machine brains

ray scanlon rscanlon at wsg.net
Tue Dec 9 20:18:40 EST 1997


Body and Soul

The ancient problem of body and soul remains with us. I see no progress;
still, each decade finds a new Solution. Some see the problem as hinging on
a misunderstanding, a misinterpretation of the meaning of words. I adopt
mind as a euphemism for soul to remove God from the equation, brain for body
to show that I am scientific. Nothing really helps; each decade the deepest
thinkers again agree that the basic problems of metaphysics allow of no
resolution, only of discussion.

I see three basic approaches: the religious, the ethical, and the
scientific. The relation of man and God interests the theologian.. The
ethicist examines the relation of man to his fellow man. The scientist looks
at the universe with man as observer. To say that one or two of these
approaches is irrelevant is to be simple minded.

The theologian sees the universe as a temporary abode of the soul; where the
soul came from and where it is going are most important. God's Will is to be
interpreted by man as best he can. The ethicist demands free will; without
the freedom to choose his analyses must fail. The scientist has need only of
an observer; he would prefer a "neutral observer" to a man if he were given
the choice. Most make use of a soul, a mind, an intelligence, an homunculus.

None of these positions is incorrect; they all partake of Truth. Almost all
men select from these three as from a smorgasbord and usually shift their
emphasis according to the discussion. Many scientists prefer a homunculus
that manipulates data. There are numerous minority positions such as those
who say the homunculus is real and the rest illusion and those who say the
homunculus is a mirage.

The homunculus is the little man who sits in the center of my head watching
a television screen and punching buttons. I am too learned to be taken in by
such a fable, instead I prefer a more sophisticated version I call an
"intelligence" (formerly mind, formerly soul). This sophisticated homunculus
selects from the data proffered by the brain, manipulates the data, reaches
a decision, and forwards the decision to the brain to turn on the muscles. I
use words such as thinking, knowledge, intelligence, memory, semantics,
intention, and free will when talking about this homunculus.

To design brains, I take the viewpoint that the homunculus is only aware of
neural activity and has no causal powers. This is solely for brain
explanation and not to be taken seriously outside the laboratory. I am fully
aware that this implies an interface between brain and soul and a one-way
transfer of energy, but that is the sort of thing with which I must live.

Why not take the easy route and simply deny soul (mind)? I cannot because
the human brain is my model and others interested in brain design always
ask, "Does the machine think?" By think they mean does the machine have a
homunculus that manipulates the data. "Does it have a soul (mind)?" I must
be careful of this possessive form since I do not have a soul, I AM a soul
(mind, self).

Being aware demands a transfer of energy from the brain to the mind. This
energy cannot be of the physical universe; it must be ethereal,
transcendent. Ascribing only awareness to the homunculus is minimal but it
is nonzero. If there is to be a passage of energy across the interface to
allow the homunculus to be aware, why should it stop there? Why not allow
energy to flow freely both ways? This is too much; the physicist will not
have it. The homunculus is either part of the physical world or it is not.
If it is part of the world then I should have physical evidence for it; I
find none. Physical science is better off without an aware mind; the passage
of energy one way across the interface is just as indefensible as passage
both ways. The materialist may easily falsify my argument by producing a
physical test for the presence of mind. Let him do it.

A minimal soul is one that merely observes. I cannot do without a watching
mind and continue the discussion. The notion that the universe will continue
to exist after my death lacks meaning for me. The mere idea of a continuing
universe involves me looking at it. I cannot conceive the universe except as
object. If I rule out dualism, I leave myself with a universe that I cannot
envision except with the help of a "neutral observer" and what is this
except God? By reducing mind to merely awareness I position myself as close
to materialism as I can without embracing it. Such a brain-mind would work
just as well with no mind.

What have I gained by postulating an aware homunculus (soul, mind,
intelligence)? Not much. I am still adrift in a dualist existence with
one-way transference of energy across the interface. At least I have
sharpened the question. I see that Turing's Test speaks only of the ability
to answer questions, not of awareness. I see that if I find myself in
Searle's Chinese Room I need not understand Chinese to be aware that I am
manipulating symbols. Similarly the computer may be fully aware that it is
switching bits without any knowledge of Chinese. I want a test for
awareness, not of thinking, not of knowledge.

I will proceed with the soul (mind, self) as neutral observer, reminding the
reader that God and free will belong in a different context. I remind those
who would eliminate the observer that the physicist is unable to do so.

aware versus alert

Consciousness has two aspects: a subjective one, awareness, and an objective
one, alertness. The soul is aware; the body is alert.

To conjugate:
      I am aware.
      You are alert.
      He behaves in an intelligent manner.

     You say you are also aware.
     I believe you.

