P3D Re: side eyed

[roberts@xxxxxxxxxxxxxxxxx (John W Roberts)]

>Date: Fri, 12 Mar 1999 09:10:31 -0700
>From: Rod Sage <rsage@xxxxxxxxxxxxxxxxxxxx>
>Subject: P3D side eyed

>I've always been currios how side-eyed creatures like birds and fish are
>able to process 2 separate views in their brains. Not to mention
>chameleons which can look forward with one eye and backwards with the
>other. 

I can think of several lines of evidence that humans have this capability
in some form:
 - Humans have roughly half of their field of vision nonoverlapped - the
   brain merges the the views of the two eyes into a continuous whole.
   Many animals with side-facing eyes have at least some overlap (and
   possibly stereo vision in the overlapping part).
 - Human vision operates by a scanning mechanism. If I turn my head around,
   I usually maintain a mental model of the things I have seen, even if they
   are not in the current field of view.
 - It is likely that non-overlapping fields of view just serve as separate
   scanners for the creation of a 3D model in the brain. Airplane pilots,
   for example, operating with non-ovelapping views from different windows,
   seem able to process the information they receive in this way.
 - I believe researchers have stated that a human uses the same part of the
   brain to imagine a visual scene as the part they use to look at the world
   around them. Most people can look at a real scene and visualize an
   unrelated scene at the same time without a problem. (How many full scenes
   can you imagine at the same time?)

On the other hand, I've known a person with diverged eyes, who would just
ignore the input from one eye or the other. So humans may have some "hard
wiring" that makes certain generalized uses difficult.

>I thought it would be interesting to make a device which could divert
>our vision out the sides of our heads (using prisms, mirrors etc.). If
>they had wide angle lenses, we could see 360 degrees. Could our brains
>process that information?

I've got a couple of those built into my car already, except they point
mostly to the rear. :-) Of course, it takes time to get accustomed to them
and to learn to make full use of them. But they're definitely useful - it
wouldn't be safe to change lanes on the highway without them.

John R


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