[Eeglablist] re-reference to average of both earlobes

[arno delorme]

Dear Andre and David,

yes, you may use the GUI to re-reference to two channels. Simply enter  
both channel indices when performing re-referencing.

If one of the channel is already the reference and is not present in  
the data (as 0), then first compute average reference (enter the  
reference channel name and location if any when computing average  
reference). You may then rereference to the average of this reference  
channel and another one. If you are doubfull, you may test after this  
procedure that your data is indeed the same as if you had simply  
subtracted half of the second channel from the command line (EEG.data  
= EEG.data - EEG.data(ref,:,:)/2).

Note that the advantage of using the GUI is that it also transform the  
ICA matrices if any to take into account re-referencing.

Best,

Arno

>  If your data was recorded using one earlobe as a reference, you can  
> use the following function:
>
> http://www.cogsci.ucsd.edu/~dgroppe/EEGLAB/reref_bimastoid.m
>
> It was written for re-referencing data to the average of the mastoid  
> electrodes, but it can do the job for you.  Where the function  
> requests the index of the non-original-reference mastoid electrode  
> (i.e., the variable "mastoid_id"), just use the index of the non- 
> original-reference earlobe electrode.