Application of adaptive filtering to steady-state evoked response

A new method to detect steady-state evoked potentials (EPs) is presented. The technique is based on a two-weight recursive least squares (RLS) adaptive filter and the Tcirc2 statistic. Simulations with known sinusoids buried in Gaussian noise and in EEG noise indicate that the adaptive filter can detect signals at 3 or 4 times lower signal-to-noise ratios that the discrete Fourier transform (DFT). Qualitatively similar results were obtained with human visual evoked potential recordings.