Principle of superposition-free memory.

The requirement that memory he superposition-free imposes a restrictive condition on the structure of neural models. A simple model which satisfies this condition consists of two levels of neurons, with primary level neurons tiring in response to external input and secondary (reference) neurons modifying activated primaries in such a way that they can later fire these primaries. Reference neurons are either activated by other reference neurons (time-ordered memories) or by primaries (contentordered memories). The model allows for general powers of memory manipulation (e.g. formation of associative memories) through rememorization and has a number of implications which correspond to features of the brain.