腦波神經調控機制分析

Abstract

本論文提出腦波神經調節機制分析(Independent modulator analysis)的理論假設，並應用在兩個不同的實驗當中，嘗試找出大腦深層影響不同腦區的神經調節機制。經實驗觀察，當人們在打瞌睡與暈車時，都不僅活化單一腦區的神經元，更影響不同腦區的神經活化，在相同的頻帶有同步(synchronization)的現象。因此，透過腦波神經調節機制分析，不僅能更深入了解大腦運作，並能了解不同腦區之間的相互作用，更可嘗試探討大腦深層影響不同腦區的神經調節機制，讓我們對大腦的了解，透過簡單的腦波分析，能更透徹明瞭。

本研究實際應用腦波神經調節機制分析(Independent modulator analysis)在打瞌睡與暈車兩個不同的實驗中，並找出不同頻帶的神經調節子：alpha modulator、theta modulator、gamma modulator，影響不同腦區的單一頻帶腦波活化，且與行為數據進行比對與分析。透過兩個不同的實驗，更完整了解腦波神經調節機制分析的功能與限制，並比對過去研究所發現的現象，能相互參照與支持。

This research proposed the independent modulator analysis (IMA) that applied the 2nd independent component analysis on spectra of the EEG cortical sources. This non-invasive method aims to decompose the task-related neural modulators that mediated the normalized logarithmic spectral activities of independent components, and to assess the underlying mechanism of the neuromodulatory systems.

Recently, independent component analysis (ICA), a widely used technique for biomedical signal processing, was applied to EEG data to identify temporally distinct sources generated by partial synchronization of cortical activities. In the previous study, spectral activities of many maximally “temporally” independent brain processes were observed to co-vary with the fluctuation of task performance, suggesting the existence of the co-modulatory brain dynamics. We applied the non-invasive IMA technique in the driving and motion sickness experiments and reported that there are task-related independent modulators affect the power of alpha, theta, and gamma bands across subjects in the two experiments.