探討禪定中之視覺誘發電位

Abstract

本篇論文主要在研究禪定過程中視覺誘發電位(VEP)的變化，由於考量到實驗組在禪定過程中可能會受到外界刺激干擾，因此本研究捨棄了一般常用的棋盤格刺激法，改採閉眼閃光刺激，並且擷取刺激後所產生的視覺誘發電位(VEP)。除了直接擷取VEP外，本研究並以主成分分析法(PCA)來對VEP訊號進行分析。主成分分析的目的在於縮減變數，並在可容忍的範圍內以較少的變數來解釋原有的資料，以達到資料簡化的目的。 本論文以傳統的平均法擷取VEP峰值，將實驗組與對照組的結果進行比較，並以PCA進一步量化VEP的相關性，另方面，PCA大量減少資訊的重複和增強資訊的輪廓。 因為VEP對於禪定方面的研究處於初步階段，受測者的數目仍然不足以達到統計意義。然而，實驗結果顯示，實驗組與對照組較大的差異在於實驗組P3為禪定前的延遲最小，對照組則是靜坐中的延遲最小。在主成分分析方面，實驗組經過禪定過程後第一主成分的變化較對照組靜坐後來的小。

This preliminary study aims to investigate Visual Evoked Potential (VEP) for the Zen-Buddhist meditators (experimental subjects) before, in, and after meditation. In consideration of reducing the interference upon the subjects, flash-stimulus VEP is collected. For comparison, VEP’s of control subjects in relaxation and analyzed. Peak amplitude and latency are important quantities characterizing the VEP. We compare the results of two groups based on the raw VEP signals derived by the conventional averaging method. In addition, principal component analysis (PCA) is applied to the VEP signals to further quantify the temporal and spatial coherence of VEP. On the other hand, PCA highly reduces the information redundancy and enhance the peak profile. Since the VEP study for the Zen-Buddhist meditation practitioners is still at the preliminary stage, number of subjects of both group is still too small to achieve statistical significance. However, our preliminary result shows that the P3 latency in VEP of the experimental group is smallest before meditation, whereas for the control group the P3 latency is smallest in relaxation.