Epoching a continuous file does not grab specified time range

[kjefferiksen]

I am trying to follow Tutorial #15 to epoch a continuous recording and not seeing the expected result. This screenshot shows how I set up the epoching to use events 3 and 4:

this shows the result of the epoching with the 150 trials for each event type:

and this shows the contents of the first epoch from stim type 3:

This indicates only the first 3 sample were put into the epoch, whereas I was expecting the whole segment from -100 to + 1000 ms, about 550 samples.

What am I doing wrong?

[Sylvain]

The [ext] suffix next to the events label in the import panel indicates the events are time extended time segments, not a single time stamp. You may want to review and edit your events to make sure they are properly handled by Brainstorm.

[kjefferiksen]

I have no idea why the events look this way to BrSt. The file is in the EEGlab standard format (.SET) and works fine in EEGlab as well as ERPlab. In both of those I can properly epoch the continuous file. Is there a way in BrSt that I can edit these events to force them to be simple event markers and not extended time segments?

[Raymundo.Cassani]

Yes, it is possible to convert extended events to simple. Use the menu Events > Convert to simple event.
You will need to indicate where to place the simple event, either at the beginning, center or end of the extended event.

https://neuroimage.usc.edu/brainstorm/Tutorials/EventMarkers#Other_menus

[kjefferiksen]

Good, that is what I was hoping for, Thank you.

[Sylvain]