As Nature went to press, the US National Institutes of Health (NIH) was preparing to announce which scientists it has chosen to help it decipher the brain. To borrow a phrase from Winston Churchill, the announcement could mark the end of the beginning of an effort described by the White House as the greatest since the Human Genome Project. Now all that remains is to unlock the mysteries of the most complex object in the known Universe.

US President Barack Obama announced the BRAIN Initiative (Brain Research through Advancing Innovative Neurotechnologies) 18 months ago. Responsibility for the US$100-million-a-year project was shared between three agencies: the NIH, the National Science Foundation (NSF) and the Defense Advanced Research Projects Agency (DARPA).

Barely had the initiative fired a synapse before critics attacked its nebulous goal of ‘mapping the brain’. Congress had no plans to grant new money for it, and neuroscientists worried that funds would be redirected from other research to support a poorly conceived govern­ment mandate. BRAIN’s creators enjoyed comparing it with the Human Genome Project, but others drew comparisons with the European Union’s Human Brain Project (HBP): a controversial €1-billion (US$1.3-billion) investment supporting a single researcher’s vision of building a computational model of the human brain.

The NIH last year put together a working group to draw up a complex 146-page plan outlining priorities and milestones for BRAIN until 2025. It did a good job. Although the resulting $4.5-billion wish list for the project is a tall order, researchers overall are satisfied with an outline for mapping and monitoring the brain that leaves room for innovation.

Fans of both top-down and bottom-up science also got their way. DARPA, with typical military precision, announced that it wanted therapeutic devices for brain disorders that affect soldiers and veterans. It awarded a handful of multimillion-dollar grants to test brain-stimulation systems for purposes such as restoring memory and treating traumatic brain injury. The therapeutic goals are regimented, but the recipients must relish the chance to learn about brain function.

The NSF, which does not normally fund medical and applied research, has taken the opposite approach. In March, it sent out a letter inviting researchers to submit any and all brain-circuit-related ideas as two-page documents. That culminated in a set of 36 small projects, developing everything from tools to image neuron activity to predictive models of brain function. More than any other agency, the NSF shows that big science need not swamp investigator-driven research.

With other brain projects springing up — Israel’s investment in brain technologies and Japan’s effort to map connections in a marmoset brain, to name just two — the world looked set to form a global collective mind. Then, in July, the HBP derailed less than a year after its launch (see Nature 511,133–134; 2014). Scientists mutinied against director Henry Markram, asking the European Commission to intervene in what they saw as poor management and a focus on simulation rather than neuroscience. As the project struggles with its future, faith in big neuroscience has been shaken and joint HBP–BRAIN plans have been postponed.

The US BRAIN Initiative has the chance to get the concept back on its feet. Success will probably be down to a careful balance between focused order and innovative chaos — much like the organ itself.