PROJECT SUMMARY The mammalian visual system builds and transforms representations of the outside world through the concerted activity of populations of neurons based on the inputs received from the retina. Decades of work on single cells and pairs have informed our understanding of visual representation beyond the retina. For example, the asymmetric dorsal-ventral retinal cone distribution is known to lead to corresponding wavelength- based asymmetries in the responses of downstream visual cells. But relatively little is known about the spike time statistics of activity beyond pairs in the early visual system. While recent studies have described population correlations and dimensionality, there remains a large gap between these analyses of population activity and what is known of visual signaling from retinal and single cell studies in the mouse visual system. Here, we propose to test the hypothesis that the amount and format of population visual stimulus information depends on the wavelength content of the visual stimulus. Testing these hypotheses requires the ability to separately stimulate each of the photoreceptor classes with arbitrary spatiotemporal stimuli across enough of the visual field to drive large population responses. We will use multiple high-density multi-electrode arrays to record populations of single neurons in an immersive environment which can separately activate photoreceptors. This work will allow us to understand how known parallel channels in mouse vision influence population statistics, and in what ways populations statistics are misestimated when using photoreceptor and visual channel-limiting stimuli.