Time-frequency microstructure of event-related EEG desynchronization and synchronization

We present a new method for analysis of event-related EEG phenomena, in particular ERD/ERS related to a voluntary movement, which offers: * high time-frequency resolution, and hence also increased ERD/ERS sensitivity (especially in the gamma band, where improvement may exceed order of magnitude), * possibility to analyze the whole picture of energy changes at once, without setting a priori the analyzed frequency bands, * parametric description of signal's structures. The main idea is based upon averaging energy distributions of single EEG trials in the time-frequency plane. As the estimator for signal's energy density we choose matching pursuit with stochastic Gabor dictionaries. Other possible estimates are presented on simulated signal and discussed briefly. Consistence of results with previous findings is evaluated on the data from a classical voluntary finger movement experiment. Keywords: ERD, ERS, ERP, gamma activity, time-frequency, matching pursuit.

Time-frequency microstructure of event-related EEG desynchronization (ERD) and synchronization (ERS) P.J. Durka, D. Ircha, Ch. Neuper, G. Pfurtscheller, Medical & Biological Engineering & Computing, Vol. 39, No. 3, pp. 315-321, May 2001