Neurocomp2003 you are correct, but might want to look at “Separate visual pathways for perception and action” by M.A. Goodale and A.D. Milner in TINS, Vol. 15, No. 1 p20-25. Or at book ISBN 0198521367 (“Visual Brain in Action” by same authors, Oxford Univ. Press, 1995) Sorry about the age of these references, probably better are now available, but I retired to Brazil almost a decade ago and have lost touch with the recent literature. (Part of the reason why I am responding and hope with your help to raise this thread to the level it deserves.)
They persuaded me that the classic “what and where” paths are better understood as “what and how.”
Their view is based in part on the fact that when the monkey only has to look at the symbol on the lids of the food wells, he does not need to shift his gaze away to the “landmark” reference. The original experiments ignored this task difference.
I also want to strengthen your statement about many paths in the visual system (not all even go through the LGN!) After the LGN, some tracks go to the SC (superior colliculus), not to V1 (primary visual cortex in the occipital lobes).
This SC path is probably responsible for the amazing things a monkey can do some weeks after both his entire occipital lobes have been removed (I should use “ablated,” the term which helps confuse the animal rights people, but I prefer to be forthright about what is done.) For example, if you throw a peanut on the cage floor of such a “cortically blind” animal, most will, without hesitation or confusion, pick it up with a well-guided hand motion and eat it!
Blind humans exhibit “blind sight” but never reach this level of performance.
You seem to be able to contribute significantly to this thread. Please get a copy of my paper (see prior post) and tell me what you think of my theory as an answer to gaussian. I am especially proud of the “viewer in movie problem” I invented in the paper, which IMHO, destroys the traditional cognitive science view that we seen by “successive computational transforms” of the retinal data. (P. Churchland et. al.)
In answer to your question about higher or lower level of gaussian`s question I want the thread to be about how we perceive with vision, not a bunch of details about where various computations take place in the brain, although this information, illusions, cerebral accidents and ablation studies etc can be very helpful in answering the difficult question.
I am sorry I can’t send it to you by Email. I will try to get a pdf version from Johns Hopkins so I will be able to do so directly instead directing you to the Editor of the APL technical digest.
If you want to know more about me and my current concerns, visit site under my name.
Neurocomp2003 said:
optical lobes....what the hell?? occipital lobes?
and is the question about the higher function of understanding images or the lower function of processing images...
There are many branchings to the optical path..and not all are accounted for in the major one which branches into 2(dorsal/ventral what vs where) then 3 or 4. which go to many other paths...