Stationary time series of Ca concentration with lengths given by the number of samples.

The sample time is 5 seconds. The spikes column indicates the number of spikes in the time series. P-values are given for the null hypothesis that each nod factor time series was generated by a linear process. The p-values are calculated by running the zeroth surrogates test, which was also used for a noise titration to get a limit for the noise that could be added without destroying evidence of nonlinearity.