Is there a way to know exact frequency of specific brainwave state ? Let's say I would like to know what exact frequency I've spent in Delta state or maybe most of time. Now I can distinguish only between 5 states, Delta, Theta, Alpha, Beta and Gamma. I am thinking to know more about my personal sleeping frequency to support it, not just Delta

From spec:
"FFT stands for Fast Fourier Transform. This computes the power spectral density of each frequency on each channel.
Absolute band powers are based on the logarithm of the Power Spectral Density of the EEG data for each channel."
Thank you.