Optimal sensory encoding
L. Zhaoping · 2002
What is optimal depends on computational tasks. Many recent works base optimality on information theoretical terms such as information transmission rates. This can be particularly revelant in the early stages of vision which are mainly concerned with transmitting information indiscriminately. We focus on the better known visual system to discuss optimal sensory coding, although coding in other sensory systems are expected to address similar concerns. Consider a simplified visual input model, with, say, 1000x1000 pixels arranged in a regular grid at one byte per pixel and 20 images per second. It provides many megabytes/second of raw data. Given the information bottleneck in the long optic nerve from retina to thalamus and the limited firing rates (thus limited data capacity) of cortical neurons (see article SENSORY CODING AND INFORMATION TRANSMISSION), early vision can greatly benefit from a data encoding that reduces the data rate without significant information loss. S