[photo-3d] Re: seeing 3-D: innate

["Abram Klooswyk" <abram.klooswyk@xxxxxx>]

Robert A. Schreiber wrote:
>Actually, one of the most famous studies in experimental 
>psychology 
(...)
>Imagine a cube 3' x 3', with a checkerboard design on it.
>Then put a 3' x 6' piece of glass over it
etc.

This is indeed the experiment found in most textbooks of
visual perception, often called a visual cliff test.

However, it is not a test of _binocular_ vision or stereopsis. 
It is a test of depth perception. The design with checkerboard
at different distances gives strong _monocular_ depth cues,
perspective and motion parallax.  Babies stopped _moving_
when seeing the cliff. So they should be able to crawl in the
first place, so they were older than about 3-4  months.

But other tests have shown that stereopsis is already
present well before that age.

Abram Klooswyk