Does the computation of the FWD solution depend on the bad channels?

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Dear all,

I am using MNE for EEG analysis and source localization. My question is: does the computation of the FWD operator (lead-field matrix) depend on the marked bad channels (given in the info parameter)?
Additionally, can I use the same lead-field matrix on 2 recordings with different ?bad? channels marked (assuming the electrode position/digitalization and MRI data did not change)?

I saw that ?_prep_eeg_channels()? is called with ?exlude=()? by the preparation of the fwd solution computation; thus it seems to me that the bad channels parameter isn?t relevant to the fwd solution computation.
Could someone confirm it?

Thanks, and have a great day,
Mathieu
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External Email - Use Caution

I am using MNE for EEG analysis and source localization. My question is:
does the computation of the FWD operator (lead-field matrix) depend on the
marked bad channels (given in the info parameter)?

No it should not make a difference. The computation should still proceed
for all electrodes, and `forward['info']['bads']` does not appear to be
used when choosing which channels to use during `make_inverse_operator`.
You can test this locally by computing the forward twice, one with some
bads marked and one without any marked, and then construct an inverse
(passing an `info` with no bads marked) and in both cases you should see
that `inv['eigen_fields']['data'].shape` is (n_channels, n_channels).

Eric
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