[Eeglablist] recording facial EMG with monopolar montage

[Maria Serena Panasiti]

Dear Makoto,

thanks for your response. Yes I agree with you one should avoid to include
facial channels from average signal in order to have a clean eeg. Actually
my concern was about having a clean EMG signal. They say that recording
monopolar EMG instead of bipolar EMG could add some noise to the EMG
signal, this is probably due to the distance between the the electrodes? Is
there any offline procedure I can use to correct it?

Thank you very much,

Serena


On 21 January 2014 23:05, Makoto Miyakoshi <mmiyakoshi at ucsd.edu> wrote:

> Dear Maria,
>
> > I read this could add some noise to the signal but it is not completely
> clear to me why this would happen and which offline procedure I could use
> to improve the SNR.
>
> I wonder why, too.
> I can think of only one possible case: when you run average referencing.
> If you don't exclude the facial channels, you may introduce EMG into scalp
> channels. You may want to exclude facial channels from those with which
> average reference is computed.
>
> I'd like to know whether there are other factors we need to consider...
>
> Makoto
>
>  2014/1/20 Maria Serena Panasiti <m.serenapanasiti at gmail.com>
>
>>  Dear List,
>>
>> we are setting up an experiment in which we would like to simultaneously
>> record EEG and facial EMG. Unfortunately at the moment we just have
>> monopolar amplifiers so we were wondering if it was actually possible to
>> measure a clean EMG activity by using monopolar  electrodes (with  cephalic
>> ground and reference) and by then offline subtracting the two channels. I
>> read this could add some noise to the signal but it is not completely clear
>> to me why this would happen and which offline procedure I could use to
>> improve the SNR.
>>
>> Any help would be very much appreciated!
>>
>> Best wishes,
>>
>> Serena
>>
>> --
>> Maria Serena Panasiti, Ph.D
>>
>> Cognitive Social and Affective Neuroscience Lab
>> Department of Psychology.
>> University of Rome "La Sapienza".
>> Via dei Marsi 78 - 00185 - Roma.
>> Phone: (+39) 06-49917635. Fax: (+39) 06-49917635
>>
>> School of Psychology & Clinical Language Sciences
>> University of Reading
>> Reading, United Kingdom
>>
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>
>
>
> --
> Makoto Miyakoshi
> Swartz Center for Computational Neuroscience
> Institute for Neural Computation, University of California San Diego
>



-- 
Maria Serena Panasiti, Ph.D

Cognitive Social and Affective Neuroscience Lab
Department of Psychology.
University of Rome "La Sapienza".
Via dei Marsi 78 - 00185 - Roma.
Phone: (+39) 06-49917635. Fax: (+39) 06-49917635

School of Psychology & Clinical Language Sciences
University of Reading
Reading, United Kingdom
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