The $1.3B Quest to Build a Supercomputer Replica of a Human Brain
Even by the standards of the TED conference, Henry
Markram’s 2009 TEDGlobal talk was a mind-bender. He took the stage of
the Oxford Playhouse, clad in the requisite dress shirt and blue jeans,
and announced a plan that—if it panned out—would deliver a fully
sentient hologram within a decade. He dedicated himself to wiping out
all mental disorders and creating a self-aware artificial intelligence.
And the South African–born neuroscientist pronounced that he would
accomplish all this through an insanely ambitious attempt to build a
complete model of a human brain—from synapses to hemispheres—and
simulate it on a supercomputer. Markram was proposing a project that has
bedeviled AI researchers for decades, that most had presumed was
impossible. He wanted to build a working mind from the ground up.
In the four years since Markram’s speech, he hasn’t backed off a
nanometer. The self-assured scientist claims that the only thing
preventing scientists from understanding the human brain in its
entirety—from the molecular level all the way to the mystery of
consciousness—is a lack of ambition. If only neuroscience would follow
his lead, he insists, his Human Brain Project could simulate the
functions of all 86 billion neurons in the human brain, and the
100 trillion connections that link them. And once that’s done, once
you’ve built a plug-and-play brain, anything is possible. You could take
it apart to figure out the causes of brain diseases. You could rig it
to robotics and develop a whole new range of intelligent technologies.
You could strap on a pair of virtual reality glasses and experience a
brain other than your own.
The way Markram sees it, technology has finally caught up with the
dream of AI: Computers are finally growing sophisticated enough to
tackle the massive data problem that is the human brain. But not
everyone is so optimistic. “There are too many things we don’t yet
know,” says Caltech professor Christof Koch, chief scientific officer at
one of neuroscience’s biggest data producers, the Allen Institute for
Brain Science in Seattle. “The roundworm has exactly 302 neurons, and we
still have no frigging idea how this animal works.” Yet over the past
couple of decades, Markram’s sheer persistence has garnered the respect
of people like Nobel Prize–winning neuroscientist Torsten Wiesel and Sun
Microsystems cofounder Andy Bechtolsheim. He has impressed leading
figures in biology, neuroscience, and computing, who believe his
initiative is important even if they consider some of his ultimate goals
unrealistic.
Markram has earned that support on the strength of his work at the
Swiss Federal Institute of Technology in Lausanne, where he and a group
of 15 postdocs have been taking a first stab at realizing his grand
vision—simulating the behavior of a million-neuron portion of the rat
neocortex. They’ve broken new ground on everything from the expression
of individual rat genes to the organizing principles of the animal’s
brain. And the team has not only published some of that data in
peer-reviewed journals but also integrated it into a cohesive model so
it can be simulated on an IBM Blue Gene supercomputer.
The big question is whether these methods can scale. There’s no
guarantee that Markram will be able to build out the rest of the rat
brain, let alone the vastly more complex human brain. And if he can,
nobody knows whether even the most faithful model will behave like a
real brain—that if you build it, it will think. For all his bravado,
Markram can’t answer that question. “But the only way you can find out
is by building it,” he says, “and just building a brain is an incredible
biological discovery process.” This is too big a job for just one lab,
so Markram envisions an estimated 6,000 researchers around the world
funneling data into his model. His role will be that of prophet, the
sort of futurist who presents worthy goals too speculative for most
scientists to countenance and then backs them up with a master plan that
makes the nearly impossible appear perfectly plausible. Neuroscientists
can spend a whole career on a single cell or molecule. Markram will
grant them the opportunity and encouragement to band together and pursue
the big questions.
And now Markram has funding almost as outsized as his ideas. On
January 28, 2013, the European Commission—the governing body of the
European Union—awarded him 1 billion euros ($1.3 billion). For decades,
neuroscientists and computer scientists have debated whether a computer
brain could ever be endowed with the intelligence of a human. It’s not a
hypothetical debate anymore. Markram is building it. Will he replicate
consciousness? The EU has bet $1.3 billion on it.
Ancient Egyptian surgeons believed that the brain
was the “marrow of the skull” (in the graphic wording of a
3,500-year-old papyrus). About 1,500 years later, Aristotle decreed that
the brain was a radiator to cool the heart’s “heat and seething.” While
neuroscience has come a long way since then, the amount that we know
about the brain is still minuscule compared to what we don’t know.
Over the past century, brain research has made tremendous strides,
but it’s all atomized and highly specific—there’s still no unified
theory that explains the whole. We know that the brain is electric, an
intricately connected network, and that electrical signals are modulated
by chemicals. In sufficient quantity, certain combinations of chemicals
(called neurotransmitters) cause a neuron to fire an electrical signal
down a long pathway called an axon. At the end of the axon is a synapse,
a meeting point with another neuron. The electrical spike causes
neurotransmitters to be released at the synapse, where they attach to
receptors in the neighboring neuron, altering its voltage by opening or
closing ion channels. At the simplest level, comparisons to a computer
are helpful. The synapses are roughly equivalent to the logic gates in a
circuit, and axons are the wires. The combination of inputs determines
an output. Memories are stored by altering the wiring. Behavior is
correlated with the pattern of firing.
Yet when scientists study these systems more closely, such
reductionism looks nearly as rudimentary as the Egyptian notions about
skull marrow. There are dozens of different neurotransmitters (dopamine
and serotonin, to name two) plus as many neuroreceptors to receive them.
There are more than 350 types of ion channel, the synaptic plumbing
that determines whether a neuron will fire. At its most fine-grained, at
the level of molecular biology, neuroscience attempts to describe and
predict the effect of neurotransmitters one ion channel at a time. At
the opposite end of the scale is functional magnetic resonance imaging,
the favorite tool of behavioral neuroscience. Scans can roughly track
which parts of the brain are active while watching a ball game or having
an orgasm, albeit only by monitoring blood flow through the gray
matter: the brain again viewed as a radiator.
Two large efforts—the Allen Brain Atlas and the National Institutes
of Health-funded Human Connectome Project—are working at levels in
between these two extremes, attempting to get closer to that unified
theory that explains the whole. The Allen Brain Atlas is mapping the
correlation between specific genes and specific structures and regions
in both human and mouse brains. The Human Connectome Project is using
noninvasive imaging techniques that show where wires are bundled and how
those bundles are connected in human brains.
To add to the brain-mapping mix, President Obama in April announced
the launch of an initiative called Brain (commonly referred to as the
Brain Activity Map), which he hopes Congress will make possible with a
$3 billion NIH budget. (To start, Obama is pledging $100 million of his
2014 budget.) Unlike the static Human Connectome Project, the proposed
Brain Activity Map would show circuits firing in real time. At present
this is feasible, writes Brain Activity Map participant Ralph Greenspan,
“in the little fruit fly
Drosophila.”
Even scaled up to human dimensions, such a map would chart only a web
of activity, leaving out much of what is known of brain function at a
molecular and functional level. For Markram, the American plan is just
grist for his billion-euro mill. “The Brain Activity Map and other
projects are focused on generating more data,” he writes. “The Human
Brain Project is about data integration.” In other words, from his
exalted perspective, the NIH and President Obama are just a bunch of
postdocs ready to work for him.
more @ http://www.wired.com/wiredscience/2013/05/neurologist-markam-human-brain/