The spatial arrangement of L and M cones in the peripheral human retina

The spatial arrangement of L and M cones in the human peripheral retina was estimated from red-green color naming of small test hashes (0.86 min of ar e, 555 nm, constant intensity) presented at different locations (grid with 1.5 min of are steps) centered at 17 degrees temporal eccentricity. Simulat ed red-green color naming ratings were generated by a model based on an ide al observer for all possible patterns of placement and relative numerositie s of L and M cones, constrained by the anatomical data on the statistics of cone spacing at this retinal location. The best matching simulated perform ance as compared to the human observer's data determined the cone array mos t likely to produce that observer's color naming results. The mosaics for t wo color normal observers showed L and M cones randomly arrayed over this r etinal region. Consequences of random cone placements for spectral sampling and color opponency are discussed. (C) 2000 Elsevier Science Ltd. All righ ts reserved.