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Article 6001 of comp.ai.philosophy:
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>From: roitblat@uhunix.uhcc.Hawaii.Edu (Herbert Roitblat)
Subject: Re: Homunculus and the witch's brew
Message-ID: <1992Jun1.072425.13178@news.Hawaii.Edu>
Keywords: computation, transduction, homunculus, sensorimotor physiology
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References: <1992May31.145204.16357@Princeton.EDU> <l2iea9INN44p@exodus.Eng.Sun.COM> <1992May31.212826.1778@news.media.mit.edu>
Date: Mon, 1 Jun 1992 07:24:25 GMT
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References: <1992May31.145204.16357@Princeton.EDU> <l2iea9INN44p@exodus.Eng.Sun.COM> 

In article <1992May31.212826.1778@news.media.mit.edu>
minsky@media.mit.edu (Marvin Minsky) wrote:

>In article <l2iea9INN44p@exodus.Eng.Sun.COM> silber@orfeo.Eng.Sun.COM (Eric Silber) writes:
>>In article <1992May31.145204.16357@Princeton.EDU> harnad@phoenix.Princeton.EDU (Stevan Harnad) writes:
>>>Many readers still do not seem to have understood ....
>>>transduction,  ....
>>>...People keep reverting to
>>>the rival computational hypothesis  ...
>>>... in which you are a computational
>>>core, with the transducers simply carrying information TO it ("you"),
>>>...But none of that
>>>refutes the hypothesis that we are transducers; nor does it make any
>>>     One thing I'm sure would not be left over would
>>>be the little homunculus that normally sees what we see, hears what we
>>>hear, and thinks what we think.
>.>   And what is a
>> 'transducer' anyway? Is it not ultimately equivalent to a 
>> mathematical 'transformation' ? That is , a 'transducer' which
>> converts a physical-event-stream-of-type-A into a 
>> physical-event-stream-of-type-B  is equivalent to a mathematical
>> transformation of a sequence.

>I have the same problem.  SH: are you using the term "transducer" in a
>non-standard way?  The brain has lots of internal information and
>processing capability, whereas the term transducer is used normally to
>refer to a (many-one) transformation; if it has much internal state,
>then this term is inappropriate because your assertion sounds totally
>Homuncular.  And your thesis makes no sense that.  way.  Perhaps you
>should withdraw this term before it is too late -- or else present a
>definition that does not require reading many difficult references.
>Otherwise, we'll have to refer to H(T)HH -- Harnad's (Total)
>Homuncular Hypothesis.

>     "Minds are simply what brains do." -- me.


It seems to me that Harnad's suggestion is a step in the right
direction.  Transduction is (in the fields with which I am familiar)
is process by which some environmental quantity is transformed into
some other quantity that can be more easily processed.  Pressure
transducers that are used in a number of mechanical systems transform
pressure into voltage, for example.  The voltage can be processed by
electronic devices, but pressure can only be processed by a small
subset of electronic devices, usually pressure transducers.  Some
electronic parts are inadvertent pressure transducers, for example,
resistors with small cracks in them can sometimes cause unintended
changes in the performance of electronic circuits.  If these circuits
were evolving by natural selection, such an inadvertent response to
pressure might be the basis for the evolution of a pressure
transducer.

It seems to me that to consider ME as a transducer is to completely
disavow any conceptualization of dualism.  One reading of Harnad's
argment is that the transduction is from sensory information to
behavior.  The response of the system, R, is a function of the sensory
information, S.  R = f(S).  This is exactly one of Skinner's
formulations of the reflex.  Skinner also argued that if all of the
relations between S and R were regular, then there would be no need to
discuss any of the processes or mechanisms that intervened between S
and R.  There would be no need for a homunculus or for any computation
in our fomulation.  Such discussions would add nothing to our
understanding of the S-R relation.

I am not accusing Harnad of turning into a Skinnerian behaviorist, but
I do think that the transduction position is about as far from a
homunculus position as one can get.

I think that the most significant contribution of the transduction
position is the importance it attaches to sensory information.  I
disagree with Searle's conclusions about the Chinese room, but he does
make the interesting and useful point that real organisms act in a
real world.  The brain does not, I think, operate on purely formal
symbols (at a basic level); rather its symbols conflate syntax and
something like semantics by virture of the way in which it is wired.
Activity in one part of the brain does not ordinarily represent just
any kind of information, rather brain regions are more or less
specialized to handle only certain kinds of information (they have
specialized transducers).  It seems to me that the implication of the
TTT is that in order to be intelligent a system has to act
intelligent.  Transduction is essential to acting intelligent, but it
is not all that is necessary to explain intelligent behavior.  S-R
relations are not sufficient in psychology and they are unlikely to be
sufficient in artificial intelligence ( I don't know anyone who would
seriously claim that they are).  In order to account for behavior we
must know something about the environmental situation and about the
behavior, but we must also know about the systems representations of
its environment and its behavior, because the relations are not as
straightforward as Skinner had hoped.  These representations in
effective systems are grounded by virtue of their systematic relation
to the stimulus events and the acts of the system.





--
Herbert Roitblat                    roitblat@uhunix.uhcc.hawaii.edu
Department of Psychology            roitblat@uhunix.bitnet
University of Hawaii                (808) 956-6727  (808) 956-4700 fax
2430 Campus Road,                   Honolulu, HI 96822 USA


