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. |
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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