Single event trial, superlab won't advance through a list

We’re running into a rather strange problem/bug, I searched the forums but wasn’t able to find discussion of it before. Basically we have a trial with a single event that shows a list of images. The images are pre-randomzied with our own software and so we just want superlab to run through them sequentially. Input is single keypress (actually a scanner trigger but that doesn’t matter, I’ve tried it both ways).

The problem is this, upon receiving an input superlab will move to the next image then hang.

I think what is happening is that without any further events in the trial superlab doesn’t loop back to look for more user input. I can fix this by adding another event that lasts for 50ms (doesn’t matter how long really) so that superlab hits event1, then this dummy event, loops back to event1 followed by the dummy event and so on.

But this hack isn’t very helpful since I’m synching to a scanner pulse (fMRI) and don’t want to have to shorten my image presentation and add a dummy event for no good reason.

Thoughts? Is this supposed to be a feature or a bug?

You can replicate this yourselves by just making a single event trial with an image list and set to it end event only upon a correct keypress from user (probably would work with any response option as well).


Without looking at your experiment I can only think of two things that might be happening:

  1. Either the correct response key is not being pressed

  2. In the Participant Input Editor, when selecting Keyboard-Single Keys, go under the Options tab. There you might have, “Only if an event designates a single key response as correct” checked on.