EyeTribe tweak calibration parameters

moreno

Hi there!

I have been trying to use an EyeTribe (got it before the company was unfortunately bought by Okulus) to test MCI patients and healthy control elderly. In few cases, I got the eye tracker calibrated (on 9 points) okeish, but often, I do not manage to get any calibration.

I believe the main reason maybe that the fixation dot moves in the screen too fast, and stays on collecting data for too little. Given that elderlies but especially patients are old subjects, I suspect they do not have the time to identify where the dot moved, and hence, once they get there, there is very little time to collect fixation data to calibrate the tracker.

Thus, I would like to try to tweak the calibration parameters such that: (a) the dot moves much slower from one location to another location in the screen and (b) that stays on that location collecting data for longer time.

I managed to do something like this on a Tobii T120, but I am not sure how should this be done with the EyeTribe.
So, I was wondering whether there is anything I could do within PyGaze to obtain such a result, and if somebody has some advice on the matter

I sincerely thank you in advance for your kind help!

Moreno

sebastiaan

Hi Moreno,

You can change these parameters in a script. If you add the following to the Prepare phase of an inline_script at the start of the experiment, this should do the trick. Or at least is should slow down the calibration; whether that solves the difficulty remains to be seen, of course.

import pygaze
# Time that dot is shown before calibration takes place
pygaze.settings.EYETRIBEPRECALIBDUR = 2000
# Calibration time for one dot
pygaze.settings.EYETRIBECALIBDUR = 2000

Cheers!
Sebastiaan

moreno

thank you Sebastiaan! I will try and let you now