EEG lab conversion

[polivaoren]

Hi. I'm getting contradicting results when converting to EEGlab format. When I load the dat file to MatLab with load_bcidat.m function I get a signal with 197720 time points. However, when I convert to EEGlab with pop_loadBCI2000.m I get 209280 time points. What is the meaning of this difference?

[mellinger]

Hi,

welcome to the BCI2000 forum.

pop_loadBCI2000.m actually uses load_bcidat.m internally, so there should be no differences.
If the problem persists, I would appreciate if you sent me an example file for which this happens, as a private message.

Best regards,
Jürgen

[polivaoren]

Found my mistake. It occurred because I uploaded the filename with an event( EEG = pop_loadBCI2000(filename,{'StimulusCode'}); ). But that leads to a follow up issue/question. When I load BCI, I can go to states and find my variables (StimulusCode). But how do I access this variable after I convert to EEGlab (and without changing the number of time points as we discovered here)?

PS I tried to attach to this thread an example dat file, but the system is sending me an error 'Invalid file extension'

[mellinger]

Events are available as EEG.events, but they are present there in "compressed" form, i.e. only changes are recorded.
If you use pop_loadBCI2000.m from inside EEGLAB, state information will be present in the GUI.
If you are not using EEGLAB, I am not sure why you would want to use pop_loadBCI2000.m instead of load_bcidat.

Upload of raw data to this forum is not possible, but you may send me a private email to mellinger@neurotechcenter.org.