IBM's latest brain-like computer chip may not be "smarter than a fifth-grader," but it can simulate millions of the brain's neurons and perform complex tasks using very little energy.
Researchers for the computer hardware giant have developed a postage-stamp-size chip, equipped with 5.4 billion transistors, that is capable of simulating 1 million neurons and 256 million neural connections, or synapses. In addition to mimicking the brain's processing by themselves, individual chips can be connected together like tiles, similar to how circuits are linked in the human brain
The team used its "TrueNorth" chip, described (Aug. 7) in the journal Science, 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, California.
Modha gave an analogy to explain how the brain-like chip differs from a classical computer chip. You can think of a classical computer as a left-brained machine, he told Live Science; 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 is composed 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 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.