Inquisit will record that information *by default* (i.e., if no <data> element is present) in one of the data file's stimulusitem columns. If you cannot find that information, you have misspecified your script's <data> element and need to add the proper amount of stimulusitem columns or other properties of interest. You will find all of this covered in the documentation for the <data> element's /columns attribute and the documentation topic for Inquisit's default data recording scheme.