AFTER much trailing, the reality is out. On April 2nd President Barack Obama announced that America's government will back a project intended to unlock the mysteries of the human brain. It was, according to the trails, to have been known as the Brain Activity Map. But someone clearly spotted that BAM, as an acronym, is a hostage to fortune and the project is now to be known as the Brain Research through Advancing Innovative Neurotechnologies initiative. By what is no doubt a complete coincidence, that spells "BRAIN." The crucial part of the initiative - the bit everyone had been waiting to hear - is the money. Mr Obama will ask Congress, in the budget he submits on April 10th, to approve $100m for its first year of operation. That is a small amount, compared with the $5.5 billion spent each year on neuroscience by America's National Institutes of Health (NIH). But it is more, even adjusted for inflation, than the $28m spent on the Human Genome Project in its first year. Comparisons with the genome project are inevitable, but misleading. That operation had an objective that was both clear and finite. The size of the human genome was already known in 1990, when the project began. It was just a question of working out the order of the chemical bases in which the message of the genes is written. The approach was known, too: break multiple copies of the genome up into random small pieces; sequence the individual pieces; then use a computer to work out, from the overlaps between those small sequences, how the whole thing fits together. Though doing that with the technology of 1990 would have taken centuries, if not millennia, it was possible in principle from the beginning. BRAIN is different. First, no one knows what success will look like. If the researchers get really lucky, they might stumble across the secret of consciousness and thus answer one of the biggest questions of all. Or they might work out, by seeing how large networks of nerve cells process information, how to build computers in different and better ways. They may reveal the details of how brains learn things. They could explain the mechanisms of currently mysterious conditions such as schizophrenia and autism, which seem to originate in the ways nerve cells are connected. And they might come to understand dementias, such as Alzheimer's disease, that threaten to cripple both many elderly people and the budgets of rich countries, whose populations are ageing rapidly. But none of this will happen with anything that looks remotely like an existing tool - for if the tools existed, then neuroscientists would be using them already. It is thus the "I" and the "N" of the acronym that are the crucial letters. For the initiative's researchers will have to invent most of the tools they use from scratch. To that end, the NIH has assembled a committee of 15 of America's best neuroscientists, chaired jointly by Cori Bargmann of Rockefeller University, in New York, and William Newsome of Stanford University, in California. It will be this committee's job to work out the milestones by which the project's success can be judged. The work itself will be spread around several institutions, for everyone has different skills, and everyone would like part of the pie. The NIH will take the lead, but the National Science Foundation and the Defence Advanced Research Projects Agency will follow close behind. Nor will the American taxpayer pick up the whole tab. Four private institutes will also contribute both expertise and dollars: the Allen Institute for Brain Science, in Seattle (which has been working on gene expression in brains); the Howard Hughes Medical Institute (whose Janelia Farm campus in Virginia is attempting to map the brains of fruit flies); the Kavli Foundation (a body that pays for a lot of existing neuroscience, and also nanotechnology that might help in the design of tools that can probe the brain); and the Salk Institute, in La Jolla, California (where people are looking at, among other things, how genes that jump around inside nerve cells affect brain development). Starting small - or smallish - has one advantage. If the new technologies do not turn up, the plug can be pulled without too many recriminations. If the initiative does work, though, it could become one of the most exciting pieces of science around. It is a cliché to say so, but watch this space.