There is provided a basic association unit for creating an information processing apparatus capable of performing information processing like information processing that actually occurs in central nerve systems of animals including human beings. The association unit is an unit for repeating input and output signals having m input terminals and n output terminals. When a first input signal which is a rectangular wave signal in the form of a pulse is simultaneously input to input terminals in a quantity less than m, an output signal having the same contents as the first input signal is output from particular output terminals which are associated with the input terminals in advance. When a third input signal is input to input terminals in a quantity less than m within a predetermined period of time after a second input signal is simultaneously input to input terminals in a quantity equal to or greater than m, an output signal having the same contents as that of the third input signal is output from all output terminals.
