[Eeglablist] How do I measure ratio of EEG frequency band for a few electrodes in decibels?

[goh victor]

I wanted to calculate the ratio of Theta/Beta in decibels for a couple of electrodes in AF3 AF4 and Cz

I was able to get these in microvolts, but would like to convert them to decibels but am unsure what is the appropriate way to do so.

For instance, should I convert it like:

    ratio1 = 10Log((Theta(AF3) + Theta(AF4) + Theta(Cz))/(Beta(AF3) + Beta(AF4) + Beta(Cz)))

or

    ratio2 = 10Log(Theta(AF3)/Beta(AF3)) + 10Log(Theta(AF4)/Beta(AF4)) + 10Log(Theta(Cz)/Beta(Cz))

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