by Priya Ganapati
August 16, 2010
Reverse-engineering the human brain so we can simulate it using
computers may be just two decades away, says
artificial intelligence expert and author of the best-selling book
The Singularity is Near.
It would be the first step toward creating machines that are more
powerful than the human brain.
These supercomputers could be
networked into a cloud computing architecture to amplify their
processing capabilities. Meanwhile, algorithms that power them could
get more intelligent.
Together these could create the ultimate
machine that can help us handle the challenges of the future, says
Kurzweil. This point where machines surpass human intelligence has
been called the “singularity.”
It’s a term that Kurzweil helped
popularize through his book.
“The singular criticism of the
singularity is that brain is too complicated, too magical and
there’s something about its properties we can’t emulate,”
Kurzweil told attendees at the Singularity Summit over the
“But the exponential growth in
technology is being applied to reverse-engineer the brain,
arguably the most important project in history.”
For nearly a decade, neuroscientists,
computer engineers and psychologists have been working to simulate
the human brain so they can ultimately create a computing
architecture based on how the mind works.
Reverse-engineering some aspects of hearing and speech has helped
stimulate the development of artificial hearing and speech
recognition, says Kurzweil. Being able to do that for the human
brain could change our world significantly, he says.
The key to reverse-engineering the human brain lies in decoding and
simulating the cerebral cortex - the seat of cognition. The human
cortex has about 22 billion neurons and 220 trillion synapses.
A supercomputer capable of running a software simulation of the
human brain doesn’t exist yet. Researchers would require a machine
with a computational capacity of at least 36.8 petaflops and a
memory capacity of 3.2 petabytes - a scale that supercomputer
technology isn’t expected to hit for at least three years, according
to IBM researcher Dharmendra Modha.
Modha leads the cognitive computing
project at IBM’s
Almaden Research Center.
By next year, IBM’s ‘Sequoia’ supercomputer should be able to offer
20 petaflops per second peak performance, and an even more powerful
machine will be likely in two to three years.
“Reverse-engineering the brain is
being pursued in different ways,” says Kurzweil. “The objective
is not necessarily to build a grand simulation - the real
objective is to understand the principle of operation of the
Reverse engineering the human brain is
within reach, agrees Terry Sejnowski, head of the
computational neurobiology lab at the Salk Institute for Biological
Sejnowski says he agrees with Kurzweil’s assessment that about a
million lines of code may be enough to simulate the human brain.
Here’s how that math works, Kurzweil explains:
The design of the brain is in the
genome. The human genome has three billion base pairs or six
billion bits, which is about 800 million bytes before
compression, he says.
Eliminating redundancies and applying
loss-less compression, that information can be compressed into about
50 million bytes, according to Kurzweil. About half of that is the
brain, which comes down to 25 million bytes, or a million lines of
But even a perfect simulation of the human brain or cortex won’t do
anything unless it is infused with knowledge and trained, says
“Our work on the brain and
understanding the mind is at the cutting edge of the
singularity,” he says.