In New Scientist 28 May 2008.
... the concept of "free energy" as it applies to artificial neural networks. Free energy originates from thermodynamics and statistical mechanics, .... It is roughly equivalent to the difference between the total energy in the system and its "useless energy", or entropy... mathematically equivalent to a problem he was familiar with: the difference between the predictions made by an artificial neural network and what it actually senses. ... whether the same concept could underlie the workings of real brains. [...] Around 2005 he proposed that a "free energy principle" explains at least one aspect of brain function - sensory perception.As usual, I've put this here for my own notes - it is linking 'big' things to information.