Notes from the last time I tried to understand this - https://www.lesswrong.com/posts/wpZJvgQ4HvJE2bysy/god-help-u...
> From the Alius interview:
"The free energy principle stands in stark distinction to things like predictive coding and the Bayesian brain hypothesis. This is because the free energy principle is what it is — a principle. Like Hamilton’s Principle of Stationary Action, it cannot be falsified. It cannot be disproven. In fact, there’s not much you can do with it, unless you ask whether measurable systems conform to the principle."
This is a big kahuna burger of a bullet to bite!
This all reminds me of Socrates' claim in the Theatetus that "Philosophy begins in wonder," wonder being roughly equivalent to the the desire to reduce uncertainty, and the Platonic idea that philosophy is central to the good life.
Which leads to the ubiquitous Whitehead quote about western philosophy consisting of footnotes to Plato...
From what I get this whole thing is more like an abstract ruleset describing how decision making in the brain works, rather than a brain model. Or am I wrong, is there anyone who built a network model based on this theory?
[1] https://en.wikipedia.org/wiki/Predictive_coding [2] http://www.jmlr.org/papers/volume6/winn05a/winn05a.pdf
"We turn to the equivalent message passing for continuous variables, which transpires to be predictive coding [...]"
It could be that belief propagation is in the context of discrete variables, whereas predictive coding is in the context of continuous, both of which are a form of (variational) message passing.