er from another is not yet a reality. But, recent breakthroughs in neural network visual technology are bringing us closer to the time when computers will positively identify a person. Current Research Studying the retina of the eye is the focus of research by two professors at the California Institute of Technology, Misha A. Mahowald and Carver Mead. Their objective is to electronically mimic the function of the retina of the human eye. Previous research in this field consisted of processing the absolute value of the illumination at each point on an object, and required a very powerful computer.(Thompson 249-250). The analysis required measurements be taken over a massive number of sample locations on the object, and so, it required the computing power of a massive digital computer to analyze the data. The professors believe that to replicate the function of the human retina they can use a neural network modeled with a similar biological structure of the eye, rather than simply using massive computer power. Their chip utilizes an analog computer which is less powerful than the previous digital computers. They compensated for the reduced computing power by employing a far more sophisticated neural network to interpret the signals from the electronic eye. They modeled the network in their silicon chip based on the top three layers of the retina which are the best understood portions of the eye.(250) These are the photoreceptors, horizontal cells, and bipolar cells. The electronic photoreceptors, which make up the first layer, are like the rod and cone cells in the eye. Their job is to accept incoming light and transform it into electrical signals. In the second layer, horizontal cells use a neural network technique by interconnecting the horizontal cells and the bipolar cells of the third layer. The connected cells then evaluate the estimated reliability of the othe...
