Wavelet analysis of normal and epileptic EEG

Human epileptic electroencephalogram (EEG) signals have been analyzed using Fourier transform (FT) and Continuous Wavelet Transform (CWT) as well as Dyadic Wavelet Transform (DWT). The power spectrum densities of EEG showed 1/f^a fluctuation as a function of frequency f. The alpha rhythms that appeared in normal EEG have not been observed in epileptic EEG. FT could not reveal localized spikes and complexes that are typical among epileptic seizures. On the contrary, both CWT and DWT analyses could clearly reveal localized low-frequency epileptic components of EEG records.