How to define Areas of interest in OpenSesame?

Rotem_M

Hello everyone!
I'm new to OpenSesame, and I'm doing a research that combining Eye-Tracker (EyeLink portable Duo). I would like to know please how I can to define AOI (Areas of interest) at OpenSesame or PyGaze? or maybe I must define AOI at EyeLink Separate program? (if PyGaze - how do I find out which PyGaze do I need?).

please help me (:

Thanks,
Rotem.

sebastiaan

Hi Rotem,

The easiest to way define ROIs is by first downloading the latest prerelease of OpenSesame 3.2 (which will be released as stable soon) from here:

• http://osdoc.cogsci.nl/3.2

And then you can assign names to elements of a sketchpad item or Canvas object. These named elements then serve as ROIs. See also the visual-world tutorial:

• http://osdoc.cogsci.nl/3.2/tutorials/visual-world/

But then you still need to decide how you want to use those ROIs. Do you want to analyze them afterwards, and if so how? Or do you want to do some kind of online analysis?

Cheers!
Sebastiaan

Rotem_M

Hi Sebastiaan!

Thank you so much!

I still don't know I'm new at all of this field of eye movements... do you have maybe an recommendation or good guides that I can learn from?
Thank you,
Rotem.

sebastiaan

Hi Rotem,

If you feel overwhelmed by the technical details, then I would start by taking a step back and formulating clearly for yourself (and us) what you want to do.

• What research question are you trying to answer?
• Do you already have an experimental paradigm in mind (even if you haven't implemented it yet), and if so what does it look like?
• What kind of data do you want to get out of this experiment? If you find this question difficult to answer, try to visualize your hypothesis in terms of a figure—what would such a figure depict?

Cheers!
Sebastiaan

Rotem_M

Hi Sebastian!

I'm so sorry about the long delay (it's really busy time for me).
I already have an experiment build in OpenSesame, I'm just not sure if all the layout of my experiment is right... I'm trying to answer the question: If you take someone else perspective, and looking at affective pictures (specificlly disgust pictures) from NAPS data, is the eyes movements and pupil size changing as will expectes from the other person (that is very high or low at disgust sensitivity scale)?
I want to get from the experiment saccade amplitudes, fixation duration, number of fixations, and pupil size (pupilmetry)...
I'm not sure if the picture needs to be stretched on all the screen or in the center of the screen? and if in the center, it's recommened that the background will be gray or black?

Thank you alot! I appreciate very much your help!
Rotem (:

sebastiaan

Hi Rotem,

I see. It actually doesn't sound like you're planning to do primarily an ROI analysis (i.e. counting the number of fixations within particular regions) but want to analyze a lot of different eye-movement properties. I would definitely decide before running the experiment how you want to analyze the data.

What do other people in your lab use? Do they use the EyeLink DataViewer? If so, then I would write messages to the EyeLink in such a way that the DataViewer understands them, so that the data is relatively easy to analyze.

I'm not sure if the picture needs to be stretched on all the screen or in the center of the screen? and if in the center, it's recommened that the background will be gray or black?

That's a judgement call. Personally, I would present them in such a way that it looks natural: not so small that it looks like a stamp, but also not so big that participants need to rotate their head in order to see everything. But there's a wide range of sizes that are acceptable. And a gray background is generally the most neutral.

Cheers,
Sebastiaan