This week our guest is professor of neuroscience at University College London, Karl Friston. Viewed by many as one of the world’s most influential neuroscientists, Friston rose to prominence when he pioneered one of the key techniques that allows neuroscientists to analyze brain activity. And as if that wasn’t enough, he has since developed the Free Energy Principle, which some see as monumental to the field as Darwin’s theory of evolution was for biology and genetics.