A positive role of noises in accurate detection of time difference by electrosensory system of weakly electric fish

Abstract

Weakly electric fish Eigenmannia can discriminate with an accuracy of the order of 1μs whether the phase of its own EOD signal is advanced or delayed compared with that of its neighbor's signal. To clarify the neural mechanism accomplishing the hyperaccurate discrimination, we present a neural model of the torus. The time difference between afferent nerve spikes arising from different sites on the body surface is detected by the two-dimensional array of small cells in the torus. The phase advance and delay are detected by integrating the outputs of small cells. The hyperaccurate detection is accomplished by the stochastic resonance induced by the spatio-temporal integration of the outputs including noises.