paper: a theory of depth from vertical disparity

[Ning Qian]

Dear Colleagues,

The following paper on "a physiological theory of depth perception
from vertical disparity" can be downloaded from:

http://brahms.cpmc.columbia.edu/publications/vertical.ps.gz

or:

http://brahms.cpmc.columbia.edu/publications/vertical.pdf

Related work on horizontal disparity and interocular time delay
(Pulfrich effect) can be found at http://brahms.cpmc.columbia.edu/

Best regards,

Ning

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A physiological theory of depth perception from vertical disparity

Nestor Matthews, Xin Meng, Peng Xu, and Ning Qian
Vision Research (in press)

Abstract

It has been known since the time of Helmholtz that vertical
differences between the two retinal images can generate depth
perception. Although many ecologically and geometrically inspired
theories have been proposed, the neural mechanisms underlying the
phenomenon remain elusive. Here we propose a new theory for depth
perception from vertical disparity based on the oriented binocular
receptive fields of visual cortical cells and on the radial bias of
the preferred-orientation distribution in the cortex. The theory
suggests that oriented cells may treat a vertical disparity as a
weaker, equivalent horizontal disparity. It explains the induced
effect, and the quadrant- and size-dependence of vertical
disparity. It predicts that horizontal and vertical disparities should
locally enhance or cancel each other according to their depth-signs,
and that the effect of vertical disparity should be orientation
dependent. These predictions were confirmed through psychophysical
experiments.