Trying to understand the lambda2 parameter in mne.minimum_norm.apply_inverse_raw

[richard (Richard Höchenberger)]

Hello! This is a recurring question, and the answer – albeit maybe unsatisfactory to you – is that you should simply assume an SNR of 3 for averaged and 1 for non-averaged data:

Estimating the regularization parameter for HCP MEG resting state source reconstruction

@Dominik I just asked @agramfort about this while we were fighting with the coffee machine (spoiler: we won! ) He said this parameter (SNR of 3 for averaged, 1 for non-averaged data) “was established by Matti Hämäläinen 20 years ago”, and that “no one touches this parameter”. Hence … I would say, case closed. Best wishes, Richard

Best wishes,
Richard