Trigger Problem
Posted: Tue Jun 19, 2018 11:13 am
Hi everyone,
In the lab, we are currently working with the BioSemi system.
Everything was fine until someone accidentally plugged out the cables connecting the stimulus computer to BioSemi.
After plugging all the cables back in, we are seeing extra trigger numbers during recording:
in the top row: we see our actual trigger numbers but with each a zero beneath them.
in the bottom row: the trigger numbers for the response box press are normally 0 & 1 but now are 2 & 3. Sometimes we also see a bunch of 2s here.
Additionally (maybe due to the extra numbers displayed during recording) when we try to analyze the EEG data, our actual trigger numbers are not saved in the bdf file but for every trigger number the number + 512 is saved. Sometimes this is also a mixture of the actual number and the number + 512. We also experienced for some participants that 1 trigger is missing or a trigger has occurred twice while this should only be once.
Can this be due to a bad connection of the cables to the stimulus computer?
Should I reinstall all the software again?
Thanks in advance!
Jaana
In the lab, we are currently working with the BioSemi system.
Everything was fine until someone accidentally plugged out the cables connecting the stimulus computer to BioSemi.
After plugging all the cables back in, we are seeing extra trigger numbers during recording:
in the top row: we see our actual trigger numbers but with each a zero beneath them.
in the bottom row: the trigger numbers for the response box press are normally 0 & 1 but now are 2 & 3. Sometimes we also see a bunch of 2s here.
Additionally (maybe due to the extra numbers displayed during recording) when we try to analyze the EEG data, our actual trigger numbers are not saved in the bdf file but for every trigger number the number + 512 is saved. Sometimes this is also a mixture of the actual number and the number + 512. We also experienced for some participants that 1 trigger is missing or a trigger has occurred twice while this should only be once.
Can this be due to a bad connection of the cables to the stimulus computer?
Should I reinstall all the software again?
Thanks in advance!
Jaana