PURPOSE: To easily obtain a neural circuit device which uses the signal change of an optical neuron network as the information by changing the neuron threshold value in term of time in response to the present and past time series signals consisting of plural data.

CONSTITUTION: An input neuron 1 has the value I(t) as a function of the time (t) and an output neuron 2 has the value O(t). Then a neuron network device has a synapse 3 containing the value J which connects both nurons 1 and 2 together. In an input process, the 1st data D1 on a 2-input AND (D1.AND.D2) is presented to the neuron 1 and then the 2nd data D2 of the 2-input AND is presented to the neuron 1. The value of the neuron 2 obtained after the data D2 of the 2-input AND is inputted to the neuron 1 is defined as the computing result. That is, the neuron threshold value is changed in terms of time in response to the present and past time series signals consisting of plural data. Thus it is possible to easily obtain a neuron network device which uses the signal change of an optional neuron network as the information.