Hi Nick, thanks! That is very unprofessional of me not to put any sources for the figures I'm using, thanks for pointing this out. The figure was based on Friston's 2010 paper "The free-energy principle: a unified brain theory? https://www.nature.com/articles/nrn2787?report=reader" Googling the free energy principle is probably the best way to go forward if you want to learn more about this theory. I can also recommend podcasts of Karl Friston, e.g. with Sean Carrol and Lex Fridman.