NASA develops 'mind-reading' system
dan at oricomtech.com
Wed Apr 14 15:03:13 EST 2004
"John H." <johnh at faraway.> wrote in message news:<407d4b71 at dnews.tpgi.com.au>...
> "dan michaels" <dan at oricomtech.com> wrote in message
> news:4b4b6093.0404130859.3585c714 at posting.google.com...
> > "John H." <johnh at faraway.> wrote in message
> news:<4079536f$1 at dnews.tpgi.com.au>...
> > Actually, there are probably at least "3" different visual pathways,
> > the 2 cortical systems mentioned here, plus another via the superior
> > colliculus, which is an evolutionary carry-over from the "original"
> > visual pathway of the amphibian optic tectum. Not just monkeys, but I
> > recall reading about people with cortical lesions who can still
> > respond to objects in the apparently blind retinal regions. They claim
> > they cannot "see" the objects [ie, consciously], but can "point" to
> > them if asked to. So, it seems there are actually several different
> > routes by which visual info moves through our brains, once past the
> > optic nerve. One might be non-functional, but 1 or 2 others still
> > functional. Maybe more, even. Maybe there are really 6.
> Yeah, make that four with the LGN, and whatever else we discover along the
> way. Eg. frontal eye fields, pfc-striatal regulation of visual attention,
> angular gyrus.
> SC important in regulating saccades. All these regions have separate roles.
> Still inclined to think blindsight mediated by LGN. Can you provide
> reference re SC?
> > Two of the principles of evolution are re-use and redundancy. The 2
> > R's. Read "An Earful of Jaw" by Stephen Gould.
> > ===========================
> Not sure redundancy is relevant here because each region plays a distinct
> role in visual processing.
No telling what might have happened "overall" regards evolution of the
visual system, except that the superior colliculus in mammals is
apparently homologous with the optic tectum of amphibians. Regards the
middle ear [cf S.G. - "AEFOJ"], certain parts of the gills of fish
[the more posterior parts] evolved into certain bones in the jaws of
reptiles [the more posterior bones], which in turn evolved into the
ossicles of the middle ear in mammals. So the story goes. Read the
article by Gould - it's fascinating.
> > "... seeing the object in full ..." What kind of slip of the tongue
> > was that?
> From a confused mind! Still can't get my head around this and yet to see a
> convincing account of how representation occurs.
One day all will be clear.
> > Or it simply means: (a) there are several parallel processing pathways
> > which contribute to the ultimate representation, or (b) that only one
> > of the pathways is responsible for creating the internal "mental
> > image" we do all of us see, and the other pathways simply perform
> > subconscious processing that our consciousness is not privy to. That's
> > news.
> Except that I think it begs the question of just what we mean by
> representation. The image we see is both identifying the object by naming
> it, locating it in space, colour(V3???), and relevance to the organism
> (pfc?, frontal eye fields?). I do not see how that can be achieved by one
> John H>
It takes 3, not 1 - maybe.
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