Chaos Detection in the Firing Activities of Retinal Ganglion Cells in Response to Natural Stimuli

The correlation dimension method and the nonlinear forecasting method are applied to analyze the firing activities recorded by a multi-electrode array (MEA) from the retinal ganglion cells (GCs) of chicken in response to natural stimuli. The results show that neither the correlation dimension method nor the nonlinear forecasting method provides any evidences for chaos in the inter-spike interval (ISI) series derived from retinal GCs. Then the first difference of the ISI (DISI) series is analyzed in the same way and different conclusions are drawn. The correlation dimension method fails again to provide evidences for chaos in the DISI series. The nonlinear forecasting method, however, demonstrates some weak but distinct evidences for chaos in the DISI series, which indicates that the nonlinear forecasting method is more efficient and reliable than the correlation dimension method for chaos detection. On the other hand, the first difference operation of the ISI series makes it comparatively easier for chaos detection in the firing activities of retinal GCs in response to natural stimuli.