Patent ID: 8112373

Claim:
A synapse equivalent circuit for simulating electric characteristics of synapses, comprising an input terminal and an output terminal, an input signal f in (t) input to the input terminal and an output signal I psp (t) output from the output terminal having the relationship expressed by the formula shown below: I psp ⁡ ( t ) = ∑ m = 1 M ⁢ k P m ⁢ f in ⁡ ( t ) + ∑ I = 1 L ⁢ k I I ⁢ ∫ 0 t ⁢ ⅇ - 1 I ⁢ ( t - τ ) ⁢ ⁢ f in ⁡ ( τ ) ⁢ ⅆ τ wherein k P is a constant within a range defined by −∞<k P <∞, k I is a constant within the range defined by −∞<k I <∞, T I is a constant within the range defined by 0<T I ≦∞, L is the total number of the kinds of first transmitter substances that synapses have, I=1, 2, . . . , L and represents the ordinal number of a first transmitter substance of synapses, M is the total number of the kinds of second transmitter substances that synapses have, m=1, 2, . . . , M and represents the ordinal number of a second transmitter substance of synapses, e is the Napier's constant, t is time, and τ is the time from t=0 to the current time.