Hi dude,

Background data:

Jean Piaget's stages of development theory (he detected 4 stages)

Dr Herman T Epstein
www.brainstages.net
Possibly the most important work on brain development pre-MRI and also early MRI, expanded on Piaget's work on genetically timed brain growth spurts and concluded 6 spurts, 6 stages.

Joseph Chilton Pearce (linked 6-stage developmental psychology and 6-stage anatomical structural development)

Carl Rogers' theory of personality and behavioral work (its implementation got him nominated for the Nobel peace prize)

Tons of individual studies and fMRIs on correlation between structure & function, much of which is common knowledge but hasn't been assembled all together before.

Alex Ramonsky (referenced all the above in matrix theory and applied emergence theory, postulating intelligence as a memory- and prediction-based system using 6 core processes in 6 networks.)

Bear in mind this is not a 6 network model of the brain or nervous system; it's a model of 6 main networks required for  intelligence. (All the details and a specific definition of “intelligence” is given in matrix theory -see library research section.)

So the 6-network system is home-grown and personal to the NHA, but appreciatively acknowledging all these sources as fundamental in its formation. It's a handy map because it provides predictable results in NH, where we're well aware that the map is not the territory, and “All maps are ultimately wrong, but some are more useful”.
Best,
AR