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MNE Python was not designed at first to process EEG data, so their ICA can present some flaws. Maybe these Apps can used other toolboxes like FieldTrip for instance.
Create meg.json
In BiDS a derivatives file called meg.json contains info about the data such as:
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FilterType
RECOMMENDED. Could be ‘low-pass butterworth’, ‘high-pass fir’, ‘band-pass iir’, etc.
HighCutoff
RECOMMENDED. Cutoff at which higher frequencies are attenuated.
LowCutoff
RECOMMENDED. Cutoff at which lower frequencies are attenuated.
HighCutoffDefinition
RECOMMENDED. Can be “half-amplitude (-6dB)” or “half-power (-3dB)”
LowCutoffDefinition
RECOMMENDED. Can be “half-amplitude (-6dB)” or “half-power (-3dB)”
FilterOrder
RECOMMENDED. The order of the filter.
FilterLength
OPTIONAL. The length of the filter
RollOff
OPTIONAL. Could be “12 dB/Octave”, etc.
TransitionBandwidth
OPTIONAL. Could be “10 Hz”, etc.
PassbandRipple
OPTIONAL.
StopbandAttenuation
OPTIONAL.
FilterDelay
OPTIONAL. Could be “linear-phase” or “non-linear-phase”
FilterCausality
OPTIONAL. Could be “causal” or “non-causal”
Direction
RECOMMENDED. Could be ‘forward’, ‘backward’ or ‘bidirectional’
DirectionDescription
REQUIRED if “Direction” is “bidirectional”. Else OPTIONAL. Could be “cutoff frequencies and filter order apply to a single filter pass” or “cutoff frequencies and filter order apply to the final two-pass filter”
Purpose
OPTIONAL. ‘antialiasing’ |
So, it would be interesting to have this information after app-notch-filtering and app-temporal-filtering for instance.
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This info doesn’t correspond exactly to the parameter values set by the User (sometimes the values are implicit and must be retrieved by looking closely at the MNE scripts). |
The file meg.json doesn’t exist in the meg/fif datatype because the information of this file should be stored in config.json (the meg.json is stored as metadata in Brainlife):
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When the data is imported from BIDS to Brainlige, the |
To put information in that field you must you the product.json, which is currently used to display messages in Brainlife UI. But we want this info to be updated after each App: so, for each app that handles meg/fif, you will need to copy the content of the meta from the input to product.json's meta for each meg/fif output, then next app does the same, and so on.