One discovery we made about Superlab in the course of setting up picolf6 was that any time that a file system path is stored within Superlab, all symbolic links within the path are expanded and the path converted to an absolute path. This complicated several aspects of the process.
There are three types of stimuli used: pictures (stored as .jpg files), words (stored as .png files) and ticket numbers (stored as .png files). If you will refer to my recent blog entry on the sl4am hierarchy, you will see the layout we used here. Under the project directory, there is a Shared directory containing all of the .sl4 Superlab scenarios, and folders for all stimuli. The general idea is that the folder for each experiment (with subjects and groups) will have a link back to the scenario for that experiment in Shared, plus a "stim" folder containing links back to specific stimulus files within Shared.
The odor labels we used were mounted on standard 1"x2" event tickets and torn off one at a time to be "scratched and sniffed" and given to the subject. So, one of the things required is for there to be an inobtrusive ticket number displayed on the screen at the beginning of each trial. In superlab, the only way to do that is to make a graphic with the numbers in the corners and then specify that superlab scale it to fill the screen. We used the least significant digits of the tickets for this, so experiment 1 used tickets 1-30, exp 4 31-42, exp 5 43-54, and exp 6 55-66. Since this was always the same for all subjects, we set up folders in Shared named ticket[1456] and stored the .png files with the images there, named, e.g., 23.png.
One thing we learned the hard way was that it is best to set Superlab up so that the scenario is in a file hierarchy identical to where the experiment will be run. So for example, we simply specified /Users/.../Shared/ticket1 and Superlab could use the same relative path at runtime and find the stimulus folders.
The other stimuli were more complicated, because they had to be different for each subject. Superlab always accesses stimulus list folder contents in alphabetical order, so while setting up the experiment, we set up dummy folders containing files with names like w/img34.png (for word image event #34). Later, when setting up the hierarchy, we put links with those names to image files in Shared. So if for example on trial #34, a certain subject needs to see the word "alligator", stim/w/img34.png would be a link to ../../../../../Shared/words/alligator.png (for example).
Now, Superlab doesn't print the name of the file in a stimulus list folder, only its sequence number. So in order to figure out which stimuli were presented to a give subject without going back to the setup data, we inserted a dummy text event into each trial. These events were simply numbered like "@=1-34=@" for experiment 1, trial 34. As part of the setup sequence, we created a sed script that we placed into each experiment folder that translates that dummy code into a condition code for that trial, for example "alligator:old". This allows the actual stimuli that were used to be determined.
We also placed a link to a superlab scenario file in Shared into each experiment subfolder. However, we were not able to use symbolic links for this, since superlab then assumes that the scenario file is actually in the Shared folder and all of the subject-specific links fail to work. As a work-around, we just used hard links for it, since it is a file rather than a directory (file system rules disallow hard-linking to directories).
Here is a tar archive (tgz) of the Korn shell scripts I used to set this experiment up. Note that you also will need to install some packages to generate the graphics versions of the textual stimuli. I also didn't include the picture stimuli we used.
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