Question

The presence of different receptive field types for retinal ganglion cells indicates that the visual image is broken into packets of information for transmission to the brain. What is the purpose of this?

Answer 1

The visual system of primates, including that of humans, famously features both exquisite spatial acuity and a high temporal resolution. This dual focus on both ‘sharpness’ and ‘speed’ is made possible through different processing streams set up already in the retina. In a recent study, Puthussery et al. now show that key differences in the processing streams that are thought to underlie these visual abilities are already set up right after the first synapse of the visual system — in retinal bipolar cells.

The retina breaks the visual world into several parallel representations prior to transmission to the brain. Each representation, or ‘channel’, is based on a different type of retinal ganglion cell that carries information about specific featuresof the visual scene — such as edges, directed motion or ‘color’.