Open AccessNonlinear phase desynchronization in human electroencephalographic data
Author(s) -
Breakspear Michael
Publication year - 2002
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.10011
Subject(s) - attractor , surrogate data , nonlinear system , electroencephalography , chaotic , coherence (philosophical gambling strategy) , computer science , measure (data warehouse) , human brain , artificial intelligence , pattern recognition (psychology) , neuroscience , psychology , mathematics , physics , statistics , data mining , mathematical analysis , quantum mechanics
Ensembles of coupled nonlinear systems represent natural candidates for the modeling of brain dynamics. The objective of this study is to examine the complex signal produced by coupled chaotic attractors, to discuss their potential relevance to distributed processes in the brain, and to illustrate a method of detecting their contribution to human EEG morphology. Two measures of quantifying the behavior of coupled nonlinear systems are presented: a measure of phase synchrony and a novel measure of intermittent phase desynchronization. These are used to quantify the behavior of numerical examples of coupled chaotic attractors. Experimental evidence of their contribution to the morphology of the human alpha rhythm is then illustrated in a study of EEG recordings from 40 healthy human subjects. Amplitude‐adjusted phase‐randomized surrogate data is used to test the null hypothesis that the observed patterns of phase coherence can be described by purely linear methods. Statistical analysis reveals that this null hypothesis can be robustly rejected in a small number (∼4%) of EEG epochs. These findings are discussed with reference to the adaptive function and complex dynamics of the brain. Hum. Brain Mapping 15:175–198, 2002. © 2002 Wiley‐Liss, Inc.