Two doubts in creating an online Experiment
Dear OpenSesame experts,
I want to replicate online an experiment that I did previously in the lab, but I’m struggling with two main problems. The experiment is a Discrimination Task, where participants see many objects from different perspectives and they have to press a button when changes the type of object. For instance, participants see many images of keys from different perspectives and they have to press the button when the image changes to the bottle opener, and so on. I’m collecting reaction times and I care about the response accuracy. Please see this short video of my experiment in the lab:
So, here are my two main doubts:
1 - I have many trials with different lengths, shorter trials have 8 images in a row, while the longest length trials have 13 images. Is it possible to have trials with different lengths in opensesame? I tried changing the show_if function, but without success (as you can see in the images below).
2 - I don’t want to collect responses at the end of each trial, but in the third to last. Thus, if the trial length is 8, I want to collect reaction time between image 6 to image 8. Moreover, I need that the stimuli continue without the wait for participants’ responses. How can I do that?
Thanks in advance for your help.
Best,
Daniela Valério
Comments
Hi Daniela,
Ad 1) Did you test setting display time to 0 for images you don't want displayed in the "shorter" trials? This way you can keep the trial sequence length constant in the software but vary the actual number of images displayed per trial.
See if this works.