The experiment is indeed feasible, with a small caveat. The attached experiment will present the sequence “prechange-ISI-prechange-ISI-postchange-ISI-postchange-ISI” and repeat it as long as the participant has not pressed a key within 75 seconds, but there is a perceptible delay in between sequences.
The reason for the delay is this: SuperLab does its best to present events within a trial as accurately as possible. This means that any “housekeeping” chores that need to be done, e.g. loading pictures, allocating memory, etc., are done before or after a trial, but never during a trial. In your experiment, this sequence is implemented as a trial that gets repeated, hence the inter-trial delay. If you can live with this small delay, then your experiment is ready to go!
Other notes about the experiment:
- Randomization is done in the trial’s [B]List Access[/B] tab, not at the block level.
- I changed the ISI events to become events of Type text, with an 80msec time limit. The effect is the same, but this change SuperLab to detect a participant response during that 80msec pause.
- You need to use SuperLab 5.0.3, which is the most recent version. If you have an earlier version, you can download the latest SuperLab 5.x update. The experiment uses a parameter of type Timer; this feature was added recently in version 5.0.3.
- While working on your experiment, I discovered a bug that happens when SuperLab loads an experiment and is unable to locate stimuli files, and then prompts you to locate the files. The bug is caused by the fact that your stimuli files in the two folders have identical names. I have renamed the files in the "Postchange Scenes" folder to circumvent this bug.
Lindsey Change Detection rev B.sl5 (37.2 KB)
Postchange Scenes.zip (32.9 MB)