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Text ROI autosegmentation?

I'm trying to build an eye-tracking experiment with OpenSesame and a Tobii tracker (I've always used EyeLink and the SR Research experiment builder/data viewer so far, so it's a bit of a transition!). I've managed to throw in the basic components of the experiment but I can't seem to figure out if it's possible to have OpenSesame auto-segment the text in each trial at runtime so that each word is a region of interest (it's a reading experiment, so it's pretty important to be able to do this).

I know that in Tobii Pro Lab one can only define the regions of interest manually, but in a reading experiment with hundreds of trials and thousands of individual words, I'd really like to find a more expedient solution! I was hoping OpenSesame might allow this, but now I'm wondering if it is bound by the inherent limitations of the tracker software running under the hood even when interfacing with PyGaze?


  • Hi Fabio,

    As far as I know, there is no "auto-segmentation" implemented in Opensesame. However, I believe with some Python coding, you should be able to segment words in a sentence and retrieve ROIs with a resonably low latency. Once you have those ROIs do you want them to be used by the Tobii online to get the ROI information into the eye data log file? Or is it sufficient to just store the ROIs along side other Opensesame variables?

    Alternatively, if you manage to present words as separate objects on the screen, you can use the mousetrap plugin to easily define ROIs based on these objects. However, how to let the eye tracker know which object was fixated online, I don't know.

    hope this helps,


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