[Eeglablist] Compatability and artifact identification issues

[Scott Makeig]

Johan -

Yes, ICA decomposition should return 1 or more ECG component(s). Removing
them from t he data, should remove the ECG -- unless you have widely
separated EMG electrodes such that each of them records a separate EMG and
ECG ( if from local ECG effects rather than volume conduction). In that
case, a single-channel component map could account for both local ECG and
EMG effects. Use enough data! (see the tutorial for estimates).

Scott Makeig

On Tue, Dec 1, 2009 at 9:47 AM, Johan <johanvandermeer at gmail.com> wrote:

> Hello!
>
> I, too, am looking for something that can remove artifacts from the
> EMG. In particular I want to remove ECG artifacts from the (surface)
> EMG recorded from muscles in the neck. This ECG artifact is
> particularly nasty when you try to calculate EMG-EMG coherence
> spectra. High-pass filtering alone won't cut it to succesfully remove
> the ECG artifact.
>
> The AAR1.3 has some functionality to remove EOG artifacts from EEG,
> but makes no mention what to do to/how to proceed to remove ECG from
> surface EMG. I do have a separately recorded ECG signal.
>
> Is there anything you could recommend?
>
> Regards,
>
> Johan van der Meer, PhD Stud.
> Academic Medical Centre, Amsterdam
>
>
>
>
>
> On Mon, Oct 12, 2009 at 6:37 PM, Klados Manousos <mklados at gmail.com>
> wrote:
> > Dear Jordan
> >
> > Automatic Artifact Rejection (AAR) Plugin for EEGLAB is availiable in the
> > EEGLAB's site. As i quickly see in the paper mentioned above they use LMS
> > algorithm for the implementation of the adaptive filters. AAR includes
> LMS
> > algorithm so you can use it (or mode it as you like...for the cascading).
> > Except LMS AAR includes another 4 (i thing) regression-based algorithms
> for
> > artifact rejection. According to my analysis and my opinion (which is
> going
> > to be published soon) among the regression techinques Schlogl's algorithm
> > (Schlogl,2007) seem to have better performance. This aglorithm doesn't
> > included in the AAR but it is very easy in it implementation. I have to
> > mention that Schlogl algorithm uses one step for the computation of
> > propagation coefficients and not an iterative procedure as adatpive
> filters.
> > If you still want to use an adaptive filter included in the AAR i propose
> > you to use LMS. Comparison's results (Klados,2008) suggest that LMS
> performs
> > well in EEG data.
> >
> >
> > Schlogl, C. Keinrath, D. Zimmermann, R. Scherer, R. Leeb, G.
> Pfurtscheller,
> > “A fully automated correction method of EOG artifacts in EEG recordings”
> ,
> > Clinical Neurophysiology 118 (2007) 98–104.
> > Ghirnikar, A.   Alexander, S.T. Stable recursive least squares filtering
> > using an inverse QR decomposition. IEEE International Conference on
> > Acoustics, Speech and Signal Processing 1990 ICASSP-90, 1990; 3 :
> 1623-1626
> > M.A.Klados, C. Papadelis, C.D. Lithari and P.D. Bamidis. The Removal Of
> > Ocular Artifacts From EEG Signals: A Comparison of Performances For
> > Different Methods, J. Vander Sloten, P. Verdonck, M. Nyssen, J. Haueisen
> > (Eds.): ECIFMBE 2008, IFMBE Proceedings 22, pp. 1259–1263, 2008
> >
> >
> > 2009/10/8 Power elf, Jordan <J.PowerElf2 at nuigalway.ie>
> >>
> >> Compatibility and artifact attenuation issues
> >>
> >> Dear EEGLAB members,
> >>
> >> I am currently conducting an electroencephalography experiment with the
> >> neuroscience division of the National University of Ireland Galway.
> During
> >> the experimental design phase I encountered much discussion about the
> >> algorithms used to attenuate artifact interference in the EEG signal.
> Many
> >> papers seem to agree that the only means of accounting for ECG and EOG
> >> artifacts is to record these signals simultaneously on a different
> channel.
> >> Once the data is collected it can then be processed using filtering
> methods.
> >> These papers (such as "Artifact removal from EEG signals using adaptive
> >> filters in cascade") include many advanced algorithms to account for
> these
> >> artifacts once all the data has been recorded. Unfortunately the sheer
> scale
> >> of my experiment makes the manual processing of my data a prohibitive
> >> prospect. I was wondering if EEGlab included a facility that applied
> these
> >> adaptive filter algorithms automatically when presented with the raw eeg
> >> data and the EKG and EOG artifacts. I would also like to know if eeglab
> is
> >> compatible with labchart, the program i am using to record my data.
> >>
> >>
> >> Any help you could provide would be greatly appreciated,
> >> Jordan
> >>
> >> _______________________________________________
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> >
> >
> >
> > --
> > Klados A. Manousos
> > Graduate Student, Research Assistant
> > Group of Applied Neurosciences
> > Lab of Medical Informatics, Medical School
> > Aristotle University of Thessaloniki
> > Thessaloniki, Greece
> > _________________________________________________
> > Tel: +30-2310-999332
> > Website: http://lomiweb.med.auth.gr/gan/mklados
> >
> >
> >
> >
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-- 
Scott Makeig, Research Scientist and Director, Swartz Center for
Computational Neuroscience, Institute for Neural Computation, University of
California San Diego, La Jolla CA 92093-0961, http://sccn.ucsd.edu/~scott
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