Hello,
I am a bit confused about the re-referencing in Brainstorm; let’s say i have an orginial signal acquired with reference in AFz; and i want to obtain the recording on the average montage reference;
Should i use standardize > re-reference EEG or standardize > Apply montage ? The goal notably is to then export the EEG amplitude to do some analysis on it.
It seems that the correct solution is Apply montage, ad re-reference is not changing the actual recording; but wanted to be sure;
Edouard
It is possible to do it in both ways, here an explanation on what is going on:
This process is only available for raw data, because re-referencing is saved as a projector just like SSP and ICA. So, it is applied on the fly on the raw data for visualization (if EEG reference is selected in the Select active projectors window), and it is applied on the raw data when importing (if Apply SSP/ICA projectors is selected.
It is possible to apply the projectors on the raw data before importing the data. This is done by using the process Artifacts > Apply SSP & CTF compensation. This will apply all the selected projectors and create a new raw file with the suffix _clean
This process is available for raw and imported data. By using the process Standardize > Apply montage, the montage is applied on the raw or imported data and the result is saved in new file with the name of the montage as suffix.
Worth to note that for raw data if there is an EEG referencing projector, and the Apply montage process is used with the option Use SSP/ICA projectors, then re-referencing happens twice (though it does not change the result if AVERAGE reference is used in both).
Thank you !