Quantal noise and decision rules in dynamic models of light adaptation.
Quantal noise and decision rules in dynamic models of light adaptation.
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光适应动态模型中的量子噪声和决策规则。
DOI：
10.1016/0042-6989(92)90193-m
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发表时间：
1992
期刊：
影响因子：
1.8
通讯作者：
Hood,DC
中科院分区：
文献类型：
--
作者：
Graham,N;Hood,DC
为了评估在光适应动力学的可计算模型中包含概率过程（例如量子噪声）的一些后果，我们考虑了一般类别模型的行为。这些模型包含四个阶段：（1）早期噪声；（2）确定性滤波和增益改变阶段；（3）晚期噪声；（4）决策规则，它是理想（信号确切已知）检测器或峰谷检测器。使用理想的检测器并且没有后期噪声，观察者的灵敏度作为平均亮度和时间频率的函数不受滤波和增益改变级的影响。因此，如果早期噪声完全是量子波动，则灵敏度将始终是平均亮度的平方根函数和时间频率的均匀（平坦）函数。后一个预测与所有已知数据相矛盾；要么理想探测器是错误的决策规则，要么灵敏度几乎总是受到量子涨落以外的噪声源的限制。然而，对于峰谷检测器，无论有或没有后期噪声，观察者的灵敏度作为时间频率的函数确实反映了低级滤波和增益改变级的灵敏度。然而，如果观察者的灵敏度作为平均亮度的函数要经过平方根和韦伯区域，则需要后期噪声。将这些结论与空间频率维度上的类似工作进行比较，突出了空间频率域和时间频率域之间的差异。最后，根据这些分析和文献证据，我们质疑量子涨落是否在任何条件下都会限制视觉灵敏度。
To evaluate some of the consequences of including probabilistic processes (e.g. quantal noise) in a computable model of light-adaptation dynamics, we considered the behavior of a general class of models. These models contain four stages:(1)early noise;(2)a deterministic filtering and gain-changing stage;(3)late noise;(4)a decision rule that is either an ideal (signal-known-exactly) detector or a peak-trough detector. With the ideal detector andwithoutlate noise, the observer's sensitivity as a function of mean luminance and temporal frequency is not affected by the filtering and gain-changing stage. Consequently, if the early noise is entirely quantal fluctuations, sensitivity will always be a square-root function of mean luminance and a uniform (flat) function of temporal frequency. This latter prediction is contradicted by all known data; either the ideal-detector is the wrong decision rule or sensitivity is almost always limited by sources of noise other than quantal fluctuations. With the peak-trough detector, however, with or without late noise, the observer's sensitivity as a function of temporal frequency does reflect the sensitivity of the low-level filtering and gain-changing stage. Late noise is needed, however, if the observer's sensitivity as a function of mean luminance is to go through both a square-root and a Weber region. Comparing these conclusions to similar work on the spatial frequency dimension highlights differences between the spatial and temporal frequency domains. Finally, on the basis of these analyses and evidence from the literature, we question whether quantal fluctuations limit visual sensitivity under any condition.