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  • Create a loop

    First, excuse me for my english, I am french!

    I, fact, I want to create a loop in a trial, and I don't arrive to make this!

    I have 4 events in a trial. If there is no response in the 4th event, I want to present the same trial again, untill 5 seconds if there is still no response (the next trial must appear if no response appears before 5 seconds).
    I don't arrive to make the loop (I arrive but it's not a clear work!), and to make this loop during 5 seconds.

    Could you help me please?
    Thanks a lot!

  • #2
    Bonjour Julie,

    If there is no response on the 4th event, do you want to present the four events all over again and then impose a 5 second time limit? Or do you want to simply display a feedback message telling the participant that they have 5 more seconds to reply?

    Hisham.

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    • #3
      Bonjour Hisham!

      Yes, I want to present the four events all over again during 5 second time if there is no reply at the 4th event...
      And I want to have a feedback at the end of the 5 seconds.
      For example:
      Image 1
      Image 2
      Image 3
      Image 4
      No reply --> Image 1, Image 2, Image 3, Image 4 again during 5 seconds.
      If there is a reply at Image 2, for example, during the loop, the feedback A appear and I want to record the reaction time to reply.

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      • #4
        Hello!

        I don't find any solution at my problem! I really need your help please!

        Comment


        • #5
          Is this what you mean?

          I'm just a fairly new SuperLab user, not an expert, but it seems to me that you don't really need a loop, but rather a sequence of unique events that present a repeated sequence of stimuli. The sequence needs to be long enough to consume your 5 s timeout interval. Here's a mini-experiment I set up as an example, using text rather than images for convenience: http://bogs.ucdavis.edu/~greg/julie.sl4.gz

          It presents the strings "one", "two", "three", "four" at 500 ms intervals, followed by the string "Try harder!" for 500 ms, and then the first four strings again with the same timing, and then the string "Bad Subject!!" for 2500 ms. The feedback for a correct response in events with actual stimuli is set to an event that presents the string "Good job!" followed by the termination of the current trial.

          I hope you don't need a lot of trials like this, because it's really tedious to set up.

          Cheers,

          Greg Shenaut

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          • #6
            Thanks a lot gshenaut!
            First, I can't read the mini-experiment you set us as example. I only can read 'y' and 'ô' letters...
            But what you explain is not really what I search to do: I don't want that the time of the 4 events is 5s at the end, but that the 4 events appears in the same order during 5s, like a video whose play and replay and replay during 5s.
            (Perhaps I don't understand what you want to say too... so excuse me if it's the case...).
            And this is to do that that I search to make a loop...
            Sorry, perhaps I'm not clear.

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            • #7
              Julie,

              I think Greg's experiment is very close to the behavior you are looking for. I've zipped it and attached it to this post to make it easier for you to download.

              The only other possibility that comes to mind for me is that you could create a movie out of your four pictures and present the movie asynchronously until the participant responds.

              If you were to use feedback to repeat the trial, unfortunately the response timer would be reset with the trial. Currently, the only way to get your behavior would be without an actual loop.
              Attached Files

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              • #8
                How to upload experiments, etc.

                Hank, what is the best way to upload an experiment or other text (for example, a fragment of a logfile or stimulus list) to this forum?

                Julie, ce que j'ai voulu faire dans ma mini-expérience était de dérouler la boucle. C'est à dire qu'il y a une séquence d'événements qui sont le produit d'une boucle conceptuelle, mais dont l'implémentation est en la forme d'une seule séquence atomique.

                C'est la différence entre dire "1 2 3 4 1 2 3 4 1 2 3 4" et dire "1 2 3 4" trois fois. Pour un petit nombre de répétitions, cette différence n'a pas d'importance pratique; autant que la longueur s'augmente, l'utilité du déroulement se diminue. Donc, s'il vous fallait par exemple 100 cycles de la boucle, mon indication ne vous marcherait pas bien.

                I hope that my "fractured French" doesn't create even more confusion.

                Hank, I should mention that it was thinking about Julie's question that led to my suggestion of allowing multiple independently conditional feedback events to form "feedback chains" (or as you put it, "feedback loops"). This would be a very natural way to implement Julie's experiment as a simple finite state machine that could loop even thousands of cycles if necessary.

                Cheers,

                Greg

                Comment


                • #9
                  Greg,

                  This user interface works a little differently from the interface of other VBB-based boards. You have to click "Go Advanced" to get the advanced options. You can't just click "reply." Once you've done that, there is a "Manage Attachments" button to allow you to upload files to the board. Currently, the largest file size allowed (by far) is with zip files. You can have SuperLab create a Zip package out of an experiment for you by selecting "Create an Experiment Package..." in the file menu. If you have stimulus files, this will include them in the zip package. This is why we allow large zips, as we expect potentially large experiments to be uploaded.

                  While Macs can readily decompress .gz and .tgz files , Windows can't decompress these files without an additional tool . Other than the fact that Unicode filename support on zip is nonstandard (and therefore nonexistent within SuperLab), zip files are the easiest method of transferring experiments.

                  If the file type is not in the list of the board's supported file types, simply zip the file and then upload it.

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                  • #10
                    Thanks! I'll keep that in mind.

                    Greg

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                    • #11
                      Thank you everyone!
                      In fact, I have find a solution: on the 4th event, I put a feedback, but this feedback don't return to an event, and it 'presents the same trial again'. But the problem is a 'refresh of the screen' (is it an english expression???!), so the presentation bugs...
                      Bye!

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                      • #12
                        Hello,

                        I've got another question: I need to know how we can stop a trial (based on the 4 pictures described in my others replies) at the end of, per example, 60 seconds?
                        Thanks a lot!

                        Comment


                        • #13
                          SuperLab doesn't currently support setting a maximum time on a trial. You can set a maximum time on an event, and you can set a minimum time on a trial (for synchronizing with an fMRI), but you can't interrupt a trial in progress at the end of a time limit.

                          I hope that helps a little.

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                          • #14
                            Thank you Hank, you have helped me! But this is not a good new
                            See you soon...

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