Syncing SMI eye tracking output with OpenSesame output
in OpenSesame
I'm running an experiment in OpenSesame and collecting data with an SMI RED-m eye tracker. The experiment runs great, but I'm having trouble interpreting the timestamps produced in the SMI output. The timestamps in the .idf file do not match up with any of those in either the OpenSesame output or the SMI logfile (which has the OpenSesame timestamps). Is there a way to either push the OpenSesame timestamps into the .idf file, or push the SMI timestamps into the OpenSesame output? Or is there a better way to sync the data? Any help would be greatly appreciated!
Comments
Hi,
I have not worked with SMI data myself, but generally, the timestamps are measured relative to a zero-point that is software specific. So, at some point during the initialization of Opensesame, the experimental clock is being started and all timestamps are measured relative to this moment. The same also holds for the SMI data, only that the zero-point is another one. Effectively, this means that you can't compare the absolute timings across the files. However, you can send messages to the eyetracker that will be written to the SMI files. If you include the opensesame time stamps, or some informative label as "stimulus appears", "response given" or whatever, you know which eye movement belong to which part of the experiment.
Unfortunately, I don't think it is possible to match up the files without having common markers. So, if you haven't sent them along, and they haven't been written per default, I don't think you can sync the data reliably.
Hope this clears things up.
Eduard
Hi Eduard - thank you so much for the prompt response! My difficulty is with sending messages to the eye tracker. So far I have only been able to push messages/time stamp info to the SMI logfile (which already has the OpenSesame time stamps, but unfortunately not the SMI ones), but not the .idf file (which has the eye data and the SMI time stamps). How can I send messages to the .idf file? Thanks!
Hello everyone.
For those who are still using SMI eye trackers / Software, im happy to pass by and let you know that we at EyeLogic have created an eye tracker that is fully compatible with SMI.
Please send me an email in case you need more informations on that, and on our upcoming new hardware and software at fabio.pinto@eyelogicsolutions.com
Thank you,
Fabio
https://www.eyelogicsolutions.com/