Import batch EDF files of different length

Dear Francois,

I try to upload of bunch of EDF+ files from the same folder (same subject/similar electrode configuration, essentially continuous raw iEEG data constituting background activity fragments from the same recording, baseline EEG), either via GUI or Process into one condition (common for all), but these EDF files are of different length, however, the imported raw tracing lengths are of the same length based on the 1st file imported. If I import them one by one, I do not have this issue and they are of different, and the correct, length. Is there a way to import them all as batch (select all from the input folder) at once at their original length? After import, I want to concatenate them in a single long continuous raw file, but keeping some info of the length of each in the file structure if I need to resplit them later. Next, they will be destined for ex processing in matlab. Please help,

Thank you,
Octavian

Dear Octavian,

Indeed, if you try to import multiple files with the interface, it will use the length of the first file in the list for all the files.
You can go around this limitation with the process “Import MEG/EEG: Time”: When selecting multiple files with different length, select the check box “All file” in the process options.
If you generate a Matlab script from the pipeline editor, this corresponds to leaving empty the option ‘timewindow’ (empty matrix: []).

After importing the files, you can add a marker to each of them to mark the beginning of the file (adding it to the field .Events). There is no process to do this, but you can just add the field in the file with the save() function.
The events structure is described in the tutorials: http://neuroimage.usc.edu/brainstorm/Tutorials/Epoching#On_the_hard_drive

Then you can run the process “Standardize > Concatenate time”.
I’ve just fixed it so it updates the timing of all the blocks correctly: update Brainstorm before you try it out.

Cheers,
Francois

Thank you Francois, it works!
Octavian