A microchip with about as much brain power as a garden worm might not seem very impressive, compared with the blindingly fast chips in modern personal computers. But a new microchip made by researchers at IBM represents a landmark. Unlike an ordinary chip, it mimics the functioning of a biological brain—a feat that could open new possibilities in computation.
Inside the brain, information is processed in parallel, and computation and memory are entwined. Each neuron is connected to many others, and the strength of these connections changes constantly as the brain learns. These dynamics are thought to be crucial to learning and memory, and they are what the researchers sought to mimic in silicon. Conventional chips, by contrast, process one bit after another and shunt information between a discrete processor and memory components. The bigger a problem is, the larger the number of bits that must be shuffled around.
The IBM researchers have built and tested two demonstration chips that store and process information in a way that mimics a natural nervous system. The company says these early chips could be the building blocks for something much more ambitious: a computer the size of a shoebox that has about half the complexity of a human brain and consumes just one kilowatt of power. This is being developed with $21 million in funding from the Defense Advanced Research Projects Agency, in collaboration with several universities.
The company’s researchers and their academic collaborators will present two papers next month at the Custom Integrated Circuits conference in San Jose, California, showing that the chip designs have very low power requirements and work with neural-circuit-mimicking software. In one experiment, a “neural core,” as the new chips are called, learns to play Pong; in another, it learns to navigate a car on a simple race track; and in another it learns to recognize images.