Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!tank!staff_bob@gsbacd.uchicago.edu
From: staff_bob@gsbacd.uchicago.edu
Newsgroups: comp.ai
Subject: Re: Left vs. Right Brain <==> Reason vs. Mysticism ?
Message-ID: <1643@tank.uchicago.edu>
Date: 27 Jan 89 18:19:00 GMT
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Organization: University of Chicago Graduate School of Business
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>In article <1511@tank.uchicago.edu> staff_bob@gsbacd.uchicago.edu writes:
>>>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.  
>>
>>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. 
> 
> So, you have something against "reason." When one gives up reasoning
>as religion and mysticism often requires then 'truths' needn't be. 
> 

I have nothing against reason, nor do I profess any sort of faith in any
sort of theism or mystical system. If I appear to be advocating an abnegation 
of reason, Mr.Meadors has misread me. I am trying to point out that the dialectic
between what I have generally termed 'mysticism' and its opposite, which
I prefer to call 'reason' may in fact be the result of a naturally occurring
dichotomy in the structure of the brain. In my mind, this in no way invalidates
reason, nor does it raise the stature of mysticism vis a vis reason. I
admit that this is a hypothesis, and it has not been proven by research.
However, it has not been disproven either, and to me it seems to fit very
well with what we have observed. To insinuate from the above passage that
I 'have something against "reason"' is insulting, and I believe Mr.Meadors
intends it to be so.

>>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.
>>....
>>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 
> 
>  It would seem to me, the fact that other, non-mirror areas can adapt
>to perform the neccesary processing, strengthens not weakens an argument
>for brain equipotentiality.
> 
Since Mr.Meadors has obviously read my posting, it appears that there are certain
points which he is either deliberately ignoring, or which he does
not understand. Immediately below this passage I provided the following
citation:

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.

"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."

This quotation, the entire article referenced and the bulk of evidence I
have seen weakens the argument against equipotentiality. If a part of
the left hemisphere is injured, and the deficit is compensated for by
another part of the left hemisphere, I see no way in which the strengthens
the argument for it.

>>>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. 
> 
> He did not deny a predisposition measurable early in life. 
> You evidently didn't notice the word "genetic" above.

Yes, and I also noticed the word 'mostly'. Dr.Minsky has equivocated quite
nicely. It seems clear from the passage that he intends to downplay the
differences between the hemispheres. If he is not denying an
early predispostion to brain asymmetry what is the point of the use
of the word 'later'?

> 
>>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.
> 
>  Minsky is being cautious. Neither he (nor I) am calling for blanket
>generalizations concerning the localization of "types of analysis"
>betwixt the hemisheres.

Nor am I. I realize that characterizing one half of the brain as logical
and the other as analogical is fraught with difficulties. However, it
is clear from what evidence we have that the two hemispheres are different,
and that the nature of the differences lie along these lines. It is
convenient, and I believe not wholly innaccurate to speak of the differences
is this way. More to the point, as I have said, I believe that the difference
between the hemispheres is fundamental to the way we think. From what
I can gleen from this passage, Minsky does not appear to agree.

To qoute Sperry, "The normal bilateral conciousness can be viewed as
a higher emergent entity that is more than just the sum of its right
and left awareness and supersedes this as a directive force in our
thoughts and actions."

>  Minsky is one of the most repected AI researchers and theorists of mind
>of our age. To dismiss his "path" as "pop-logic" in favor of Jaynes and
>(you've got to be kidding) Casteneda is a grave injustice. The pop-path
>here is to take the evidence of "somewhat polarized behavioral deficits" 
>from damage to either side of the brain and turn it into some sort of
>holy grail of organization: postulating a rational/irrational or
>logical/emotional tug of war. The pop notion is that one hemisphere
>provides an logical analysis and the otherside provides a wholistic
>analysis of any given situation. This is not supported by the evidence.
> 

From Sperry, who in some quarters recieves quite as much respect
as Minsky:

"the mute, minor hemisphere is specialized for Gestalt perception,
being primarily a synthesist in dealing with information input. The
speaking, major hemisphere, in contrast, seems to operate in a more
logical, analytical fashion." ("The Three Pound Universe", 222-223)

Again, Mr.Meadors does not appear to be understanding what he has obviously read.
Nowhere in my posting did I make an argument in favor of Jaynes and Casteneda,
except to say that they have raised a lot of questions. In fact, I explicitly 
apologize for having appeared to do so in a previous article, in which I 
also mentioned Bhuddism. He cited the above passage

>>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. 

and, I might add, left out the next lines:

>>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.

