[Eeglablist] changing the reference electrode for use the SIFT toolbox

[Tim Mullen]

Dear John,

If you are using connectivity measures with channel data, an average
reference or laplacian reference are better choices than linked mastoid
reference.  See the following paper for a good discussion in the context of
coherence analysis (with applicability also to Granger causality):

Nunez, P. L., Srinivasan, R., Westdorp, A. F., Wijesinghe, R. S., Tucker,
D. M., Silberstein, R. B., & Cadusch, P. J. (1997). EEG coherency. I:
Statistics, reference electrode, volume conduction, Laplacians, cortical
imaging, and interpretation at multiple scales. *Electroencephalography and
clinical neurophysiology*, *103*(5), 499–515.
Be aware that connectivity measures applied to channels will generally
suffer from an increased rate of spurious coupling (false positives) due to
volume conduction. Spatial laplacians can help mitigate this.

If you are using components then the choice of reference is irrelevant (ICA
produces a reference-free signal).

Tim


On Fri, Nov 8, 2013 at 2:20 PM, jfochoaster . <jfochoaster at gmail.com> wrote:

> Dear EEG experts,
>
> I have a lot of eeg data with the average as reference. This data comes
> originally with one electrode near to CZ as reference
>
> Is valid re-reference the data to linked mastoid?
>
> This is because I am using the SIFT toolbox over the channels and the DFT
> measure is applied over eeg data with linked mastoid as reference
>
> If I use components instead of channels, I can forget the reference?
>
> Thanks in advance
>
> --
> John Ochoa
> Docente de Bioingeniería
> Universidad de Antioquia
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>



-- 
---------  αντίληψη -----------
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20131113/efbad66d/attachment.html>