Phase analysis of single-trial EEGs: Phase resetting of alpha and theta rhythms

We perform phase analysis of the αα (8–13 Hz) and θθ (4–7 Hz) rhythmic components of the single-trial electroencephalograms (EEGs), which comprise the most dominant contributions to the event-related potentials (ERPs). The oscillatory ERP patterns of two components are well described by the phase resetting and the inter-trial phase coherency. A method for the estimation of the nonlinear dynamic dependency between two components is proposed. According to the method, the coupling is asymmetric with the coupling from the θθ to the αα rhythms stronger than the reversed one.