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How to copy randomized positions to the next display?

Hi,
I would like to present 2,4 or 6 lines on the screen twice and ask to participant decide whether anything changed. On half of all trials, one item in the test display either change color or orientation compared to the memory display. It is a visual short term memory test. The problem is, i am using xy_circle to randomize positions of lines, but on the second display, all of lines changing their locations. All lines must be on the same location in two displays which presented in order.
I have one more issue which is less important. These lines have 5 different colors, and 4 orientations. In my design, I cannot control that change is color or orientation or both.
If anybody can help, i will be grateful. Thanks in advance!



Comments

  • Let's start with this:

    The problem is, i am using xy_circle to randomize positions of lines, but on the second display, all of lines changing their locations. All lines must be on the same location in two displays which presented in order.

    I assume you mean that the lines change location from rect_6 to rect_6d, right? This happens simply because you recreate the position list after determining the positions for rect_6 but before rect_6d. You can see that on line 14 of your script. If you remove this, then the locations on both sketchpads will be the same. (Provided of course that the two sketchpads are similar.)

    Cheers!
    Sebastiaan

    There's much bigger issues in the world, I know. But I first have to take care of the world I know.
    cogsci.nl/smathot

  • Hi Sebastiaan,
    It works, thank you!
    I didn't specified what this sketchpads are for. Myorder randomly pick a number, let' say 5, and it shows rect6 which means 6 lines, then it shows rect6d which means 6 lines with a different one. There will be rect7 instead of rect6.
    The next problem is controlling the change. It's not necessary but if I can it would be great.
    Last question, is there any way that prevent displaying same lines?
    Thanks.

  • Hi,

    You'll have to explain the paradigm in much more detail for me to be able to answer that question! What exactly do you want to do? What have you done so far? And in what sense doesn't it work as you'd like it to?

    Cheers!
    Sebastiaan

    There's much bigger issues in the world, I know. But I first have to take care of the world I know.
    cogsci.nl/smathot

  • "Visual short-term memory. Participants viewed displays containing colored lines (red, green, blue, pink,
    and black) at different orientations (vertical, horizontal, tilted to the left, or tilted to the right). Each line measured .2 1.6 and had a center-to-center distance of at least 3.5. Participants first viewed a display containing 2, 4, or 6 lines for 100 ms. This memory display was followed by a blank screen for 900 ms, and then a test display. On half of all trials, one item in the test display either changed color or orientation compared to the memory display, and participants indicated whether anything changed. Accuracy was
    emphasized over speed. Participants completed 24 practice trials and 144 test trials" (Boot et al., 2008).

    Trial sequence shows 2, 4 or 6 lines depending on myorder value, after a fixdot.
    I have removed "shuffle myorder" code. Because it wasn't match with correct response. I will use Latin Square to randomize order of conditions.
    In this experiment, rect2d(ifferent), rect4d, rect6d using variable rect7 instead of rect2, and that provides change. To control the change(orientation or color or both), I suppose I can choose every rect7 and rect2 conditions by cancelling shuffle codes but it can be a problem for randomization. Every participant would gave gave stimuli in same order. Is there any other way to do it?
    Do you think it will be a problem? Sorry for my English, I'm trying to improve.

  • Hi,
    I finished it. Randomization or controlling the change is not a problem anymore.
    I am just wondering how do I tell OpenSesame that do not show same pictures in one trial. As you see on the picture, there is png files and sometimes it choose same files for different rect variables. Is it possible to block this?
    Thanks for your all contributions!

  • Hi,

    I am not sure whether I understand your task correctly. Regardless, I don't think there is an easy way to tweak your experiment a little and get the desired behaviour. What I would do is not using the loop table for this but another inline_script in which you define one list with all the images and next, select the images from the list, taking all the restrictions into account that you need.

    For example. Here a just a little bit of code that would do that:

    import random
    
    images = [ 'img1.png','img2.png','img3.png']
    
    # select first, random stimulus
    stimuli.append(random.choice(images))
    
    # choose the second and make sure it is not the same as the first one
    second_stim = random.choice(images)
    while second_stim == stimuli[0]:
        second_stim = random.choice(images)
    
    stimuli.append(second_stim)
    

    Does that make sense?

    Eduard

  • Sorry, I'm late.
    It works, thanks for your all contributions!
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