Empirisoft Support

    Welcome to Empirisoft Support
Results 1 to 12 of 12

Thread: Providing feedback on stimuli from stimlist (case 22054)

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    Nov 2011
    Posts
    13

    Providing feedback on stimuli from stimlist (case 22054)

    Hi there,
    I want to use stimlist so that stimuli will be presented randomly without replacement ($), but - I also want to provide feedback (<). Each stimulus on the list has 4 possible responses of which only 1 is correct. I want to provide "wrong" feedback for the other 3 responses. Is there any way to indicate for each stimulus in the list which response will lead to the "wrong" feedback (e.g., add a < near each stimulus in the list, as is done with regular stimuli in the time column)?
    Thanks!
    Tali
    Last edited by jason_reed; 12-14-2015 at 09:19 AM.

  2. #2
    Join Date
    Feb 2013
    Posts
    1,093
    Can you give me an example of what you mean by "each stimulus on the list has 4 possible responses of which only 1 is correct?"
    Jason Reed
    Empirisoft Software Support Specialist

  3. #3
    Join Date
    Nov 2011
    Posts
    13
    Quote Originally Posted by jason_reed View Post
    Can you give me an example of what you mean by "each stimulus on the list has 4 possible responses of which only 1 is correct?"

    Say I'm running a 4 color Stroop task, so I have 4 possible responses (e.g., green, red, blue, yellow), but for the stimulus red written in green, the only correct answer is green. I want participants to get a "wrong" feedback if they respond red, blue or yellow to this stimulus. (of course each color is assigned a key, e.g., D for red, F for green, G for blue, and H for yellow).

    Thanks!

  4. #4
    Join Date
    Feb 2013
    Posts
    1,093
    Take a look at the attached .csv input file. Taking your example of the stroop task, I modified one of the stroop examples from the Samples folder that comes with DirectRT.

    If you want to give feedback of correct or incorrect, this requires defining which keypresses are correct or incorrect. However, this can't be done when using a sitmlist without random replacement. So, to achieve the effect, you have to explicitly put the each stimuli in the .csv input file. You can then use the same positive nonzero integer in the wgr field of all the trials to get random presentation of the trials without repetition of already presented trials.

    Let me know if this is what you wanted.
    Attached Files Attached Files
    Jason Reed
    Empirisoft Software Support Specialist

  5. #5
    Join Date
    Nov 2011
    Posts
    13
    Thanks, but this is not what I meant - the attached csv file is what I already know how to do...
    My problem is that on some blocks I want to present only some of the stimuli (e.g., i have a total of 20 stimuli, but want to present only 8), and in a random (with no replacement) order. That's why I have to use a stimlist, and that's why I need to connect correct/incorrect responses to the stimuli in the stimlist.

  6. #6
    Join Date
    Feb 2013
    Posts
    1,093
    To present a subset of trials that are randomized with the wgr field, insert a row into the block of these trials after the last row of the number of them you want presented. If you have 8 trials but only want 4 presented, simply put a trial after the fourth row of all the rows that have the same nonzero positive integer in the wgr field. Take a look at the attached file for an example.

    Note how the trial 6 uses a value of 0 in its wgr field to ensure that only four trials with with the value of 1 in the wgr field will be presented. DirectRT will still select from all of the trials with a value of 1 in the wgr field, but only present four of them in this example.

    Trial 6 also skips over the rest of the trials by using the skip command to jump to trial 11. You can use this feature to jump to anywhere you want in your .csv input file.
    Attached Files Attached Files
    Jason Reed
    Empirisoft Software Support Specialist

Similar Threads

  1. Providing feedback on stimulus-response match in real-time (case 1671)
    By dlyoung in forum DirectRT v2018: How Do I...
    Replies: 2
    Last Post: 12-12-2015, 11:52 AM
  2. Providing participant's RT as feedback
    By varia in forum DirectRT v2018: How Do I...
    Replies: 1
    Last Post: 06-17-2013, 03:55 PM
  3. Providing feedback?
    By Srdan in forum MediaLab Older Versions: General Questions
    Replies: 2
    Last Post: 02-11-2010, 03:44 PM
  4. Repeating stimuli when using $ random selection in stimlist
    By jarvis24 in forum DirectRT Older Versions: Troubleshooting
    Replies: 6
    Last Post: 06-28-2007, 11:57 AM
  5. providing block-level feedback
    By olsza7 in forum DirectRT Older Versions: How Do I...
    Replies: 1
    Last Post: 11-28-2005, 04:41 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •