By sdandeneau - 3/10/2015
Hi,
Before I get to my question, I'd like to point out that I believe there is an error in calculating the /ConflictEffect expression the current ANT script in the Task Library:
/ConflictEffect = expressions.meanrt_correctcongruent - expressions.meanrt_correctincongruent
SHOULD BE : /ConflictEffect = expressions.meanrt_correctINcongruent - expressions.meanrt_correctcongruent
At least, this is my reading of Fan's original computes.
My question: I'd like to adapt the current ANT script to use facial stimuli instead of "arrows". Instead of a "left pointing arrows" there would be smiling face, and instead of "right pointing arrow" there would be a frowning face. Sounds like a pretty easy fix, however the problem I get into is that the flankers are dynamically defined for each trial, which is easy when you only have 1 item representing each stimuli (e.g. left arrow). As is stands, flankers are defined in each trial by the select.flankertarget "value" which assigns a value of 3 or 4 in order to get the 3rd and 4th items listed in the <stimuli> element.
<item stimuli>
/1 = "+"
/2 = "dot"
/3 = "right arrow"
/4 = "left arrow"
/5 = " "
</item>
I'd like to make the 3rd and 4th items of the stimuli element each refer to a pool of images, for example,
/3 = "pool of smiling faces"
/4 = "pool of frowning faces"
I'm pretty sure this is not possible, however, I'm having trouble figuring out how to go about I could easily make the "left arrow" item a pool of pictures instead of a static image/text.
In an effort to limit modifying the script, I'm looking for a way to make the 3rd and 4th items of the stimuli element refer to a "list/pool of something" instead of a static image/text.
Thanks in advance,
Stéphane
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By Dave - 3/10/2015
See the attached script for an example using 3 "smiling face" stimuli and 3 "frowning face" stimuli. (The code is meant to demonstrate how to go about this and making the result obvious on-screen; I have not put any effort into making the result look pretty.)
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By sdandeneau - 3/11/2015
This is great! Amazing the help we get here!
One of the reasons I originally asked if it was possible to refer to a "pool of pictures" is that ideally, Flankers would NOT be the same as each other on one trial. I.e, flankers would be chosen from a list of items to populate the flankers instead of choosing one flanker from the list and reproducing that item across all flankers during that trial. As is stands, it appears as though the trials define ONE flanker item to be used for all four flankers... I may need to define all four flankers separately?
I'm attaching the modified script with more pictures and adjusted the stimuli to better fit on screen.
Again... thanks a lot!
Stéphane
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By Dave - 3/11/2015
> I may need to define all four flankers separately?
Yes. You need separate <values> entries -- one for each flanker and/or cue -- and then populate those with valid item numbers from the applicable <list> elements. This works essentially the same as with the code I already provided. The <list> elements *must* be set to /selectionrate=always, otherwise they'll only return a single item number per trial.
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By Dave - 3/11/2015
For illustration purposes, work through the modifications to <trial nocue> in the attached revision of your script. Make analogous changes to the other relevant <trial> elements.
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