[FieldTrip] Lost reference location

[Casper van Heck]

Dear Christine,

As there are only a few possibilities, this might work! We'll try that!

Dear Vladimir,

If the original reference is close to an electrode we're interested in, and
we do not see an effect on that electrode, then we cannot determine if
there is indeed no effect or if the original reference made the effect
disappear (due to it also 'seeing' the same activity).

Thanks, all!

Best regards,

Casper

On 21 September 2016 at 16:26, Vladimir Litvak <litvak.vladimir at gmail.com>
wrote:

> If you need to know the reference for analysis purposes the easiest thing
> is to just rereference to another electrode or the average reference. Then
> it wouldn't matter what the original reference was.
>
> Best,
>
> Vladimir
>
> On Wed, Sep 21, 2016 at 1:57 PM, Blume Christine <
> christine.blume at sbg.ac.at> wrote:
>
>> Dear Casper and Tineke,
>>
>>
>>
>> As voltage is always the difference between the reference and an
>> electrode, voltages are lowest for electrodes closest to the reference
>> electrode. You could check where voltages are minimal across trials and for
>> each participant. If then for example that is close to Cz, it is likely
>> that data were referenced to the vertex. Just an idea, it might work…but
>> perhaps someone else has a better idea?
>>
>>
>>
>> Best,
>>
>> Christine
>>
>>
>>
>> *Von:* fieldtrip-bounces at science.ru.nl [mailto:fieldtrip-bounces at scie
>> nce.ru.nl] *Im Auftrag von *Casper van Heck
>> *Gesendet:* Mittwoch, 21. September 2016 14:25
>> *An:* fieldtrip at science.ru.nl
>> *Betreff:* [FieldTrip] Lost reference location
>>
>>
>>
>> Dear all,
>>
>>
>>
>> We've recently started working on an old dataset, but have ran into a
>> problem; nobody bothered to write down where the reference was placed...
>> Does anybody have ideas on how to reconstruct the location of the
>> reference, based on (some aspect of) the data?
>>
>>
>>
>> Best regards,
>>
>>
>>
>> Casper van Heck and Tineke van Rijn
>>
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>
>
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