It is noteworthy that Friston has, as of November 2018, neither (1) formalised free energy minimisation (FIM) with sufficient precision that it goes beyond a vague research heuristic, that can (and is) adapted in ad-hoc ways; nor (2) come up with sufficient empirical evidence for his claim that FIM is how human or animal brains works -- despite the recent revolution in our ability to measure live neurons, and despite having been asked (in private) by working neuro-scientist, including at his university.
It is noteworthy that Friston has, as of November 2018, neither (1) formalised free energy minimisation (FIM) with sufficient precision that it goes beyond a vague research heuristic, that can (and is) adapted in ad-hoc ways; nor (2) come up with sufficient empirical evidence for his claim that FIM is how human or animal brains works -- despite the recent revolution in our ability to measure live neurons, and despite having been asked (in private) by working neuro-scientist, including at his university.