Hi,
The raw data are saved in units μV (if I load this manually with read_raw_brainvision). I pass the data to the automated MNE-BIDS pipeline. I cannot find the specified code where it is loading the raw data though. I checked the info of the preprocessed file and this indicates that it is saved in V if I am correct 'unit': 107 (FIFF_UNIT_V).
I was looking through some forum posts again and found this comment of Dan McCloy on another post regarding ERPs:
" FYI, in MNE-Python everything is stored in SI units. Sometimes our plotting functions will convert the units before plotting, just so that the axis labels don’t range from say 0.000001 to 0.000006 V, but instead from 1 to 6 μV. Again this is only on the plot, the underlying data object still stores the numbers in SI units." https://mne.discourse.group/t/how-to-specify-units/5961/2
Is it possible that this explains why the units of the raw EEG and the one of the preprocessed EEG may differ? In the forum post they only mention it is because of the plotting function though…
I saw that conversion may be the solution https://mne.discourse.group/t/rescale-data-import-from-fieldtrip/3402 But this then turns the values even smaller (10e-13). Do I need to do the conversion before passing the data to the automated MNE-BIDS pipeline?