Constitution and phase analysis of alpha waves

Alpha waves are electroencephalogram discovered by Hans Berger in 1929 and have been studied by many researchers. Recently the amplitude and the phase of alpha waves attract attention, and various studies are reported. So far the alpha waves are not concretely modeled to explain how they are constituted. In this paper, we analyze the phase of alpha waves for their future modeling. As pre-processing, we extract alpha wave data from EEGs and divide the data into alpha wave constituent waves. Analyzing the feature quantity of the alpha wave constituent waves, it turns out that the amplitude and the wavelength of alpha wave constituent waves are correlated with a constant time delay.