Hello! I have started collecting data for my EEG experiment using your Stim Trigger box wirelessly connected to the CGX 20-channel headset. I am presenting auditory stimuli through Presentation. The trigger markers seem to be correctly sent by the Stim Trigger to the acquisition software. However, after importing the data in EEGlab, it looks like there is not event marker at all – see screenshot below:
Has this ever happened to anyone? I am trying to understand where the issue comes from (from the acquisition software, the stimtrigger, or EEGlab), so any suggestion is much welcome!
How were you able to tell that the trigger markers seem to be correctly sent by the StimTrigger? is that by observing the Audio LED on the front panel?
The trigger markers were sent via USB serial port. The Code A LED on the front panel lit up at every presentation and the markers seemed to be correctly being sent to the acquisition software. The .vmrk file saved from the CGX acquisition also seems to list all markers.
It looks like your issue is with EEGlab. Alas, this is outside our area of expertise.
A side question: since you have StimTracker, why did you send the event markers via USB instead of using the built-in functionality in StimTracker itself? Just curious…
Do you mean sending the marker through the audio port? The reason is practical: we are replicating an EEG experiment we conducted a few years back with a different EEG system, and we wanted to use the exact same Presentation script. We also need to mark the audio files with specific codes depending on the surrounding context, so we figured that the easiest thing to do was to minimally adjust the Presentation script as required by the new system, without any further complication.
