Stimuli selection from item pool not working


Author
Message
pops
pops
Esteemed Member (2.4K reputation)Esteemed Member (2.4K reputation)Esteemed Member (2.4K reputation)Esteemed Member (2.4K reputation)Esteemed Member (2.4K reputation)Esteemed Member (2.4K reputation)Esteemed Member (2.4K reputation)Esteemed Member (2.4K reputation)Esteemed Member (2.4K reputation)
Group: Forum Members
Posts: 69, Visits: 85
Inquisit is not behaving as I would expect but I have no idea why:
I have three stimulus pools coded as items that have my jpg files in them.

<item angryPics>
/ 1 ="004_o_m_a_a.jpg"
/ 2 ="004_o_m_a_b.jpg"
/ 3 ="066_y_m_a_a.jpg"
/ 4 ="066_y_m_a_b.jpg"
/ 5 ="079_o_f_a_a.jpg"
/ 6 ="079_o_f_a_b.jpg"
/ 7 ="140_y_f_a_a.jpg"
/ 8 ="140_y_f_a_b.jpg"
</item>

<item fearPics>
/ 1 ="004_o_m_f_a.jpg"
/ 2 ="004_o_m_f_b.jpg"
/ 3 ="066_y_m_f_a.jpg"
/ 4 ="066_y_m_f_b.jpg"
/ 5 ="079_o_f_f_a.jpg"
/ 6 ="079_o_f_f_b.jpg"
/ 7 ="140_y_f_f_a.jpg"
/ 8 ="140_y_f_f_b.jpg"
</item>

<item neutralPics>
/ 1 ="004_o_m_n_a.jpg"
/ 2 ="004_o_m_n_b.jpg"
/ 3 ="066_y_m_n_a.jpg"
/ 4 ="066_y_m_n_b.jpg"
/ 5 ="079_o_f_n_a.jpg"
/ 6 ="079_o_f_n_b.jpg"
/ 7 ="140_y_f_n_a.jpg"
/ 8 ="140_y_f_n_b.jpg"
</item>

I then have three pictures where these items are inserted using 'noreplace'

<picture CentralAngryPic>
/ items = angryPics
/ select =noreplace
/ size = (parameters.imageheight, parameters.imageheight)
</picture>

<picture CentralNeutralPic>
/ items = neutralPics
/ select =noreplace
/ size = (parameters.imageheight, parameters.imageheight)
</picture>

<picture CentralFearPic>
/ items = fearPics
/ select =noreplace
/ size = (parameters.imageheight, parameters.imageheight)
</picture>

I determine the trial type using a list:

<list trialselectionfaceType>
/items = (1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3)
/replace = false
/selectionmode=random
</list>

Then during the trial I insert the required pic.

<trial trialfaceCentralDistractor>
/ ontrialbegin = [
    values.trialType = list.trialselectionfaceType.nextvalue;
    if (values.trialType == 1){
    trial.trialfaceCentralDistractor.insertstimulustime(picture.CentralAngryPic, values.fixationduration + parameters.blankduration);
    values.currentPic = picture.CentralAngryPic.currentitem}
    else if (values.trialType == 2){
        trial.trialfaceCentralDistractor.insertstimulustime(picture.CentralFearPic, values.fixationduration + parameters.blankduration);
        values.currentPic = picture.CentralFearPic.currentitem}
    else if (values.trialType == 3){
        trial.trialfaceCentralDistractor.insertstimulustime(picture.CentralNeutralPic, values.fixationduration + parameters.blankduration);
        values.currentPic = picture.CentralNeutralPic.currentitem}
/ validresponse = (parameters.responsekey_Targethorizontal, parameters.responsekey_Targetvertical)
/ correctresponse = (values.correctResponse)
/ beginresponsetime = values.fixationduration + parameters.blankduration;
/ timeout = 2000 + values.fixationduration + parameters.blankduration;
/ ontrialend = [
trial.trialfaceCentralDistractor.resetstimulusframes();
</trial>

<block faceBlocksReward>
/trials = [1-48 = trialfaceCentralDistractor]
</block>

I am expecting each image to be shown exactly twice in each block. Each time the picture is called I expect it to insert one of the 8 pictures into the trial and then once the pool is empty, cycle through them again. But that is not what is happening. Even though I am getting 16 trials of each of the three conditions in each block, some pics are shown more than others.
What am I doing wrong??
Thank you for any advice


GO

Merge Selected

Merge into selected topic...



Merge into merge target...



Merge into a specific topic ID...





Reading This Topic

Explore
Messages
Mentions
Search