From brain-like computers to artificial life

To establish the significance of his information processing paradigm, Cellular Nonlinear Networks (CNN), Professor Leon Chua summoned Shakespeare: "There is a tide in the affairs of men/ Which, taken at the flood, leads on to fortune; / Omitted, all the voyage of their life/ Is bound in shallows and in miseries," (Julius Caesar IV iii).

The field of computer science floats on such a sea, explained Professor Chua, and we are riding the crest of a highly complex but revolutionary wave, one that will transform the speed and accuracy with which we process information.

Professor Chua, Professor of Electrical Engineering and Computing Sciences at the University of California, Berkeley, was delivering his talk, "From Brain-like Computers to Artificial Life", as part of CityU's Distinguished Lecture Series, on 28 November 2001.

He explained that the hardware implementation of the CNN paradigm, the CNN Universal Chip, is capable of two trillion operations per second, making it more powerful than conventional supercomputers such as the US Department of Energy's Blue Mountain Supercomputer in its National Laboratory in Los Alamos, New Mexico.

Mimicking the human brain
Professor Chua has been working on the CNN paradigm for several years and has published widely on this topic, including his 1996 book, CNN: A Paradigm of Complexity. He hopes production of the Universal Chip will begin in the very near future and will have a profound impact on many fields of study and areas of application.

"The CNN is very different from today's computers," said Professor Chua, "because it is not digital. Instead, it mimics the architecture of the human brain and exploits emergent computation and exhibits graceful degradation. And it is fast: the interconnections within the paradigm work faster than brain cells, taking only one nanosecond to transmit." The CNN is inspired by the structure of the human brain and its processing systems. The networks consist of a series of mathematical models that imitate the properties of a human nervous system. Within the paradigm there are a large number of processing elements that are comparable to neurons that are tied together with connections similar to synapses, the junctions across which nerve impulses are passed from axon terminals to neurons.

The paradigm is less complex than a human brain and, although the CNN Universal Chip is extremely powerful, a fully operational artificial brain is still far from being achieved. But the CNN Chip is very fast and reproduces images and information with great precision.
In addition, said Professor Chua, the conceptual aspects of the CNN paradigm underpin several other paradigms that will have an enormous impact in many areas of life; for example, in the early prediction of epileptic attacks, map making, enhancing image processing and developing artificial life.

"The CNN is an important step in discovering just how far technology can go, especially in the areas of artificial life." Referring back to Julius Caesar, Professor Chua reminded the audience that "we must take the current when it serves/ Or lose our ventures." In this case, the venture is to develop faster, more powerful information processing systems and the CNN paradigm promises to play a vital role in achieving this aim.