EEGLAB not loading events properly

Question

I recorded EEG data for Motor Imagery using BCI2000. Motor Imagery involved two simple tasks (Subject was asked to imagine moving right hand, when Stimulus 1 appears and left foot when stimulus 2 appears).

I loaded the data into EEGLAB and a window poped up to “Select Events”(Figure 1)Figure 1 showing events list which has options like “StimulusCode”, “StimulusType”,”StimulusBegin” etc. I used “StimulusCode(Each Stimulus is associated with different number, in my case it’s 1 for 1st stimulus and 2 for 2nd stimulus)”.

When I looked at my data (using Plot>Channel Data Scroll)Figure 2 showing EEG data with selected event all I see is a word “StimulusCode” , but not the number associated with the stimulus.

1. Why is EEGLAB not displaying my Stimulus Code,
2. Do I need to change any settings in BCI2000 during data acquisition(I loaded the sample BCI2000 data provided by BCI2000 for tutorial purposes onto EEGLAB, even for those data sets above problem occurs)
3. Do I need to import separate event list into EEGLAB, if so How can I do it?

Answer 1

According to the BCI2000 import tutorial:

http://www.bci2000.org/wiki/index.php/User_Reference:EEGLabImport#Load_the_TestData.dat_Data_Set)

Your event type (for example "StimulusCode") will be in the EEG.event.type field, while the value of that stimulus code will be in the EEG.event.position field.

If you want to replace the text "StimulusCode" with the actual code value, for example for plotting, you could do something like this:

for eIdx = 1:length(EEG.event)
   EEG.event(eIdx).type = EEG.event(eIdx).position;  
end
EEG = eeg_checkset(EEG);