Fifty years from now, when Malia and Sasha are grandmothers, their father’s presidency might seem most consequential because of a small sum — $100 million — devoted to studying something small. “As humans,” President Obama said when announcing the initiative to study the brain, “we can identify galaxies light-years away . . . but we still haven’t unlocked the mystery of the three pounds of matter that sits between our ears.”

Actually, understanding the brain will be a resounding success without unlocking the essential mystery: How does matter become conscious of itself? Or should we say, how does it become — or acquire — consciousness? Just trying to describe this subject takes scientists onto intellectual terrain long occupied by philosophers. Those whose field is the philosophy of mind will learn from scientists such as Princeton’s David Tank, a leader of the BRAIN Initiative, which aims at understanding how brain regions and cells work together, moment to moment, throughout our lives. …

Biological causes have been determined for only about 3 percent of the disorders listed in the Diagnostic and Statistical Manual of Mental Disorders. With “mapping,” scientists may at last establish connections between neurotransmitters and particular mental disorders. This might influence how pharmaceutical companies direct their research. And treatments of post-traumatic stress disorders might benefit from learning how the mind erases disturbing memories.