[Eeglablist] imported BrainVision data: finding the reference electrode

[Ricardo Moura]

Hi,
Thanks for your answer.
The reference channels were recorded at the left (recording reference) and
right (recorded as a normal eeg channel) mastoids. The right reference is
available when I open the data in EEG lab, but not the recording reference.
The reference channel always appear as "unknown" at the main eeglab window,
and when I go to the "channel locations", it only shows me 64 electrodes
(the 65th electrode, which would be the recording reference, is missing).
This is a problem because I need this channel in order to re-reference the
data to linked-ears (don't I?). But I don't need to use it as an active
electrode.

So when I try the  "Add current reference channel back into the data" , I
allways have the following message: "there are no reference channel
defined, add it using the channel locations".


Any idea about how to recover this channel (in case I really need it to
perform the linked-ears reference)?

Best,
Ricardo


On 24 September 2012 14:50, Stephen Politzer-Ahles <politzerahless at gmail.com
> wrote:

> Hi Ricardo,
>
> May I ask what your reference was? In my experience using Brain Vision
> data, the recording reference (in my case it was on the nose) was just not
> included in the data that I imported to EEGLAB. This wasn't a problem for
> me because I wasn't interested in analyzing that electrode anyway after I
> re-referenced; but it might matter for you if your reference is something
> that you care about as an active electrode, like Cz. You may be able to get
> that channel back by using the "Add current reference channel back into the
> data" command and specifying its location (but I haven't tried that myself
> with BV).
>
> Best,
> Steve
>
> On Mon, Sep 24, 2012 at 8:55 AM, Ricardo Moura <ricardoojm at gmail.com>wrote:
>
>> Dear all,
>>
>> I am new to the EEGLab. Now I am trying to analyze data that were
>> recorded using the BrainVision recorder, but I never find the reference
>> electrode. Going to "Channel Locations" only shows me the EEG electrodes.
>> It is a problem for me because I want to re-reference the eeg signal to the
>> linked-ears. The second reference electrode is always there (once it was
>> recorded as a regular eeg electrode), but not the actual reference.
>>
>> I would appreciate any help,
>> Best,
>> Ricardo Moura
>>
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>
>
>
> --
> Stephen Politzer-Ahles
> University of Kansas
> Linguistics Department
> http://people.ku.edu/~sjpa/
>
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