I wanted to plot the spectral content of my EEG data using MNE but I am unable to understand what this graph actually gives.
I am having troubles in understanding the y-axis. From what I have gathered so far, a Decibel is calculated "relative" to something. In this case it is amplitude^2 per frequency. I think I am unable to understand what it truly means, and how do I relate it to this definition I found: "When expressing a power ratio, it is defined as ten times the logarithm in base 10. That is, a change in power by a factor of 10 corresponds to a 10 dB change in level."
This figure (reference) has power 20 decibels at 2 Hz, but what does it mean in terms of power/base 10?
