[Eeglablist] ICA decomposition of possibly 2 different conditions....

[Marco Congedo]

Hello Klados,

   you can use the fact that you have two conditions explicitly to recover
sources characteristic of each condition. The appropriate framework is
described in length in

On the blind source separation of human electroencephalogram by approximate
joint diagonalization of second order
statistics.<http://www.ncbi.nlm.nih.gov/pubmed/18993114?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=2>

Congedo M, Gouy-Pailler C, Jutten C.
Clin Neurophysiol. 2008 Dec;119(12):2677-86.

Cheers,
Marco Congedo
Senior Scientist, cnrs
GIPSA-lab Grenoble

On Tue, Jan 12, 2010 at 11:42 PM, Klados Manousos <mklados at gmail.com> wrote:

> Dear IIya
>
> According to my opinion i suppose that you have to separate them because
> other pools of neuron (different sources) are activated with eyes opened and
> other with eyes closed...And if you see the mathematical background because
> you have a two condition experiment the underlying sources will be more than
> in one codition....so some sources will be merged in one component...i think
> that it is not preferable...it is better to reduce "normally" your data
> dimensionality by separating the recording session....and a 2 mins record is
> not a short epoch for ICA...There is an heuristic rule which says that ICA
> can be succesfully applied in epochs with sample points grater than
> channel^2 => Sample Points>= Channels^2.
>
> I hope to helped you...
>
> 2010/1/12 Ilya Adamchic <dr.ilya at yahoo.com>
>
>>  Dear All.
>>
>>
>> We have an experiment set up, when a patient should sit 2 min with eyes
>> closed and 2 min with eyes open and so on several times. This is a
>> spontaneous recording: no actions are performed in both conditions. When we
>> perform ICA decomposition, is it reasonable to leave these 2 conditions
>> mixed as a continuous file and let ICA decompose the continuous file. Or we
>> need to separate eyes closed from eyes open conditions and only then perform
>> ICA on the short epochs, which might be to short (2 min) for the 128 channel
>> decomposition.
>>
>> Thank you all for your replies in advance.
>>
>>
>> _______________________________________________
>> 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
>>
>
>
>
> --
> Klados A. Manousos
>  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
>
>
>
>
> _______________________________________________
> 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
>



-- 
Marco Congedo
http://www.lis.inpg.fr/pages_perso/congedo/MC_Home.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20100113/9739f4ce/attachment.html>