Acknowledgments

The frames at the heart of this book have an ancestor. Jeff Hawkins and the Numenta team’s Thousand Brains Theory proposed that a brain is many small models with their own reference frames, learning through movement and prediction, and that idea is load-bearing here: PRA keeps the sensorimotor-prediction core because that is the part that does the real work. Where PRA departs is in making two things explicit that the theory left open: a metric for scoring one interpretation against another, and a mechanism by which the set of frames is itself learned, by selection rather than search. The departures are documented, claim by claim, in the project’s design record. The debt is documented here.