hydrocephalus & IQ

Bill Skaggs bill at nsma.arizona.edu
Thu Jan 6 16:02:06 EST 1994


lmk2 at garnet.berkeley.edu (Leslie Kay) writes:

   In article <EDSTROM.94Jan5093559 at elmer.hsc.ucalgary.ca>,
   John Edstrom <edstrom at elmer.hsc.ucalgary.ca> wrote:
   >I remember having read an article in Science, I think, around 1987
   >concerning a study of people who had had hydrocephalus while young but
   >who seemd to have recovered and lived apparently normal lives but
   >then, with CAT scans many years later, it was found that a large
   >proportion of their cerebral hemisphers was missing despite their
   >normal intelligence.
   >

   I saw this in a class I was TAing.  They reported on it in the
   PBS series on the Brain (10 part series or something like that).
   THey reported on a woman who had normal or high intelligence even
   though all her "processing" or activity was done in a very small
   part of her brain, part of the occipital lobe, I think.  I don't
   remember the citation or the names of researchers, but maybe
   someone else does . . .


This is a classic urban myth.  It seems to pop up over and over again,
like the story of worms in McDonald's hamburgers.  Anyway, when it
popped up on comp.ai.philosophy a couple of years ago, I was provoked
into going to the library and doing a bit of reading, which I will now
summarize. 

The source of the myth is a story (not a research report) in Science,
from December 12, 1980 (vol. 210, p 1232), called "Is your Brain
Really Necessary?"  The story is about a physician named Jeff Lorber
who specialized in hydrocephaly and was going around saying some very
provocative things.  Among other things, he described cases of people
with normal or high intelligence whose brain weights were far below
normal.  But it was all anecdotal.  There was no solid evidence cited
to show that these people truly had shrunken brains, and to my
knowledge no such evidence has ever appeared.  (I didn't see the PBS
series, so I can't evaluate it.)

In the years between 1980 and the present, Lorber has never published
any case study of an adult with an extremely thin cortical mantle and
normal intelligence.  Conceivably, of course, he wrote the stuff up
but couldn't get it past hostile reviewers.  He did, though, continue
to work on the neurology of hydrocephalus, publishing several papers
and co-authoring a book, but none of it mentions anything related to
the Science story -- at least, none of it that I could find.  (I
couldn't find anything later than 1984; I don't know if he's still
alive.)

He does quite definitely state that there have been cases having
cortical mantles only one or two mm thick *at the time of treatment*
who went on to develop normal or superior intelligence, but that's a
very different matter.  They were treated as infants, and the brain is
very plastic at that age.

Finally, at the end of the Science story Lorber is described as
admitting with a smile that he doesn't really mean to suggest that
brains are unnecessary for intelligence, and that he may have somewhat
overstated his case for dramatic impact.

I hope this sheds a little light on the situation.

	-- Bill




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