The human brain is a marvelous instrument, capable of the subtlest thoughts, feelings and perceptions, and of dreams even the gods might envy. Yet for all our cleverness in other areas, we still know embarrassingly little about how our own brains actually work.
That's why President Barack Obama's plan to launch a 10-year research initiative to map the intricate connections in the brain that give rise to everything we think, see and feel is a welcome first step toward enlarging our understanding of this amazing organ. Success could give doctors new tools to treat a wide range of disorders, from Alzheimer's, Parkinson's and traumatic brain injury to schizophrenia and autism.
The scale of the project, however, is in some ways even more ambitious than the effort to map the human genome that began in the 1990s. Understanding how the brain works requires mapping hundreds of billions of individual neurons, the cells in the brain than communicate with each other by firing tiny electrical signals. The sheer number of possible connections between them dwarfs the 20,000 to 25,000 bits of DNA information in the human genome.
Yet the technology for sequencing the human genome didn't exist either when that project began in the 1990s, and the program was still completed years ahead of schedule. Mr. Obama says it will take a decade of work by government and university researchers to map the active human brain, and the National Institutes of Health, the Defense Advanced Research Projects Agency and National Science Foundation will lead the effort. His 2014 budget includes $100 million for the initial phase of the project, which is expected to rise to $300 million annually once the program is fully up and running.
At a time of tight federal budgets, some may question the wisdom of spending billions of dollars on research whose practical benefits remain speculative. But this is the kind of investment that can yield huge returns to both medical science and the economy in general. Mr. Obama points to the fact that every dollar spent on the human genome project, which cost about $3.8 billion in total, returned $140 to the economy. A federal study put the total return on investment from the genome project at $800 billion by 2010.
Mapping the brain is vastly more complicated than sequencing the human genome, however, because it involves tracking the interactions of hundreds of billions of neurons simultaneously. Currently, researchers are only able to observe a few thousand cells at a time, and they must use invasive procedures that require inserting physical probes directly into the brain. Some neuroscientists have suggested using instead fleets of nano-robots — molecule-size machines that can travel through the body and report back like the shrunken submarine and crew of the 1966 science fiction movie "Fantastic Voyage." But so far such devices still exist only in the minds of science fictions writers.
Even if such tiny robots could be developed, moreover, scientists would still need a way to keep track of the ocean of information transmitted by them, which would tax the capacity of the largest supercomputers today. Developing the computing and data storage power needed to map the brain would have far-reaching implications not only for medical research but for fields as varied as theoretical physics, weather forecasting, macroeconomic analysis and artificial intelligence.
Not surprisingly, the president's proposal has its skeptics. The obstacles to such a breakthrough are formidable, comparable perhaps only to those that had to be overcome in order to launch the first artificial satellites at the dawn of the space age. Some scientists question whether mapping the complete human brain is even possible, or whether trying to do so is worth the effort.
Yet the payoff could be tremendous, especially if in addition to helping doctors treat mental illnesses and brain injuries more effectively it led to practical therapies for disorders caused by aging, such as dementia and Alzheimer's. As the country's elderly population rapidly expands due to longer life expectancies, the number of such cases is expected to skyrocket over the coming decades. If mapping the brain enables doctors to prevent or slow the onset of these diseases, the savings on medical costs alone could far exceed the value so far of the human genome project.