Presenting only one stimulus from a group


I’m designing an experience with superlab under the same-different paradigm. My stimuli are images (dot matrices) and I woul like that, for the “same” trials the program could present randomly only one of four possible pairs. As I understand, this is not possible to do with the stimulus list option. Is there a way to make this work? Thank you!


If you’re just trying to display one of four possible images per trial, you can use Feedback to end your trial after one image is displayed. Just go to the Event Editor window and click the Feedback tab. From here you can provide feedback Always, at the end of the event. Just set What to Do to Skip remaining events and present next trial. Oh, and don’t forget to randomize the events in the trail under the Trial Editor.

If you have a stimulus list, you can Expand Events that Use Lists. This option can be found under the Experiment menu in the menu bar. This will expand all events and trails that use the stimulus list. From there you can specify which images are associated with which trials.

Hope this helps.


Thank you! This surely will be usefull in the future!

My actual problem is more complex, since I have 4 events associated with each trial: the first stimulus, the interstimulus interval, the comparison stimulus, and a “end” screen. This way I cannot randomize the events…


I’m having a hard time trying to figure what you want exactly.
If you could provide more detail about what you want.
Is the first stimulus the same set as the comparison stimulus?
Are you trying to do something similar to what’s being done in this thread here?

More information would definitely be of help.