ROBERT SIEGEL, HOST:
At the White House today, the president said our brains remain an enormous mystery.
PRESIDENT BARACK OBAMA: The BRAIN Initiative will change that by giving scientists the tools they need to get a dynamic picture of the brain in action, and better understand how we think and how we learn and how we remember.
SIEGEL: But NPR's Jon Hamilton reports, any practical application is probably many years away.
JON HAMIILTON, BYLINE: When Obama asks for $100 million to kickstart the public-private effort in 2014, his idea is to help scientists study working brains in unprecedented detail. Ideally, this would mean monitoring millions or even billions of individual neurons, as they interact to form thoughts or create memories.
Francis Collins, director of the National Institutes of Health, says calling the project ambitious would be an understatement.
FRANCIS COLLINS: To understand how the human brain works is about the most audacious scientific project you can imagine. It's the most complicated structure in the known universe.
HAMIILTON: But Collins says the technologies that allow scientists to watch the brain at work are advancing with amazing speed. So he says it's the right time to take a chance.
COLLINS: Five years ago, this might have seemed out of reach. Five years from now, it will seem like we waited too late to take advantage of the opportunity.
HAMIILTON: Collins was the scientist in charge of the Human Genome Project. But he says this initiative is a bit different.
COLLINS: Clearly, the Genome Project, we were able to say in 2003: We're done, because we read out all three billion letters of a reference human DNA instruction book. The brain, being able to say you're done, well, I can't imagine what that will look like.
HAMIILTON: In the meantime, the scientists who first proposed the BRAIN Initiative say it could provide some really helpful research tools. John Donoghue is at Brown University.
JOHN DONOGHUE: What's going on in the brain is like a conversation between thousands of neurons all at once. And the brain is able to sort this out as thoughts and creativity and emotions. So the tools we need are the ability to pick up many, many cells at the same time. And you have to pick them up so you can hear each conversation very clearly.
HAMIILTON: Donoghue's says the ability to do that would make a big difference in his own efforts to allow paralyzed people to control a robotic arm, as if it were their own.
DONOGHUE: We know enough to get crude approximations. But if we really understood the brain's language, the brain's code, we could in fact potentially recreate everything that you do with your own arm.
HAMIILTON: Other brain scientists say they're excited by the new initiative, but cautious about what it's likely to accomplish. David Van Essen, of Washington University in St. Louis, is the principal investigator of the Human Connectome Project, an NIH-funded effort to map connections in the human brain.
Van Essen says the new BRAIN Initiative's goal of measuring the activity in individual neurons is incredibly ambitious, because people have so many of them - nearly 100 billion. He says researchers would be more likely to succeed with creatures that have much smaller brains.
DAVID VAN ESSEN: Like mice and fruit flies and other animals. But I honestly don't think it will be realistic to have that kind of sensitivity for mapping the human brain.
HAMIILTON: Van Essen also says the BRAIN Initiative is likely to be much tougher than, say, mapping the human genome. One reason, he says, is that every brain is different.
ESSEN: Whether you're talking about one individual human brain to another human brain, or one mouse brain to a monkey brain to a human brain, the differences are vastly greater than the differences in the genome.
HAMIILTON: And, of course, the Human Genome Project got $3 billion over 10 years. By comparison, the BRAIN Initiative, if Congress decides to fund it, would get a fraction of that amount in the first year with no clear promise of how much would follow.
Jon Hamilton, NPR News.