The free-energy principle: a rough guide to the brain?
Friston's short, readable entry point to the free-energy principle — perception, action, and attention as one variational bound.
The best on-ramp Friston has written. The later formulations are more complete and much harder to enter; this one gets to the load-bearing idea in a few pages with a glossary attached.
The idea: a system that persists must resist the dispersion of its own sensory states, which means minimizing surprise, which it cannot compute — so it minimizes a variational bound on surprise instead. Free energy. Then perception is minimizing that bound by changing the model, action is minimizing it by changing the sensory input, and attention is the precision-weighting that decides which prediction errors get to matter.
Three separate faculties collapsing into one quantity is the kind of consolidation I look for. It sits directly upstream of A Beautiful Loop, which asks what has to be added to this machinery before it becomes an account of consciousness rather than of inference.
Neighborhood