Fun_People Archive
8 Jan
Things You Learn in Dreams...

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From: Peter Langston <psl>
Date: Fri,  8 Jan 99 01:14:47 -0800
To: Fun_People
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Subject: Things You Learn in Dreams...

X-Lib-of-Cong-ISSN: 1098-7649
Forwarded-by: pozzo
From: Brooks Talley

...I had an interesting conversation last night.  Thing is, it was in a
lucid dream.  While riding on a train, I had a spirited discussion with a
woman about just how the visual parts of a dream actually happen in one's
brain.

We were using the passing landscape (rolling hills, incongurously populated
with a variety of everything from bushes to pine trees) as the basis of the
discussion.  She was of the opinion that the trees, hills, etc. were
basically replayed memories, adjusted in real-time to reflect lighting,
occlusion, etc.  She believed that they were all stitched together to create
a composite image of what the dream "world" looks like.

My take on the matter was that the trees, hills, and such were created in
the brain after the parts of the visual cortex that identify objects and
such, and were really just representations that, while dreaming, we process
as if they were real.

She brought up the point that you could really look at the trees, and see
the light on them, and their different branch patterns and other unique
details.  I rebutted that these, too, could all be thoughts or ideas, and
not actual visual representations.  She was starting to get upset at this
point, and I must admit that I tactlessly pointed out that she, too, was
simply a symbollic representation of a person and did not actually have
visually brown hair, though my brain was clearly processing her as a "brown
haired woman".

Anyways, it went on like that for a while, and then we turned to lucid dream
parlor tricks (putting flowers on other passengers' heads, mentally cleaving
dinner plates in two [for some reason this was quite enjoyable], etc) before
it eventually slipped back into a normal dream.

But upon waking and thinking about it, I'm still not sure about the visual
nature of dreams.  To what degree are they symbollic representations, and
to what degree is there some real visual processing going on? All those
details -- reflections, shadows, motion blur, and so on -- seem so real.

I've done some looking on the net, and I can't really find anything that
directly addresses the issue.  Anyone know, or know of a source that could
settle the issue?

-b

	[No one knows.
	
	 Look at Dan Dennett's _Consciousness explained_.  He sketches a
	 mechanism where dreams can see realistic, but just be the result
	 of an open-loop in your sensory inputs.  Basically, our senses are
	 the result of a dialog between a hypothesis generator and our
	 sensory equipment (there are almost as many neurons going back *to*
	 the retina from the visual cortex as coming from the retina to the
	 visual cortex, for example).  ``Does it look like a dog?'' ``Yes,
	 it does, oh, now it looks like a tree!''  That sort of thing.

	 One can see this kind of mechanism at work sometimes in waking
	 life.  It's amazing how one's perception of a foul smell can be
	 transformed by thinking ``nice cheese''. ---
	 pozzo]

© 1999 Peter Langston