[Mne_analysis] noise covariance

[Gustavo Sudre]

hey all

So, I inherited several resting state datasets but empty room data were not collected for any of them. I was wondering about your experiences analyzing resting state in source space using an identity noise covariance matrix. 

Some questions that come to mind: 

- any suggestions for regularization levels? 
- if I'm interested in frequency domain, what about constructing my noise matrix with the filtered signals of a non-interesting band (i.e. band-stop on the frequency band of interest)? 
- say I'm interested in the usual 4-5 frequency bands, maybe using the same noise covariance that's constructed using high frequency signals (> 100Hz, outside of the bands of interest)?
- how would the answers above change in the context of a MNE vs LCMV beamformer analysis?

Thanks in advance,

G