[Eeglablist] Help on ICA components in data analysis

[Makoto Miyakoshi]

Dear Imali,

No, your dipoles are not coregistered correctly. Redo the head modeling.

>Their selected activations are in visual, mid central and left motor
cortex. Therefore I was looking at selecting components 1, 8, 10, 16,
17,18, 22, 23,25 for the connectivity analysis.

This seems fine.
Always remember that the more ICs you include, the more difficult it is for
SIFT to model the network well. If you don't see good results in modeling,
try to reduce the number of ICs (though 9 ICs should be fine).

Makoto

2013/3/21 IMALI THANUJA HETTIARACHCHI <ith at deakin.edu.au>

>  Dear Makoto,****
>
> ** **
>
> Things have been held up on our own data collection as there has been
> amendments for the ethics approval.  ****
>
> ** **
>
> Therefore I decided to go ahead with some available real data for my
> connectivity analysis. I downloaded and had a good exploring on the
>   animal/distractor task data available on
> http://sccn.ucsd.edu/~arno/fam2data/publicly_available_EEG_data.html . ***
> *
>
> ** **
>
> What I need to do is to identify and extract the ICA activations (source
> waveforms) of the components that look like neural activity for this visual
> categorisation task.  I initially looked at the ICA maps for the subject
> ‘cba’ on the ‘animal’ task (cbaanimal.set) and the the component maps are
> as follows;****
>
> ****
>
> ** **
>
> However when I looked at the dipole locations also available with the data
> set, the 1st dipole corresponding to the 1st ICA component was in the
> attached figure. This was a bit confusing as the component 1 clearly is a
> bilateral occipital dipole.  ****
>
> ** **
>
> **1.)    **Do you see any reason for this? And/or what can I do to fix
> this?****
>
> ** **
>
> **2.)    **Also accordin to the first published work on this data set
>
> ****
>
> Delorme, A., Rousselet, G., Mace, M., Fabre-Thorpe M. Interaction of
> Bottom-up and Top-down processing in the fast visual analysis of natural
> scenes*. Cognitive Brain Research*, 103-113. Author's PDF<http://www.sccn.ucsd.edu/%7Earno/mypapers/DelormeCBR2003.pdf>
> ****
>
> ** **
>
> Their selected activations are in visual, mid central and left motor
> cortex. Therefore I was looking at selecting components 1, 8, 10, 16,
> 17,18, 22, 23,25 for the connectivity analysis.****
>
> ** **
>
> Do you think these are reasonable?****
>
> ** **
>
> I really appreciate any guidance and help that you can give for my
> analysis.  Thank you very much for your valuable time. ****
>
> ** **
>
> Kind regards****
>
> Imali****
>
> * *
>



-- 
Makoto Miyakoshi
JSPS Postdoctral Fellow for Research Abroad
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego
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