The Apollo space missions cost more than US$100 billion in today's terms, the Large Hadron Collider $10 billion and the development of the Airbus A380 $15 billion — making the projected $4.5 billion for the BRAIN (Brain Research through Advancing Innovative Neurotechnologies) initiative look paltry by comparison (see Nature http://doi.org/tmh; 2014).

If we spent that much putting a man on the Moon, smashing particles and building a flying hotel, why not spend at least $10 billion trying to solve the greatest mystery of all?