Maximum likelihood difference scaling was used to measure suprathreshold contrast response difference scales for low-frequency Gabor patterns, modulated along luminance and L-M color directions in normal, protanomalous, and deuteranomalous observers. Based on a signal-detection model, perceptual scale values, parameterized as $ d^\prime $d', were estimated by maximum likelihood. The difference scales were well fit by a Michaelis-Menten model, permitting estimates of response and contrast gain parameters for each subject. Anomalous observers showed no significant differences in response or contrast gain from normal observers for luminance contrast. For chromatic modulation, however, anomalous observers displayed higher contrast and lower response gain compared to normal observers. These effects cannot be explained by simple pigment shift models, and they support a compensation mechanism to optimize the mapping of the input contrast range to the neural response range. A linear relation between response and contrast gain suggests a neural trade-off between them.

中文翻译：

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在正常和异常三色性眼中的阈上对比反应。

最大似然差标度用于测量低频Gabor模式的阈上对比响应差异标度，这些标度是在正常，原定和氘异常观察者中沿亮度和LM颜色方向调制的。基于信号检测模型，通过最大似然估计参数化为$ d ^ \ prime $ d'的感知尺度值。Michaelis-Menten模型可以很好地拟合差异量表，从而可以估计每个受试者的反应和对比增益参数。异常观察者在亮度对比度方面，与正常观察者相比，在响应或对比度增益上没有显着差异。但是，对于彩色调制，异常观察者显示出比正常观察者更高的对比度和更低的响应增益。这些效果无法通过简单的色素偏移模型来解释，并且它们支持补偿机制，以优化输入对比度范围到神经反应范围的映射。响应和对比增益之间的线性关系表明了它们之间的神经折衷。