Laming Donald
University of Cambridge, Department of Experimental Psychology, Cambridge, England.
Seeing Perceiving. 2010;23(2):155-71. doi: 10.1163/187847510X503579.
This paper looks at Fechner's law in the light of 150 years of subsequent study. In combination with the normal, equal variance, signal-detection model, Fechner's law provides a numerically accurate account of discriminations between two separate stimuli, essentially because the logarithmic transform delivers a model for Weber's law. But it cannot be taken to be a measure of internal sensation because an equally accurate account is provided by a chi(2) model in which stimuli are scaled by their physical magnitude. The logarithmic transform of Fechner's law arises because, for the number of degrees of freedom typically required in the chi(2) model, the logarithm of a chi(2) variable is, to a good approximation, normal. This argument is set within a general theory of sensory discrimination.
本文从随后150年的研究角度审视了费希纳定律。结合正态、等方差信号检测模型，费希纳定律为区分两个不同刺激提供了数值精确的描述，这主要是因为对数变换给出了韦伯定律的一个模型。但它不能被视为内部感觉的一种度量，因为卡方模型也提供了同样精确的描述，在该模型中刺激按其物理量值进行缩放。费希纳定律的对数变换之所以出现，是因为对于卡方模型通常所需的自由度数量，卡方变量的对数近似服从正态分布。这一论点是在感觉辨别一般理论的框架内提出的。
