[Eeglablist] ICA vs. regression-based artifact correction effects on sensor level phase

[Baris Demiral]

Hi Manousos,

Thank you for pointing out the link, I am actually aware of your
paper, and I think it is a good alternative to just taking out the
artifactual ICs by visual inspection.
I have some questions though:

a) As I understand, you apply regression based correction on the
artifactual ICs by using EOG channels. How do you decide which ICs are
artifactual at the first place?

b) Are the EOGs recorded as monopolar or bipolor? I assume they are
monopolar. Does it matter?

c) Do you include EOGs in the ICA?

Overall, my question initially was theoretical, to asses how much
impact such corrections have on phase information and connectivity.

Thanks,
Baris


On Sat, Feb 18, 2012 at 2:21 PM, Manousos Klados <mklados at med.auth.gr> wrote:
> Dear Baris,
>
> Check this out-->
> http://www.sciencedirect.com/science/article/pii/S1746809411000061 Manousos,


>
> REGICA is a hybrid method combining the ICA with the regression-based
> techniques, dealing with the known problems of both methodologies...
>
> If you search the EEGLAB site you can find the REGICA plugin...
>
> Best Regards
>
> Manousos Klados
>
> 2012/2/16 Baris Demiral <demiral.007 at googlemail.com>
>>
>> Hi,
>>
>> Here are the questions:
>>
>> a) If we take out artifactual ICs (say, eye blinks), do the final
>> sensor data loose their crucial phase information?
>> b) If we apply linear regression based algorithms to exclude
>> artifacts, will this influence the sensor level phase information?
>> c) How do these two methods influence sensor based connectivity analysis?
>> d) Which sensor-based connectivity measures are robust against volume
>> conduction?
>>
>> I favor source- and ICA-based multivariate connectivity analyses where
>> you really do not need to take out ICs, but work on the components of
>> interest.
>> But, there are plenty of papers out there reporting only pairwise
>> sensor connectivity while ignoring the effects of volume conduction
>> and artifact correction.
>>
>> Thanks,
>> Baris
>> --
>> Ş. Barış Demiral, PhD.
>> Department of Psychiatry
>> Washington University
>> School of Medicine
>> 660 S. Euclid Avenue
>> Box 8134
>> Saint Louis, MO 63110
>> Phone: +1 (314) 747 1603
>>
>> _______________________________________________
>> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
>> To unsubscribe, send an empty email to
>> eeglablist-unsubscribe at sccn.ucsd.edu
>> For digest mode, send an email with the subject "set digest mime" to
>> eeglablist-request at sccn.ucsd.edu
>
>
>
>
> --
> Manousos A. Klados
> ________________________________________________
> B.Sc Mathematics
> M.Sc Medical Informatics
> ________________________________________________
> PhD Candidate -- Research Assistant
> Group of Applied Neurosciences
> Lab of Medical Informatics
> School of Medicine
> Aristotle University of Thessaloniki
> P.O. Box 323 54124 Thessaloniki Greece
> _________________________________________________
> Tel: +30-2310-999332
> Fax:+30-2310-999263
> Website: http://lomiweb.med.auth.gr/gan/mklados
>
> ________________________________________________________________
> Δρώ γιατί Αντιδρώ: Δεν τυπώνω αυτό το mail γιατί προστατεύω το περιβάλλον.
> Acting by Reacting: By not printing this e-mail I help protect the
> environment.
> ________________________________________________________________
>



-- 
Ş. Barış Demiral, PhD.
Department of Psychiatry
Washington University
School of Medicine
660 S. Euclid Avenue
Box 8134
Saint Louis, MO 63110
Phone: +1 (314) 7477 1603