<div dir="ltr">Dear Alexander,<div><br></div><div><span style="font-size:12.5714282989502px">> After following this pipeline, this data set is basically composed of</span><br style="font-size:12.5714282989502px"><span style="font-size:12.5714282989502px">flat lines except for a few short periods with pikes.</span><br></div><div><span style="font-size:12.5714282989502px"><br></span></div><div><span style="font-size:12.5714282989502px">My brute suggestion: check the scale when you see these flat lines. What does it say?</span></div><div><span style="font-size:12.5714282989502px"><br></span></div><div><span style="font-size:12.5714282989502px">> When checking the data visually before epoching, I do not </span><span style="font-size:12.5714282989502px">notice anything odd or peculiar, but after epoching all most everything </span><span style="font-size:12.5714282989502px">becomes flat.</span><span style="font-size:12.5714282989502px"><br></span></div><div><span style="font-size:12.5714282989502px"><br></span></div><div><span style="font-size:12.5714282989502px">It's hard to imagine the epoching function misbehaves; however, I know I tend to noticed something weird after epoching. Let's get more info for troubleshooting.</span></div><div><span style="font-size:12.5714282989502px"><br></span></div><div><span style="font-size:12.5714282989502px">Makoto</span></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Jun 10, 2015 at 12:01 PM, Alexander Quent <span dir="ltr"><<a href="mailto:alexander.quent@rub.de" target="_blank">alexander.quent@rub.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Dear eeglab users,<br>
I have encounter a weird problem. I followed Makoto's pipeline for<br>
pre-processing with a small deviation that I used linked mastoids rather<br>
than average reference but I cannot imagine this causing my problem.<br>
I pre-processed 27 data sets and all but one show satisfactory results<br>
after pre-processing.<br>
After following this pipeline, this data set is basically composed of<br>
flat lines except for a few short periods with pikes. I tracked the<br>
problem down to the function<br>
pop_epoch. When checking the data visually before epoching, I do not<br>
notice anything odd or peculiar, but after epoching all most everything<br>
becomes flat.<br>
<br>
Since I am a brute beginner, I indeed have no clue where the problem<br>
might have hid. Have anybody encountered something similar?<br>
<br>
With best regards<br>
Alexander Quent<br>
<br>
<br>
Appendix:<br>
% for a = 4:length(population)<br>
% EEG =<br>
pop_fileio(strcat('C:\Users\Joern\Documents\MATLAB\Daten\BA\eeg\',<br>
population{i},'.eeg')); % loads data file<br>
% if a < 12<br>
% EEG = pop_loadset('filename',<br>
strcat(population{a},'_Cut.set'),'filepath','C:\Users\Joern\Documents\MATLAB\Daten\BA\eeg\wholeData');<br>
<br>
% else<br>
% EEG =<br>
pop_fileio(strcat('C:\Users\Joern\Documents\MATLAB\Daten\BA\eeg\wholeData\',<br>
population{a},'.eeg')); % loads data file<br>
% end<br>
% EEG.setname = strcat(population{a},'_Processed.eeg'); % names<br>
dataset for continuous data<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = pop_cleanline(EEG,<br>
'bandwidth',2,'chanlist',[1:32] ,'computepower',1,'linefreqs',[50 100]<br>
,'normSpectrum',0,'p',0.01,'pad',2,'plotfigures',0,'scanforlines',1,'sigtype','Channels','tau',100,'verb',1,'winsize',4,'winstep',1);<br>
<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = pop_eegfiltnew(EEG, [], 1, 1650, true, [], 1);<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = pop_editset( EEG, 'chanlocs',<br>
'C:\\Users\\Joern\\Documents\\MATLAB\\eeglab_current\\eeglab13_4_4b\\sample_locs\\neuroscan_32_EOGincluded.ced');<br>
<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = eeg_checkset( EEG );<br>
% EEG.data = EEG.data - repmat(EEG.data(17, :) * 0.5,<br>
[EEG.nbchan 1]); % Re reference to linked mastoid, see also<br>
<a href="http://sccn.ucsd.edu/pipermail/eeglablist/2012/005585.html" rel="noreferrer" target="_blank">http://sccn.ucsd.edu/pipermail/eeglablist/2012/005585.html</a><br>
% EEG = pop_select( EEG,'nochannel',{'REFlinks'});<br>
% EEG = pop_rejchan(EEG, 'elec',[1:31]<br>
,'threshold',5,'norm','on','measure','kurt');<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = pop_epoch( EEG, { 'S 10' 'S 11' 'S 12' 'S<br>
13' 'S 14' 'S 15' }, [-1 2], 'newname',<br>
strcat(population{a},'_Epochs', 'epochinfo', 'yes');<br>
% display('Exclude eye channels from joint')<br>
% if length(EEG.chanlocs) < 31<br>
% EEG = pop_jointprob( EEG );<br>
% else<br>
% EEG = pop_jointprob( EEG,1,[3:26 28 29:30] ,6,2,1,0);<br>
% end<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = eeg_checkset( EEG );<br>
% EEG = pop_runica(EEG, 'extended',1,'interupt','on');<br>
% EEG = eeg_checkset( EEG );<br>
% [ALLEEG,EEG,CURRENTSET,com] = pop_ADJUST_interface<br>
(ALLEEG,EEG,CURRENTSET );<br>
% EEG = eeg_checkset( EEG );<br>
% stop = input('Press 1 to continue: ');<br>
% EEG = pop_subcomp( EEG );<br>
% EEG = pop_eegfiltnew(EEG, [], 45, 148, 0, [], 1);<br>
% EEG = pop_jointprob(EEG,1,[1:length(EEG.chanlocs)]<br>
,3,3,1,0);<br>
% EEG = eeg_checkset( EEG );<br>
% pop_eegplot( EEG, 1, 1, 1);<br>
% stop = input('Press 1 to continue: ');<br>
% EEG = eeg_checkset( EEG );<br>
% for j = 1:length(conditions)<br>
% EEG =<br>
addEventsBasedCorrectness(EEG,conditions{j},triggerNums(j), responses);<br>
% EEG = eeg_checkset( EEG );<br>
% end<br>
% EEG = pop_saveset(EEG, 'filename' ,<br>
strcat(population{a},'_ProcessedERPEpochs'), 'filepath',<br>
'C:\Users\Joern\Documents\MATLAB\Daten\BA\eeg\analyzedERPLAB'); % Saving<br>
current data to file<br>
% EEG = eeg_checkset( EEG );<br>
% end<br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr">Makoto Miyakoshi<br>Swartz Center for Computational Neuroscience<br>Institute for Neural Computation, University of California San Diego<br></div></div>
</div>