Chip mimics hearing.Chip mimics hearing Confirming a 40-year-old theory of how the brain perceives pitch, two scientists have built a computer chip that duplicates the human ability to "hear" a fundamental note missing from a harmony. The analog chip An analog chip is a set of miniature electronic analog circuits formed on a single piece of semiconductor material. The circuits in analog chips operate with voltage and current varying in a continuous fashion; in contrast, digital chips only use and create voltages , which contains 125,000 transistors arranged in patterns that follow known structures in the brain, analyzes a "sound wave"--actually a varying electrical signal--as fast as a human ear can, report John Lazarro and Carver Mead Professor Carver Andress Mead (born 1 May 1934, in Bakersfield, California) is a prominent U.S. computer scientist. He is the Gordon and Betty Moore professor emeritus at the California Institute of Technology (Caltech), having taught there for over 40 years. of the California Institute of Technology California Institute of Technology, at Pasadena, Calif.; originally for men, became coeducational in 1970; founded 1891 as Throop Polytechnic Institute; called Throop College of Technology, 1913–20. in Pasadena. They describe the device in the December PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES The Proceedings of the National Academy of Sciences of the United States of America, usually referred to as PNAS, is the official journal of the United States National Academy of Sciences. (Vol. 86, No. 23). The chip splits a complex signal into 62 sine waves, each sent to a processor that delays the wave and compares its signal with that of an undelayed wave. If the two signals line up, a "correlation neuron" fires. And if all the frequencies in the input signal are multiples of a missing fundamental frequency, the circuit's output conveys only the missing element. Although the chips require a great deal of expertise to build, they provide a powerful tool for testing theories about the nervous system, says vision researcher Terrence J Terence Jenkins (born July 12, 1983 in New York City, New York, United States) is an American television personality and one of the current hosts of the popular Black Entertainment Television show 106 & Park. . Sejnowski of the Salk Institute for biological Studies The Salk Institute for Biological Studies is an independent, non-profit, scientific research laboratory located in La Jolla, California. It was founded in 1960 by Jonas Salk, M.D., the developer of the polio vaccine. in La Jolla, Calif. "It's a harbinger of the types of models that we need to develop," he says. Sejnowski predicts, however, that "it's going to be a while before experimental biologists will be able to fully appreciate the power of this particular technique, because it's so far removed from the techniques they're familiar with." |
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