Iain McGilchrist is a psychiatrist and writer. Before he came to medicine, he was a literary scholar -- and his work on the brain is shaped by a deep questioning of the role of art and culture. As his official bio puts it: "He is committed to the idea that the mind and brain can be understood only by seeing them in the broadest possible context, that of the whole of our physical and spiritual existence, and of the wider human culture in which they arise -- the culture which helps to mould, and in turn is moulded by, our minds and brains."

His recent book The Master and His Emissary explores the nature of the brain's two hemispheres (the right is the "master," in McGilchrist's terms). How have our two hemispheres evolved to relate -- and how did their relationship create our consciousness, our culture, and our ability to understand our own brains?