What is the main cause of a low frequency cutoff of the CSF?

The low-frequency cutoff of the contrast sensitivity function (CSF) is primarily influenced by lateral inhibition. This phenomenon occurs when activated neurons inhibit their neighboring neurons, enhancing the perception of edges and contrast. In terms of spatial frequency, lateral inhibition allows the visual system to effectively distinguish higher frequency patterns while suppressing lower frequency information.

In other words, lateral inhibition helps the visual system to filter out low-frequency, low-contrast stimuli, which might otherwise not provide sufficient information for clear perception. As a result, it plays a crucial role in determining the sensitivity to various spatial frequencies, contributing significantly to the low-frequency cutoff observed in the CSF. The mechanisms of lateral inhibition thus directly influence our ability to detect contrast at different spatial frequencies, especially when it comes to distinguishing between fine details versus broader patterns in the visual field.

The other potential causes, such as the density of photoreceptors, optical limitations, and color vision defects, do not primarily dictate the CSF's low frequency cutoff as effectively as lateral inhibition does. Photoreceptor density relates more to overall sensitivity and visual acuity rather than specifically to how contrast is processed across spatial frequencies. Optical limitations focus on how image clarity can affect perception but do not specifically account for the reduction in sensitivity to low