From newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!tdatirv!sarima Thu Dec 26 23:57:38 EST 1991
Article 2321 of comp.ai.philosophy:
Path: newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!tdatirv!sarima
>From: sarima@tdatirv.UUCP (Stanley Friesen)
Newsgroups: comp.ai.philosophy
Subject: Re: Scaled up slug brains
Message-ID: <345@tdatirv.UUCP>
Date: 19 Dec 91 19:30:27 GMT
References: <12723@pitt.UUCP> <40705@dime.cs.umass.edu> <329@tdatirv.UUCP> <40828@dime.cs.umass.edu>
Reply-To: sarima@tdatirv.UUCP (Stanley Friesen)
Organization: Teradata Corp., Irvine
Lines: 123

In article <40828@dime.cs.umass.edu> yodaiken@chelm.cs.umass.edu (victor yodaiken) writes:
|In article <329@tdatirv.UUCP> sarima@tdatirv.UUCP (Stanley Friesen) writes:
|
|>I would tend to define "computation" as something like "data transformation".
|
|Semantic content: nil. What physical process is not "data transformation"?

I guess I view things a little differently.  I do not view data as physical,
it is abstract.  Any physical changes in a data transformation are merely for
the purpose of encoding the changed data.  Any other physical changes are
irrelevant to the data transformation.

If there were a way to encode data that was not physical, a data transformation
would not involve a physical change. A physical prosess would still entail
a phisical change.

A general physical process rarely encodes data, it just is.  Thus physical
changes do not necessarily correspond to abstract data transforms.

|>The issue then becomes: do biological neurons have operationally
|>relevant properties that are not captured in the digital models?
|>
|>If not, then neurons are performing Turing computation.  If so, then, and
|>only then, is the operation of the brain not computable in principle.
|
|Mais non. There are certainly digital programs which are not Turing 
|computable, and many more which are, in principle, Turing computable
|but not, in principle, computable by any conceivable compute
|(e.g. one in which data storage for a bit requires at least one atom).

But since neurons are themselves finite, I believe we can rule those out
a priori.

And if there are digital programs that are not Turing computable, then what
sort of machine computes them?  Can they be instantiated on existing electronic
computers?  If so, then I would consider 'computable' to have a broader
meaning than just 'Turing computable'

|>Fine, but I will require evidence of some other influence on cognition before
|>I will even seriously entertain the ideas that "mind" is *not* the result of
|>neuronal activity.
|
|If you want to work within self-imposed blinders, go ahead. But, please
|realize that you are operating on faith, not science.

I am not putting on blinders, I am just requiring evidence.
Show me the evidence and I will change my conclusion.
Waiting for evidence *is* scientific.

|>They *may* refer to something meaningful, but I do not even have an *objective*
|>way of telling if *I* show these features!  And given how pervasive self-
|>delusions are, I do not trust my "intuition" on this issue.
|
|Because we have no current means of identifying a process, does not mean
|that the process does not exist. Electricity existed before voltmeters.

I know, but until we can *detect* (not measure) it we cannot be sure it exists.
And I object to assuming processes that are not detectable.  Especially if the
the reason they are not detectable is because they are not well-formulated.

When Searle's concepts have been formulated well enough so that a detection
scheme can be planned (even if it cannot be built), they will be worth more
consideration.  Until then Searle has demonstrated nothing.  He has just shown
that his axioms are inconsistant with the axioms of other philosophers.  Now
he must provide observables (not thought experiments) that *demonstrate* his
axioms, and thus make them conclusions.

|>But we *can* add up numbers all day and get a total.  The anaology with a
|>physical process is only valid if cognition is *primarily* a physical process.
|>If it is primarily an informational process, then informational processes
|>can duplicate it in reality.
|
|and that's part of the question.

No, its the *whole* question.
If cognition is primarily an informational process then Searle is plain wrong.
If cognition is essentially physical, them Searle may be right.

But his attempts to *argue* the case based on pure logic are not sufficient.
He must provide testable criteria for evaluating his claims.
Logic is fallable, because axioms are *always* suspect.

|>And I believe that the "mind" shows all of the properties of an informational
|>process.  So your analogy is irrelevant.
|
|Unfortunately, your beliefs do not have the same weight as experimentally
|verified facts.

I do not claim they do.  I just require observationally verified facts to
change them.  Especially when they seem to cover all of the relevant facts
that I know.

|>Yes, there is a big gap between slugs and humans, but there are various other
|>animals that fill in almost the entire intervening span.  There are very few,
|>if any, human mental traits that are not at least foreshadowed in the apes.
|>We just carry them further, and use them in strange, unheard of synergies.
|>The individual components remain similar to our ancestors'.
|
|your faith is touching, if not persuasive.

This is not faith. This is applied comparative anatomy and taxonomy.
There is nothing in the anatomy of the human brain that is not in the anatomy
of the brains of great apes.  The only difference is size and connectivity.
we have the same types of neurons, distributed in the same ways in our brains,
we use the same neurotransmitters, we have mostly the same cortical regions,
with nearly identical connectivities, and identical cellular organizations.
All we have that apes do not is a few additional cortical regions with
appropriate connections, and proportional enlargements of a few other regions.

Similar small differences can be traced all the way back to insectivores
amoung living mammals.  (The most primitive living primates are little
different than insectivores in most areas of anatomy, including neuro-
anatomy).  Add in fossils (at least those that have intact skulls for
brain casts) and the sequence can be traced even further back.

Each small step is just a little different than the previous.  An insectivore
may well have fewer neuron types than the apes and humans, it certainly has
only a few of the cortical regions.  But the 'gap' is only an illusion
created by ignoring all of the intermediate forms.
-- 
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uunet!tdatirv!sarima				(Stanley Friesen)



