Paper available: Subregion Correspondence Model of Binocular Simple Cells

[Ken Miller]

The following paper is now available at
    ftp://ftp.keck.ucsf.edu/pub/ken/dispar.ps.gz (compressed postscript)
    ftp://ftp.keck.ucsf.edu/pub/ken/dispar.ps    (postscript)
    http://www.keck.ucsf.edu/~ken                (click on 'Publications')

This is a preprint of an article that appeared as Journal of
Neuroscience 19:7212-7229 (1999):
http://www.jneurosci.org/cgi/content/abstract/19/16/7212

------------------------------

	The Subregion Correspondence Model of Binocular Simple Cells
		      Ed Erwin and Kenneth D. Miller
			 Dept. of Physiology, UCSF
ABSTRACT:
     We explore the hypothesis that binocular simple cells in cat
areas 17 and 18 show subregion correspondence, defined as follows:
within the region of overlap of the two eye's receptive fields, their
ON subregions lie in corresponding locations, as do their OFF
subregions.  This hypothesis is motivated by a developmental model
(Erwin and Miller, 1998) that suggested that simple cells could
develop binocularly matched preferred orientations and spatial
frequencies by developing subregion correspondence.
     Binocular organization of simple cell receptive fields is
commonly characterized by two quantities: interocular position shift,
the distance in visual space between the center positions of the two
eye's receptive fields; and interocular phase shift, the difference in
the spatial phases of those receptive fields, each measured relative
to its center position.  The subregion correspondence hypothesis
implies that interocular position and phase shifts are linearly
related.  We compare this hypothesis with the null hypothesis, assumed
by most previous models of binocular organization, that the two types
of shift are uncorrelated.
     We demonstrate that the subregion correspondence and null
hypotheses are equally consistent with previous measurements of
binocular response properties of individual simple cells in the cat
and other species, and with measurements of the distribution of
interocular phase shifts vs. preferred orientations or vs. interocular
position shifts.  However, the observed tendency of binocular simple
cells in the cat to have ``tuned excitatory'' disparity tuning curves
with preferred disparities tightly clustered around zero (Fischer and
Kruger, 1979; Ferster, 1981; LeVay and Voigt, 1988) follows naturally
from the subregion correspondence hypothesis, but is inconsistent with
the null hypothesis.
     We describe tests that could more conclusively differentiate
between the hypotheses.  The most straightforward test requires
simultaneous determination of the receptive fields of groups of 3 or
more binocular simple cells.

--------------------------------

Ken
 
        Kenneth D. Miller               telephone: (415) 476-8217
        Dept. of Physiology		fax: (415) 476-4929
        UCSF                            internet: ken at phy.ucsf.edu
        513 Parnassus			www: http://www.keck.ucsf.edu/~ken
        San Francisco, CA 94143-0444