Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Supported by

mouse response


I'm new to using OpenSesame and am having some problems with using the mouse response. I want to present 3 numbers on the screen, then have participants select the smallest number by clicking on it.

I've defined the three numbers as three separate variables (num_1, num_2 and num_3) and used these in the sketchpad. I've manually set the correct response in the block_loop table, typing in whichever of the variables is correct (e.g. if [num_2] is the smallest then I've defined this as the correct response for that row). I've then linked the mouse response to this sketchpad. However this doesn't consistently work - sometimes all response are judged correct, or the correct is recorded as incorrect. Any suggestions would be appreciated!


  • Hi,

    Did you use the mousetrap plugin? How did you define the ROIs? Maybe you can share your experiment with us?


  • Hi Eduard,

    Thanks for getting back to me.

    I used the mouse response item - is that the same thing as the mousetrap plug-in? I created a sketchpad with the three separate variables, then linked this sketchpad to the mouse response item. I thought that this would automatically define the ROIs but I might have misunderstood the manual. I've attached the draft version of my experiment:



  • Hi Jonathan,

    I have the hunch , the automatic ROI definition is not compatible with correct_response definition.

    So, in order to do provide feedback, you first need to do some computing. The attached experiment includes code to do that. Let me know if it does not what you want it to do.

    Some more notes:

    • you should remove the fixation dot, as this one is counted as a response option otherwise.
    • consider drawing boxes around the options, otherwise the mouseclicks have to be reallly precise


    @sebastiaan Is it true that using clicks in ROIs cannot be used as correct response in a mouse response item?

  • edited September 2019

    > Is it true that using clicks in ROIs cannot be used as correct response in a mouse response item?

    Yes, that's correct. The correct response refers to which button is clicked, and not the ROI. (That's not ideal, because you're usually more interested in what participants clicked on than in which button they used to click on it. I'll think of a way to improve this while maintaining backwards compatibility.)

  • Thank you both for the responses, that helps to clarify why things weren't working as expected. I'll take a look at the attached experiment and let you know if I have any more questions!

Sign In or Register to comment.