Chip Thinks Like a Brain

Thursday, August 21, 2014 @ 04:08 PM gHale


A postage-stamp-size chip with 5.4 billion transistors is capable of simulating 1 million neurons and 256 million neural connections, or synapses. In other words, it thinks like a human brain.

In addition to mimicking the brain’s processing, individual chips can connect together like tiles, similar to how circuits link in the human brain.

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The team used its “TrueNorth” chip to perform a task that is very challenging for conventional computers: Identifying people or objects in an image.

“We have not built a brain. What we have done is learn from the brain’s anatomy and physiology,” said study leader Dharmendra Modha, manager and lead researcher of the cognitive computing group at IBM Research – Almaden in San Jose, CA.

Modha gave an analogy to explain how the brainlike chip differs from a classical computer chip. You can think of a classical computer as a left-brained machine It’s fast, sequential and good at crunching numbers. “What we’re building is the counterpart, right-brain machine,” he said.

Classical computers — from the first general-purpose electronic computer of the 1940s to today’s advanced PCs and smartphones — use a model described by Hungarian-American mathematician and inventor John von Neumann in 1945. The Von Neumann architecture contains a processing unit, a control unit, memory, external storage, and input and output mechanisms. Because of its structure, the system cannot retrieve instructions and perform data operations at the same time.

In contrast, IBM’s new chip architecture resembles that of a living brain. The chip consists of computing cores that each contain 256 input lines, or “axons” (the cablelike part of a nerve cell that transmits electrical signals) and 256 output lines, or “neurons.” Much like in a real brain, the artificial neurons only send signals, or spikes, when electrical charges reach a certain threshold.

The researchers connected more than 4,000 of these cores on a single chip, and tested its performance with a complex image-recognition task. The computer had to detect people, bicyclists, cars and other vehicles in a photo, and identify each object correctly.

The project was a major undertaking, Modha said. “This is [the] work of a very large team, working across many years,” he said. “It was a multidisciplinary, multi-institutional, multiyear effort.”

The Defense Advanced Research Projects Agency (DARPA), the branch of the U.S. Department of Defense responsible for developing new technologies for the military, provided funding for the $53.5 million project.

After the team constructed the chip, Modha halted work for a month and offered a $1,000 bottle of champagne to any team member who could find a bug in the device. But nobody found one, he said.

The new chip is not only much more efficient than conventional computer chips, it also produces far less heat, the researchers said.

Today’s computers — laptops, smartphones and even cars — suffer from visual and sensory impairment, Modha said. But if these devices can function more like a human brain, they may eventually understand their environments better, he said. For example, instead of moving a camera image onto a computer to process it, “the [camera] sensor becomes the computer,” he said.



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