P3D Re: perception

[Ronald Beck <ronald-beck@xxxxxxxxxxxx>]

>  I simply suggest that the brain can ignore or
> "desensitize" itself to all stereo input in favor of its preconceptions. 
> It's not so strange to me that we can often *not* see something that is
> objectively in front of us.  We do it all the time.  So the illusion seems
> familiar phenomenon to me, and within my ability to control.
> 
> I bet some of you are skeptical!
> 
> Bruce  

No, I agree with you.  I believe the brain CAN ignore or desensitize
itself and use preconceptions of depth.  We normally see a face and
expect it to be convex.  So, when we see a concave face, our brain
automatically uses its prior experience on faces to make it look
convex.  With concentration and study, you can override this
preconception construct and actually "see" what's there, i.e. the
concave face.  I believe the term "signal to noise ratio" is
appropriate.  The signal (the concave face) is disturbed by the noise
(the precoceived expectations of faces in general).  Focusing on the
signal (the concave face) helps reduce the noise (the preconceived
ideas) and allow the person to see what's actually there.

To demonstrate this further, make the following on your color printer...


	Look at the following list and state what color
	the words are in.


		RED - (color this word green)
		BLUE - (color this word yellow)
		GREEN - (color this word orange)
		YELLOW - (color this word red)
		ORANGE - (color this word blue)

What you'll find is that you'll have a very hard time saying "green" for
the word RED.  That's because our minds are so conditioned to associate
the color red for the word RED that it takes great concentration to
actually state the COLOR of the word.  The signal (the color of the
characters) is overridden by the noise (the knowledge that RED should be
red, not green).

It reminds me of pseudo viewing of a scene.  Your mind tries very hard
to make sense of a scene where the ground is poking out and the people
are receeding.

Regards,
Ron