Moreover, they showed a striking resemblance to the original images. The resulting reconstructions were similar across all retinas tested. then attempted to reconstruct the original images using just the electrical activity recorded. Based on these recordings, plus existing knowledge about RGC responses, Brackbill et al. recorded the responses of macaque retinas to real-life images of landscapes, objects, animals or people. Using electrode arrays to monitor hundreds of RGCs at the same time, Brackbill et al. These primates are also similar to humans in their high-resolution central vision and trichromatic color vision. These include the numbers and types of RGCs present in the retina. Studying the macaque retina was important because the primate visual system differs from that of other species in several ways. set out to answer these questions by measuring and analyzing the electrical activity in isolated retinas from macaque monkeys. But exactly what input each RGC sends to the brain, and how the brain uses this information, is unclear. Each encodes a different visual feature, such as the presence of bright spots of a certain size, or information about texture and movement. The primate retina contains roughly 20 types of RGCs. From this information, the brain constructs our entire visual world. They are the only source of visual information that the brain receives. Spikes from RGCs then travel along the optic nerve to the brain. They pass these signals to neurons called retinal ganglion cells (RGCs), which convert them into electrical signals called spikes. Light-sensitive cells called rods and cones absorb incoming light and convert it into electrical signals. Vision begins in the retina, the layer of tissue that lines the back of the eye. Spatiotemporal reconstructions exhibited similar spatial properties, suggesting that the results are relevant for natural vision. Simulated reconstructions, using linear-nonlinear cascade models of RGC light responses that incorporated measured spatial properties and nonlinearities, produced similar results. Correlated activity and nonlinearities had statistically significant but minor effects on reconstruction. ON and OFF cells conveyed largely independent, complementary representations, and parasol and midget cells conveyed distinct features. The optimal reconstruction filter for each RGC – its visual message – reflected natural image statistics, and resembled the receptive field only when nearby, same-type cells were included. Reconstructions were highly consistent across retinas. This possibility was explored by linear reconstruction of natural images from responses of the four numerically-dominant macaque RGC types. The visual message conveyed by a retinal ganglion cell (RGC) is often summarized by its spatial receptive field, but in principle also depends on the responses of other RGCs and natural image statistics.
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