DocumentCode :
636474
Title :
Existence of millisecond-order stable states in time-varying phase synchronization measure in EEG signals
Author :
Jamal, Wasifa ; Das, S. ; Maharatna, Koushik
Author_Institution :
Sch. of Electron. & Comput. Sci., Univ. of Southampton, Southampton, UK
fYear :
2013
fDate :
3-7 July 2013
Firstpage :
2539
Lastpage :
2542
Abstract :
In this paper, we have developed a new measure of understanding the temporal evolution of phase synchronization for EEG signals using cross-electrode information. From this measure it is found that there exists a small number of well-defined phase-synchronized states, each of which is stable for few milliseconds during the execution of a face perception task. We termed these quasi-stable states as synchrostates. We used k-means clustering algorithms to estimate the optimal number of synchrostates from 100 trials of EEG signals over 128 channels. Our results show that these synchrostates exist consistently in all the different trials. It is also found that from the onset of the stimulus, switching between these synchrostates results in well-behaved temporal sequence with repeatability which may be indicative of the dynamics of the cognitive process underlying that task. Therefore these synchrostates and their temporal switching sequences may be used as a new measure of the stability of phase synchrony and information exchange between different regions of a human brain.
Keywords :
biomedical electrodes; cognition; electroencephalography; medical signal processing; pattern clustering; synchronisation; time-varying systems; EEG signals; cognitive process; cross-electrode information; face perception task; human brain region; information exchange; k-means clustering algorithms; millisecond-order stable states; phase synchrony stability; quasistable states; synchrostate optimal number; temporal switching sequences; time-varying phase synchronization measure; Clustering algorithms; Continuous wavelet transforms; Electroencephalography; Phase measurement; Switches; Synchronization; CWT; EEG; brain dynamics; k-means clustering; phase synchronization; synchrostate;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Engineering in Medicine and Biology Society (EMBC), 2013 35th Annual International Conference of the IEEE
Conference_Location :
Osaka
ISSN :
1557-170X
Type :
conf
DOI :
10.1109/EMBC.2013.6610057
Filename :
6610057
Link To Document :
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