Electrode drift in EEG

I coudn’t find an image of electrode drift for my slides, so here I quickly generated one. The only fancy thing is the usage of datetime to have minutes on the x-axis (I also made this post so I don’t forget this trick ;))

Thanks to Anna Lisa Gert for this dataset

% Load Data
EEG = pop_loadeep_v4('subj23.cnt');
% Load filtered data (takes 35min to filter...)
EEG_filt = pop_loadset('2_subj23_lowpass_resample_deblank.set');
%%
% Convert time to actual time
timesnew = datetime(EEG.times/1000,'ConvertFrom','epochtime','Epoch','2000-01-01');
% select random channels
chix = [5,63,27];

% Plot the unfiltered data
plot(timesnew,EEG.data(chix,:)')
% Make the plot beautiful
datetick('x','MM','keeplimits','keepticks') % only show minutes
xlabel('time [min]') 
ylabel('voltage [µV]')
legend({EEG.chanlocs(chix).labels},'Location','East')
box off
title('EEG Electrode Drift (DC Amplifier, avg ref)')
set(gca,'fontsize', 14) % for a presentation
set(gca, 'FontName', 'HelveticaNeueLT Pro 45 Lt')
%%
% Convert again because data have been resampled
timesnew = datetime(EEG_filt.times/1000,'ConvertFrom','epochtime','Epoch','2000-01-01');

plot(timesnew,EEG_filt.data(chix,:)')

datetick('x','MM','keeplimits','keepticks')
xlabel('time [min]')
ylabel('voltage [µV]')
legend({EEG.chanlocs(chix).labels})
box off
title('EEG Electrode Drift (avg ref, 0.1Hz filter)')
set(gca,'fontsize', 14) % for a presentation
set(gca, 'FontName', 'HelveticaNeueLT Pro 45 Lt')