# Mapping image files from MWorks to BrainIO **URL:** \ **Category:** Support\ **Created:** [September 1, 2022, 9:49pm UTC](https://mworks.discourse.group/t/mapping-image-files-from-mworks-to-brainio/826 "2022-09-01T21:49:30Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\ **Post date:** [September 6, 2022, 2:43pm UTC](https://mworks.discourse.group/t/mapping-image-files-from-mworks-to-brainio/826/3 "2022-09-06T14:43:21Z")
Hi Jon, There’s no built-in variable named “stimulus\_presented”. That must be defined by the particular experiment(s) you’re looking at, so I can’t say when and how it’s being set. The usual way to get info about stimulus presentations is to extract the variable [#stimDisplayUpdate](https://mworks.github.io/documentation/latest/reference/sysvars.html#stimdisplayupdate) from the event file. The value of that variable is a list of dictionaries, where each dictionary contains the tag and properties of a stimulus that was on screen during that display update. For image file stimuli, the dictionary contains a `filename` key, whose value is the full path of the image file loaded by MWorks, and a `file_hash` key, whose value is the SHA-1 hash of the image file ([more info](https://mworks.discourse.group/t/using-the-file-hash-to-verify-an-image-stimulus/49)). If the filenames used when running the experiment don’t match those in your database, the file hash should provide a way to create a mapping between the two. Does that answer your question? Apologies if I misunderstood: This is my first day back at work after three weeks of vacation, and my brain isn’t back up to speed yet 🙂 Cheers, Chris --- _[View the full topic](https://mworks.discourse.group/t/mapping-image-files-from-mworks-to-brainio/826)._