The latest piece of my PhD work is now published! Check it out at https://www.nature.com/articles/s41586-024-08212-3
We explain how correlated responses in the retinal output may arise when nonlinear receptive fields are stimulated with natural scenes. We think that these concerted responses violate the decorrelation prediction of efficient coding in a cell-type-specific manner in both marmosets and mice.
The "high-correlation-mode" within or between types of ganglion cells we examined probably reflects the computation of a visual feature related to fine spatial contrast in natural scenes.
How these robust spatial-contrast signals are used by cortical or subcortical areas is an open question. Pure speculation here, but "coarse-to-fine" processing during fixations may require nonlinear and fast parasol cell responses that predict the upcoming (higher-spatial-frequency) midget cell responses.
The main change since the preprint is that we introduced Fourier-based quantification of information and redundancy (thanks to the anonymous reviewer for pushing us in this direction).
Preprint here: https://www.biorxiv.org/content/10.1101/2023.01.10.523412v1