An adaptive information processing system includes input terminals adapted to receive N input signals s.sub.1, s.sub.2, . . . s.sub.N representing an "input"; output terminals adapted to present n output responses r.sub.1, R.sub.2, . . . r.sub.n representing a "response"; and information processing apparatus, connecting the input with the output terminals, and operative to carry out the processing steps required to "map" different inputs into responses in accordance with a particular passive modification algorithm. This algorithm permits the recognition of unknown inputs and separates inputs which are in different classes but which are originally close to one another.