Alertness is everywhere; all animal life exhibits alertness. Alertness
subsumes all those actions that animal life performs under the direction of
a neural net when interacting with its milieu.  Alertness admits of degree;
the clinician talks of normal alertness, confusion, somnolence, stupor, and
coma.

I use awareness to describe the private experience in which I know of my
body and of the universe. I do not think, my brain thinks and I am aware of
its thoughts. I do not remember, my brain remembers and I am aware of the
memory. I do not decide, my brain decides and I am aware of the decision.
What may the brain not do? It may not observe itself. Pain neurons may be
excited but the brain feels no pain, only I (soul, mind, intelligence, self)
may feel pain. I am aware, my brain is not. Awareness is a mystery and must
remain so. All the rest I can explain away, but not awareness.

The soul observes, that is all; it lacks causal effect. Because of this lack
of causal effect I cannot infer the existence of mind from observable
behavior. I can only postulate the existence of other minds by an act of
faith.
By thus limiting awareness to mere observation, I can put the soul-body
problem more clearly. I would like a physical demonstration of awareness. I
ask of the neuroscientist a statement such as: with this pattern of
molecules there is awareness, or with this neural net there is awareness, or
with this voltage trace or this MRI there is awareness. Any test that
involves alertness is not acceptable, in particular, any test that uses
language. I must be ready to decide that this dog is aware or not aware by
using a physical test. I do not expect ever to see such a test, but I am
open to being surprised.

Awareness is the central issue. I can be aware without thinking. Thought is
not necessary. To equate thinking with awareness is to create confusion
where I want clarity. I can be aware without knowledge. To equate knowledge
with awareness similarly confuses. So I will not talk of thinking, of
knowledge, but of awareness. I can say nothing objective about being aware,
but then neither can anyone else. One thing seems certain, the brain would
work just as well without awareness.

To say that the relationship between mind and brain "is largely unknown" is
an evasion; it is wholly unknown. Neuroscientists have shown nothing,
absolutely nothing, as  sufficient for awareness. They have shown nothing,
absolutely nothing, as necessary to awareness. The mind observes, that is
all. If the mind is to have no causal effect, what is left but observation?
Because of this lack of causal effect I cannot infer the existence of mind
from observable behavior. I can only postulate the existence of other minds
by an act of faith. Any attempt to reconcile my awareness of the exterior
world with my awareness leads to difficulties. Agnosticism is my refuge.

I can use intelligence as a descriptor of alertness or as a euphemism for
soul or for mind. I say an organism that can more finely discriminate
nuances of the milieu is more intelligent; the more responses it has, the
more intelligent. It is a euphemism; it tells of unease. Those who cannot
say soul, say mind; those who cannot say mind, refer to an intelligence.

I concentrate on awareness to let materialism have full play. By insisting
only on awareness, I allow materialism to explain the physical universe, the
brain, and thinking. I have reduced the mind-body problem to two
things--awareness and that of which I am aware. This is all the physicist
needs.

Exaltation

At times, certain neurons rise to my awareness. I call these neurons
"exalted". Since I do not know what makes these neurons "exalted", I can
only speculate.

What is this condition? It could be activity, say a burst of axonal pulses,
or a total absence of axonal activity. Or it could be some dynamic (and
momentary) configuration of molecules. Or maybe it is a dynamic cusp of the
electromagnetic field that pervades the brain centered on this neuron for an
instant. I don't know and it seems likely that I shall never know. Let me
say that the neuron is "exalted" for whatever reason and by whatever means
and thus I am aware of it. Why I do not know. "Exaltation" will be the word
I use in my description of brain action.

Signal energy passing through the brain exalts particular neurons. These
exalted neurons are the objective aspect of a thought. For this thought to
have a subjective aspect, an homunculus must be present. It cannot be
otherwise. A materialist who says he may speak of being aware of a thought
without invoking an homunculus deludes himself.

Is it possible to think of the mind without an homunculus as object? When I
think of myself, signal energy has exalted which neurons?

The Cartesian Theater

In "Consciousness Explained" Daniel Dennett rejects the Cartesian Theater, a
region of the brain in which the soul (mind, intelligence) makes contact
with the body (brain). He lacks an argument for non-existence of the
theater, he merely repeats at intervals that there is no such thing. Perhaps
he is thinking of the simplistic homunculus that sits in the center of the
brain watching a television screen that is UPSIDE DOWN. Since he feels that
this theater is so obviously wrong and must be rejected by all
right-thinking people, he needs no argument. I agree that there is probably
nothing like that in the brain, but there are other less simplistic
formulations.

