1. A method of detecting or predicting a neurological event, the method comprising the steps of: (a) receiving an input signal; (b) determining a time-weighted function of the input signal; (c) determining a percentile tracking filter estimate from the time-weighted function; (d) comparing the percentile tracking filter estimate to a reference signal in order to detect or predict the neurological event; and (e) communicating the detection or prediction of the neurological event, wherein each of the above steps is performed on a programmed computer.