Computers That Learn

One of the great themes of science fiction is the computer that becomes as smart or smarter than a human being although not many novels and movies have been made in which this is the central theme. Off hand I can only think of a couple of movies, Colossus the Forbin Project and HAL in 2001, A Space Odyssey. In most science fiction the thinking machines are robots. At present computers can do many marvelous things, but none can compare with the human brain that makes sense of countless diverse, quickly changing stimuli without effort. Doing what we do with ease is often an impossible task for computers.

Nonetheless, researchers in artificial intelligence are hard at work trying to achieve the goal of computers that think as well or better than a human being. For example, Researchers at the Leipzig Max Planck Institute for Human Cognitive and Brain Sciences and the Wellcome Trust Centre for Neuroimaging in London have developed a mathematical model which could significantly improve the automatic recognition and processing of spoken language. In the future, such algorithms that imitate brain mechanisms could help machines perceive the world around them. Perception of its environment would go a long way toward achieving true artificial intelligence.

If you've ever had to deal with a voice activated automated telephone system, you probably realize how difficult it is for a computer to understand even simple words. If you speak a little too quickly or slowly, if your pronunciation is not clear, or if there is background noise, the system fails to understand you.

According to Stefen Kiebel of the Leipzig Max Plank Institute, the brain classifies the various signals from the smallest, fast-changing components such as single sound units like a vowel or consonant up to big, slow-changing elements such as the topic. The significance of the information at various duration levels is probably much greater than previously thought for the processing of perceived information. The brain searches for time dependent structures in the environment to determine what happens next. In this way, the brain can, for example, predict the next sound based on the slower-changing information.

To test this hypothesis, the researchers constructed a mathematical model to imitate, in a highly simplified manner, the brain processes that occur during the comprehension of speech. The processes were described by algorithms that process speech at different duration levels. The model succeeded well. In contrast to other artificial speech recognition devices, it could process speeded up speech sequences. In addition it could predict the next speech sound. If a prediction turned out to be wrong, the model detected the error. This indicates that the model represented processes in a way that was similar to the way the brain functions.

This new approach may be the beginning of a truly intelligent computer.