title: Connectivity analysis of multichannel EEG signals using recurrence based phase synchronization technique.
abstract: Real world biological systems such as the human brain are inherently nonlinear and difficult to model. However, most of the previous studies have either employed linear models or parametric nonlinear models for investigating brain function. In this paper, a novel application of a nonlinear measure of phase synchronization based on recurrences, correlation between probabilities of recurrence (CPR), to study connectivity in the brain has been proposed. Being non-parametric, this method makes very few assumptions, making it suitable for investigating brain function in a data-driven way. CPR's utility with application to multichannel electroencephalographic (EEG) signals has been demonstrated. Brain connectivity obtained using thresholded CPR matrix of multichannel EEG signals showed clear differences in the number and pattern of connections in brain connectivity between (a) epileptic seizure and pre-seizure and (b) eyes open and eyes closed states. Corresponding brain headmaps provide meaningful insights about synchronization in the brain in those states. K-means clustering of connectivity parameters of CPR and linear correlation obtained from global epileptic seizure and pre-seizure showed significantly larger cluster centroid distances for CPR as opposed to linear correlation, thereby demonstrating the superior ability of CPR for discriminating seizure from pre-seizure. The headmap in the case of focal epilepsy clearly enables us to identify the focus of the epilepsy which provides certain diagnostic value.
authors: Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore 560012, India. Electronic address: abhi88iisc@gmail.com.
authors: D
authors: D
authors: Rangaprakash
mesh_terms: D001921:Brain / Q000503:physiopathology*; D058407:Electroencephalography Phase Synchronization; D004827:Epilepsy / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008959:Models, Neurological; D012815:Signal Processing, Computer-Assisted
keywords: Brain connectivity; Brain headmap; Correlation between probabilities of recurrence; EEG signals; Epileptic seizure; Linear correlation; Phase synchronization; Recurrence quantification analysis