Interstimulus interval


I’m new to Superlab. Can anyone tell me how to set interstimulus intervals please?

The solution I already tried was to create a new event for each interval, but of course it doesn’t work if you want to present your stimuli randomly - you can end up with two intervals after the other and no intervals between some stimuli.

Any help would be appreciated!

It’s hard to tell without seeing the experiment, but from the description, I’m guessing that you have randomization turned on at the trial level instead of the block level. If you turn it on at the block level, then all events within a trial will remain in the order that you define.

Thanks for your reply Hisham. I actually do want the stimuli to be randomized. But I want a 500 ms interval (blank screen) between each stimulus. Is it possible?

Yes. You need to have two events per trial, and you need to turn off “randomize the events in this trial.” One of the two events will be your stimulus while the other is the ISI. Then, you will randomize the trials in the block.

The Letter Rotation Experiment shows how to create a stimulus list and randomize the stimuli. The difference from your experiment is that the trial “Letters” would have one additional event–the ISI.

Ahaa! Wish I had thought of it myself!

I’ll let you know how I get on.