Dear all,
We are using Brainstorm in combination with the Polhemus Fastrak to digitize EEG electrode positions (BioSemi, Active, 64 electrodes).
Most of the time it works really great! But sometimes we can’t digitize the last anatomical fiducial (i.e., RPA) and then everything is/looks wrong. We register the anatomical fiducials twice and it’s usually the second time that it doesn’t work. We’re not sure what we’re doing wrong. We have tried to modify the set-up several times to ensure that there is as little interference in the environment as possible. If someone has an idea what could be the cause of this, we’d really like to know!
Thanks very much,
Tam
Here are the error messages (not copy and paste but typed):
Error using set
Width and heigth must be > 0
Error in pane_digitze>CreateHeadPointsFigure (line 936)
set(hFig,‘Position’,Figure);
Error in panel_digitize>BytesAvailable_Callback (line 1499)
CreateHeadPointsFigure();
Error in instrcb (line 36)
feval(val(1),obj,eventStruct,val(2:end));
Hi Tam,
After collecting the fiducials, the digitizer opens a figure for plotting the points. It seems that the error occurs at this point. Are you using one monitor or two? If two, are you using the ‘extend’ display? Also, what version of brainstorm are you using (in the command window, type brainstorm license, the version number and date is in the splash screen.)
Beth
Hi Beth,
Thanks for the quick reply.
Yes, we use two displays but in ‘mirror’ mode - is that a problem?
I am not too sure about the Brainstorm version (I am not in the lab and someone else is collecting the data).
It’s probably 3.2.141105 or a version earlier. But we can update that easily.
What would you advise?
Tam
I don’t know what in your screen configuration causes the figure size to be set incorrectly.
I added a test to skip the line that sets the figure position if the dimensions are not correct. It will prevent this error to occur, but I don’t know where the figure would land on your screen.
It might too small to be visible, or out of the screen. If it doesn’t work correctly I would need to ask you for more details to debug this…
Please update Brainstorm and try again (menu Help > Update Brainstorm).
Hi Francois,
We’re running Matlab R2013b (64-bit) on a Windows 7 machine. The Brainstorm version is v3.2 141117.
The display settings are: 1|2 Multiple Monitors, 1920x1080, Landscape, Duplicate displays.
(Sorry I am really not in the lab, so I can’t get more information than this.)
We’ll give it a try with only one monitor next week and see whether this solves the problem.
Thanks,
Tam
Hi,
Just to update you: we tried to digitise without the second monitor (disconnect it completely) and the problems were still there.
You sure that this is a monitor-related problem? We did not update Brainstorm, btw, as we were in the middle of an experiment.
We’re still using Brainstorm for digitisation and will try out a couple of more things but if something crosses mind, please do let us know!
Thanks,
Tam
If you are using mirrored displays, the problem is probably not coming from the monitor configuration anyways.
There are two solutions you could test:
Try to run the last version of Brainstorm, just for the digitization. It would be great to know if the fix I added in the code solves your problem.
Then you can keep on doing all the data analysis with the older version of Brainstorm if you really have to.
This would work at the present time because there were no recent modifications of the database structure. In general, you should only work with one version of Brainstorm at a time, and always the most recent one.
Make sure you close Matlab between the execution of two different Brainstorm versions.
Try with a more recent version of Matlab (2014b or 2015a pre-release).
If you cannot download any newer version of Matlab, you can try running the compiled version, using the MCR 2014b.
Follow the instructions for running Brainstorm without Matlab on the Installation page of the website.
