Correct responses depend on prior trial

I have a trial set up that presents 1) a picture from a stimulus list for 50ms and then 2) a response screen. Participants view the very brief stimulus and then respond to it during the response screen with a button press. I’d like to use tags to designate correct responses, but can’t determine how to make the “correct” response to the response screen be based on the picture that was presented just before it (because the pictures are from a list and are randomized).

Is there any way to do this?

The best way to achieve this is to make the response screen event also use a stimulus list, then tag the response list. There is no problem with using the same response event stimulus repeated many times on a list. There is a sample experiment posted here: http://community.cedrus.com/showthread.php?t=1838

I see how that works! However, I have 144 picture stimuli and only 12 responses. Would I need to make 144 copies of the response screen (so they are parallel to the pictures) and tag every one?
Thanks!

To use the stimulus list approach, then yes you will need both lists to have 144 items.

However, there are two alternative approaches. If the scoring for correct and incorrect is only for analysis, and not for showing feedback to the participant during the experiment, then you can use spreadsheet formulas to automatically score the responses after SuperLab saves the data. Here is one example of using formulas: http://www.screencast.com/t/mROe6OU3Vj

If you do require presenting feedback to the participant, then in SuperLab 5 you can use a Trial-Rule. The Rule would state:

If:

  • Trial's tag is red-tag [U]and[/U] response is Y

Perform actions:

  • Present event "feedback correct"