[Eeglablist] cluster ERP projected on scalp electrodes
Marco Bellami
mrcbellami at gmail.com
Mon Jun 10 10:25:46 PDT 2013
Hi All,
I performed an ICA decomposition on my raw EEG data (for each subject
and condition). Then, I created a STUDY and a design and I clustered ICs.
Now, I want to calculate, for each cluster and condition of my design,
the projection of the ERP of the cluster on the channels and I'd like to
know if my approach is correct.
First, I calculated the projection on the scalp of each component of
each cluster (using the icaproj function). Then, I averaged the
projected ERPs between the components of the same cluster:
for example, let clust=1
for cond = 1:total_conditions % choose a condition (from STUDY.condition)
% compute average cluster ERP projected on EEG channels
for ic = 1:length(STUDY.cluster(clust).allinds{cond}) % for
each component in the cluster
design_idx = STUDY.cluster(clust).setinds{cond}(1,ic);
setidx = STUDY.design(design_number).cell(design_idx).dataset;
%select the component
comp = STUDY.cluster(clust).allinds{cond}(1,ic);
%load the dataset with the selected component
[ALLEEG EEG CURRENTSET] = pop_newset(ALLEEG, EEG,
CURRENTSET,...
'retrieve',setidx,'study',CURRENTSTUDY);
winvs =
ALLEEG(setidx).icawinv(:,:)*STUDY.cluster(clust).topopol(ic);
% calculate the projection of the IC on all channels
prjics(:,:,ic)=icaproj2(mean(ALLEEG(setidx).data(:,:,:),3),pinv(winvs),comp);
end;
%average projection over trials
prjclus=mean(prjics,3);
Thanks,
Marco
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