Random presentation of picture stimuli / Judging process

Hi, folks.
I’m having a little problem with PsychoPy about the randomization.
In my experiment, in each block, I’m going to present several pictures to subjects one by one, and the aim is to let them remember the pictures. And then I wanna show them another picture, to let them identify if this picture has appeared before.
So in my opinion, the crucial part is the randomization of the picture presentation. Through the previous search on discourse.psychopy.org, I think that I can set up several lists that point to all the pictures, and… maybe use the shuffle demand.
And as for the identification process, after subjects respond to PsychoPy, can I let the system (or the program) automatically judge if the subject has chosen the right answer? Maybe by using if…then…?
Sorry :joy: These are what I have learned about Python. Just remind me if there are mistakes.

Would you mind giving me some advice about the coding e.g. what functions are needed? Any great help would be highly appreciated. Thank you in advance.

If I understand your task well, this is an old-new task. Usually in this task the experimenter knows in advance the old and new images.

If so, this is pretty straight forward and no coding is required.
You will need:

  • an excel file that will contain the file names only of the images to be remembered.
  • an excel file that will contain (some?) of the old images’ file names plus the new image images’ file names. A second column that will contain the correct responses for eacch image.
  • On PsychoPy create a routine that will contain an image component and enclose it in a loop pointing to the first excel file
  • Create another routine that will contain an image component and a keyboard component. Enclose it into another loop and point it to the second excel file.

This should do the job and should be ported to pavlovia without any extra work.

I hope this helps

1 Like

Hi, @Yiannis
So many thanks that you shared a method to this experiment.
Yes, your understanding is right. (And thank you to let me know the old-new task)
So the logic is to use two loops, and these two loops are connected to old pictures and new pictures separately. And how to let PsychoPy know what pictures exactly are? Just by creating two excel (.xlsx) file to let them connect together.
Thank you. Your reply has made me clearer!

1 Like