Open sesame and Eye tribe

amandine

Hello,
I 'm sorry to bother , but I need help . In fact , I use eye tribe and open sesame , and I try to display targets and display a circle corresponding to the position of the eyes in real time.
The problem is that it works for the first 3-4 trials but after the circle for the eye position is not correct anymore , it's like the signal was completely lost, so I have a circle but it doesn't correspond to the position of the eyes . Do you have any idea how to fix this problem ?

Thank you

sebastiaan

Hi Amandine,

To get a real answer, you'll have to provide much more details about exactly what you're doing--ideally uploading the experiment so that we can see it.

However, one simple things comes to mind already: Is the EyeTribe maybe simply losing the signal? If it works in the beginning, right after you've calibrated, but doesn't work later on, this may be because you moved your head a little bit, or because the EyeTribe lost your eye for some other reason. Are you sure that's not it?

Cheers,
Sebastiaan

amandine

Thanks for the answer, you can find my experiment and the stimuli here:

https://drive.google.com/file/d/0BzQXLwjFWLkxLTZ5Mm9tWUkzVUE/view?usp=sharing

https://drive.google.com/folderview?id=0BzQXLwjFWLkxUkFXcUY1cEtCSEE&usp=sharing

Yes i was thinking of a problem with the EyeTribe, but I'm sure that i'm not moving so I don't really see where it came from.

Also, if it's not too much to ask , how do I insert a message in the logger to distinguish the records based on the target and the condition ( feedback , sansfeedback ) ? I tried eyetracker.log but it does not work ..
Then in the log , I wanted to add target and eccentricity but variable in the data file does not appear.

I'm really sorry to ask so much things but I have to do this experiment for next week and I have a lot of issues..

Nynke

Amandine, I hope you don't mind me breaking into your topic. I was wondering how your experience with the EyeTribe in combination with Pygaze is? I have much difficulties in calibrating subjects with the Pygaze calibration routine (about 50% of subjects keep failing, also after multiple calibration attempts without make-up, no glasses, lenses, etc.).

Josh

Hi Amandine,

Did you insert a drift correction item at the start of each trial?

Josh

amandine

Hi Nynke, I don't have any problems with the calibration routine, it works really well even for people with glasses.. I just have problems with trials but I think that it's not a big one.

amandine

Hi Josh, no I didn't but thanks for the ldea I think it can helps but how does it works because I don't understand it very well..
Thanks for helping

amandine

I've tried to put a drift correction but it does not fix the problem

sebastiaan

Hi @Amandine,

The drift correction actually does nothing for the EyeTribe. It only checks whether gaze is where it should be, but it doesn't do an automatic recalibration (some other eye trackers do, hence the name).

Your experiment looks fine, so I really think that the problem is that the EyeTribe loses the eye. Here are a few suggestions:

• Before starting the experiment with OpenSesame, use the EyeTribe UI to check that the camera is in a good position. The EyeTribe UI is a separate program that is included with the EyeTribe server.
• Use a dark environment. Not completely dark, but just not too much light.
• Try a few different people. Some eyes are more difficult to track than others. Generally speaking, make up (mascara etc.) is problematic.
• If the drift correction hangs, press 'q' and calibrate again.

@Nynke I've personally had pretty good experiences with the EyeTribe, even in difficult environments. For example, I've used the EyeTribe on science fairs (fête de la science in France) with young children, and even that went pretty ok. You need to get the hang of it though. Please see my tips above.

Cheers,
Sebastiaan

paddy

Hi, I have a similar issue. The eye tribe seems to have some sort of a drift after sometime. It runs perfectly for the first few experiments but then it starts drifting from the point. Is there a way to fix this?