Choosing Pictures From Different Lists, With No Repetition


This experiment has four stimulus lists. Rather than a full randomization, we want to pick a picture at random from one list, another picture at random from another list, and so forth. After a picture has been presented from each list, we go back to choosing a different picture from each list again until all pictures have been used.

How It’s Done

  • Four codes are created (the number of codes needs to match the number of stimulus lists). The codes are used as flags to determine which list had an item presented from.
  • In the Event Editor's [B]Feedback[/B] tab, we set the code value. For example, if the event presented a picture from list "Monkey", we set code to "Monkey Presented" to "Yes".
  • In the Block Editor, we create four macros, one for each list. The macro checks to see if the last presented trial was from the "Monkey" list, and if it is, sets the value of code "Monkey Presented" to "Yes" for [U]all the trials[/U]. This is needed to avoid picking another item from the same list.
  • In the Trial Editor, we set the condition expression as follows:
  • We create a macro that runs only after all the trials in the block have been presented. Its sole purpose is to reset the code values for all the trials to "No".
  • We duplicated the block so that we had a total of five, one per each list item.


SuperLab 4.0.7 or later is needed.

Choosing Pictures From Different Lists (Mac Version).zip (1.23 MB)

Choosing Pictures From Different Lists (Windows Version).zip (1.24 MB)

macros in choosing pix from different lists

I am programming a task that makes use of the sample experiment, “choosing pix from different lists.” Have attached my task here. The added wrinkle is that rather than a single stimulus image, I have two images per trial (differing in emotional valence). I am struggling to get the macros to work right – rather than running one trial from each list and then moving to the next item in the block, the trials within a block currently select EACH of the items in the stimulus list (n = 3) instead of n = 1.
(ultimately, my paradigm should do the following: Present 36 randomly ordered trials, 18 with LeftNegRightPos, and 18 with RightNegLeftPos).

Any advice most welcome!!!
–inge-marie (4.84 MB)

This is something that will be faster if discussed over the phone. I will contact you via private message to set up a time.

This experiment is not working

Experiment could not run since some of the image files are missing in the zip folder

The images are in a folder that are included in the zip. You may have to search the files for them.

Adding a participant response

I used the example superlab files given in this thread so create my own experiment file. For my experiment, I only use 2 stimulus sets (not 4 like in the example), and I have 40 pictures in each set. So I made the changes to the example superlab file, but I am experiencing a few problems…

  1. Superlab is not randomly selecting from my stimulus lists. The stimulus lists are being presented in the order that they were uploaded. How can I fix this?

  2. I need participants to respond to the second stimulus set (they see a picture from the first stimulus for a time limit, then they see a picture from the second stimulus list and need to respond to the picture before continuing). I have added response options in the past and they have always worked. However, when I added response options to the event that presents my second stimulus set, superlab will not acknowledge the response during testing. It freezes and will not continue. Is there a way to fix this?

It would be helpful if I can see your experiment. Can you post it as an Experiment Package? This is found under the File menu within SuperLab.