[Eeglablist] Should Average Reference Include Eye Channels?

[Thomas, Robin D. Dr.]

Others may weigh in on this to correct me if I'm wrong here.  My understanding (from Dien, 1998 and others) is that the theory behind rereferencing to the average derives from the zero integral property of the global field around the full sphere of the head (if we could put an infinite number of electrodes all across the entire head-sphere even underneath it, the field potential would integrate to 0).  Thus, for an actual electrode array, if a head is densely sampled (covering as much around as possible) with all the electrodes referenced to the same common at recording, then the average approximates the zero integral well enough that the 'average' is a good electrically neutral 'electrode' that would be a good candidate for a reference.  Bottom line, you should be ok in using the eye electrodes for average rereferencing.

I hope I'm correct.

Robin 

-----Original Message-----
From: eeglablist-bounces at sccn.ucsd.edu [mailto:eeglablist-bounces at sccn.ucsd.edu] On Behalf Of Matthew Stief
Sent: Wednesday, February 08, 2012 8:35 PM
To: eeglablist at sccn.ucsd.edu
Subject: [Eeglablist] Should Average Reference Include Eye Channels?

Greetings!

I am using a 128 channel BioSemi active system, and am importing my files using the average mastoids as the reference.  I would like to rereference to the average, but am unsure if I should use my four eye electrodes.  I read in the archives that this shouldn't be done for eye electrodes that do not have the same reference as the scalp electrodes, but given that in this case they do is there any reason not to do it?

--
_________________________________________________________________
Matthew Stief
Human Development | Sex & Gender Lab | Cornell University http://www.human.cornell.edu/HD/sexgender


Heterosexuality isn't normal, it's just common.
-Dorothy Parker
_______________________________________________
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