PsychoPy version : 1.85.4
I’m new in Psychopy and I’m trying to design my first experiment.
I got stucked with a problem of stimuli selection.
Basically, this experiment consists of 120 images of 3 types (40 positive, 40 neutral and 40 negative). Each of these images could appear in one of four conditions, defined by the combination of other two variables, namely the position (ABOVE or BELOW the center of the screen) and the response required (UP or DOWN arrow key). So, the experiment counts 120x4 total conditions.
I would like to split the experiment in 4 block, in which all the 120 images are presented once and are balanced between the 4 conditions: for example in block 1, 10 negative images appear in ABOVE-UP, 10 in ABOVE-DOWN, 10 in BELOW-UP and 10 in BELOW-DOWN. The same procedure shuold apply to positive and neutral images and this assignment to each condition should be done randomly. Moreover, in the subsequent blocks, the images in one condition should now be inserted in another of the remaining conditions.
I hope everything is clear -_-’’
Currently, I am trying to do this within the coder, but since I’m not an expert python coder, I’m having difficulty. Is there a way to do this within the buider component? I know I should do a .csv file specifying all the possible combinations of stimuli and conditions, but I get stucked with this random assignment of the stimuli in the blocks. Any suggestion would be appreciated
Thank you in advance for your help.