A numerical study of red–green colour opponent properties in the primate retina

Authors

  • Hiroshi Momiji,

    1. Department of Bioengineering, Imperial College London, Exhibition Road, London SW7 2AZ, UK
    2. Department of Visual Neuroscience, Division of Neuroscience and Mental Health, Imperial College London, Charing Cross Campus, St Dunstan's Road, London W6 8RP, UK
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  • Mark W. Hankins,

    1. Nuffield Laboratory of Ophthalmology, University of Oxford, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, UK
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  • Anil A. Bharath,

    1. Department of Bioengineering, Imperial College London, Exhibition Road, London SW7 2AZ, UK
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  • Christopher Kennard

    1. Department of Visual Neuroscience, Division of Neuroscience and Mental Health, Imperial College London, Charing Cross Campus, St Dunstan's Road, London W6 8RP, UK
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Dr H. Momiji, Department of Computer Science, University of Sheffield, Regent Court, 211 Portobello Street, Sheffield S1 4DP, UK.
E-mail: h.momiji@dcs.shef.ac.uk

Abstract

It remains an important question whether neural function is mediated entirely by its tailored circuitry. A persistent debate in retinal colour vision is whether the centre and the surround of a ganglion cell receptive field receive dominant inputs either from L or M cones in an antagonistic manner (the selective wiring model) or mixed inputs (the mixed wiring model). Despite many anatomical, physiological and psychophysical experiments, a decisive conclusion has not been reached. An in-depth examination of what the pure mixed wiring mechanisms predicts is therefore important. These two models make different predictions both for the fovea and for the peripheral retina. Recently, a dynamic cellular model of the primate fovea was developed [Momiji et al. (2006) Vis. Res., 46, 365–381]. Unlike earlier models, it explicitly incorporates spatial non-uniformities, such as the random arrangement of L and M cones. Here, a related model is developed for the peripheral retina by incorporating anatomically reasonable degrees of convergence between cones, bipolar cells and ganglion cells. These two models, in which selective wiring mechanisms are absent, are applied to describe both foveal and peripheral colour vision. In numerical simulations, peripheral ganglion cells are less colour sensitive than foveal counterparts, but none-the-less display comparative sensitivities. Furthermore, peripheral colour sensitivity increases with temporal frequency, relative to foveal sensitivity. These results are congruent with recent physiological experiments.

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