Randomization of image files


I am a student and new to PsychoPy. I would like to create a children version of the Stroop Task:
Two animals are simultaneously presented, a big one and a small one (e.g. elephant and butterfly). In congruent trials, the elephant image is presented largely on screen, the butterfly small. For incongruent trials, it is the other way round (elephant image small, butterfly image large). I started by creating an excel file with my conditions: it contains the following four rows:


In every row, I have two columns for the images (left image, right image) and columns for the image sizes. I inserted specific image files, e.g. “animal_images/s1.jpg” in the cells of my excel file, and the experiment runs. Now, I would like to substitute these image files with some value that refers to some list (maybe another excel file?) where all my images are contained - resulting in a randomized selection of two images in every one of the four conditions. (In total, I have 12 big and 12 small animal images)

The solutions proposed on similar topics were not fitting or I was unable to understand them.
Does someone have an idea on how I should proceed?


conditions_Stroop.xlsx (10.1 KB) Stroop.psyexp (11.0 KB)
b1 s1
→ sorry, my “eye.png” image could not be uploaded

Here it is.


Dear Ermi,

I do not yet understand how you want to randomize your pictures. The eyes.png is your fixation. So you have 12 small, 12 large animals, left and right side. Do you want a random selection of small and large animals giving you new pairings for each participants? In addition, the small and large animals should appear randomly on the left and right side? In your Excel-file your realized all possible combinations of two pictures and two sides which is apparently not what you want?

Best wishes Jens