[Eeglablist] changing the epoch duration

[Cockburn, Jeffrey]

I found that a simple solution is to remove event by latency after epoching
the data.

% epoch the data to the events of interest
EEG = pop_epoch( EEG, {  'event_of_interest'  }, [-2  2], 'epochinfo',
'yes');

% remove all events from each epoch not at time-point 0
EEG = pop_selectevent( EEG, 'latency','-0.01<=0.01','type', {'
event_of_interest'},'deleteevents','on','deleteepochs','off','invertepochs','off');

After removing all events other than those of interest, you can re-epoch the
data without worrying about duplicate events being captured. Hope that helps
anyone else having the same issue.

-- Jeff

On Wed, May 4, 2011 at 5:23 PM, Tarik S Bel-Bahar
<tarikbelbahar at gmail.com>wrote:

> a possible solution may be to specify the time window for event of
> interest,
> or renaming every first event that you are looking for in each epoch, so as
> to eliminate the "multiple same events" problem. please let me as well as
> eeglab list know if you come up with a solution that works for you.
>
> Overall, it seems that it would be useful to also have a de-epoching
> function in EEGLAB.
>
> Please let me and EEGLAB list know
>
> On Tue, May 3, 2011 at 10:18 AM, Cockburn, Jeffrey <
> jeffrey_cockburn at brown.edu> wrote:
>
>> Greetings.
>>
>> I like to take long epoch durations to give ICA a little more data to work
>> with (about 5 seconds from start to finish surrounding my events of
>> interest). After running ICA and extracting the components I need, I would
>> like to reduce the epoch duration around the events of interest (about 1
>> second from start to finish). I can't use the 'extract epochs' function
>> because this produces duplicate events since the original 5 second epoch
>> window captures more than one event of interest in each epoch. I've also
>> tried manually reshaping EEG.data and EEG.times, but this seems to confuse
>> EEGlab as to when events occur in relation to the raw EEG data. Is there an
>> easier way to do this?
>>
>> Thanks
>>
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