Millisecond Forums

> The script randomly assigns the stimuli to spots in the 3 x 3 grid

Instead of assigning stimuli to positions (as the above suggests), you should assign positions to stimuli. Example:

<trial mytrial>
/ stimulusframes = [1=a,b,c]
/ validresponse = (a,b,c)
/ inputdevice = mouse
</trial>

<text a>
/ items = ("A")
/ hposition = list.hpos.nextvalue
</text>

<text b>
/ items = ("B")
/ hposition = list.hpos.nextvalue
</text>

<text c>
/ items = ("C")
/ hposition = list.hpos.nextvalue
</text>

<list hpos>
/ items = (35%, 50%, 65%)
/ selectionrate = always
</list>


Then you have the information you want directly.

I meant to include the script in the original post but had problems with the upload. 
Here is the dropbox link to the task and stimuli - please enter 3000 for subject number. 
https://www.dropbox.com/s/h1jh66q4a5dk3v7/GardnerMatrix.zip?dl=0 

I didn't describe the script right... it does assign a position to stimuli, as you mention. However, I can't figure out how to get the stimuli that was associated to each "distractor" at each trial. 

Thanks!!

You retrieve it via the stimulus element's currentitem property. Going back to my original example:

<block myblock>
/ trials = [1-2=mytrial]
</block>

<values>
/ myvalue = ""
</values>


<trial mytrial>
/ ontrialend = [if (trial.mytrial.response == "a") values.myvalue = text.a.currentitem]
/ ontrialend = [if (trial.mytrial.response == "b") values.myvalue = text.b.currentitem]
/ ontrialend = [if (trial.mytrial.response == "c") values.myvalue = text.c.currentitem]
/ stimulusframes = [1=a,b,c]
/ validresponse = (a,b,c)
/ inputdevice = mouse
</trial>

<text a>
/ items = ("A1", "A2")
/ hposition = list.hpos.nextvalue
</text>

<text b>
/ items = ("B1", "B2")
/ hposition = list.hpos.nextvalue
</text>

<text c>
/ items = ("C1", "C2")
/ hposition = list.hpos.nextvalue
</text>

<list hpos>
/ items = (35%, 50%, 65%)
/ selectionrate = always
</list>

<data>
/ columns = [response latency values.myvalue]
</data>

Wonderful... this works great!
Thanks a lot!