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[open] very specific recursion problem

edited January 2016 in OpenSesame


I have a very strange problem, that is also time-sensitive:

I have two experiment files that the only difference between them
is that one of them includes practice procedure and the other one don't.

The file with the practice runs just fine.
The file without the practice stops in a random time with the following msg:
"Recursion detected! Is variable 'total_responses' defined in terms of itself (e.g., 'var = [var]') in item 'Experiment'.

I tried versions 3.01 and 3.05.
This problem is specific to running on full screen in windows XP or window 10, in both OS versions.
If I run it in window it works fine.
I don't have this problem with windows 7.
Very similar experiment also works just fine.

I will really appreciate any kind of help...



Here is a link to the files. S1 works, S2 is the problematic one.
To start S2, one needs to hit "5" five times, and wait for 6 seconds.


  • edited 9:27AM

    Hi Tali,

    That this is such an unpredictable error, and that you're using the parallel plug-in, suggests that this plug-in is the source of the problem. (Although it's not obvious how.)

    The parallel plug-in is notoriously unreliable because of the way it works technically (using threads). I have recently been working on an alternative (coroutines) that should be much more reliable and does roughly the same thing. If you really need parallel functionality, for example because you want to collect responses and show a sequence of sketchpads at the same time, then I would use coroutines.

    You can find more information about this here:

    If you use this plug-in, please share your experiences. It's very new right now (but it seems to work well).


    There's much bigger issues in the world, I know. But I first have to take care of the world I know.

  • edited 9:27AM

    Hi Sebastiaan

    Thanks for your response.
    Right now it works OK on win7,
    and because this is an fMRI study, I don't know if testing new plugin will be
    a good idea...
    The timing is quite good! I had deviations of maximum 3 ms, and I present stimuli
    for 700 ms. In one trial I had a deviation of 50 ms. But it's still okay...

    I'll sure try the coroutines in my next experiments!

    Thanks again!


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