Nonlinear systems analysis: comparison of white noise and sum of sinusoids in a biological system

The Gaussian white noise and the sum-of-sinusoids methods of systems analysis provide equivalent descriptions of nearly linear and strongly nonlinear transductions in the cat retina. Smoothness in the frequency domain is a common characteristic of biological transductions. This permits a substantial improvement in the signal-to-noise ratio by using the sum-of-sinusoids method, as is demonstrated for the transductions of the cat retina.