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Thread: N-back task

  1. #1
    Join Date
    Feb 2006
    Posts
    2

    N-back task

    Has anyone had any success in creating the n-back task in medialab?

    Here is what I would like to do. I would like to present a list of numbers on the screen, one at a time, for a set amount of time (say 5 minutes). All the person has to do is hit a button, preferably the space bar, if the current number listed one that was presented 2 screens ago (the 2-back task).

    The problem I face is this. I wanted each number to say on the screen for 2 seconds (regardless if they answer or not) then move onto the next number. I also want to know where medialab stops the person in the list (since the overall time is fixed for 5 minutes).

    Anyone have any type of experience with this or have any ideas on how to do this?

    If you have already successfully created the n-back task with medialab please contact me)!

  2. #2
    Join Date
    Nov 2005
    Posts
    3,328
    You could certainly do this in DirectRT. I think you could do it in MediaLab but I'd have to play around with it. Can you send me what you have so far and I'll take a look?
    -Blair

  3. #3
    Join Date
    Nov 2005
    Posts
    3,328
    This is definitely easier to pull off in DirectRT. But if you are willing to twist some arms and legs, I think MediaLab will do it for you. I've attached a modification of the sample you sent me. Details of the arm twisting follow...

    I changed your fill in the blanks to essays. I did this because essays have a "key press monitoring" feature. Note that each item has a "k32" parameter which basically tells MediaLab to watch for the spacebar being pressed during the item and write a timestamp of the occurrence to a special datafile named after that variable. OK, so then your d2 parameter took care of the 2-second time limit. I added a t1000 parameter to move the big essay text box off screen. I also added a param(a2,t.5) to the question wording to center the numbers vertically and horizontally. Finally, I created a quickstyle file (nback.mlq) to create a larger font for the numbers. Data analysis for this will be a bit of a dog because each number gets its own keypress file. It wasn't designed for this type of task, but I think it works. Let me know if you want to try it in DirectRT because, unlike MediaLab, DirectRT could do this kind of thing in its sleep.

    Hope that helps,
    Blair
    Attached Files Attached Files

  4. #4
    Join Date
    Nov 2005
    Posts
    3,328
    Regarding DirectRT approach, see also: http://www.empirisoft.com/support/showthread.php?p=17379

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