[Eeglablist] May I have a question about eeg editing?

[GreenOnion]

Hello, I’m wondering whether I can get some guidance wrt EEG editing. 
I’ve resting EEG collected in eye-closed condition. For some cases, I see segments of obvious (visible) theta oscillation between segmentes of alpha oscillations. I know increased theta oscillation may reflect drowsiness or meditation state. So, my question is: in term of qEEG analysis, should I delete the theta oscillation segments? Or simply leave them there?

Many thanks for any inputs. Jimmy ~