Norwich K H, Wong W
Department of Physiology, University of Toronto, ON, Canada.
Percept Psychophys. 1997 Aug;59(6):929-40. doi: 10.3758/bf03205509.
Many of the laws and empirical observations of fundamental psychophysics can be unified with a single equation, which has been called the complete form of Fechner's law. It can be shown that this law embraces both of the commonly used forms: Stevens's and Fechner's laws. It assumes one or the other form with appropriate values of the parameters. However, the complete equation confers an advantage beyond simply containing the classical laws. It offers greater flexibility in the representation of experimental data. It is shown that psychophysical phenomena may be represented by any number of triplets of quantities: subjective magnitude of stimulus, subjective just noticeable difference (jnd), and differential threshold. Each of the preceding quantities are functions of the physical magnitude of the stimulus. The investigator has the license to choose two of these quantities in the form he or she thinks is best; the third quantity is determined by the choice of the first two. Thus, for example, different forms of the law of sensation and different forms of the mathematical function for differential threshold may coexist with equal validity.
基础心理物理学的许多定律和实证观察结果都可以用一个单一方程统一起来，这个方程被称为费希纳定律的完整形式。可以证明，该定律涵盖了两种常用形式：史蒂文斯定律和费希纳定律。在参数取适当值时，它呈现出其中一种形式。然而，完整方程所带来的优势不仅仅是简单地包含了经典定律。它在实验数据的表示上提供了更大的灵活性。研究表明，心理物理现象可以用任意数量的三个量的组合来表示：刺激的主观大小、主观刚刚可察觉差异（jnd）和差别阈限。前面提到的每个量都是刺激物理大小的函数。研究者有权以他或她认为最佳的形式选择其中两个量；第三个量则由前两个量的选择决定。因此，例如，不同形式的感觉定律和不同形式的差别阈限数学函数可以同样有效地共存。
