title: Time-frequency component analyser and its application to brain oscillatory activity.
abstract: Currently, event-related potential (ERP) signals are analysed in the time domain (ERP technique) or in the frequency domain (Fourier analysis and variants). In techniques of time-domain and frequency-domain analysis (short-time Fourier transform, wavelet transform) assumptions concerning linearity, stationarity, and templates are made about the brain signals. In the time-frequency component analyser (TFCA), the assumption is that the signal has one or more components with non-overlapping supports in the time-frequency plane. In this study, the TFCA technique was applied to ERPs. TFCA determined and extracted the oscillatory components from the signal and, simultaneously, localized them in the time-frequency plane with high resolution and negligible cross-term contamination. The results obtained by means of TFCA were compared with those obtained by means of other commonly used techniques of ERP analysis, such as bilinear time-frequency distributions and wavelet analysis. It is suggested that TFCA may serve as an appropriate tool for capturing the localized ERP components in the time-frequency domain and for studying the intricate, frequency-based dynamics of the human brain.
authors.affiliation: Bilkent University, Department of Electrical Engineering, 06533 Bilkent, Ankara, Turkey.
authors.forename: Ahmet Kemal
authors.initials: AK
authors.lastname: Ozdemir
authors.forename: Sirel
authors.initials: S
authors.lastname: Karakaş
authors.forename: Emine D
authors.initials: ED
authors.lastname: Cakmak
authors.forename: D Ilhan
authors.initials: DI
authors.lastname: Tüfekçi
authors.forename: Orhan
authors.initials: O
authors.lastname: Arikan
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors