[percy-l] Re:Seminal events of consciousness
wriddick at usa.net
Sun Dec 15 22:37:53 EST 2002
>I've been reading accounts of the genetic basis of mental disorders for the
>past 30 years -- until one of them comes up with a passably interesting
>account of what a mental disorder is I will continue to dismiss them out of
>hand. Same goes for the so called genetic "explanations" of language --
>until the geneticists demonstrate some understanding of what makes the study
>of language interesting I consider their research beside the point. How can
>they identify the genes for language when neither they or anyone else yet
>knows what language is or who has the capacity for it? Seems to me the
>nature and distribution of language ability (like that of so called mental
>disorders) is only self evident to those who understand it least.
I have to agree with Marcus that we're venturing into gnostic territory
here. Saying that there's a mechanistic basis which allows for language
doesn't explain anything about the origins of language.
I don't think we'll ever understand exactly which genes do what to make
language, but by studying families who all lack the same gene or possess a
specific mutation, you can begin to get an idea. If I'm remembering it
correctly, the British family discussed in the NYT article had one mutation
different from normal humans whereas chimps have two and they had a
facility for language somewhere between chimps and regular people.
Using knockout mice that, say, lack the gene for iNOS or some other
molecular messenger has advanced the knowledge of how important these
various genes are and what role they play. What's surprising is that life
is pretty resilient. Even lacking certain genes thought to be crucial some
of these mice still manage to survive.
While I don't think it would ever be ethical to put in/knock out human
brain genes in rodents, mutations are part of the human reproductive
process and sometimes cases like the British family do crop up (men are a
far greater source of genetic risk here, but as women keep having children
later and later in life, their share of error is increasing).
Schizophrenia and autism are much more complex in terms of what's going
wrong. There are genetic components to schizophrenia. Autism in
particular appears to be an apoptotic disease of too many connections among
the neurons. As we learn, we clip unnecessary associations among neurons.
If your mother says "apple" while holding an apple, it doesn't matter that
a plane is taking off nearby and rattling the house - although for an
autistic who can't stop his brain from being overstimulated, it does. He
doesn't know to distinguish "apple" from a roaring jet engine and he gets
confused whenever he hears one but not the other. This is why autistics
have brains 1-3% larger than normal. There are too many connections.
Autistics don't necessarily think in terms of pictures, they just have to
whittle it down to one sense so that they can think at all. The NYT
recently ran an article on an autistic boy who had no trouble talking and
responding to speech - provided he could ignore everything else going on
and get his other senses to "calm down."
While babies come primed for receiving language, these genetic discoveries
can never explain what words they receive or how they are affected by
language. It merely gives them the facility. The things we see and hear
affect our brain development in ways that will always remain difficult to
analyze. Saying something has its roots in a mechanistic process does not
limit the thing. The things we read throughout our lives are always
altering our neurological connections. What genetics does is simply
explain how the basis for that action may differ in important ways from the
rest of the animal kingdom. Good. So what? If someone loses some ability
to use language, we want to restore it right? Whether it was through
stroke, neurotoxin or edema, right?
If someone loses his ability to speak or to write or read or even large
portions of his experience drop out of thought, does he lose who he is? If
he loses part of his language, does he lose part of himself? What is it
we're all saying here?
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