You’re going to have to do some juggling to get what you want here.
Let me try and describe what you have to do.
Event 1 will need to be the LAST event of the PREVIOUS trial.
Event 2 will be a stimulus list of images which is, by default, random without replacement.
Event 3 will have to actually consist of 15 events. Each event displaying a mask. Now, each of the events here need to provide Feedback. So you’ll have to go through these events and Provide Feedback If Always, at the end of the event. And for What To Do: Present event 4 Evaluation, Present event 1 Fixation Cross, Skip remaining events and present next trial in this exact order. So, you’ll have 15 events that will have feedback set up this way.
Event 4 will also need Feedback. So, Provide Feedback If Always, at the end of the event. And for What To Do Present event 1 Fixation Cross. Just have this, and only this for What To Do.
Now, to take care of the randomizing of the events. The trail that does that randomizing should include Event 2 (stimulus list) and the 15 events for the masks. Edit the trial and check Randomize the events in this trial and also check Except the first one. The first event in this trial should be Event 2.
That should do it. Remember that Event 1 needs to be the LAST event of the PREVIOUS trial
Also note that Event 4 isn’t part of any trial. It’s just a feedback event.
I’ve attached an example experiment to help make this clear.
experiment.zip (369 KB)