[Eeglablist] fmrib plugin gradient correction question

[basile pinsard]

Hi EEGlab users,

I am quite new to EEGlab and trying to use the fMRIb plugin to correct from
MRI artifacts.
My questions are:

- having volume markers, is there any interest in switching to slice
markers (that I could add myself, the scanner being regular)? Does the
gradient template is then computed on slices and windowed on let say 30
slices instead of 30 volumes? Or does this slice splitting is already
performed in the software?

- I removed the 4 ECG channels recorded from the residual artifact
correction as suggested, however, there remains high-frequency content in
the signal (see screenshot
<http://s3.postimg.org/uyzdb2zgj/gradient_correction.png> with 1 ECG
channel and EEG channels) only for these channels. Is that because the
correction didn't work that well for these channels ? Is that something
that I can fix? Does low-pass filter is compulsory in this step? Why EEG
channels are not affected?

Thank you very much for your help and ideas on this.

basile
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