[Eeglablist] EGI data re-reference (reref)

[Jeff Eriksen]

Darren,

 

I recommend reading this paper:

 

Junghöfer M, Elbert T, Tucker DM & Braun C. (1999) The polar average
reference effect: a bias in estimating the head surface integral in EEG
recording.  Clinical Neurophysiology 110(6): 1149-1155 

 

Basically, the best “practical” reference would cover the whole body evenly,
or at least the whole head evenly, in order to approach the
“reference-at-infinity” used in physics. The more channels, the better. The
only reason to exclude any channel is if it is known to have noise on it.

 

The only subtle catch is that one should include the original reference
electrode in the calculation, if its location is known. It just gives one a
little extra information.

 

-Jeff Eriksen

 

From: eeglablist-bounces at sccn.ucsd.edu
[mailto:eeglablist-bounces at sccn.ucsd.edu] On Behalf Of Darren Weber
Sent: Wednesday, February 06, 2008 5:13 PM
To: eeglablist at sccn.ucsd.edu
Subject: [Eeglablist] EGI data re-reference (reref)

 


Hi,

I have an EGI dataset loaded into EEGLAB.  It was acquired using an EGI
HydroCel Geodesic Sensor Net (128 channels).  I would appreciate advice
about re-referencing the data to average reference.  I've never done this
before and I'm wondering if there are any important or subtle catches.  I am
concerned that some of the channels should not be included in the average
reference.

Regards, Darren

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20080207/3ba205ef/attachment.html>