禪定組與控制組的腦電波之空間非線性相互依存源與波源特性關係之研究=Investigation of spatially nonlinear interdependence in correlation with focalized source characteristics of Zen meditation and resting EEG
Brain dynamics in Zen-meditation state has aroused the researchers’ attention for decades. In this thesis, we attempted to explore the difference of microstate of nonlinear interdependence and the corresponding focal-source characteristics between Zen-meditation EEG (electroencephalograph) and resting EEG. Nonlinear-interdependence analysis based on phase space reconstruction may provide a feasible way to access brain dynamical interactions among regional neural networks. The analysis mainly involves the construction of similarity-index matrix (SIM), classification of microstate SIMs, and long-term EEG interpretation based on the classification results of microstate SIMs. Our previous study proposed the systematic approach for determining appropriate implementing parameters to evaluate the SI coefficient between two EEG channels and then to construct the complete 30-by-30 microstate SIM (miSIM) for the 5-millisecond, 30-channel EEG epoch. This thesis is mainly focused on1)theclassification of microstatesof spatially nonlinear interdependence of more Zen-meditation and resting EEG data, and 2) analysis of the corresponding focalized-source (dipole) characteristics based on the four-shell concentric spherical head model. The microstate SIMs are classified by Fuzzy c-means clustering. The results of 4 classification can be adopted for long-term EEG interpretation. The cluster centers of all the clusters are most representative for characterizing the nonlinear brain dynamics.
Chapter 1 Introduction 1 1-1 Background and Motivation 1 1-2 Introduction of Zen meditation 6 1-3 Dipole model 7 1-4 Nonlinear Interdependence Analysis 8 1-5 Aims of This Study 11 1-6 Scope of thesis 11 Chapter 2 Methods and Theories 13 2-1 Introduction of EEG 13 2-2 Reconstruction of System Dynamics from observation 15 2-3 Nonlinear Interdependence Measure 18 2-3-1 Definition and Estimation 18 2-3-2 Nonlinear Interdependence Analysis 21 2-3-3 Asymmetric property 23 2-4 Dipole Model 23 2-4-1 The Forward Problem 25 2-4-2 The Inverse Problem 30 2-5 fuzzy c-means clustering 31 Chapter 3 Experiment Setup and Procedure 38 3-1 Experiment Protocol 38 3-1-1 Experimental Group 38 3-1-2 Signal Acquisition 39 3-2 Dipole Model Implementation 41 3-2-1 The scheme of dipole iteration 41 3-3 Signal Analysis 44 3-3-1 Outline of the scheme 44 Chapter 4 Results and Discussion 46 4-1 Results of Analyzing Zen-meditation EEG 52 4-1-1 Results of Analyzing First Zen-meditation EEG 52 4-1-2 Results of Analyzing Second Zen-meditation EEG 66 4-1-3 Dipoles Analysis of Zen-meditation EEG 80 4-2 Results of Analyzing Resting EEG 84 4-2-1 Results of Analyzing First Resting EEG 84 4-2-2 Results of Analyzing Second Resting EEG 100 4-2-3 Dipoles Analysis of Resting EEG 114 Chapter 5 Conclusions 118 5-1 Conclusions 118 5-2 Future Work 133
