Quantum Fluctuations and Adaptive Spatial Interactions in the Visual System

The effect of retinal spatial interactions on photon-fluctuation noise is studied. We show that lateral inhibition results in an increase of the susceptibility to that noise, whereas spatial summations result in the opposite. We present a quantitative assessment of the adaptive changes in the form of the receptive field that should accompany changes in luminance, in order to achieve an optimum trade-off between resolution and noise.