The free-energy principle: a unified brain theory? (opens in new tab)

Karl Friston shows that different global brain theories all describe principles by which the brain optimizes value and surprise. He discusses how these brain theories fit into the free-energy framework, suggesting that this framework might provide a unified account of brain function. A free-energy principle has been proposed recently that accounts for action, perception and learning. This Review looks at some key brain theories in the biological (for example, neural Darwinism) and physical (f...