I'd like to find out whether visual perception of depth based on information
*other* than stereopsis (e.g., using linear perspective or texture gradients)
is processed preattentively.
It seems that some depth information based on retinal disparity is derived
preattentively. But in the absence of binocular input, the visual system can
still extract some depth information from a static scene using cues such as
texture gradients. Is it possible that these are processed automatically by
the visual system to yield information about depth, or must an observer focus
on a specific part of a scene before the visual system can integrate the
right visual elements to determine depth?
I've read a number of sources (including works by Marr, Treisman, Julesz) but
this issue is still not clear to me. Almost everyone talks about depth in
relation to binocular information. Introductory texts such as Goldstein's
_Sensation and Perception_ discuss depth from pictorial cues but don't make
it clear at what point in visual processing the information becomes available.
My apologies if the answer to my question is really obvious. I would
appreciate any pointers to papers that discuss experimental evidence bearing
on this question.
-- Mike Hucka
University of Michigan, Ann Arbor, Mich.