Millisecond Forums

What you're describing is basically similar a 1-back task. You can look at the n-back scripts available in the library for elaborate examples on how to implement something like this. I could give you a more concrete example / some skeleton code, but you would have to spell out the exact matching rules you wish to implement first.

Here's a simple example with two different digits between 1 and 9 sampled randomly in each trial. In match trials, one of the previous digits will be kept, the other will be replaced with a different one. In mismatch trials, both previous digits will be replaced with different ones.

<trial start>
/ ontrialbegin = [
values.n1 = list.numbers.nextvalue;
values.n2 = list.numbers.nextvalue;
]
/ stimulusframes = [1=number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("n")
</trial>

<trial match>
/ ontrialbegin = [
list.numbers.reset();
values.matchposition = replace(1,2);
if (values.matchposition == 1) {
values.not1 = values.n1;
values.not2 = values.n2;
values.n2 = list.numbers.nextvalue;
} else if (values.matchposition == 2) {
values.not1 = values.n1;
values.not2 = values.n2;
values.n1 = list.numbers.nextvalue;
}
]
/ stimulusframes = [1=number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("y")
</trial>

<trial mismatch>
/ ontrialbegin = [
list.numbers.reset();
values.not1 = values.n1;
values.not2 = values.n2;
values.matchposition = 0;
values.n1 = list.numbers.nextvalue;
values.n2 = list.numbers.nextvalue;
]
/ stimulusframes = [1=number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("n")
</trial>

<block example>
/ trials = [1= start; 2-21 = noreplace(match, mismatch)]
</block>

<text number_one>
/ items = ("<%values.n1%>")
/ position = (48%, 50%)
</text>

<text number_two>
/ items = ("<%values.n2%>")
/ position = (52%, 50%)
</text>

<values>
/ n1 = 0
/ n2 = 0
/ matchposition = 0
/ not1 = 0
/ not2 = 0
</values>

<list numbers>
/ items = (1,2,3,4,5,6,7,8,9)
/ replace = false
/ selectionrate = always
/ not = (values.not1)
/ not = (values.not2)
</list>

<data>
/ columns = (date time subject group blocknum blockcode trialnum trialcode response latency correct values.n1 values.n2 values.matchposition)
/ separatefiles = true
</data>

This was very helpful, thanks!

Thank you so much again for your help! I have been working on adapting the code you sent to work with images. I will have one image on top of the other. The number of dots in each image will either match or non match. 

Is this even possible? I have attached the code I have been working with as well as the data file. 


<trial start>
/ stimulustimes = [0=box,number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("n")
/ ontrialbegin = [
values.n1 = picture.number_one.nextvalue;
values.n2 = picture.number_two.nextvalue;]
</trial>

<trial match>
/ ontrialbegin = [
list.dominoes.reset();
values.matchposition = replace(1,2);
if (values.matchposition == 1) {
values.not1 = values.n1;
values.not2 = values.n2;
values.n2 = picture.number_two.nextvalue;
} else if (values.matchposition == 2) {
values.not1 = values.n1;
values.not2 = values.n2;
values.n1 = picture.number_one.nextvalue;
}
]
/ stimulustimes = [0=box,number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("y")
/ ontrialend = [
values.not1 = picture.mismatch1.nextvalue;
values.not2 = picture.mismatch2.nextvalue;
]
</trial>

<trial mismatch>
/ ontrialbegin = [
list.dominoes.reset();
values.not1 = values.n1;
values.not2 = values.n2;
values.matchposition = 0;
values.n1 = picture.number_one.nextvalue;
values.n2 = picture.number_two.nextvalue;
]
/ stimulustimes = [0=box,number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("n")
/ ontrialend = [
values.not1 = picture.mismatch1.nextvalue;
values.not2 = picture.mismatch2.nextvalue
]
</trial>

<block example>
/ trials = [1= start; 2-21 = noreplace(match, mismatch)]
</block>


