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Eye Tracker Log Skipping Messages (OpenGaze)


I am using Gazepoint in a few different experiments and in every eye tracking log .tsv file I have noticed it sometimes skips messages that I try to log, and other times it writes the message multiple times. I have tried logging in an inline script with eyetracker.log("message") in the run tab, as well as logging with the built-in pygaze_log item (pause between messages set to default 2ms). I have them placed in a sequence before a sketchpad item as my intention is to mark in the eye log when each different sketchpad is being displayed so that when analyzing the eye log I can see what was being displayed, is there a better way to go about doing this?

Thank you!


  • Hi Brandon,

    This is a consequence of the inherent limitations of GazePoint's OpenGaze API. It works by adding a log message to a particular sample, and thus will log the 'active' log message when a sample is logged. This can lead to logging the same message twice.

    The missing log messages are more worrying, as the log function I wrote should wait until at least one sample with the message is logged. There should also be an additional log where all log messages are registered too, which does not suffer from the OpenGaze log limitations. Do your log messages show up in there? This file should be [filename]_log.txt, where your data file is called [filename].tsv.


  • Thanks for the response, Edwin (and sorry for this late reply I haven't been in lab over the winter break). The additional .txt log file you mentioned does have all the log messages properly showing!


  • Hi Brandon,

    Excellent, thanks! That means that at least logging is working on some level.

    Few different things to double-check:

    1. Nothing currently appears in the "USER" column? This is the right-most column in the TSV file.

    2. Could you make sure that your messages are logged during the Run phase? The best ways of writing messages are by using an inline_script item (not nested in a sub-sequence) directly after a sketchpad that has a duration of 0 ms (you can add an advanced_delay item after the inline_script if needed). This inline script should just say eyetracker.log("sketchpad_onset") (feel free to edit the message) within its Run phase. Alternatively, you could use a pygaze_log element, which should have the option for automatic logging of all variables disabled, and should just say sketchpad_onset (or your own message) in the text box. If you want to use variables, you can refer to them with square brackets.

    If you still don't see any messages in your log file, I might need your experiment script and log file to debug what's going on.


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