Re: Cool visual illusion


Wolf Kirchmeir wrote:


> In any case, if certain behaviorist strategies work better/worse than
> others, then presumably they do so because they implicitly assume
> different "mediations" (as Glen calls them), ie different internal
> mechanisms. Not that they can provide very fine-grained detail, you're
> quite right about that. But they can indicate where to look for that
> detail. AFAIK, all studies of the fine structure of the brain begine
> with behaviorist observations that suggest a "fruitful area of inquiry",
> and all entail behaviorist studies in the experimental design.
>


Well yes, no one is debating that. However, as pointed out, this only
gets us as far as items #1 or #2 of the list I presented earlier. The
journey has barely begun. What and how are very different problems.

Since Curt never responded to my post from a few days ago, I'll patch
it in, since it's relevant here .... cf, Curt's comment "... Except
that knowledge of the illusion IS knowledge about the internal
mechanisms...".

======================
Curt Welch wrote:
> "feedbackdroids" <feedbackdro...@xxxxxxxxx> wrote:

> > Visual illusions are, as they say, systems-level problems, and need to
> > be addressed and analyzed as such. You cannot do it by pure
> > reductionism, and you cannot do it without some actual knowledge of
> > "internal" mechanisms.


> Except that knowledge of the illusion IS knowledge about the internal
> mechanisms. So once you have that knowledge, you can very much "do it" by
> pure reductionism from that knowledge. The rest of the details about how
> the human body creates that illusion is just implementation details.


How do you analyze it? You have a retina with 4 or so types of
photoreceptors, several classes of bipolar and horizontal cells at the
outer plexiform layer, several classes of ganglion and amacrine cells
at the interplexiform layer, and that's just the retina.

Now, add in interactions at the LGN, plus 400,000,000 cells in V1, and
then another 30+ cortical visual areas, with roughly as many cells
each. Then, whatever happens at higher levels in the brain. Then, the
billions of feedback signals between areas, and also from higher to
lower. Then, the various feedback loops between all of these areas and
the parts of the brain below the cortical level. What effect does the
midbrain superior colliculus [ancient visual-movement center] have on
this? Do signals rebound off the cerebellar cells? On and on.


How many total cells are involved in the illusion? Since it covers a
wide area of retina, I'd say at least 5 million retinal cells, and 5
billion in brain, just a guess. How many synapses? Say a trillion.


If starting from ..... "Except that knowledge of the illusion IS
knowledge about the internal mechanisms ...", and given the complexity
of the internal system described, tell me what you can say about those
internal mechanisms with any certainty, without going inside and doing
the measurements. Which of the 40-50 total areas mentioned are NOT
involved in the illusion? What can you really be sure of, when sitting
from without? Not much.
===============

.

Relevant Pages

  • Re: Cool visual illusion
    ... >> Wolf Kirchmeir wrote: ... >>>Except that knowledge of the illusion IS knowledge about the internal ... several classes of bipolar and horizontal cells at the ... whatever happens at higher levels in the brain. ...
    (comp.ai.philosophy)
  • Re: Cool visual illusion
    ... others, then presumably they do so because they implicitly assume different "mediations", ie different internal mechanisms. ... AFAIK, all studies of the fine structure of the brain begine with behaviorist observations that suggest a "fruitful area of inquiry", and all entail behaviorist studies in the experimental design. ... the human body creates that illusion is just implementation details. ... several classes of bipolar and horizontal cells at the ...
    (comp.ai.philosophy)
  • Re: Cool visual illusion
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    (comp.ai.philosophy)
  • Re: Cool visual illusion
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    (comp.ai.philosophy)
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