PROJECT- ARTIFICIAL BRAIN

F or the last four years, Henry Markram has been building a biologically accurate artificial brain
Powered by a supercomputer, his software model closely mimics the activity of a vital section of a rat’s grey matter
Dubbed Blue Brain, the sim- ulation shows some strange behaviour. The artificial “cells” respond to stimuli and pulse and flash in spooky unison, a pattern that isn’t programmed but emerges spontaneously
“It’s the neuronal equivalent of a Mexican wave,” says Markram, referring to what happens when successive clusters of stadium spectators briefly stand and raise their arms, creating a ripple effect
Such synchronized behaviour is common in flesh-and-blood brains, where it’s believed to be a basic step necessary for decision-making. But when it arises in an artificial system, it’s more surprising
Blue Brain is based at the École Polytechnique Fédérale de Lausanne in Switzerland
The project hopes to tackle one of the most perplexing mysteries of neuroscience: How does human intelligence emerge? The Blue Brain scientists hope their computermodel can shed light on the puzzle, and possibly even replicate intelligence in some way
“We’re building the brain from the bottom up, but in silicon,” says Markram, the leader of Blue Brain, which is powered by a supercomputer provided by International Business Machines Corp. “We want to understand how the brain learns, how it perceives things, how intelligence emerges.”
Blue Brain is controversial, and its success is far from assured
Christof Koch of the California Institute of Technology, a scientist who studies consciousness, says the Swiss project provides vital data about how part of the brain works. But he says that Markram’s approach is still missing algorithms, the biological programming that yields higher-level functions
“You need to have a theory about how a particular circuit in the brain” can trigger complex, higher-order properties, Koch says. “You can’t assemble ever larger data fields and shake it and say, ‘Ah, that’s how consciousness emerges’.”

Despite the challenges, the push to understand, replicate and re-enact higher behaviours in the brain has become one of the hottest areas of neuroscience
With the help of a $4.9 million (Rs23.9 crore) grant from the US department of defence, IBM is working on a project with five US universities to build a tiny, low-power microchip that simulates the behaviour of one million neurons and 10 billion synapses
The goal, says IBM, is to develop brainy computers that can better predict the behaviour of complex systems, such as weather or financial markets
The Chinese government has provided about $1.5 million to a team at Xiamen University to create artificial brain robots with microcircuits that evolve, learn and adapt to realworld situations. Jeff Krichmar and colleagues at the University of California have built an artificial brain robot that learns to sharpen its visual perception when moving in a lab environment, another form of emergent behaviour, a form of spontaneous self-organization
And researchers at Sensopac, a project backed by a grant of €6.7 million (Rs45.8 crore) from the European Union, have built part of an artificial mouse brain
The scientists behind Blue Brain hope to have a virtual human brain functioning in 10 years—a lengthy time period that underscores the scientific challenge. The human brain has 100 billion neurons that send electrical signals to each other via a network of at least 100 trillion connections, or synapses. How could this dizzying complexity ever be recreated in a virtual model? Markram adopted a systematic, if painstaking, approach
He decided to work out the blueprint of its wiring and use that to rebuild the brain in an artificial form. He focused on a rat’s neocortical column (NCC) an elementary building block of the brain’s neocortex, which is responsible for higher functions and thought. In a rat’s case, that includes planning to obtain food
A rat’s NCC, comprised of about 10,000 neurons and their 10 billion connections, functions much like a computer microprocessor. All mammals have NCCs, and the ones in humans aren’t all that different from the ones in rats
However, humans have far more NCCs, which means far greater brain power. Markram figured that if a rat simulation did a good job of correctly mimicking activity in a real rat’s brain, he could use the same model as a road map for simulating the human brain
Markram began by collect- ing detailed information about the rat’s NCC, down to genes, proteins, molecules and the electrical signals that connect one neuron to another. These complex relationships were then turned into millions of equations, written in software
He then recorded real-world data—the strength and path of each electrical signal—directly from rat brains to test the accuracy of the software
At the Lausanne lab one re- cent afternoon, a pink sliver of rat brain sat in a beaker containing a colourless liquid. The neurons in the brain slice were still alive and actively communicating with each other. Nearby, a modified microscope recorded some of this activity in another brain slice. “We’re intercepting the electro-chemical messages” in the cells, then testing the software against it for accuracy, said Markram
The rat’s NCC has 10,000 neurons, and it takes the power of one desktop computer to mimic the behaviour of a single neuron. To model the entire NCC,Markramrelies on an IBM computer that can perform 22.8 trillion operations a second. This enables the simulation to be rendered as a three-dimensional (3D) object
When Blue Brain is running, its deepest inner workings are seen in astonishing detail, as a 3D simulation unfolding on a computer screen
In a darkened room, Blue Brain displays a virtual NCC as a column-like structure, its blue colour signifying a state of rest. When zapped by a simulated electrical current, the neurons start signalling each other and their wiring progressively sparks to life different colours. Tests show the same areas light up in the model as do in a real rat’s brain, suggesting that Blue Brain is accurate, says Markram
More complex things start to happen. First there’s a burst of red, then white, then red again, as the NCC’s wiring fills up with a cascade of myriad signals. There are so many connections, the NCC looks like an incredibly dense tangle of undergrowth
Then, two successive waves of yellow colour suddenly race through Blue Brain. It’s a sign that the neurons have synchronized their behaviour on their own. “The cells start to take on a life of their own,” says Markram. “That’s what your brain is (and when such patterns become sophisticated) it becomes your personality.”

If Blue Brain ever gets so- phisticated enough to closely mimic the human brain, will it exhibit consciousness? Says Markram: “If it does emerge, we’ll be able to tell you how it emerged. If it doesn’t, we’ll know that it’s the result of more than just 100 billion neurons interacting.”


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