Variability of the electric organ discharge interval duration in resting Gymnotus carapo

We recorded the electric organ discharges of resting Gymnotus carapo specim ens. We analyzed the time series formed by the sequence of interdischarge i ntervals. Nonlinear prediction, false nearest neighbor analyses, and compar ison between the performance of nonlinear and linear autoregressive models fitted to the data indicated that nonlinear correlations between intervals were absent, or were present to a minor extent only. Following these analys es, we showed that linear autoregressive models with combined Gaussian and shot noise reproduced the variability and correlations of the resting disch arge pattern. We discuss the implications of our findings for the mechanism s underlying the timing of electric organ discharge generation. We also arg ue that autoregressive models can be used to evaluate the changes arising d uring a wide variety of behaviors, such as the modification in the discharg e intervals during interaction between fish pairs.