禪坐之腦電位分佈之微狀態分析

Abstract

本篇論文主要目的是提出一套分析腦電波α波空間分佈的微狀態的方法，並探討禪坐者與一般人的腦電波在微狀態中的特性及差異性。 首先利用小波分解(wavelet decomposition)和小波重建(wavelet reconstruction)將腦電波中的α波頻帶擷取出來，再以各頻帶的能量比例判斷是否為α波，並將這α波能量計算為一個30維度的能量份佈(alpha brain mapping)；接著以馬氏(manalanobis)模糊C-means(MFCM)最為分類法對各個能量分佈情形進行分類，最後選取特定的分類結果作為狀態分析。 在微狀態分析的結果中發現，在禪坐者的前額α波有較長的微狀態維持時間，根據相關的研究認為，微狀態所維持的時間與大腦中資訊處理有相當的關聯，一個 較穩定的腦部活動會有較長的微狀態維持時間，也代表在當時有較少的資訊在處理中，視為較為穩定的腦波活動狀態。

The aim of this study is to propose a method for detecting alpha wave in EEG (electroencephalograph) and analyzing the alpha spatial characteristics in a microstate aspect. We investigated and compared the brain microstates between Zen-meditation practitioners (experimental group) and non-practitioners (control group). Firstly, EEG epochs of interest were extracted by alpha-power percentage that is at least fifty percent of total power. In the analysis, wavelet decomposition and reconstruction was adopted. Then Mahalanobis Fuzzy C-means clustering was employed in the classification scheme for various alpha mappings. Finally, the alpha-brain microstates were explored and compared for both experimental and control groups. The preliminary results reveal a longer duration of frontal-alpha microstate observed in Zen-meditation practitioners in comparison with control subjects. From the literatures, a longer duration of microstate may imply that the brain is involved in slight information processing, reflecting a rather stabilized dynamics.