[Eeglablist] Best Approach for Running ICA on EEG Data for Classification(ME & MI) (Pragati Dode)

[Yamil Vidal]

Dear Pragati,
Undoubtedly, you need to keep all your data together for running ICA, and
actually for all of your preprocessing. You should only divide the data in
conditions as a last step for the purpose of running the classification.
This is because if you first divide your data in conditions and then do
further preprocessing, be this ICA cleaning or anything else, you are
likely to introduce differences in the data across conditions which your
classifier might later pick.
In this way, you might find differences between conditions, even if there
are no real differences.
One way to think of it is that you are likely going to use ICA to remove
blinks, cardiac and muscle artifacts, which should not differ across
conditions and therefore you don't need to divide the data beforehand.
Another reason not to divide the data is that ICA benefits from having
plenty of data.
I hope this is helpful.
Best,
Yamil

Dr. Yamil Vidal
Predictive Brain Lab
Donders Centre for Cognitive Neuroimaging
Nijmegen
the Netherlands