A Question about mne_setup_forward_model

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1

Hi MNE Users

    I have a question about the --ico option in the script
mne_setup_forward_model. Does the ico number have to be the same as
the one which we wish to use for the source space in computing the
forward solution
or is this independent? It creates a file
structural_mri-5120-5120-5120-bem-sol.fif, which I think corresponds to
ico 4.

Now is it OK to use this BEM file for computing forward solution if I wish
to have ico 5 source space corresponding to (10242*2sources)?

mne_forward_solution --src
$SUBJECTS_DIR/$SUBJECT/bem/structural_mri-ico-5-src.fif --mri
$SUBJECTS_DIR/$SUBJECT/mri/T1-neuromag/sets/COR-asalazar-090406-142236.fif
--meas $SUBJECTS_DIR/$SUBJECT/eeg_mri/base/dec_base_raw-ave.fif --bem
$SUBJECTS_DIR/$SUBJECT/bem/structural_mri-5120-5120-5120-bem-sol.fif --fwd
dec_base_raw-ave-eeg-all-fwd.fif --eeg --all

Thanks
Supra

d_solution --src ../../bem/structural_mri-ico-5-src.fif --mri
../../mri/T1-neuromag/sets/COR-asalazar-090406-142236.fif --meas
base_raw-ave.fif --fwd structural_mri-eeg-ico-5-fwd.fif --eeg

2

They are independent. The BEM model resolution essentially determines
how close to the inner skull surface the sources can be for the field
computation to be accurate.
The ico 4 choice for the BEM should be sufficient. It is practically
not possible to go to higher resolution due to memory limitations and
accumulating numerical errors in the computation.

- Matti