3. The Head Doctrine
The cerebral cortex (is) where matter is transformed
into consciousness ... . - Carl Sagan, Cosmos,
1980 -
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In western thought and mainstream science, it
is generally
assumed that the neurological activities of the brain generate human
consciousness
and the mind. The mind is identified with the brain in the head,
and it is assumed that consciousness and the mind disappear with the
disintegration
of the brain. This is the essence of the head doctrine.
Kenneth Pelletier, in
Towards
a Science of Consciousness (1978) labels this “the under the hat theory
of consciousness.” He writes:
Our present science and common sense support the
concept that
awareness resides predominantly at a point behind the eyes, between the
ears, and above the neck.(p.22)
Pelletier himself considers alternative views but begins by
establishing
this basic assumption underlying consciousness research and
theory.
This seems quite reasonable. Thus, Roger Sperry, a
prominent
neuroscientist, voices the widespread assumption: “I don’t see
any
way for consciousness to emerge or be generated apart from a
functioning
brain.”
The head doctrine assumes that the origins of
consciousness
are in matter, produced by neurological activity within the brain; and
not in spirit, soul or anything immaterial beyond the physical
realm.
The mind and brain provide the foundation for experience, self or “I,”
for human intelligence and self-consciousness. These are
fundamental
assumptions underlying so-called exact psychology and science. |
Carl Sagan embraces this
basic assumption
regarding the nature of human consciousness and mind. In The
Dragons
of Eden, he explicitly stated:
My fundamental premise about the brain is that its workings–what we
sometimes call ‘mind’–are a consequence of its anatomy and
physiology,
and nothing more. ... because of the clear trend in the recent history
of biology and because there is not a shred of evidence to support it,
I will not in these pages entertain any hypotheses on what used to be
called
the mind-body dualism, the idea that inhabiting the matter of the body
is something made of quite different stuff, called mind. (1977,
p.7)
Contemporary scientists take human beings to be higher primates that
have
evolved through random genetic changes and the process of natural
selection.
There is no immaterial mind, spirit or soul, and the highest or most
noble
human faculties are regarded as being dependent upon the cerebral
cortex.
These themes run through Sagan’s writings:
The cerebral cortex (is) where matter is transformed into consciousness
... . The cortex regulates our conscious lives. It is the
distinction
of our species, the seat of our humanity. Civilization is a
product
of the cerebral cortex. ... What distinguishes our species is
thought.
The cerebral cortex is a liberation. We need no longer be trapped
in the genetically inherited behavior patterns of lizards and baboons.
(Cosmos, 1980, pp. 277-8)
Thinking and reasoning, language faculties and various other cognitive
abilities can be localized within various areas of the cerebral
cortex.
Further, neurologists have identified the sensory-motor strip of the
cortex
as a site of bodily sensation and control; while emotions, drives and
passions
are related to the limbic system and mid-brain structures. All
such
findings suggest the general notion that consciousness and mental
states
are dependent upon the brain, particularly the cortex which is so
richly
developed in the higher primates. Cortical areas are required for
abstract thought and language faculties, and hence are regarded by
Sagan
as the “seat of our humanity.”
Nevertheless, Dr. Sagan steps out on a limb in
declaring
that “the cerebral cortex is where matter is transformed into
consciousness
... .” (p.277) He does not define consciousness, nor
elaborate what it is, nor where and how it is transformed out of
matter.
These are simply declarations that are unsubstantiated by
evidence.
While it may seem natural to identify human consciousness most
intimately
with the cerebral cortex, there is still something fundamental missing
in these accounts from a scientific perspective.
In 1995, Dr. Sagan continued to maintain this same basic
position.
In an interview in Psychology Today, he comments:
“... the mind is merely what the brain does. There’s nothing
else, there’s no soul or psyche that’s not made out of matter, that
isn’t
a function of 10 to the 14th synapses in the brain.” (p. 65)
There are other diverse views within mainstream psychology as to what
consciousness
entails, and how it is produced or localized within the brain.
Sometimes,
different states of consciousness are identified with different
divisions
of the brain; for example, with the left and right hemispheres,
or
with MacLean’s triune brain model (i.e., the reptilian, old mammalian,
and new mammalian brains). Other theorists regard the
sub-cortical
areas as more directly involved in generating consciousness,
particularly
the reticular activating system and the brain stem. These structures
are
involved in mediating arousal, wakefulness and the control of
attention.
