Importing in Database - Baseline problem

Hello,

I am having a problem with baselines for my events from SEEG data. The experiment is a basic presentation of faces with different emotions. I have added the event times from an outside .txt file and they all seem to be correctly captured in the raw data file. However when I want to import the events in database for further analysis, for some reason, I can't choose the epoch time. Is is automatically selected for me (-1000, 2000) this time window would be good but then when I open the time series for each category, the is not the 1000ms before the onset and thus I am missing my baseline.

This problem does not occur when I read the events from my trigger channel using Brainstorm. But in this case, I get 120 events that are in the same category and then I cannot distinguish between them which is crucial for the experiment.

Any suggestions what I should do? Please see the image of the 'Import in database' step.

Thank you for your help!

Daniel

Hi Daniel,

The issue here is that your events are extended (thus the [ext] in their name). As such when importing, the epoch values are ignored (-1000-2000ms) and the duration of the events is used, which I assume is 2000ms.

Solution
Change your events from extended to simple (point) events.

  • Open your raw file, then in the Event section of the Recording tab, select your Event groups
  • Go to the menu, Events > Convert to simple event
  • Here, you may want to select Start. So the simple event will be located at the beginning of the extended event, i.e, at time 0.
  • Close the figure to save the changes in the Events
  • Then proceed to import, and you should be able to set the Epoch time to -1000-2000ms or the desired values

Best,
Raymundo

Hi Raymundo,

This worked!

Thank you very much!!

Daniel