1. An associative pattern conversion system for allowing recognition of an input signal, said conversion system comprising: generating means for sensing a first object and for generating input data which is representative of selected characteristics of said sensed first object; a memory for storing at least said input data, weight data, output data nd reference data; weight variable determining means for evaluating a relationship between said input data, said output data and said reference data stored in said memory and determining the value of a weight variable based on said relationship so as to decrease said weight variable over time in such a manner that said weight variable never increases; weight changing means for changing said weight data, which is stored in said memory, in accordance with said weight variable; and recognition means for receiving said input signal, and for outputting, based upon said input signal and said weight data, an associated recognition signal.