K C Cheng kccheng at postoffice.idirect.com
Wed Jun 3 10:37:44 EST 1998

Re.Cortical Plasticity=A1G
Based on clinical evidence, some of which was mentioned in the past few
days in this newsgroup, there is no doubt that the cortical neural
networks undergo postnatal functional differentiation according to the =

sensory input channels.  Those hooked to the visual pathways undergo
memory storage of visual inputs; those in the auditory cortices undergo
auditory input memory storage, etc.  These processes naturally gradually
change and therefore differentiate the prenatally undifferentiated
neurons into visual neurons, auditory neurons, etc.   However, unlike
the   differntiation of the blood stem cells into different lines of
cells, some leucocytes, others erythrocytes, etc.;  this  postnatal
neural differentiation  is only functional,  not histological.  That is
why the individual  cortical cells in the visual cortices are
histologically indentical to  those in other primary cortical areas such
as the auditory cortices.   Yet, they function differently.   That's
because of their postnatal exposure to different stimulus inputs.  This
is further suported by the very fact that  cortical neurons of  even
different  species, expected to have some interspecific chemical and
genetic differences,  still do subserve identical functions.  Hence, =

auditory cortical neurons of the dogs could equally sense as, or even
sense better than,  those of human brain.   In other words,  minute
histological or chemical differences do not impair the basic neural
capacity to sense various stimuli.  Only the type of the  stimulus
input  determines what specific memories and functions these  cortical
neurons possess.
 Although their postnatal functional differentiation potentials are not
entirely lost after maturity,  for obvious reasons(i.e. the more exposed
to visual stimuli,  the more it contains visual memories,  and,  the
loss of learning or memory ability in the aging or degenerating
neurons),  the younger the person it is when re-differention  is
commenced, such as using visual cortical areas to learn  auditory
functions, etc.,   the better the success rate.  =

Details in the 10th volume of my Electromagnetism of Memroy, Mentation &
Behaviour which would be published only when I have the financial
capacity to have transcribers,  printers,  etc.   But, when available, =

I'll let you know.

Cheng Reseaerch Institutes,  Fax  (416)5359531(Canada)


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