Simultaneous picture stimuli

SuperLab SuperLab 4 Support
1

Hello!

I would presented 2 stimuli simultaneously.
These stimuli are 2 pictures.
I have seen the option which can permise to present 2 stimuli simultaneously, but I can’t run it, I don’t know how to make the application…
Thanks a lot for your help!

Julie

2

Hi Julie,

Within SuperLab, click on the Help menu then click on Help Contents. A help page comes up. Under the “How Do I…” section, there is a step by step example on how to present two stimuli at the same time.

Let me know if you need additional help.

Hisham.

3

Hi Hisham!
Thanks a lot for your quick reply!!!
I’ve done what the “Hox Do I Present Two or More Visual Stimuli at the Same Time” page says, but I can not get a good result…
Pictures are not displayed on the screen, and I don’t know why because I’ve done what it was wrtitten on “Help”.
So can you help me more please!!!

I must “Click on the Input tab and click on the Immediately after the event is presented checkbox to turn it on.” But if the end of the event appears immediately after the event is presented, we can’t see anything on the screen, no? The preoblem comes from this point perhaps…
What do you think?

4

Hi Julie,

Selecting the event Immediately after the event is presented setting is important, but equally important are the two other settings in the Picture Settings dialog.

To summarize, the first picture must have the following settings:

  • In the Input tab, the checkbox [B]Immediately after the event is presented[/B] must be turned On.
  • In the Picture Settings dialog, the [B]Keep stimulus invisible[/B] checkbox must be turned On.
For the second picture, in the Picture Settings dialog:
  • Make sure that the [B]Erase screen before presenting stimulus checkbox[/B] is turned Off, otherwise the first stimulus will be erased.
  • Turn Off the [B]Keep stimulus invisible[/B] checkbox, otherwise neither the first stimulus nor the second one will appear.
If you have followed all these directions and you still cannot get the two images to appear simultaneously, then double-check that the images are not overlapping on the screen.

Hisham.

5

Thanks again!

I am sorry, but I still cannot get the two images to appear simultaneously :frowning:
I see the pictures, but it’s really brief. It’s normal, no? Because we don’t have given a time to the trial. But I try to give 5000ms to the trial, and it’s the same, I see the pictures, but I have not the time to see what it is because it disappear immediatly!..
Or what I would, it’s that the 2 stimuli appears in the same time, but appears on the screen during, for example, 5000ms…

6

Since it makes them invisible, the pictures are invisible!
It this point that I don’t understand too!!!

7

Since it makes them invisible, the pictures are invisible!
It this point that I don’t understand too!!!

If you make both pictures invisible, then of course they will not appear. The second picture should not be marked as Keep invisible. The idea is to keep only the first picture invisible until the second has been drawn as well, and then both will appear at the same time.

8

Oh, I’m sorry, there were the pictures I’ve chosen which are not good, the problem came to my pictures…
The experiment works now!!!
Sorry Hisham, and thanks a lot, really, you always find the solution!!!
Thanks for your help!
Bye!

9

Sorry, but you are going to hate me!!! :mad:
If we want the pictures appear to the screen, we have to turn on ‘After this trial has started, wait x milliseconds before starting the next trial in this block’.
And we can’t programm a participant’s response. Rather, I’ve try to programm a participant’s response, but it doesn’t work.
What would you done if you would that the 2 pictures appears during an unillimited laps, and if you would the participant click on the keyboard when he wants to respond (and so it goes to another trial)?
Have you got a solution?!!!
Thanks!

10

Don’t worry, I won’t hate you. :slight_smile:

The option After this trial has started, wait x milliseconds has nothing to do with presenting pictures simultaneously. Avoid using it unless you are designing your experiment to run in an MRI scanner.

It’s hard to picture what you’re trying to do without seeing the experiment. Can you post it?

11

Hi!

In my experiment, I want to peesent in

  • time1: for example, a square.
  • time2: a round in the time1 's square.

With no blank between the two times. The 2 forms must be appear simultaneously in time2.
But I don’t use the MRI scanner… I use a PC…
Thanks :wink:

12

Hi!
Must I consider that it’s not possible to do this experiment on a pc?
Bye.
Julie

13

Have considered using a movie file for your stimuli? I’ve found that if you set the frame rate of the video to whatever you need, for example, 4 frames per second, these little animations are fairly easy to set up and use as Superlab stimulus files.

Greg Shenaut

14

I see two possibilities here:

  1. The second image will need to be transparent to be drawn round over top of the square.
  2. The second image will need to be a composite image of both the circle and the square.

I would recommend the second approach, since you’re running on Windows. It’s been a long time since I’ve played with transparent images in SuperLab, but I had issues on Windows, and I seem to recall disabling transparency in the Windows version of SuperLab.

If you want the time between the first and second stimulus to be constant, you will need to set the first event to end after a time limit. If you want a response during the first event to cause the trial to end, you need to set up a feedback to that event that will cause the remaining events in the trial to be skipped.

15

Thanks a lot for your reply.
To simplify the programmation of the experience, I would superpose 2 stimuli, but I think that your solution is right, I tried it, but it’s very long because we need many combinations.
Thanks!

Julie

16

Transparency should work fine in SuperLab on the Mac, but if you are restricted to Windows, then that’s the appropriate route to take.

17

Ok thanks a lot for your help :wink:
Bye!