Path: utzoo!attcan!uunet!lll-winken!ames!ucsd!orion.cf.uci.edu!uci-ics!venera.isi.edu!smoliar
From: smoliar@vaxa.isi.edu (Stephen Smoliar)
Newsgroups: comp.ai
Subject: Re: Left vs. Right Brain <==> Reason vs. Mysticism ?
Message-ID: <7313@venera.isi.edu>
Date: 19 Jan 89 16:11:56 GMT
References: <1470@tank.uchicago.edu>
Sender: news@venera.isi.edu
Reply-To: smoliar@vaxa.isi.edu.UUCP (Stephen Smoliar)
Organization: USC-Information Sciences Institute
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In article <1470@tank.uchicago.edu> staff_bob@gsbacd.uchicago.edu writes:
>> 
>In article <7301@venera.isi.edu>, smoliar@vaxa.isi.edu (Stephen Smoliar)
>writes...
> 
>>Granting that you HAVE
>>the sort of right hemisphere you want to "clean up" (and I tend to agree
>>with Minsky that one should be suspicious of such brain division), 
>
>I'm sorry, but I'm going to have to call you (and Minsky) out on this one.
>Exactly what do you mean, 'that one should be suspicious of such brain 
>division'? Left/Right brain laterality wasn't invented by Julian Jaynes.
>There's a very extensive body of research, approaching 20 years in age,
>that effectively *proves* differences between left and right hemispheric
>processing. Sperry, the researcher who 'discovered' the phenomenon while
>examining fomer epileptics who had had their corpus callosum cut, was
>recently awarded the Nobel prize in biology. It might be convenient for
>Minsky to ignore this sound, scientific research, just as it's convenient
>for him to ignore the fact that he hasn't made a significant contribution
>to the field of AI since it was in its infancy, and most of the trails
>he blazed have turned out to be dead ends, but that makes it no less 
>valid.
>
I think this matter might best be resolved by my citing Minsky's expression
of his suspicions which I agree with (these paragraphs are from Section 11.8
of THE SOCIETY OF MIND):

**********************************************************************

The two hemispheres of the brain look so alike that they were long assumed to
be identical.  Then it was found that after those cross-connections are
destroyed, usually only the left brain can recognize or speak words, and
only the right brain can draw pictures.  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.  Our culture soon
became entranced by this revival of an old idea in modern guise:  that
our minds are meeting grounds for pairs of antiprinciples.  On one side
stands the Logical, across from Analogical.  The left-side brain is Rational;
the right side is Emotional.  No wonder so many seized upon this
pseudoscientific scheme:  it gave new life to nearly every dead
idea of how to cleave the mental world into two halves as nicely
as a peach.

What's wrong with this is that each brain has @i[many] parts, not only two.
And though there are many differences, we also ought to ask about why those
left-right brain halves are actually so similar.  What functions might this
serve?  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.
Probably even when there is no injury, an agency that has consumed all
the space available in its neighborhood can expand into the mirror region
across the way.  Another theory:  a pair of mirrored agencies could be useful
for making comparisons and for recognizing differences, since if one side
could make a copy of its state on the other side then, after doing some work,
it could compare those initial and final states to see what progress had been
made.

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.  Otherwise, we might become paralyzed by conflicts, because many agents
would have to serve two masters.  Eventually, the adult managers for many
skills would tend to develop on the side of the brain most concerned with
language because those agencies connect to an unusually large number of other
agencies.  The less dominant side of the brain will continue to develop, but
with fewer administrative functions--and end up with more of our lower-level
skills, but with less invovlement in plans and higher-level goals that engage
many agencies at once.  Then if, by accident, that brain half is abandoned to
itself, it will seem more childish and less mature because it lags so far
behind in administrative growth.

***************************************************************

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.