My dismissal of Minsky's 'logic' was not in favor of that of Jaynes and
Casteneda. It was in favor of Molfese, et.al. who have done research
which demonstrates bilateral asymmetry in early life. The fact
that Minsky is one of the giants of the field makes it all the more important
that he not mislead people to make the facts appear to fit
his theories. You say below that you "object to the claim that
the hemispheres are doing different and complementary types of 
analyses", and I daresay that you believe Minsky does also. 

>>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.
> 

>I agree. This is the point. The point is that some 
>would take the laterlization evidence as "clearly" showing that the
>"right" hemisphere is doing some "special, non-logical, intuitive" processing
>that is distinct from a more "analytic kind." More to the point, the
>finding that damage to the left causes a greater decrement to languange
>and reasoning skills while damage to the right to spatial-temporal skills
>does not show that "a considerable part of the human mind" is devoted
>to some analogical or irrational aspect of human intelligence. It doesn't
>even show that those activities are "largely performed by those regions."
>To interpret a deficit as indicating that those activities impaired are
>performed "there" is the most common mistake of all in interpreting the
>data of neuroscience. They usually alert students to this, over and over,
>in those courses. 
>>

You seem to imply that those some who feel that the left hemisphere is 
more analytical than the right, and that the right is more holistic than
the left, are worse that inattentive students. Let me refer you to

Bever,J (1975) "Cerebral asymmetries in humans are due to the differentiation
of two incompatible processes: Holistic and analytic." In Aronson &
Rieber (eds.) "Developmental psycholinguistics and communication disorders."
New York Academy of Science."

As far as I know, Bever paid attention in his elementary psychology
classes. If one reads the literature, one sees very little evidence
for hemispheric symmetry, with notable exceptions. In normal humans,
EEG scans reveal that during most cognitive and motor tasks, both
hemispheres do an approximately equal amount of 'work', regardless
of the supposed lateralization of the task being performed. I paid
attention in class too, and we were taught that the left hemisphere
is tuned to time, the right to space, and that logic, counting, etc.
were left lateralized skills.

>> [no name provided]
>>
>  If I didn't make it clear enough, I object to the claim that
>  the hemisheres are doing different and complementary types of
>  analyses as well as the idea that some fundamentally "irrational"
>  component need be added to models of intelligence. While the 
>  traditional AI approaches are of course early and crude attempts
>  at capturing our processing character this is not a fundamental
>  failure to capture some "artistic half" as some would have it.  
>  AI is in need of a new paradigm (perhaps pdp control systems),
>  not an "irrational twin" theory. 
> 
>tonyM                                                

Feel free to object. In my opinion, this theory does not fit the data.
As for adding some fundamentally irrational component to models of
intelligence, I'm not quite sure what this means. If we are trying to
model the human brain, and so pass the Turing test, I don't see how we
can do it without building in an irrational component. If, by 'intelligence',
one wishes to exclude everything that is illogical and irrational, obviously
no model of intelligence could include these components. I am not trying
to say that the irrational, 'mystical', part of the brain can never be
understood, and is fundamentally 'mystical'. Quite the contrary. I believe
that it can be, and should be, understood, and that such an understanding
is central to the understanding of the human mind.

One final note. The tone of Mr.Meadors posting seems to me quite acrimonious,
and I believe that is due in part to my rather personal attack of
Dr.Minsky's credentials. I should know better than to villify a god,
and as I have already confessed, my doing so was a hasty and ill-advised
response to a posting in which Minsky was cited as an authority who 
was skeptical of the left/right brain division. My criticism that Minsky
hadn't done anything for years was ignorant, as my only way of evaluating
him was through references to him in the literature. I have not read
"Society of Mind", except for one brief excerpt, but I fully intend to.
I would therefore like to apologize for these remarks, and hope we
can leave it at that.

                      Bob Kohout