Hi Lucie,
When you specify --projoff the EEG average reference projection is
still included with the output file but the average EEG reference is
not automatically switched on when you load the data to
mne_browse_raw. To see the effect of the average electrode reference,
go to "Manage averages..." and click on "Proj..." where you can switch
the average EEG reference on and off.
However, when the inverse operator is created, the average EEG
reference is switched automatically on.
- Matti