I am reading a lot about Nengo and it is clear that it is based on the Neural Engineering Framework (NEF) and also on the Semantic Pointer Architecture (SPA), both of which are, at this point, hypotheses.
What will happen in case some of the assumptions in NEF or SPA prove to be false? What will happen to Nengo as a tool and to NEF or SPA as frameworks? Can they be adapted radically in case their hypotheses are false? Also given that Nengo is used to build scientific models, which are usually published and new research is constantly based on top of the previous published work, what would a false assumption on the NEF/SPA mean for the validity of this body of published work?
One more question that naturally stems from the previous one has to do with the other available neural simulators (NEST, BRIAN, NEURON etc…). In most publications about Nengo it is mentioned that it is based on the NEF and SPA frameworks, but I have never managed to find any information regarding the frameworks the other simulators use to build their models. Where are those simulators based on?
PS: I am not sure if SPA is a framework that is used to build Nengo or if it is also built using the NEF .