Hitting head, seeing stars
kenneth paul collins
KPCollins at postoffice.worldnet.att.net
Fri Oct 18 20:11:32 EST 1996
Ron Blue wrote:
> On 17 Oct 1996, Stephen Black wrote:
> > The question reminds me of that old principle with the quaint title called
> > "the law of specific nerve energies" which was enunciated by Johannes
> > Muller in 1838, long before the birth of neurophysiology (which Muller
> Thanks for reminding me of this important fact. Nice post.
> > This may also be my source of the 19th century speculation that "if the
> > auditory and visual nerves were crossed, leaving their connections to the
> > brain intact, then we could _see_ thunder and _hear_ lightning. I
> > understand that this has actually been accomplished anatomically in the
> > ferret (Roe et al, 1990). No word from the ferret yet on what this does
> > to its perception of a thunderstorm.
> Yes, I agree that if the connections were crossed that perception
> would be like seeing thunder, but only due to the memories previously
> stored. If done at birth the animal would perceive every thing
> normally but now in new areas of the brain. Also if the total
> brain mass was increased the perception would increase if reduced the
> perception skills would be reduced.
> The important point is that the principle of equal potentiality
> allows the brain to self organize for different functions.
> Ron Blue
...I've not read the ferret study, but although the brain can massively
rewire itself by sending out collateral fibers to take advantage of the
available cortical "real estate" when a sensory tract is lesioned, it's not
the case that all of the cortex is so "equipotent" that one portion of it can
do the work of any other portion of it just as well... even if the transposed
cortical areas share similar microscopic architecture, such would just not
work well because the design of the brain is so tightly integrated... one
cannot rewire only one pathway, one must rewire =all= pathways, so as to
maintain all of the brain's Geometric consistency with the body-environment
interface (in Duality Theory: the "special topological homeomorphism"; the
"internal frame of reference")...
...when Karl Lashley discovered "equipotentiallity" in experiments that
successively lesioned increasing portions of cortex, what he actually
discovered was that "memory" is =distributed=... but the cortical areas are
not "equipotent", it's just that each cortical area makes its own
modality-specific contribution to all "memories"... lesion a particular
cortical area, and that area's modality-specific contribution to "memory" is
lost... but the memory can still be accessed via the intact cortical areas,
minus the contribution of the lesioned area... ken collins
People hate because they fear, and they fear because
they do not understand, and they do not understand
because hating is less work than understanding.
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