when i asked BTS to use the EEG and the MEG signal to compute sources, i obtained the message “Warning, BST inverse models do not properly handle the combination of MEG and EEG yet”.
What do you mean by "properly "? What’s the matter? Is it impossible to compute the simultaneous MEG/EEG inverse models?
You get this warning because we do not have a correct way to combine the EEG and MEG information together yet.
There is still little information on the amount and type of information that one modality is capturing and not the other.
To my knowledge, all the combined MEG/EEG reconstruction methods are based on weighted contributions based only on the level of noise on the different categories of sensor, which is most likely not such a good approach because the two modalities might be capturing different features of the brain (and muscle) activity.
In terms of modeling, this weighting is done correctly in Brainstorm, and you can combine MEG, EEG, ECOG and LFPs in the same source model.
However, our recommendation is to do the reconstructions separately, due to some uncertainties in the combination mechanisms.