Transformation of stimulus correlations by the retina

TL;DR

This study investigates how the retina processes correlated stimuli, revealing that retinal output correlations remain stable across different stimuli, with specific cellular adaptations influencing this consistency.

Contribution

It demonstrates that the retina maintains stable pairwise correlations across diverse stimuli by cellular and network mechanisms, advancing understanding of sensory encoding.

Findings

Retinal output correlations are stable across different stimulus types.

Spatial correlations increase retinal response correlations.

Cellular properties adapt to stimulus correlation levels.

Abstract

Redundancies and correlations in the responses of sensory neurons seem to waste neural resources but can carry cues about structured stimuli and may help the brain to correct for response errors. To assess how the retina negotiates this tradeoff, we measured simultaneous responses from populations of ganglion cells presented with natural and artificial stimuli that varied greatly in correlation structure. We found that pairwise correlations in the retinal output remained similar across stimuli with widely different spatio-temporal correlations including white noise and natural movies. Meanwhile, purely spatial correlations tended to increase correlations in the retinal response. Responding to more correlated stimuli, ganglion cells had faster temporal kernels and tended to have stronger surrounds. These properties of individual cells, along with gain changes that opposed changes in effective contrast at the ganglion cell input, largely explained the similarity of pairwise correlations across stimuli where receptive field measurements were possible.