以時移腦殼分佈圖和非線性相位耦合探討禪定腦電波之對稱性

Abstract

在過去的幾十年之中對稱性的腦電波分析早已被廣泛的研究，然而大多數的相關研究主要都在探討不同頻段腦電波對於整個頭殼不同區域的能量非對稱性，因此這篇論文主要是針對禪定時腦電波的時域對稱性加以研究。本篇論文提出了兩種方案以深入分析腦電波的時域對稱性：1) TSSP (顯著峰值的時移分析) 2) 雙頻分析方案。 透過全腦30通道的腦電波量測(非侵入式)以及各通道腦電波的顯著峰值偵測，TSSP提供了一條有效的途徑加以探索腦神經網路活動之間的時間差以及其活動/關聯性型態。另一方面，雙頻分析則是應用於時域演化性的研究，探討八組空間對稱的腦電波訊號之相位耦合，其中包含了五類側對稱組(F7–F8, T7–T8, C3–C4, P7–P8, O1–O2)以及三類縱對稱組(Fz–Pz, F7–P7, F8–P8)。 由TSSP的結果我們得到，相較於控制組(閉眼休息)，實驗組(禪定)在第九類結果「無時間偏移」中顯現出較高的所占百分比；而另一部分，雙頻分析的結果顯現出實驗組與控制組的相位耦合頻段有相當大的差異，其中，控制組(閉眼休息)的耦合主要發生於theta頻段(4-8赫茲)，而實驗組(禪定)則發生在low-alpha頻段(8-10赫茲)。如此的初步結果對於研究禪定修行者在禪定時，腦功能各區域神經網路的時空交互作用提供了嶄新的觀點。

Symmetrical analysis of EEG has been extensively studied for decades. However, most of the researches are focused on the power asymmetry of different EEG rhythms. This thesis is aimed to investigate the temporal symmetrical properties in Chan-Ding EEG. Two schemes of EEG symmetrical analysis are developed in this research, 1) TSSP (Time Shift of Significant Peak) scheme, and 2) Bispectral analysis scheme. TSSP provides a way to explore the time differences of neural network activities and neural-network activation/association modalities by detecting the significant peaks among 30 EEG channels over the scalp (non-invasive recording). On the other hand, bispectral analysis is employed in the investigation of temporal evolution of phase coupling between eight spatially symmetrical EEG pairs, including five lateral pairs (F7–F8, T7–T8, C3–C4, P7–P8, and O1–O2) as well as three longitudinal EEG pairs (Fz–Pz, F7–P7, and F8–P8). The results of TSSP scheme reveals the relatively higher proportions of null shift (without any time difference) in Chan-Ding group. Besides, the results of biepctrral analysis scheme reveal quite different frequency regions of dominant resonance-phase coupling between Chan-Ding group (low-alpha band, 8-10 Hz) and control group (theta band, 4-8Hz). The preliminary results may open an alternative view in the investigation of the spatio-temporal brain-functioning interactions among various regional neural networks for the Chan-Ding practitioners.