Sandberg has made some rough calculations of how much computing power that would demand and how fast computer power is rising, and he's fairly confident a whole-brain emulation will be possible in a matter of a few decades. Exactly how a whole-brain emulation would behave, he isn't sure.
"I don't know whether a complete simulation of a brain, one to one, would actually produce a mind," he said. "I find it pretty likely, but I don't have evidence for that. I want to test it."
Sandberg made an exit stage right, replaced at the podium by Randal Koene, a neuroscientist at the European technology firm Fatronik-Tecnalia. Koene offered some reasons for why anyone would want to work so hard to make a whole-brain emulation in the first place. Even if it just behaved like a generic human brain rather than my brain or yours in particular, scientists could still use it to run marvelous new kinds of experiments. They might test drugs for depression, Parkinson's and other disorders. Koene is also a strong advocate of so-called mind uploading—the possibility of not just running a brain-like simulation on a computer but actually transferring a person's mind into a machine. To him, it is the liberation of our species. "We must free the mind," said Koene.
For a little ground-truthing I called Olaf Sporns, a neuroscientist at Indiana University.
"This is not going to happen," he said.
Sporns is in a good position to judge. He and his colleagues have carried out just about the closest thing to whole-brain emulation that scientists can manage in the early twenty-first century. They use a high-resolution method called diffusion spectrum imaging to map the long fibers that link regions of the brain together. Sporns and his colleagues have analyzed the connections between 1,000 regions and have found the brain's network is organized according to some of the same rules of other large networks—including the Internet. For example, several regions act as hubs, while most regions are connected to only a few others.
In 2009, Sporns and his colleagues created a computer model of this brain network and let each region produce signals that could spread down the fibers. They found their simulation of a brain at rest produced distinctive waves that spread back and forth around the entire brain similar to the way waves spread across our own.
Whole-brain emulations will become more sophisticated in the future, Sporns told me, but he found it ridiculous to expect them to be able to capture an individual's mind. In fact, mind uploading is a distraction from the truly revolutionary impact whole-brain emulations will have. By experimenting with them, researchers may discover some of the laws for building thinking networks. It may turn out human brains can only work if their networks have certain arrangements. "It's like learning the laws of physics when you want to build an airplane. It helps," said Sporns.
Discovering those laws may allow computer scientists to finally build machines that have mental processes similar to ours. Sporns thinks scientists are already moving in that direction. In 2009, for example, IBM won a contract with the military to "fabricate a multichip neural system of about 108 neurons and instantiate into a robotic platform performing at 'cat' level."
"That is going to happen," said Sporns. This is the best I can manage for skeptics. Uploading your mind is science fiction. But endowing robots with a humanlike cognition? Only a matter of time.
"I hope you didn't believe a word of that last talk."
I stood in a long line for the men's room during a coffee break. The women's room next door was empty. I thought how only at a meeting like the Singularity Summit would I find myself in this situation. When I heard someone talking to me, I turned to see a tousle-haired psychologist named Gary Marcus.