Abstract
In previous experiments we studied interactions between the center and the surround of receptive fields of neurons in the retino-geniculate pathway and their consequences for human visual perception. To be able to correlate the physiological and the psychophysical data, it is important to consider that a visual stimulus is encoded not by one cell, but by a cell array, the receptive fields of which have different locations relative to the stimulus. We have developed an algorithm with which the spatial distribution of the receptive fields of retinal ganglion cells within the primate fovea can be simulated. To calculate the positions of central points of the receptive fields, the model uses Delaunay triangulation with a superimposed jitter (Zhan and Troy, Visual Neuroscience 17, pp. 23–39). The resulting array is subsequently stretched according to the cell density variation with retinal eccentricity. Our model considers the literature data on the anatomical structure of the primate central retina. However, the model simulates the positions of the receptive fields rather than the locations of the ganglion cells' bodies, which in the fovea might be different owing to the lateral displacement of the ganglion cells. For the human retina, the simulated patch has a diameter of approximately 3 degrees and contains about 500 ON- and 500 OFF-center magnocellular cells. Other cell subpopulations were also considered. Any array size can be chosen depending on the visual stimulus projected on the retina.