The theoretical prediction in H is empirically supported when different human participants are classified as carrying either low (black) or high (red) noise via median split across participants ( K), but not when different blocks from the same participant are classified as carrying either low (black) or high (red) noise via median split across blocks ( J). Membrane current of retinal rods of Caudiverbera caudiverbera (Amphibia. Red elements illustrate the case of internal noise intensity equal to 2. The common ones that most should know are read noise (probably the most well known), dark current, and the signal itself. It is uncorrelated with sensitivity (plotted on y axis). There are a number of noise sources that reduce the SNR if our images, some of which are well known, and others which are not quite so obvious. In both cone and rod vision, the estimated dark noise coincides with Poisson fluctuations of the estimated dark light if 17 (best estimate) of max -quanta incident at the. The clipping point (indicated by red horizontal arrow in H) is a monotonically decreasing function of internal noise intensity ( I) specified by a transcendental equation ( Neri 2020). Figure 2 Internal noise (>400 independent estimates) is on average (green arrow) 1.3X greater than the stimulus-driven component of the decision variable (indicated by orange vertical line), and the distribution of its magnitude across different stimuli/tasks/observers is log-normal. The dark noise was estimated by a maximum-likelihood procedure from frequency-of-seeing data and compared with the dark light derived from increment-threshold functions. In the presence of internal noise ( F), the ideal template is a clipped version of the signal (red dashed line in H) rescaled to lie within the 0-1 range (red solid line). In the absence of internal noise, the ideal template is the signal itself ( E). The detection device is asked to identify which of two stimuli contains a smooth signal ( A) added to a white noise source ( C versus G). Figure 4 Ideal templates depend on internal noise.

Intrinsic dark noise