inter stimulus interval


I’m trying to program an experiment where sets of words are presented on the screen. I have each sub-set of words as a stimulus list, which has it’s own event. I then want to run them all randomly intermixed, appearing for 5 seconds each. So far this all works fine, but ideally I would like there to be a one-second blank screen between words. Is this possible? I found when I set up an event that was an inter-stimulus trial, it occurred once only, not between all my stimuli.

How can I make it alternate a ISI with each (random) stimulus presented?


It sounds like you probably also only have one trial. You should create a trial for each stimulus list. In each trial, there should be two events: the one-second blank screen, and the event presenting the word. You will NOT randomize events in the trial, but you WILL randomize trials in the block.

When you use a stimulus list, the list doesn’t get expanded inside of the trial; the trial gets duplicated to match your layout, one copy for each stimulus. When you create a trial with a stimulus list, you are creating a template–not a trial with a bunch of events. You can see how SuperLab will handle your stimulus lists at runtime by selecting “Expand Events that Use Lists…” from the experiment menu. A new experiment window will be created that no longer uses stimulus lists. You can either work with this as if it were a new experiment or you can close it and go back to your original experiment.

I hope this helps!