Stimuli Dependent on Response


Is there any way I can set up the follow experiment in Superlab please?

Show subject two faces side by side (I have worked out how to show two pics simultaneously).

Then go to blank screeen during which:-

Subject selects which picture they prefer by pressing either X key for left hand pic or M key for right hand pic.

They are then shown one of two outcomes:

  1. they are shown the picture they chose in the same position it originally appeared
  2. the are shown the picture they did NOT choose but in the same position as the pic they DID choose, so if they chose X (left hand pic) they would be shown the right hand pic but at the left of the screen.

In other words, how can I get superlab to show an outcome which is dependent on the response?

Many thanks,


Currently this is not possible in SuperLab.

Hi Monika,

Thanks for your reply. I’ve been looking at the manual and it says that with conditional branching it is possible to ‘alter the order in which trials are presented based on the participant’s response’. This sounds just what I want to do - what do you think?


We are still thinking how to accomplish this, but first I need a little more information.

  1. How is the display of the pictures organized? Are the two picture positions randomized?

  2. When the participant is shown 1 of the 2 outcomes, how do you decide which outcome to show them? Is it based on a 50/50 chance, or based on a participant response?

Hi Monika,

No, the picture display is not randomised, for the 15 trials I select which picture goes on the left and which on the right so they are fixed.

With regard to the outcomes, this is how I want it to work:

Participant is shown a screen with two pictures on, one on L hand side and one on R hand side. There is a fixed time for them to look at them, and then a blank screen appears. They are then prompted to choose which pic they preferred, pressing L key for the left hand one, and R key for the right hand one. On some pre-selected trials I want the original choice to appear in the original position (e.g. pick L pic, so original L hand pic appears on L of screen). In other pre-selected trials I want the opposite pic to the one they chose to appear, but in the same position as their original choice (e.g pick L pic, the original R hand pic appears but on the L of screen). So the outcome is dictated by the participant’s original choice - in the non-manipulated trials the outcome is the same as they original saw, in the manipulated trials the outcome is the alternative picture but in the same place as the original.

Hope this makes sense!

Cheers and thanks for your help!


The only way to go about doing this is to have the picture position be determined on a 50/50 chance. If this works for you please let me know and I will be happy to post a sample experiment for you.

Hi Monika,

If having the picture appear 50/50 chance is the only option, then I think I can work with this, so yes, please, if you could post a sample experiment I’d be really grateful.

Many thanks,


I have attached a sample experiment and a diagram explaining how the stimulus lists are paired. Also, a Trial Variable for Screen location was created to present feedback.

Jill.sl4 (5.96 KB)