The neurons that signal energy has exalted at any particular instant form
the image on the screen of  my Cartesian Theater. This ever changing
constellation has no resemblance to the image on a television monitor.
Instead I am aware of a single exalted neuron, or a group of ten, or of a
hundred as a percept, a concept, a memory, or a thought. If the diencephalon
were to be exposed and the exalted neurons were to flash as colored lights,
I should make no sense whatsoever of it. I should see it as through a
kaleidoscope. But, subjectively, it is perfectly clear. I am remembering my
sister, as a young girl, holding a cat up to her face and talking to it.

First I ask myself, "Am I aware of the world directly, or am I instead aware
of the sensory neurons that are in turn affected by the exterior world"? I
expect no definitive answer. I make my choice on personal grounds. Any
rational discussion of this matter tends to be a recital of prejudices. I
like to think that I am aware only of neurons in my brain, but that is only
my own, personal, narrow view.

Next I ask myself am I aware of sensory neurons directly or of interneurons?
Again I have opinion. No matter how strongly felt, no matter how loudly
defended, it remains opinion. I can look at the case of the phantom limb. A
patient who has had a limb amputated still feels as though the limb were
present. The surgeon has removed the limb, the sensory neurons went with the
limb, but the patient feels that it hurts, that the leg twists under him,
that his toes curl under. I say it is of a subset of the neurons in his
central nervous system that he is aware.
Are all neurons in the central nervous system candidates for exaltation, or
do they reside in a particular region? Wilder Penfield, who studied under
Sherrington and then under Cajal and who spent his working life time doing
neurosurgery, thought they were to be found in a region that includes parts
of the thalamus and the hypothalamus. He said:

    "The indispensable substratum of consciousness lies outside the cerebral
cortex, probably in the         diencephalon (the higher brain-stem)."

Penfield was speaking of awareness not alertness in this statement.

What good is this homunculus?

I find no homunculus when I examine the physical universe. The zombie
argument demonstrates that I need none to explain the actions of men. As a
practicality, most men, at most times, have denied awareness to animals
other than man. Animals, to them, navigate their world perfectly well
without awareness.
In discussions involving consciousness an homunculus is very useful. It
makes explicit what most philosophers would like to gloss over. I can ask of
each, "Just what is your homunculus?" "Does the brain do the thinking, or is
it the homunculus?" If I wish to be scientific I have a choice between no
awareness and a minimal homunculus.

My homunculus

I wish to examine the human brain from a position as close to materialism as
I find possible. This is Chalmers's position. What homunculus is good enough
for me? The thinker is too much. I should need the thinker for "free will"
but the price is too high. I would rather give up free will than allow a
thinker. If I give up free will, only awareness remains. My homunculus is
only aware, all the rest of the universe I give over to science. Let my
brain do the thinking, I would only be aware of its thoughts.

I see a problem, my awareness must have energy if it is to be aware of
qualia. Let it be some transcendent energy that does not interfere with the
physical universe. But if this transcendent energy may flow one way then why
not the other. I am back with a thinker.

By fiat I declare that the transcendent energy flows only one way--from my
neurons to me as an awareness. It does not flow from me to my brain as "free
will".

Please note that this "aware only" homunculus is just for explanation of the
activity in the mammalian brain and for electronic brain design. I have
other homunculi for ethical and theological discussions.

I introduce the homunculus as a tool, a meter stick, against which I can
measure any assignment of causal activity to the soul. Many are uneasy with
"soul", they prefer euphemisms. They speak of the self or the intellect.
Some would restrict the use of language to our knowledge of the external
world. They say that which I cannot talk about does not exist. I use the
homunculus as a gauge to measure how far a person departs from that
position. For anyone who would include soul in his universe, there is a
minimalist position . . . soul may be aware only. Different beliefs lead to
different homunculi. Some would say I do not "have" a soul, I "am" a soul.
The materialist would deny the homunculus. He would eliminate everything
mental from his world unless he can find a physical basis for it. He needs a
molecular explanation of mind.

At first glance I see none. The material universe seems to function
perfectly well without any minds about. If I say that a mind is part of a
human being, or of animal life, I still see a universe that got along very
well for some billions of years without mind.

Given the existence of this mindless universe, I have the problem of
determining how and when minds evolved. How did part of the universe come to
feel that it could not get along without a mind?

Until a physical scientist comes up with a molecular configuration that is
sufficient for mind, I must deny its existence. But if there is no mind,
what of me? Is my existence a self-generated illusion? Some would say so.
That is all right for them, but not for me. I am not my brain. No matter how
essential to consciousness the brain may be, I am not my brain.

All these things are puzzles without answers. I can form the question but
cannot satisfy the conditions. If all my data is the awareness of
observation how can I possibly speak of a universe without an observer. I
know only objects but what is an object without a subject.

