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From: staff_bob@gsbacd.uchicago.edu
Newsgroups: comp.ai
Subject: Re: Left vs. Right Brain <==> Reason vs. Mysticism ?
Message-ID: <1511@tank.uchicago.edu>
Date: 20 Jan 89 21:10:27 GMT
Sender: news@tank.uchicago.edu
Organization: University of Chicago Graduate School of Business
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>I do not feel that Minsky is in any way writing off Sperry's observations in
>this passage.  I think he is only cautioning us against interpreting them too
>simplistically.  Much of THE SOCIETY OF MIND is concerned with similar
>messages--that we should not be seduced by simple answers to complicated
>issues.  Perhaps it is this attitude which exposes him to AD HOMINEM attacks
>such as the one expressed above.  Unfortunately, we are too easily seduced by
>simplicity, which is why many folks seems a lot more inclined to cite Jaynes
>and Casteneda than to cite Minsky.

To begin, I would like to apologize for appearing to cite Casteneda and
Jaynes. My mention of Casteneda was intended to demonstrate that mystics
often seem to explicitly cite abnegation of reason as a prerequisite to
understanding their own, mystical 'truths'. One need not look so far
afield to find similar critiques of reason. See for example, "The
Dreams of Reason" by the physicist, Heinz R. Pagel. As for Jaynes, he
is frequently cited in this conference and provides a convenient point
of reference. I do not consider him an authority, and would not cite him
as such.

More to the point, I guess the question is, who's being easily seduced by 
simplicity? For  example, in your citation from Minsky, he states

(Minsky)
>For one thing, we know that when a major brain area is damaged in a
>young person, the mirror region can sometimes take over its function.

We do often observe brain damaged children to do a much better job of 
compensating for their injuries than similarly disadvantaged adults.
Minsky has seized upon this fact and used it to support his own wishful
thinking. He would like us to believe that this compensation implies
an initial equivalence of hemispheric capabilities.

The point Minsky wishes to make has not escaped psychologists,
who have endeavored to study it. See Denckla,M.B. et.al, 
"The  Development of a Spatial Orientation Skill in Normal, Learning Disabled, 
and Neurologically Impaired Children," pp.44-59, of "Biological Studies of 
Mental Processes", MIT Press 1980. They state, for example,

"Even when brain damage is more subtle, inferred from signs, and presumably
congenital, right-hemispheric deficit contributes mores heavily to
impaired spatial performance in children than does left."

Moreover, when there is compensation for damaged areas of the brain, it
is not clear that this compensation is achieved by the mirror region in
the other hemisphere. What is clear is that 

"the likelihood of language disturbances to one cerebral hemisphere 
is greater with left than with right lesions. In infancy, the two hemispheres 
are not equally at risk for disordered language." 
(M. Dennis an H.A. Whitaker "Hemispheric Equipotentiality and Language 
Acquisition).

(Minsky)
>My own theory of what happens when the cross-connections between those brain
>halves are destroyed is that, in early life, we start with mostly similar
>agencies on either side. Later, as we grow more complex, a combination of
>genetic and circumstantial effects lead one of each pair to take control of
>both.

An interesting theory, which has been disproven any number of times. See,
for example, the chapter entitled "Infant Cerebral Asymmetry", by Dennis
Molfese, which appears in the book "Language Development and Neurological
Theory" (Academic Press 1977). The fact is that we can find evidence of
hemispheric specialization in very early in life. 

Hemispheric asymmetry a very complex subject, and not only is Minsky guilty 
of gross over simplifications, his position contradicts a large body of 
established research. The hemispheres *are* different from the start. Is it 
not Minsky himself who wishes to seduce us with simplistic arguments? Is he 
not misleading us in order to discourage us from wondering about the 
irrational component of the human mind ? Jaynes and Casteneda both raise
far more questions than they answer. There seem to be quite a few
people who, like Minsky, wish to dismiss these questions out-of-hand,
as somehow being beneath them. That is the simple path. The difficult
path is to leave them open and examine them, to construct hypotheses and
to test them experimentally. The simple path is the self serving pop-logic
exhibited here by Minsky. The difficult path is the path of science.

To be fair, I believe that it is safe to say that the left brain is
not exclusively logical, nor is the right brain completely analogical.
Minsky is quite correct in his belief that the two halves of the brain
seem to be much more alike than different. The fact is that the brain,
taken as a whole, is both logical and analogical. This is not the point.
The point is that the focus of what is now called 'Artificial Intelligence'
is today almost exclusively upon the logical, rational, symbol processing
aspects of human intelligence, while it is clear that a considerable part of
the human mind seems to be thus excluded from consideration.

As for 'AD HOMINEM' attacks, what is the point of Minsky's 

>More recently, when modern methods
>found other differences between those sides, it seems to me that some
>psychologists went mad--and tried to match those differences to every
>mentalistic two-part theory that ever was conceived. 

it may be convenient and even humorous to characterize people with whom
he disagrees as mad, but *if* such an attempt was made, it was not
madness, it was science.