We can build cities and robots, but can we understand the kilogram or so of grey matter that sits between our ears? Despite dizzying breakthroughs that bring man and machine ever closer, the brain is still “a black box”. This series seeks to unravel the mystery by asking three questions. How can we better understand mental health? How can brain science help us to reach our potential, and avoid our pitfalls? What are the promises and perils of new brain technologies?