AnewmethodofphasespectralanalysisofEEGisproposedforthecomparativeanalysisofphasespectrabetweennormalEEGandepilepticEEGsignalsbasedonthewaveletdecompositiontechnique.Byusingmultiscalewaveletdecomposition,theoriginalEEGsaremappedtoanorthogonalwaveletspace,suchthatthevariationsofphasecanbeobservedatmultiscale.Itisfoundthatthephase(andphasedifference)spectraofnormalEEGsaredistinctfromthatofepilepticEEGs.Thatisthevariationsofphase(andphasedifference)ofnormalEEGshaveadistinctperiodicpatternwiththeelectricalactivityproceedsinthebrain,butdonottheepilepticEEGs.ForepilepticEEGs,onlyatthosetransientpoints,thephasevariationsareobvious.Inordertoverifytheseresultswiththeobservationaldata,thephasevariationsofEEGsinprincipalcomponentspaceareobservedandfoundthat,thefeaturesofphasespectraisincorrespondencewiththatthewaveletspace.TheseresultsmakeitpossibletoviewthebehaviorofEEGrhythmsasadynamicspectrum.
