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Seeking data on unoriented visual neurons in mammalian V1

Michael Hucka hucka at eecs.umich.edu
Fri Apr 18 01:41:06 EST 1997


Although much emphasis is placed on the spatially oriented visual neurons in
V1 and other visual areas, it is known that a certain percentage of cells are
unoriented [1-7].  These tend to occur most in the CO blob layers, but they
also seem to appear outside of the CO blob regions (for example, in layers 5,
2-3, and 4ca [3]).  Unoriented cortical cells tend to have circular-surround
receptive fields, though some have no inhibitory surround [7], and most cells
are selective for wavelength, though some are not [1,5]; the latter were
termed "broadband" cells by Livingstone & Hubel [1].  Unoriented cells in V1
tend to be complex cells [3], and they tend to respond to lower spatial
frequencies than do the more common oriented simple and complex cells [6].

I'm working on a simulation into which I would like to incorporate a model of
the broadband unoriented cortical cells.  But I'm having a difficult time
finding data on the parameters of these cells.  Can anyone suggest to me
where I can find the following kind of information?

1) What are the spatial-frequency bandwidths of cells in this class?

2) Assuming these cells are appropriately modeled with difference-of-Gaussian
   circular receptive fields of the form

      k_center * G(sigma_center)  -  k_surround * G(sigma_surround)

   what are appropriate mean values for the sigma's of the Gaussians and the
   weighting constants k_center and k_surround?

3) Are there any theories about the functions of the broadband unoriented
   cells?

4) Are there any existing models of the receptive fields of the broadband
   unoriented cells?

I'd appreciate any help.  -- Mike Hucka

References:

[1] Livingstone, M.S., & Hubel, D.H. (1984). Anatomy and Physiology of a Color
    System in the Primate Visual Cortex.  Journal of Neuroscience,
    4(1):309-356.

[2] De Valois, R.L., & De Valois, K.K. (1988). Spatial Vision.  Oxford
    University Press.

[3] DeBruyn, E.J., Casagrande, V.A., Beck, P.D., & Bonds, A.B. (1993).
    Visual Resolution and Sensitivity of Single Cells in the Primary Visual
    Cortex (V1) of a Nocturnal Primate (Bush Baby): Correlations with
    Cortical Layers and Cytochrome Oxidase Patterns.  Journal of
    Neurophysiology, 69(1):3-18.

[4] Saito, H.-A., Tanaka, K., Fukada, Y., & Oyamada, H. (1988). Analysis of
    Discontinuity in Visual Contours in Area 19 of the Cat.  Journal of
    Neuroscience, 8(4):1131-1143.

[5] Ts'o, D.Y., & Gilbert, C.D. (1988). The Organization of Chromatic and
    Spatial Interactions in the Primate Striate Cortex.  Journal of
    Neuroscience, 8(5):1712-1727.

[6] Tootell, R.B.H., Silverman, M.S., Hamilton, S.L., Switkes, E., & De
    Valois, R.L. (1988). Functional Anatomy of Macaque Striate Cortex.  V.
    Spatial Frequency.  Journal of Neurosicence, 8(5):1610-1624.

[7] Young, R.A., & Lesperance, R.M. (1993). A Physiological Model of Motion
    Analysis for Machine Vision.  Technical Report GMR-7878, General Motors
    Research Laboratories, Warren, Michigan.

-- 
Mike Hucka    hucka at umich.edu    http://www.eecs.umich.edu/~hucka    University
 PhD to be, computational models of human visual processing (AI Lab)     of
   UNIX systems administrator & programmer/analyst (EECS DCO)         Michigan



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