Use the @ parameter for each such item in your .que file. As detailed in the MediaLab manual (http://www.empirisoft.com/medialab/h...tm#timestamp);
"By entering @ as a parameter for any item in a questionnaire, you can have MediaLab write a time stamp at the onset of that item in order to keep track of events in real time. When you do this, a time stamp will be appended to a file called "timestamps.csv" located in the Data folder. Each time stamp will include the Subject ID, the variable name, the time at which the item started (e.g., 12:33:22), the milliseconds elapsed from the beginning of the experiment and the number of milliseconds passed since the last timestamp. The timestamp function can be used with all item types."
Jason Reed
Empirisoft Software Support Specialist