Changing rows in conditions file dynamically within loop

Builder
1

Hello,
I am trying to select rows from a conditions file dynamically. I also want to dynamically select rows within a single loop.

So, I tried 1 loop, setting the trialProperties Selected row component to a variable ($selectedRow). The variable depends on the response made for each routine.

selectedRow = str(choice-1)+':'+str(choice)

Begin Experiment:

choice = 1

End routine:

if key_resp.keys == '1':
    choice = n1node
if key_resp.keys == '2':
    choice = n2node

n1node and n2node are stimuli.

On the next loop, instead of showing the updated choice (n1node or n2node), the previous stimulus is shown again. Any help is appreciated!!

2

You can’t change the selected rows once a loop has started. However, you could do it with two concentric loops. Put a Routine in the outer loop (after the inner loop) which sets the selected row for the inner loop (or breaks the outer loop if the task has finished)

3

As @wakecarter mentioned, you can’t do this out of box. But you can manipulate trials by understanding that “under the hood” a spreadsheet is imported to psychopy as a list of dictionaries. You can make custom trial lists through manipulating that list of dictionaries. It is a bit more involved but here is a tutorial we run in our workshops in this topic.

Hopefully this is helpful,
Becca

4

Very helpful–thank you!