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machine brains

Michael Edelman mje at mich.com
Fri Feb 26 08:27:35 EST 1999



Ray Scanlon wrote:

> Michael Edelman wrote in message <36D40248.45F3D1CB at mich.com>...
>
>    (snip)
> >
> >This is the point at which I find myself shaking my head. Who is aware of
> >thinking? When you say "subjectively" you imply a subject. Who is that
> >subject?
> >
> >You have not argued for the non-existence of mind or self-awareness. You
> >merely
> >assert that it does not exist.
>
> Nope. The brain exists in the material universe, the mind in the spiritual
> universe. I enjoy both but I keep them separate.

You are merely defining away mind. Unless you can explain the subjective
experience of mind that we all have, you can't justify this.

> Your entire post was an example of what I am attacking, the desire to talk
> about the mind rather than the brain.

That's like attacking the study of physiology for talkking about life instead of
body.

> The title of the thread is "machine
> brains". Why can't we just talk about the brain as a machine and leave the
> mind out of it.

Because the function of the higher levels of the brain *is* mind.

> When sensory neuron is efferent on a motor neuron, as it is in some
> jellyfish, there seems to be no problem in comprehending the neural net.
> When the interneuron is interposed, as it is in some other jellyfish,
> difficulties arise. (But only the tiniest of difficulties.) As the
> interneurons proliferate in the vertebrates, why do we say that a difference
> arises?

Becasue we observe one. You argue that mind doesn't exist because you don't see
its precursor in simple CNSs. And yet we all know what mind is.

> In mammals the reticular nucleus appears, synaptic events are
> indefinitely added yet the nervous system is still a machine. A machine is
> comprehensible, possibly most difficult but still comprehensible by man.

There is nothing in the notion of the brain as a machine that prevents us from
assuming that mind is a function of  the brain.

Your argument strikes me as similar to this: All cells are entities that have
various mechanisms to implement homeostatis. These mechanisms can be fully
described and replicated. Ergo no such thing as "life" exists.

And yet "life" is a very convenient construct, and one that may not be
completely predictable from the state of individual cells. We find it useful to
say that a person is alive or dead regardless of the state of most of his cells.
Doctors find it entirely meaningful to say a person is dead or alive
independantly from the question of how many cells are maintaining homeostatis.
We never say someone is 10% dead, or 50% dead. Life in that sense is a property
of the entire organism, not its constituent parts.

And so mind is a property of the brain as a whole. Mind is what the brain does.
It is perceived as an entity, though it probably consists of heirarchies. In
your model you may see functional structures that incorporate the activity of
many neurons or nuclei; these nuclei may in turn participate in higher order
assemblies, and on and on upward. At some level we find functional entities
emerging that we can still label in a behaviorist mode. Here is "attention" or
"reflex". We may or may not be able to fully describe the neuronal activity that
makes up these mechanisms, and indeed, as we go higher up, we may see that it is
*not* the case that the same physical mechanisms always underlie the same
observed higher-order activities.

As move move to higher levels of complexity, we see the emergence of the
heirarchy of mind. Each successive level communicates with levels above and
below. We as individuals cannot attend directly to the receptors in our ears;
instead, we attend to the phenomenological experience of "sound". Ditto vision.
When we get high enough, we see the emergence of a top-level monitor that is
responsible for awareness of self and deciding what to do next.

It may occur to some that if mind is a property of hierarchial systems, there's
no reason that there could not exist minds above those of individuals as a
consequence of the interaction and communication between individuals. The
obvious example is the anthill, which  Hofsteader used as a metaphor for mind.
And the more adventurous may wonder: If an anthill can be said to have a certain
degreee of intelligence, could not the same be said for a large population of
human beings- particularly a population in constant communiction via speech,
books, and the internet? Perhaps. That's what George Dyson suggested in "Darwin
Among the Machines"- and what Hobbes suggested centuries ago in "Leviathan".


--
Michael Edelman     http://www.mich.com/~mje





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