Verdon W, Haegerstrom-Portnoy G
School of Optometry, University of California at Berkeley 94720-2020, USA.
Vision Res. 1996 Feb;36(3):373-90. doi: 10.1016/0042-6989(95)00103-4.
It is well established that the spectral sensitivity under photopic conditions varies across the human retina. We investigate the mechanisms underlying these spectral changes. Through the use of color appearance, flicker sensitivity, additivity, discrimination at threshold and modeling, we show that the changes in spectral sensitivity on a photopic white background across parafoveal retina are consistent with shifts in cone weightings to (L-M) and (M-L) chromatic channels. This two channel model, developed to account for foveal spectral sensitivity curves (Sperling & Harwerth, 1971 Science, 172, 180-184), provides a better description of parafoveal data than both a single color channel upper envelope model (comprised of a single red-green opponent channel and an achromatic mechanism) and a vector model (combining a red-green opponent channel with an achromatic component). Thus while the two channel model ([L-M] and [M-L]) of foveal color vision is generalizable to the parafovea, simple models with a unitary red/green process are not. Although the two channel model can accurately fit parafoveal spectral sensitivity curves without it, a small contribution from a luminance mechanism might improve the ability of the two channel model to account for threshold discrimination and additivity data.
在明视觉条件下，光谱敏感性在人类视网膜上存在差异，这一点已得到充分证实。我们研究了这些光谱变化背后的机制。通过使用颜色外观、闪烁敏感性、相加性、阈值辨别和建模，我们表明，在明视觉白色背景下，视网膜旁中央凹区域的光谱敏感性变化与视锥细胞对（L-M）和（M-L）色通道的权重变化一致。为解释中央凹光谱敏感性曲线而开发的这个双通道模型（Sperling & Harwerth，1971年，《科学》，172卷，180 - 184页），与单颜色通道上包络模型（由单个红-绿对立通道和一个消色差机制组成）和矢量模型（将红-绿对立通道与一个消色差成分相结合）相比，能更好地描述旁中央凹数据。因此，虽然中央凹颜色视觉的双通道模型（[L-M]和[M-L]）可推广到旁中央凹，但具有单一红/绿过程的简单模型则不行。尽管双通道模型无需考虑亮度机制就能准确拟合旁中央凹光谱敏感性曲线，但亮度机制的微小贡献可能会提高双通道模型解释阈值辨别和相加性数据的能力。
