Temporal learning neural network

A temporal learning neural network for implementing input temporal associative learning, the neural network comprising:

• a substrate,
• a plurality of temporal learning neural processing elements integrated on said substrate, and
• an input/output control section including input terminals and output terminals;
• each of said processing elements comprising:
• learning means, and
• calculation means comprising:
• an input memory section with inputting means for inputting a plurality of signal pulses, and means for storing the signal pulses input from said inputting means, and
• a response calculation circuit which calculates a sum of (a) a total summation value of a product of (i) input values to said input memory section and (ii) corresponding input terminal connection efficacies, and (b) an internal potential remaining in the processing element at a current time, which is obtained by decaying the internal potential of the processing element at a preceding time, the sum forming an accumulated value, said response calculation circuit including comparing means for comparing the accumulated value with a predetermined threshold value and, (i) when the accumulated value exceeds the predetermined threshold value, outputting an output 1 signal, and storing, as the internal potential for the processing element at a subsequent time, a value obtained by deducting a constant from the accumulated value, and (ii) when the accumulated value does not exceed the predetermined threshold value, outputting an output 0 signal and storing the accumulated value as the internal potential of the processing element of the subsequent time, said learning means comprising:
• a history evaluation circuit for determining an input history evaluation value, and
• a learning processing circuit for generating new connection efficacies in a processing element wherein said calculation circuit has output an output 1 signal, by receiving an input history evaluation value from said history evaluation circuit, the input history evaluation value (i) strengthening the connection efficacies when the evaluation value is positive, (ii) weakening the connection efficacies when the evaluation value is negative and (iii) leaving the connection efficacies unchanged when the evaluation value is zero, wherein said history evaluation circuit includes:
• means for using an input history value of the processing element of the preceding time for the input history value of the processing element of a current time, which is obtained by accumulating the input signals with decay,
• means for comparing the input history value with an enhancement learning threshold value and a decreased learning threshold value, generating the input history evaluation value whereby a changing direction for the connection efficacies is (i) positive when the obtained input history value is equal to or higher than the enhancement learning threshold value, (ii) negative when the obtained input history value is lower than the enhancement learning threshold value and is equal to or higher than the decreased threshold value, or (iii) zero when the obtained input history value is lower than the decreased threshold value, and
• means for distributing the input history evaluation value to the input memory section of each of the processing elements, and
• wherein said input/output control section includes
• means for receiving at said input terminals (i) the output 1 and output 0 signals output from said response calculation circuit and (ii) the input history evaluation value from said history evaluation circuit, and
• means for sending, from said output terminals, the signals input from said response calculation circuit and from said history evaluation circuit, to said input memory section of each of said plurality of processing elements.