[Eeglablist] isolating a CNV with ICA

[Joseph Dien]

You might try doing a PCA in the temporal domain instead of an ICA in  
the spatial domain, if the time course is sufficiently consistent.

Cheers!

Joe

On Sep 8, 2009, at 1:01 PM, Keith Yoder wrote:

> Hi all,
> Our group has EEG time-series data collected with a BioSemi  
> ActiveTwo 128-electrode cap.  Our paradigm includes a Go-NoGo, with  
> an alerting stimulus (S1) preceding the presentation of the Go-NoGo  
> stimulus (S2).  S1 and S2 are separated by 3 seconds.  When we  
> examine ERPs from single electrodes, we observe a typical contingent  
> negative variation (CNV).  However, when we run ICA (runica), none  
> of the components isolate the CNV.  We've tried highpass filtering  
> at 0.5hz (obviously to high), 0.01hz and without any highpass  
> filtering, all without success.  Has anyone else run into a similar  
> problem?  Does anyone have any additional advice for isolating a CNV  
> with ICA?
> Thanks,
> Keith Yoder
> --
> Research Assistant
> Belmonte Autism Lab
> Cornell University
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--------------------------------------------------------------------------------

Joseph Dien,
Senior Research Scientist
Center for Advanced Study of Language
University of Maryland
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