informed reader - if you are not, you are left on
your own to become informed (although the included glossary can be
quite helpful). This was a welcome challenge, and several times I had
to engage in extra research to understand the basic concepts being
casually discussed.
In the end, Conversations on Consciousness gave me a unified view of
the beliefs of the scientific community: a view that helped me place in
context the principles I learned in class. Many of the classical
neurological puzzles discussed (e.g. the Cartesian theater, the
philosophers zombie, the China room) were relevant to the course, but
were never actively discussed in class. Reading Conversations on
Consciousness allowed me to see when the discussions of the class
closely paralleled classical debates. But we were never prompted into
open discussions of these debates. On one hand, this allowed us to find
out own meaning given the data presented. But on the other hand, I feel
that the lack of connectivity made the class discussions seem more
trivial. I feel it would have enriched the discussions if those
involved had been aware of the rich history of debate - and the current
discussions - that we were continuing. For example, our discussion of
human behavior independent of the I-function could have been enriched
with knowledge of the ongoing discussion of the philosopher's zombie.
Our discussion of the location of the I-function could have similarity
benefited from the inclusion of the arguments for and against the
Cartesian theater. In my opinion, knowledge of how what we wondered
fits into the overall study of neurobiology, would have aided in our
quest to contribute to the scientific community. Indeed, how could we
try to contribute without informed knowledge of what those around us -
the eminent scientists of the field – have already contributed?
Especially given that their thoughts so closely mirrored our own. In
biology, the community is a resource that should not be ignored. One
person, or a group of people, working towards a theory, will always
benefit by the addition of one more thinker with his own individual
theory. The creation of an uninfluenced opinion is important, but so
too is the inclusion of the broader community into the deliberations.
In reading Conversations on Consciousness, I learned what theories are
being discussed, and was able to begin to formulate my own opinions
based both on my own observations and on the theories of those who
worked on the problem of consciousness before me.
1) Note: Authors of mentioned theories, in order: Bernard Baars, Thomas Metzinger, V.S. Ramachandran, John Searle, Petra Stoerig, and Roger Penrose.
2) Blackmore, Susan. Conversations on Consciousness: What the Best Minds Think About the Brain, Free Will, and What It Means To Be Human. Oxford: Oxford University Press, 2006.