eye tracker closing unexpectedly

DanieleP

here is my big problem.
I'm analyzing the data of my first experiment with Eyetribe and PyGaze (which I found amazingly simple to use) and the eye tribe (first model) and everything seemed great. Except that I run it at 30 hz (then I realised there is a command to run the eyetribe at 60hz, next time I'll use it!) and.. now I just realised that the eye tribe automatically shut off after about 6 minutes, with every subject!!!!

Some background. I'm running a python/pygame-based script to present stimuli and record data. So my script records behavioural measures (key pressed, reaction times) on a CSV and I used PyGaze to record simultaneously eye gaze data. When I noticed that I missed a lot of trials from the eye data I checked what happened, and here's the terrible surprise: with the great majority of participants the tracker AUTOMATICALLY sent the message "stop_recording" for some reason. First thing I thought is that I did some mistake in the code, so that my script would automatically stop the tracker for some unknown reason. But now I'm 100% positive it does not. In fact I only gave the message "tracker.stop_recording()" at the very end of the experiment, and only once.

But there's something even more weird: many subjects had only about 6 minutes of recording (1.9 to 2.3 mb of tsv file), but some of them had much less (3 min, 1 min, nothing).
The funny thing is that even in these subjects the eyetracker automatically sent the message "stop recording"

Do you have any idea of what is going on? The only thought that came to my mind is that the eyetribe (or the pygaze) somehow automatically dumps the data on the file is the eye tracker froze for some reason. This reason could be overheating. Is it possible that pretty constantly the eyetracker overheated after 6 minutes and triggered the saving into the tsv before crashing?
Unfortunately I don't have the eyetracker at hand so I cannot check it myself, but I'm sure you might have some insights about this problem.

Otherwise I'll write to the EyeTribe.

p.s. all the rest worked very smoothly. I even double checked the raw and average gaze data and they were very similar. It's a pity that I had this problem, but luckily it was just a student practice experiment, which had exactly the purpose of testing the whole setup

looking forward to hearing your opinion on this, and thanks so much in advance for the help and for developing this amazing tool.

sebastiaan

Hi Daniele,

It would be helpful if you upload:

• The experimental script; and
• The data file.

And also an explanation of how we can tell from the data file that something went wrong.

First thing I thought is that I did some mistake in the code, so that my script would automatically stop the tracker for some unknown reason. But now I'm 100% positive it does not. In fact I only gave the message "tracker.stop_recording()" at the very end of the experiment, and only once.

Right, that would be my first thought as well. Where do you get this 100% certainty from?

Cheers,
Sebastiaan