PC Magazine's Covery Story: "The Man-made Brain"
PC Magazine's July 17, 2007 issue features a Cover Story on "Five Ideas That Will Reinvent Modern Computing". One of the five technologoies is on IBM Research's work on Cognitive Computing. The following is an excerpt from the story.
It could be the most ambitious computer science project of all time. At IBM's Almaden Research Center, just south of South Francisco, Dharmendra Modha and his team are chasing the holy grail of artificial intelligence. They aren't looking for ways of mimicking the human brain, they're looking to build one-neuron by neuron, synapse by synapse.
"We're trying to take the entire range of qualitative neuroscientific data and integrate it into a single unified computing platform," says Modha. "The idea is to re-create the 'wetware' brain using hardware and software."
The project is particularly daunting when you consider that modern neurology has yet to explain how the brain actually works. Yes, we know the fundamentals. But we can't be sure of every biological transaction, all the way down to the cellular level. Three years into this Cognitive Computing project, Modha's team isn't just building a brain from an existing blueprint. They're helping to create the blueprint as they build. It's reverse engineering of the highest order.
Their first goal is to build a "massively parallel cortical simulator" that re-creates the brain of a mouse, an organ 3,500 times less complex than a human brain (if you count each individual neuron and synapse). But even this is an undertaking of epic proportions. A mouse brain houses over 16 million neurons, with more than 128 billion synapses running between them. Even a partial simulation stretches the boundaries of modern hardware. No, we don't mean desktop hardware. We're talkin' supercomputers.
So far, the team has been able to fashion a kind of digital mouse brain that needs about 6 seconds to simulate 1 second of real thinking time. That's still a long way from a true mouse-size simulation, and it runs on a Blue Gene/L supercomputer with 8,192 processors, four terabytes of memory, and 1 Gbps of bandwidth running to and from each chip. "Even a mouse-scale cortical simulation places an extremely heavy load on a supercomputer," Modha explains. "We're leveraging IBM's technological resources to the limit."
Written with ordinary C code, this initial simulation is a remarkable proof of concept. As neuroscience and computing power continue to advance, Modha and his team are confident they can build cortical simulators of even greater complexity. And as they do, they hope to advance neuroscience even further, learning more and more about the inner workings of the brain and getting closer and closer to their ultimate goal.
Once they've simulated a mouse brain in real time, the team plans on tackling a rat cortex, which is about three and a half times larger. And then a cat brain, which is ten times larger than that. And so on, until they've built a cortical simulator on a human scale.
What's that good for? Anything and everything. "What we're seeking with cognitive computing is a universal cognitive mechanism, something that can give rise to the entire range of mental phenomena exhibited by humans," says Modha. "That is the ultimate goal."