A reinterpretation of critical flicker-frequency (CFF) data reveals key details about light adaptation and normal and abnormal visual processing.
A reinterpretation of critical flicker-frequency (CFF) data reveals key details about light adaptation and normal and abnormal visual processing.
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对临界闪烁频率（CFF）数据的重新解释揭示了有关光适应以及正常和异常视觉处理的关键细节。
DOI：
10.1016/j.preteyeres.2021.101001
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发表时间：
2022
影响因子：
17.8
通讯作者：
Rider AT
中科院分区：
文献类型：
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作者：
Rider AT
我们看到闪烁的能力有一个频率上限，超过这个上限，闪烁就看不见了，称为“临界闪烁频率”（CFF），它通常随着光强（I）的增加而增加。CFF和I之间的关系是近200年研究的焦点，大致是对数关系，即，CFF对数（I）-一个称为费里-波特定律的关系。然而，为什么会出现这种规律，以及它与潜在生理学的关系，从来没有得到充分的解释。在过去的二十年中，我们测量了正常观察者和视网膜基因缺陷患者的CFF。在这里，我们重新分析和建模我们的数据和历史CFF数据。值得注意的是，在患者和正常观察者的广泛条件下测量的CFF与I函数在双对数坐标中绘制时都具有大致相似的形状，即，log（CFF）-versus-log（I）.因此，整个数据集可以通过固定形状模板的水平和垂直对数移位来表征。形状不变性可以通过一个简单的视觉处理模型来预测，该模型由一系列低通滤波器、减法前馈阶段和增益调整组成（Rider，Henning & Stockman，2019）。它主要取决于在给定强度下接近幂律区域的视觉处理阶段的数量以及在较高光水平下与频率无关的增益降低。与直觉相反，CFF与Irelation主要取决于视觉响应的增益，而不是其速度，这一结论改变了我们对人类闪烁感知的理解和解释。费里-波特“定律”仅仅是形状不变模板的近似。
Our ability to see flicker has an upper frequency limit above which flicker is invisible, known as the “critical flicker frequency” (CFF), that typically grows with light intensity (I). The relation between CFF andI, the focus of nearly 200 years of research, is roughly logarithmic,i.e., CFF ∝ log(I)—a relation called the Ferry-Porter law. However, why this law should occur, and how it relates to the underlying physiology, have never been adequately explained. Over the past two decades we have measured CFF in normal observers and in patients with retinal gene defects. Here, we reanalyse and model our data and historical CFF data. Remarkably, CFF-versus-Ifunctions measured under a wide range of conditions in patients and in normal observers all have broadly similar shapes when plotted in double-logarithmic coordinates,i.e., log (CFF)-versus-log(I). Thus, the entire dataset can be characterised by horizontal and vertical logarithmic shifts of a fixed-shape template. Shape invariance can be predicted by a simple model of visual processing built from a sequence of low-pass filters, subtractive feedforward stages and gain adjustment (Rider, Henning & Stockman, 2019). It depends primarily on the numbers of visual processing stages that approach their power-law region at a given intensity and a frequency-independent gain reduction at higher light levels. Counter-intuitively, the CFF-versus-Irelation depends primarily on the gain of the visual response rather than its speed—a conclusion that changes our understanding and interpretation of human flicker perception. The Ferry-Porter “law” is merely an approximation of the shape-invariant template.