I cannot see the "these routines [being] available in the development version of the next SPM release". The development version is a 111 MB zip file [1]. When I uncompress the file I get a big flat directory with 100s of files. Which of those is is the software used in the paper? I have a bad feeling about this. I don't see how the authors are displaying intellectual integrity by
not releasing, concurrently with the paper, software for such an important problem public health issue.
ideas are hardly vague.
Hard to understand
The core intuition is easy to understand: brain predicts its observations including observations about itself (proprioception) and acts in a way to minimise surprise. This can be seen as a form of self-supervised learning in the terminology of contemporary machine learning. Lots of people have said somewhat similar things before at a similar level of vagueness. Nobody disagrees that "somehow" the brain learns about the world by prediction and interaction. The interesting question is to go beyond this vagueness: what
exactly is the brain doing? Where exactly is the brain minimising 'free energy'? Can I have a testable prediction please?
If read literally, Friston's core intuition is false: people regularly and deliberately expose themselves to surprise, e.g. gambling, watching sports, speed dating. Now there are various ad-hoc fixes to save free-energy-minimisation, which should make the theory more testable, but Friston then has to state clearly which of the many conflicting ad-hoc fixes are in place, and explain how they manifest themselves in the brain! Friston has been confronted with those problems many times, but he basically ignores them.
[1] https://www.fil.ion.ucl.ac.uk/spm/covid-19/#software
If read literally, Friston's core intuition is false: people regularly and deliberately expose themselves to surprise, e.g. gambling, watching sports, speed dating. Now there are various ad-hoc fixes to save free-energy-minimisation, which should make the theory more testable, but Friston then has to state clearly which of the many conflicting ad-hoc fixes are in place, and explain how they manifest themselves in the brain! Friston has been confronted with those problems many times, but he basically ignores them.
[1] https://www.fil.ion.ucl.ac.uk/spm/covid-19/#software