Hello,
I'm using the latest version of Brainstorm. I have a protocol with a template anatomical MRI and the same EEG cap. I want to compute a covariance matrix on baseline signals for each participant. But it only gives me a single covariance matrix stored in Common files. Is this a bug? Or is there a new output option?
I recall In later versions of Brainstorm, it used to compute one matrix per participant, which is correct...
None, it is not a bug, nor it is a new output option.
It seems that you used as Default channel file the option Yes, use only one global channel file when the Protocol was created. Please note that option it not recommended.
The recommended option is No, use one channel file per acquisition run. You would need to set the same cap for each Subject and each Run (aka Session). This is recommended way as the channel file besides the sensor positions contains additional information that is related to the Run; e.g. ICA projectors, selection of bad channels, etc.
More info in here:
There is one (noise or data) covariance matrix exist per one channel file. So the issue you are getting is cause by having only one channel file for the protocol.
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