[Eeglablist] Concatenate data across visits prior to ICA?

[Malte Anders]

Hi Steve,

I'm afraid you shouldn't do that. Let me quote Makotos preprocessing
pipeline:

*To apply a single ICA, your subject cannot take off the electrode cap!* If
you did this, then ICA may show ICs with very similar scalp topographies
with differently block-separated activations (active only in some blocks,
otherwise green) in ERPimage.

Unless you subjects wear the cap for 6 months straight... The cap will
never be at the exact same locations as before, thus ICA and DIPFIT will
produce different results. Analyze the data for each visit independently
and see if you get matching results.

Best,
Malte


Coombes, Stephen A <scoombes at ufl.edu> schrieb am Mo., 23. März 2020, 15:56:

> Dear EEG list members,
>
> We have EEG data from a cohort of subjects who come into the lab for 3
> visits spaced over a 6 month period. It is a repeated measures design with
> visit being the only variable. We have resting data and data during a task.
> For each data set (i.e., resting & task based), should we concatenate the
> data for each subject across visit before running ICA, and if so why?
>
> For the task based analysis we will run ICA then DIPFIT and then MPA. We
> are still exploring different options for the resting state pipeline once
> ICA and artifact removal is complete.
>
> Any advice greatly appreciated. Hope everyone is safe and well out there.
>
> Many thanks,
> Steve
>
> __________
> Stephen A. Coombes, Ph.D.
> Laboratory for Rehabilitation Neuroscience
> University of Florida
> Phone: 352.294.1768
> Website: lrnlab.org<http://www.lrnlab.org/>
>
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