Out of the Blue

[David Farber <dave () farber net>]

From: Randall Webmail <rvh40 () insightbb com>
Date: March 3, 2008 2:59:39 PM PST
To: dave () farber net
Cc: dewayne () warpspeed com
Subject: Out of the Blue

[Seen on Eugen Leitl's Transhuman list]:

<http://www.seedmagazine.com/news/2008/03/out_of_the_blue.php?page=all&p=y 
>

Out of the Blue

Can a thinking, remembering, decision-making, biologically accurate  
brain be
built from a supercomputer?

by Jonah Lehrer • Posted March 3, 2008 05:50 AM

A computer simulation of the upper layer of a rat brain neocortical  
column.
Here neurons light up in a "global excitatory state" of blues and  
yellows.
Courtesy of Alain Herzog/EPFL

In the basement of a university in Lausanne, Switzerland sit four black
boxes, each about the size of a refrigerator, and filled with 2,000 IBM
microchips stacked in repeating rows. Together they form the  
processing core
of a machine that can handle 22.8 trillion operations per second. It  
contains
no moving parts and is eerily silent. When the computer is turned on,  
the
only thing you can hear is the continuous sigh of the massive air
conditioner. This is Blue Brain.

The name of the supercomputer is literal: Each of its microchips has  
been
programmed to act just like a real neuron in a real brain. The  
behavior of
the computer replicates, with shocking precision, the cellular events
unfolding inside a mind. "This is the first model of the brain that  
has been
built from the bottom-up," says Henry Markram, a neuroscientist at Ecole
Polytechnique Fédérale de Lausanne (EPFL) and the director of the Blue  
Brain
project. "There are lots of models out there, but this is the only one  
that
is totally biologically accurate. We began with the most basic facts  
about
the brain and just worked from there."

Before the Blue Brain project launched, Markram had likened it to the  
Human
Genome Project, a comparison that some found ridiculous and others  
dismissed
as mere self-promotion. When he launched the project in the summer of  
2005,
as a joint venture with IBM, there was still no shortage of skepticism.
Scientists criticized the project as an expensive pipedream, a blatant  
waste
of money and talent. Neuroscience didn't need a supercomputer, they  
argued;
it needed more molecular biologists. Terry Sejnowski, an eminent
computational neuroscientist at the Salk Institute, declared that Blue  
Brain
was "bound to fail," for the mind remained too mysterious to model. But
Markram's attitude was very different. "I wanted to model the brain  
because
we didn't understand it," he says. "The best way to figure out how  
something
works is to try to build it from scratch."

The Blue Brain project is now at a crucial juncture. The first phase  
of the
project—"the feasibility phase"—is coming to a close. The skeptics,  
for the
most part, have been proven wrong. It took less than two years for the  
Blue
Brain supercomputer to accurately simulate a neocortical column, which  
is a
tiny slice of brain containing approximately 10,000 neurons, with  
about 30
million synaptic connections between them. "The column has been built  
and it
runs," Markram says. "Now we just have to scale it up." Blue Brain  
scientists
are confident that, at some point in the next few years, they will be  
able to
start simulating an entire brain. "If we build this brain right, it  
will do
everything," Markram says. I ask him if that includes  
selfconsciousness: Is
it really possible to put a ghost into a machine? "When I say  
everything, I
mean everything," he says, and a mischievous smile spreads across his  
face.

Henry Markram is tall and slim. He wears jeans and tailored shirts. He  
has an
aquiline nose and a lustrous mop of dirty blond hair that he likes to  
run his
hands through when contemplating a difficult problem. He has a talent  
for
speaking in eloquent soundbites, so that the most grandiose  
conjectures ("In
ten years, this computer will be talking to us.") are tossed off with a
casual air. If it weren't for his bloodshot, blue eyes—"I don't sleep  
much,"
he admits—Markram could pass for a European playboy.

But the playboy is actually a lab rat. Markram starts working around  
nine in
the morning, and usually doesn't leave his office until the campus is
deserted and the lab doors are locked. Before he began developing Blue  
Brain,
Markram was best known for his painstaking studies of cellular  
connectivity,
which one scientist described to me as "beautiful stuff...and yet it  
must
have been experimental hell." He trained under Dr. Bert Sakmann, who  
won a
Nobel Prize for pioneering the patch clamp technique, allowing  
scientists to
monitor the flux of voltage within an individual brain cell, or  
neuron, for
the first time. (This involves piercing the membrane of a neuron with an
invisibly sharp glass pipette.) Markram's technical innovation was  
"patching"
multiple neurons at the same time, so that he could eavesdrop on their
interactions. This experimental breakthrough promised to shed light on  
one of
the enduring mysteries of the brain, which is how billions of discrete  
cells
weave themselves into functional networks. In a series of elegant papers
published in the late 1990s, Markram was able to show that these  
electrical
conversations were incredibly precise. If, for example, he delayed a  
neuron's
natural firing time by just a few milliseconds, the entire sequence of  
events
was disrupted. The connected cells became strangers to one another.

When Markram looked closer at the electrical language of neurons, he  
realized
that he was staring at a code he couldn't break. "I would observe the  
cells
and I would think, 'We are never going to understand the brain.' Here  
is the
simplest possible circuit—just two neurons connected to each other—and I
still couldn't make sense of it. It was still too complicated."

Cables running from the Blue Gene/L supercomputer to the storage unit.  
The
2,000-microchip Blue Gene machine is capable of processing 22.8 trillion
operations per second—just enough to model a 1-cubic-mm column of rat  
brain.
Courtesy of Alain Herzog/EPFL

Neuroscience is a reductionist science. It describes the brain in  
terms of
its physical details, dissecting the mind into the smallest possible  
parts.
This process has been phenomenally successful. Over the last 50 years,
scientists have managed to uncover a seemingly endless list of  
molecules,
enzymes, pathways, and genes. The mind has been revealed as a Byzantine
machine. According to Markram, however, this scientific approach has
exhausted itself. "I think that reductionism peaked five years ago,"  
he says.
"This doesn't mean we've completed the reductionist project, far from  
it.
There is still so much that we don't know about the brain. But now we  
have a
different, and perhaps even harder, problem. We're literally drowning in
data. We have lots of scientists who spend their life working out  
important
details, but we have virtually no idea how all these details connect
together. Blue Brain is about showing people the whole."

In other words, the Blue Brain project isn't just a model of a neural
circuit. Markram hopes that it represents a whole new kind of  
neuroscience.
"You need to look at the history of physics," he says. "From  
Copernicus to
Einstein, the big breakthroughs always came from conceptual models.  
They are
what integrated all the facts so that they made sense. You can have  
all the
data in the world, but without a model the data will never be enough."

[snip]

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