Thus, while scientists put forth various possibilities concerning the
generation
and localization of consciousness, they share the basic assumption that
consciousness and the mind are centred exclusively in the brain, in the
head–hence, I call this “the head doctrine.” |
Nobel laureate, Francis
Crick,
is another prominent theorist who articulates the head doctrine.
Given the conventional viewpoint that he espouses, the title of Crick’s
recent work The Astonishing Hypothesis: The Scientific Search for the
Soul
(1995), is quite misleading. His “astonishing hypothesis” is
anything
but “astonishing.” Crick merely restates the common belief, or
assumption,
held within psychology and science for the past century:
The Astonishing Hypothesis is that “You,” your joys and your sorrows,
your memories and your ambitions, your sense of personal identity and
free
will, are in fact no more than the behaviour of a vast assemble of
nerve
cells and their associated molecules. As Lewis Carroll’s Alice might
have
phrased it: “You're nothing but a pack of neurons.” This hypothesis is
so alien to the ideas of most people alive today that it can truly be
called
astonishing. (p. 3)
Crick’s point is that this hypothesis is astonishing when contrasted
with
the popular belief in spirit and the existence of the soul. The
subtitle
of Crick’s book is misleading, however, in that he makes no effort to
review
the scientific work of scientists who do search for the soul, or who
explore
alternate views of consciousness. Instead, Crick deals
exclusively
with attempts to explain how consciousness might be generated by
neurons
within the brain. How astonishing!
Although Crick suggests the need for a broader
investigation
of the nature of human consciousness, he focuses exclusively on trying
to understand visual awareness. He explains that the neural
substrate
of visual awareness involves various cortical areas (layers 4, 5 and
6),
which subserve visual analysis in association with activity in the
thalamus.
# In summarizing his work, Crick expresses a number of
reservations:
So much for a plausible model. I hope nobody will call it the Crick
Theory of Consciousness. While writing it down, my mind was constantly
assailed by reservations and qualifications. If anyone else
produced
it, I would unhesitatingly condemn it as a house of cards. Touch
it, and it collapses. This is because it has been carpentered
together,
with not enough crucial experimental evidence to support its various
parts.
Its only virtue is that it may prod scientists and philosophers to
think
about these problems in neural terms, and so accelerate the
experimental
attack on consciousness. (p. 252)
What is most contrived about Crick’s model of consciousness is that it
is based exclusively on an analysis of visual awareness processes, and
leaves aside all of the other psychological processes which are
subjectively
experienced–such as thoughts, emotions, sensations, desires, self
awareness,
digestive problems, sexual arousal, and so on.
Crick himself recognizes the tentative and
incomplete
nature of his model, and his main aim is to encourage scientists to
focus
their efforts on this “mystery of consciousness.” He notes
that the issue of consciousness has been widely ignored by both
psychologists
and neuro-scientists, and yet it constitutes the fundamental enigma in
the life sciences.
Crick notes that “this book has very little to do
with the human soul as they (readers) understand it.” Certainly,
this is true, as he never gives the soul hypothesis any serious
attention.
Most importantly, Crick recognizes that the issue of the existence of
the
soul is intimately tied to the issue of the nature of human
consciousness;
and it is high time that scientists face this critical issue.
Further,
he recognizes that his theory is simply a “hypothesis,” which is
“plausible,” but not established with any certainty. In fact, it
may be little more than a “house of cards” ready to collapse with the
slightest
breeze. Crick portrays the mystery of consciousness as a central
problem in science which must be addressed, yet he assumes, from the
outset,
that the question to be answered is simply which neurons in the brain
produce
consciousness. Crick’s theory has no substantive basis in experimental
fact and is simply another fiction of cognitive science. |
David Chalmers, of the
philosophy
department at the University of Arizona, is another prominent
mainstream
consciousness theorist. Chalmers suggests that the search for the
neural
correlates of consciousness (or NCCs) is “the cornerstone in the recent
resurgence of the science of consciousness.” (2000, p.1) He
defines
a neural correlate of consciousness as a neural state that directly
correlates
with a conscious state, or which directly generates
consciousness.
