# Direct feedback from eyelink in your experiment (matlab, psychtoolbox, eyelink)

**URL:** <https://psychtoolbox.discourse.group/t/direct-feedback-from-eyelink-in-your-experiment-matlab-psychtoolbox-eyelink/1547>\
**Category:** Uncategorized\
**Created:** [August 24, 2006, 6:26pm UTC](https://psychtoolbox.discourse.group/t/direct-feedback-from-eyelink-in-your-experiment-matlab-psychtoolbox-eyelink/1547 "2006-08-24T18:26:02Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Allen\_Ingling](https://avatars.discourse-cdn.com/v4/letter/a/a183cd/32.png) [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\
**Post date:** [August 24, 2006, 6:26pm UTC](https://psychtoolbox.discourse.group/t/direct-feedback-from-eyelink-in-your-experiment-matlab-psychtoolbox-eyelink/1547/1 "2006-08-24T18:26:02Z")

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Hi all,   
  
As I'm new to this group (and to the use of the toolboxes) this will  
probably be one of those RTFM questions, but I couldn't find an answer  
after searching the archives, so I'll just post another message hoping  
someone can point me in the right direction. Very sorry in advance if  
it is indeed an RTFM question. :)  
  
Here goes - I've programmed an experiment in Matlab, using another  
toolbox called Cogent graphics. However, now that I want to use direct  
feedback from the eyelink II, I'm running into troubles and I'm  
looking into other toolboxes.  
  
What I need to do is the following: as soon as a subjects fixates a  
target, my stimulus has to change positions (kinda like the double  
step paradigm). So just to make it clear: it should use the data it  
receives from the eyelink tracker in realtime to alter the screen.   
  
I was wondering if anyone in this group has had any experience  
programming an experiment like the one I described above - one that  
uses "realtime" data from the tracker in the experiment, and one that  
uses the psychtoolbox and the eyelink toolbox for matlab (on windows  
XP with matlab 6.5 or 7.1).   
  
Information I'm particulary looking for includes information on how  
easy/hard it would be to setup an experiment like that in the  
toolboxes I mentioned and how the coordinate systems of the two  
toolboxes work together.   
  
Thanks in advance guys, and keep up the great work!  
  
- Arthur