<values>
/ n1 = 0
/ n2 = 0
/ matchposition = 0
/ not1 = 0
/ not2 = 0
</values>


<picture domino>
/ items = domino
/ size = (50%, 50%)
/ erase = false
</picture>

<item domino>
/1 = "1.png"
/2 = "2.png"
/3 = "3.png"
/4 = "4.png"
/6 = "5.png"
/6 = "6.png"
</item>

<picture number_one>
/ items = domino
/ position = (50%, 68%)
/ select = replace
</picture>

<picture number_two>
/ items = domino
/ position = (50%, 32%)
/ select = replace
</picture>


<picture box>
/ items = box
/ size = (55%, 55%)
/ erase = false
</picture>

<item box>
/1 = "dominostim/box.png"
</item>


<list dominoes>
/ items = (1,2,3,4,5,6)
/ replace = false
/ selectionrate = always
/ not = (values.not1)
/ not = (values.not2)
</list>


<list not1>
/ items = (1,2,3,4,5,6)
/ not = (values.n1)
/ replace = true
</list>

<list not2>
/ items = (1,2,3,4,5,6)
/ not = (values.n2)
/ replace = true
</list>

<picture mismatch1>
/ items = domino
/ select = list.not1.nextvalue
/size = (40%, 40%)
</picture>

<picture mismatch2>
/ items = domino
/ select = list.not2.nextvalue
/size = (40%, 40%)
</picture>

<data>
/ columns = (date time subject group blocknum blockcode trialnum trialcode response latency correct values.n1 values.n2 values.matchposition stimulusitem stimulusitem stimulusitem values.not1)
/ separatefiles = true
</data>

Thank you very much, and again happy to clarify!

Of course it's possible. Just use values.n1 and values.n2 to select the item in the <picture> elements, i.e.

/ select = values.n1

and

/ select = values.n2

respectively.

<trial start>
/ ontrialbegin = [
values.n1 = list.numbers.nextvalue;
values.n2 = list.numbers.nextvalue;
]
/ stimulusframes = [1=number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("n")
</trial>

<trial match>
/ ontrialbegin = [
list.numbers.reset();
values.matchposition = replace(1,2);
if (values.matchposition == 1) {
values.not1 = values.n1;
values.not2 = values.n2;
values.n2 = list.numbers.nextvalue;
} else if (values.matchposition == 2) {
values.not1 = values.n1;
values.not2 = values.n2;
values.n1 = list.numbers.nextvalue;
}
]
/ stimulusframes = [1=number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("y")
</trial>

<trial mismatch>
/ ontrialbegin = [
list.numbers.reset();
values.not1 = values.n1;
values.not2 = values.n2;
values.matchposition = 0;
values.n1 = list.numbers.nextvalue;
values.n2 = list.numbers.nextvalue;
]
/ stimulusframes = [1=number_one, number_two]
/ validresponse = ("y", "n")
/ correctresponse = ("n")
</trial>

<block example>
/ trials = [1= start; 2-21 = noreplace(match, mismatch)]
</block>

<picture number_one>
/ items = domino
/ position = (50%, 32%)
/ select = values.n1
</picture>

<picture number_two>
/ items = domino
/ position = (50%, 68%)
/ select = values.n2
</picture>

<item domino>
/1 = "1.png"
/2 = "2.png"
/3 = "3.png"
/4 = "4.png"
/6 = "5.png"
/6 = "6.png"
</item>

<values>
/ n1 = 0
/ n2 = 0
/ matchposition = 0
/ not1 = 0
/ not2 = 0
</values>

<list numbers>
/ items = (1,2,3,4,5,6)
/ replace = false
/ selectionrate = always
/ not = (values.not1)
/ not = (values.not2)
</list>

<data>
/ columns = (date time subject group blocknum blockcode trialnum trialcode response latency correct values.n1 values.n2 values.matchposition)
/ separatefiles = true
</data>

Ah, I see. Thank you very much!!