In a paper on NCC’s, Chalmers lists a number of proposal which have
been
forwarded to explain the nature and location of consciousness.
These
include:
40-hertz oscillations in the cerebral cortex
Intralaminar nuclei in the thalamus
Re-entrant loops in thalamocortical systems
40-hertz rhythmic activity in thalamocortical systems
Extended reticular-thalamic activation system
Neural assemblies bound by NMDA
Certain neurochemical levels of activation
Certain neurons in inferior temporal cortex
Neurons in extrastriate visual cortex projecting to prefrontal areas
Visual processing within the ventral
system
(2000, p. 1)
All of these suggestions or hypotheses are variants of the
head doctrine
and localize consciousness within one or more areas of the brain.
Each is derived from research investigating the neurological basis of
particular
mental processes, and none really deal with the issue of the substance
of consciousness, or with its subjective nature. Although many
researchers
recognize the enigmas and mysteries of consciousness, the possibility
that
consciousness might exist outside of, or apart from, the neurological
activity
of the head brain is never given any consideration. The head
doctrine
is the basic assumption underlying most modern consciousness research
and
speculation.
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Theorist John Searle
(2003)
writes about “The Problem of Consciousness,” at his website,
www.ecs.soton.ac.uk;
and his comments again illustrate the assumptive basis of the head
doctrine:
“The most important scientific discovery of the present era will come
when someone–or some group–discover the answer to the following
question:
How exactly do neurobiological processes in the brain cause
consciousness?
This is the most important question facing us in the biological
sciences
.... By ‘consciousness’ I simply mean those subjective states of
sentience
or awareness .... Above all, consciousness is a biological phenomenon.
... Conscious states are caused by lower level neurobiological
processes
in the brain and are themselves higher level feature of the brain. ...
the critical functional elements are neurons and synapses. ... we
simply
know as a matter of fact that brain processes cause conscious
states.
W don’t know the details about how it works and it may well be a long
time
before we understand the details involved. ... Given our present
explanatory
apparatus, it is not at all obvious how, within the apparatus, we can
account
for the causal character of the relation between neuron firings and
conscious
states. But, at present, from the fact that we do not know how it
occurs,
it does not follow that we do not know that it occurs. Many
people
who object to my solution of the mind-body problem, object on the
grounds
that we have no idea how neurobiological processes could cause
conscious
phenomena. But that does not seem to me a conceptual or logical
problem.
That is an empirical/theoretical issue for the biological sciences. The
problem is to figure out exactly how the system works to produce
consciousness,
and since we know that in fact it does produce consciousness, we have
good
reason to suppose that there are specific neurological mechanisms by
way
of which it works.”
Searles’ comments illustrate the assumptive
basis
of the head doctrine; and how assumptions end up being taken as
‘facts.’
At one point, Searle admits that we have no idea how neurobiological
processes
produce consciousness, but a moment earlier, he has just stated: “...
we
simply know as a matter of fact that brain processes cause conscious
states.”
The facts seem to have disappeared from Searle’s account, and it is
instead
plagued with assumptions. Searle has “promissory science” to
offer
us–promising in the future to fill in the gaps in the mysteries of
consciousness–and
he certain consider that he has no need for any metaphysical
considerations.
A last illustration of the head doctrine,
and its
assumptive basis, is provided by G. Roth’s
recent
Scientific American article: “The quest to find
consciousness.”
Roth maintains that: “Individuals consciously perceive only
that
information processed in the associative regions of the cerebral
cortex.
But many regions that operate on a subconscious level participate in
the
various states of consciousness.” (2004, p.
35)
Under the title of “The Seat of Consciousness.” Roth offers a picture
of
the cerebral cortex showing its various lobes, responsible for varied
mental
functions. At the same time, Roth does admit that there is “no
consensus”
as to how consciousness arises, nor of what it consist, but all the
while
he assumes it is simply figuring out which of the brain’s interactive
processes
produce it. Roth also ends on a promissory note:
“For now, no definite explanations exist, but that is not likely to
remain true forever. Consciousness has a rather unique character,
but at least some of the mysteries that surround it should
nonetheless–eventually–fall
away in the face of persistent scientific inquiry.” (p.39)
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