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machine brains

Jerry Hull ZZZghull at stny.lrun.com
Wed Feb 17 17:00:58 EST 1999


On Wed, 17 Feb 1999 11:23:18 -0500, "Ray Scanlon" <rscanlon at wsg.net> wrote:

>
>
>Michael Edelman wrote in message <36C9C1FB.467DF4A3 at mich.com>...
>>
>>Ray Scanlon wrote:
>>
>>> We know a great deal, a very great deal about the brain. Why not talk
>>>about what we know?
>>
>>Because it takes us away from the only interesting question- i.e., what is
>>mind, and how does it arise out of a physical decice like the brain?
>
>The nature of the soul (mind) is a theological question and of the greatest
>interest. But if is only a distraction if our interest is in a materialistic
>explanation of how the brain works. It is my thesis that the brain may be
>simply explained if we keep the beauty of our thoughts out of it.

Isn't studying the brain irrespective of its ability to support mind kinda
like disregarding chocolate as a component of fudge?  It's not only
theologians that believe that "mind" exists in some sense -- it's just about
EVERYBODY, save for a radical few.  The term 'soul' on the other hand does
have a rather theological bent (at least in English), as something that lives
on after our death.  But surely one can believe that minds exist, yet do not
survive our death.

>>> Look at the reticular nucleus of the thalamus that is in
>>> position to halt the inflow of signal energy through the medial and
>>>lateral geniculate bodies and through the basal ventral complex of 
>>>the thalamus.  It can also halt motor programs at the ventral 
>>>lateral-ventral anterior nuclei
>>> on their way to the motor and premotor cortex. Here is a mechanism for
>>> interpolating extra synaptic events between incoming signal energy and
>>> outgoing motor programs.
>>
>>The problem with this strictly physiological approach is that it ends up
>>defining a perception mechanism, a memory storage, peripheral control,
>>etc., and you end up with a robot with a little homunculus sitting somewhere 
>>watching the perceptions and operating controls. Where's mind? You've 
>>got a computer sitting there humming away and no program.
>
>To the contrary, that is exactly what you do not end up with. The nervous
>system has sensory neurons, interneurons, and motor neurons. Signal energy
>enters through sensory neurons, filters through interneurons, and exits
>through motor neurons. No computation ensues. There is certainly no
>homunculus.

Though there need be no DIGITAL computation, surely something akin to signal
processing is going on, something that could be described as ANALOG computing.

>The soul (mind) is extraneous to a materialistic explanation. It is only
>when we turn to religion that we find need of a soul (mind).

Most folks need mind as an explanation of the ability to EXPERIENCE, where
that experience can be distinguished from the objects of the physical world.
You cannot experience my pain in the direct way that I experience my pain.  We
need a "place" to put such unshared, 1st person aspects of experience:  that
place is called 'mind'.

>>Using computers as a model for the brain isn't really productive unless you
>>have a real theory of AI to explain it. Otherwise you may as well build your
>>model from hydraulics for all it'll reveal about mind.
>
>I do not think of the computer as a model for the brain. I think of the
>brain as a network of leaky integrators.

Taking your 'computer' as "digital computer", for me this puts you on the side
of the angels.

>>> Is this part of what we are subjectively aware of
>>> as thinking?
>
>>Big question: WHO is aware? When you say we're aware of some neurons or
>>activation or whatever, you're simply moving mind back another level.Unless
>>you talk about mind, you're not going to answer any interesting questions.
>
>When we speak of the subjective, we leave science of the material world and
>enter theology.

Then everybody but a small, rigid coterie of reductionists becomes a
theologian.  Most psychologists, and it would appear many neural scientists,
are theological by this stipulation, since they take the existence of 1st
person experience as given.

>It is the soul (mind) that is aware. I maintain that the relationship
>between the brain and the soul (mind) is past our understanding. We lack the
>needed mental equipment.

At least here you seem to accept the existence of mind, contrary to my prior
jibe.  I think part of the problem is that you have identified mind & "soul",
where the latter does involve theological-type issues best ignored by science.

>A materialistic explanation of the brain is interesting enough for me. I am
>particularly interested in how the mammalian brain interpolates synaptic
>events between sensory input and motor output by means of the reticular
>nucleus of the thalamus.

Would you still be interested in this were you not aware of its implications
VAV "desires" & "beliefs" & other customarily "subjective" things?

--
Jer
"However far you may travel in this world, you will still occupy 
the same volume of space".  Traditional Ur-Bororo saying.



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