I can speak of things that cannot exist so I can speak of unobserved
observables. Few have any great difficulty with a universe that existed
before living forms. There was nothing there to observe it but it Was. I
think this differs from the flower blooming unseen in the desert. Someone
could have been there to see it. But with the universe before life this is
not so. No one could have been there to see it because there was literally
no one available.

On the question of a possible resolution Chalmers is an optimist. McGinn a
pessimist.

The Envelope

The envelope is my universe, soul and other, as it would be seen by an
observer of higher dimension. I cannot be such an observer. I cannot
envision in any way my universe as seen by such an observer. Why do I try?
Every attempt to stand outside my universe is to be rejected. But I will, I
must, continue to do it.
Scientific explanation is an attempt to foretell the future on the basis of
the past. I postulate particles and interactions between these particles on
the basis of a limited number of forces. As I approach the envelope this
simple view dissolves. Nothing is solid, nothing firm.

It is inherent in my view of the scientific approach to knowledge that I
should include all of the past. Everything has some pertinence. Can I
project this view into the future? A hundred years? A thousand? A million?
This seems irrational. One sees a future (and not too far off) when men
shall be overwhelmed by the past. Does mankind approach a vertical
asymptote? Possibly the human race will over extend itself and the portion
of human activity that is not directed to the production of food will drop
toward zero. All the excesses of civilization will disappear in the frantic
struggle to exist.

If someone wishes to restrict their view (from the inside) of the envelope,
that is their privilege. Some would wish to say that any view that is to be
labeled "scientific" must be reducible (in some sense) to particle physics.
What does this mean? Particle physics cannot be extended upwards to the
molecule. If not to the molecule, then what hope is there of ever
characterizing an assemblage of molecules? One says, "In principle"? And
what is this "in principle"? The phrase seems to be something of the nature,
"I could do it if I had the time". But time is what I lack.

I am free to say that my brain thinks and I, as soul, am aware of those
thoughts. A neuron is exalted when it rises to my awareness. Neurons are
exalted by signal energy. The signal energy may be recent, very recent, or
not so recent. As the signal energy becomes older it exalts neurons that
differ from those exalted by recent signal energy. I am aware of this older
signal energy as chimeras. It is in this way that I am aware of abstract
things. Abstractions that are farther and farther removed from reality.

Finally I am led to musings about soul itself. I am back to pushing against
the envelope.

Some minor points remain:

Vitalism

If I restrict intentionalism to biological structures, as Searle would do,
am I resurrecting vitalism? Am I postulating a quality that resides only in
living things?

Self awareness

If I say the self is aware of itself, then aware of what? If I am aware only
of the excitation of the neurons, then which of these are excited when my
brain thinks of my self? One possibility is the neurons that are not
excited. Another is the excitation of neurons involved with language.

Evolution of awareness

Evolution is a useful viewpoint from which I consider the physical universe.
Awareness is not part of the physical universe. Applying evolution to
awareness is a category error.

Does the machine think?

I would point out that in the Age of Connectionism thinking has moved from
mind to the brain. It is my brain that thinks and it is I who are aware of
the thoughts. The world at large wants to know whether the machine is
thinking. I say only that the question is out of date, of course it thinks.
They should ask whether the machine is aware.

If a brain may think and decide, then a machine may think and decide. I
should ask not if the machine is thinking, but is it aware that it is
thinking. Not if the machine knows something, but is it aware that it knows
something. The behaviorists are correct. Awareness is irrelevant to science.
Every objective event that I would lay to mentalism can be just as easily
ascribed to the brain.

Turing

Turing asserted, "Thinking is the silent manipulation of language." If the
machine produces language that I can not distinguish from that of a native
speaker, then the machine is thinking. Note that I never take the position
that the machine might be the questioner, might pose the problems. My
interest is in awareness, not thinking; Turing's test is irrelevant.

A Turing machine is a formalism, nothing less, nothing more. When the
statement is made, "The brain is a Turing machine," I take this to mean that
a portion of the brain's activity may be described by a Turing machine, that
the activities of the Turing machine will more or less predict what this
portion of the brain will do.

Searle

Searle is right when he says that a particular arrangement of atoms and
electrons is not enough to guarantee the presence of mind, but he is wrong
when he infers that some different arrangement is sufficient. It comes down
to faith: either I believe that I can cobble electrons together to make
mind, or I do not. I certainly have no proofs.

The truth that is expressed by the Chinese Room is that mind need not be
present; semantics does not follow from syntax, but then neither does it
follow from anything else. The brain driven organism survived; to attempt to
extend this explanation to mind is a category error.

Searle is not certain what it is that makes a configuration of molecules
aware but he is positive that it is not the programming of a computer. The
notion that awareness is without physical cause is anathema to him.






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