Sequential pulling of stimuli

Support
1

Hi Chris,

I have a quick question about the ordering of stimulus pulling with video stimuli in MWorks.

I have a student who would like his experiment to run in sequential order and have videos not completed (i.e. monkey broke fixation), repeated until they are successfully completed before moving on to the next stimulus. For example, stimulus log would be “stim_1, stim_2, stim_3 (broke fixation), stim_3, stim_4, stim_5 (broke fixation), stim_5 (broke fixation), stim_5, stim_6”.

I was wondering first if this is possible at all, and second if this is possible with videos when you run them ‘deferred = on’. We have been running the video stimuli deferred because they are too large to load in bulk, so instead MWorks pulls them from the folder in real time. Is it possible to pull these stimuli sequentially when they are deferred? And is it possible to have videos repeat until completed successfully before progressing to the next video?

Thank you so much,
Ani

4

Hi Ani,

Sure, all of this is possible.

If you’re using a selection variable to pick the videos to run, you can run them in sequential order by setting the selection parameter to sequential. To repeat any video that isn’t completed, just accept or reject the selections one at a time; rejecting a selection will result in the rejected value being drawn next from the selection variable.

All of this is compatible with deferred = explicit and loading the videos one at a time. I guess, in the case of an incomplete video, you might want to skip unloading, since you’ll just have to reload it immediately, but I’m not sure that the small time savings is worth the added complexity.

If you need more info, please let me know.

Cheers,
Chris