[Eeglablist] Rejecting data using events

[Dénes Szucs]

Hi,

I load data recomputed to average reference to EEGLab (i.e. the re-
referencing happens outside EEGLab). Is it important from the point of view of 
ICA to know this? If yes, how can I tell EEGLab that the data is alreade re-
referenced?
Thank you,
Denes

> Dear Puneet,
> 
> there is no way yet to remove events the way you mentioned using EEGLAB 
> graphic interface. However, while preserving backward compatibility, we 
> have added a duration field to each event that will be standard and 
> could be processed in EEGLAB (this was possible before but the duration 
> information could not be used in a systematic way). So we are heading in 
> that direction.
> In the meantime, you can always remove events from the command line, 
> using something like
> 
> % find events 1 latencies
> % --------------------------
> eventtypes       = cell2mat( {EEG.event.type}); % assumes number for type
> eventlatencies = cell2mat( {EEG.event.latency});
> boundaries = find(eventtypes == 1);
> eventlatencies = eventlatencies(boundaries);
> 
> % remove regions
> % ------------------
> removeregions = reshape( eventlatencies, length(eventlatencies)/2, 2);
> EEG = eeg_eegrej(EEG, removeregions)
> 
> % update GUI
> % -------------
> [ALLEEG EEG CURRENTSET] = eeg_store(ALLEEG, EEG, CURRENTSET);
> eeglab redraw;
> 
> Arno
> 
> Puneet Khattar wrote:
> 
> > We have continuous eeg data that is collected in neuroscan (cnt 
> > file) and we want to remove the artifacts. It seems that EEGLab only 
> > allows artifact rejection in continuous data through visual 
> > inspection. We went into neuroscan and set a threshold to mark the 
> > artifacts. When we imported this cnt file into EEGLab, the marked off 
> > areas that we want to reject are inbetween events of type 1. Is there 
> > a way to remove the continuous data inbetween two events? (start 
> > removing data when event 1 occurs, stop when event 1 occurs again, and 
> > repeat)
> >  
> > Puneet Khattar
> > Cognitive Neuroscience Laboratory
> > UCSD
> 
> 
> 
> -- 
> 
> *Arnaud Delorme, Ph.D.*
> Computational Neurobiology Lab, Salk Institute
> 10010 North Torrey Pines Road
> La Jolla, CA 92037 USA
> 
> *Tel* : /(+1)-858-458-1927 ext 15/
> *Fax* : /(+1)-858-458-1847/
> *Web page *: www.sccn.ucsd.edu/~arno <http://www.sccn.ucsd.edu/%7Earno>
> *To think upon*:
> 
>     If the book we are reading does not wake us, as with a fist
>     hammering on our skull, why then do we read it? A book must be an
>     ice-axe to break the sea frozen inside us.
> 
>         /Frank Kafka/  
> 
> 
> _______________________________________________
> Eeglablist mailing list Eeglablist at sccn.ucsd.edu
> Eeglablist page: http://www.sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to eeglablist-unsub at sccn.ucsd.edu
> To switch to digest mode, send an empty email to eeglablist-digest at sccn.ucsd.edu

Denes Szucs
Lecturer in Neuroscience and Education
University of Cambridge, UK
Shaftesbury Road, Cambridge, CB2 2BX, UK
Tel: +44-(0)1223 369631
Fax: +44-(0)1223 324421