[Eeglablist] neck mucles and ICA

[Pedro Reis]

Hi Klaus,

Thanks for the reply. I am using a 64 electrode cap with 4 extra sEMG sensors and have been trying to figure out if the muscle decomposition would work as well with just these electrodes. 

Although I believe that it is possible to remove muscle artifacts this way. There are some that think it is not or having trouble with it.

Maybe we can talk among ourselves, find consensus and make development swifter :) ( Pål Gunnar Larsson <pall at ous-hf.no> ; Guillaume Chanel <Guillaume.Chanel at unige.ch>


Regards,

Pedro Reis

Department of Sport and Exercise Medicine
Friedrich-Alexander Universität Erlangen-Nürnberg
Institute of Sport and Sport Sciences
Gebbertstr. 123b
91058 Erlangen

Tel.: 0049 9131 85 20754

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On 2012/01/26, at 07:47, Klaus Gramann wrote:

> Hi Pedro,
> 
> Just wanted to make sure you got my reply to your EEGLAB question re neck muscles as I never received any copy of my reply through the list server.
> In case you didn't get the email before please see below,
> 
> Klaus
> 
> 
> Anfang der weitergeleiteten E‑Mail:
> 
>> Von: Klaus Gramann <klaus.gramann at gmail.com>
>> Datum: 11. Januar 2012 22:53:38 MEZ
>> An: Pedro Reis <Pedro.Reis at sport.uni-erlangen.de>
>> Kopie: eeglablist at sccn.ucsd.edu
>> Betreff: Re: [Eeglablist] neck mucles and ICA
>> 
>> Pedro,
>> 
>> from my experience, additional EMG electrodes (or simply EEG electrodes places below the inion down the neck) will defnitively help to identify sources reflecting neck muscle activity. In our experiments we were able to identify several neck muscles distributed symmetrically to both sides of the neck. This is what you would expect given the high number of posterior neck muscles including prominent sternocleidomastoideus activity. You can see some of the muscle component cluster from a study of treadmill walking and running in a recent paper (http://www.frontiersin.org/human_neuroscience/10.3389/fnhum.2010.00202/full - see figure 1 for IC clusters representing neck muscle activity). 
>> 
>> The more electrodes you have to cover the neck (and of course other areas with supracranial and facial muscels) the better you will be able to decompose ICs reflecting single muscle activity. We used 256 channels with an infracerebral cap that allowed us to record neck EMG activity starting somewhere above C3-C4. However, dependent on the kind of movements your participants will perform a special neck band to apply the electrodes or single electrodes attached with adhesive tape might work better (e.g., for rotational movements of the head). You mentioned sEMG electrodes which I assume will do the same. One problem to be considered is the assumption of stationarity for activity originating from certain muscles during rotations of the head. This assumption might not be valid because of the movements of some muscles during contraction. 
>> 
>> From our results it looks as if the equivalent dipole models for neck muscle ICs are located at or near the attachment of the neck muscles to the skull, i.e. for most of the medial neck muscles between the inferior and superior nuchal line. The sternocleidomastoideus will have dipole locations close to the mastoid processes.
>> 
>> So yes, additional electrodes placed at the neck will help you identifying neck muscle activity and with enough electrodes you might be able to distinguish several different neck muscles.
>> 
>> Hope that helps,
>> 
>> Klaus
>> _________________________________
>> 
>> Klaus Gramann
>> 
>> Institute of Cognitive Science
>> University of Osnabrueck
>> Albrechtstrasse 28
>> 49076 Osnabrück
>> 
>> Tel: +49-541 969.3353
>> Fax:+49-541 969.3381
>> Email: kgramann at uni-osnabrueck.de
>> __________________________________
>> 
>> 
>> On Wed, Jan 11, 2012 at 10:22 AM, Pedro Reis <Pedro.Reis at sport.uni-erlangen.de> wrote:
>> Dear colleagues,
>> 
>> Does anyone know if placing a couple of sEMG electrodes on the neck back muscles help ICA/AMICA to remove muscle artifact components? 
>> 
>> regards,
>> Pedro Reis
>> 
>> Department of Sport and Exercise Medicine
>> Friedrich-Alexander Universität Erlangen-Nürnberg
>> Institute of Sport and Sport Sciences
>> Gebbertstr. 123b
>> 91058 Erlangen
>> 
>> Tel.: 0049 9131 85 20754
>> 
>> 
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