[Eeglablist] why ICA is reference-free?

[Iman M.Rezazadeh]

Hi, 

Yes, I did ! but I think it does not answer my question thoroughly . It
talks about the Rank in matrix and reducing it after referencing !

-Iman 

 

From: Makoto Miyakoshi [mailto:mmiyakoshi at ucsd.edu] 
Sent: Monday, March 17, 2014 5:29 PM
To: Iman M.Rezazadeh
Cc: EEGLAB List
Subject: Re: why ICA is reference-free?

 

Dear Iman,

 

Did you check out this page?


http://sccn.ucsd.edu/wiki/Linear_Representations_and_Basis_Vectors#EEG_Data_
Reference_and_Re-referencing

 

Makoto

 

2014-03-17 16:30 GMT-07:00 Iman M.Rezazadeh <irezazadeh at ucdavis.edu
<mailto:irezazadeh at ucdavis.edu> >:

Hi, 

Could you please elaborate why ICA is reference-free? In other words, does
different kinds of referencing methods (avg-ref or .) effect on ICA maps and
source series ? 

Suppose: x(t) is the signal then we have s(t)=M(^-1). x(t) ;where s(t) is
source signals and M is the mixing matrix.

Now how come for  y=x(t)-r(t) -  where r(t) is another reference-  result
same/different maps and source series would be obtained and how could
someone get the same dipole locations with different re-referencing methods?

 

It would be great if someone gives in depth methodological and mathematical
explanations rather than just qualitative explanations.

 

Best

Iman

 

-------------------------------------------------------------

Iman M.Rezazadeh, Ph.D

 

Research Fellow

Semel Intitute, UCLA , Los Angeles

& Center for Mind and Brain, UC DAVIS, Davis

 

 

 





 

-- 

Makoto Miyakoshi
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego

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