An electrical analogue model for frequency dependent lateral inhibition refering to the omega neurons in the auditory pathway of the cricket

An electrical analogue model for the recurrent lateral inhibition system formed by the omega neurons in the cricket's auditory pathway is described (Fig. 1A). The two reciprocally coupled inhibitory neurons are mimicked by the action of two inverting operational amplifiers in circuit with RLC combinations. The oscillatory properties of this reciprocal arrangement introduce a time delay in action of the feedback in the circuit, which corresponds to half the period of the characteristic frequency of the two-cell resonator. Varying degrees of coupling between the two inhibitory arms of the model produce a family of resonance curves (Fig. 4A) for frequency dependent contrast enhancement which allows the compromises observed in the physiological circuit to be discussed.In psychophysical experiments using the model circuit as an input stage for the human auditory pathway, frequency dependent lateral inhibition markedly improved identification of the apparent location of the sound source when the frequency of the input signals matched the resonant frequency of the circuit.Correspondence to this address