[Eeglablist] Removal of ocular artifact from EEG using ICA

[Stefan Debener]

Take all 32 channels (except bipolar channels), eye blinks contribute 
(with different weights) to all channels. You may evaluate the quality 
of ICA-based artifact correction by comparing the voltage maps at eye 
blink peak latencies before and after correction. Let's assume dataset 1 
is the uncorrected and dataset 2 is the corrected cnt file, and 'lat' 
contains the latency (in sampling points) of an eye blink of interest:

 >>figure;
 >>subplot(1,2,1);
 >>topoplot(ALLEEG(1).data(:,lat), EEG.chanlocs);
 >>subplot(1,2,2);
 >>topoplot(ALLEEG(2).data(:,lat), EEG.chanlocs);

Hope this helps,
Stefan



KRISHNAVENI THIRUMURTHY wrote:
> Dear Sir,
>  
> I am working with ICA algorithms for removing ocular artifacts from EEG. I have 
> downloaded the data from
>  
> http://www.sccn.ucsd.edu/~arno/famzdata/publicly_available_EEG_data.html
>  
> EOG interference will be dominant in the EEG recorded from the electrodes placed 
> on the patient’s forehead. Hence, samples from the frontal channels are taken 
> for analysis. I have taken 10 frontal channels and fed that as input to ICA 
> algorithm and from the independent components obtained, ocular artifacts are 
> identified and removed from the original data.
>  
> My question is,
>  
> Since the recorded signals are assumed to be linear combination of all the 
> source signals, should i take all the 32 channels for my analysis, or is it 
> sufficient to take only 10 frontal channel recordings for my analysis.
>  
> Kindly help me in this regard.
>  
> with regards,
> Krishnaveni
>  
>  
>   
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