Millisecond Forums

I am designing a RSVP task. In this task letters flash for 15ms followed by a blankspace of 75ms and this is repeated 20ish times. At some point in the stream I set one of the letters to be a target (set it as a different color).

The problem I am having is that the letters cannot repeat, but in the code I show below they are repeating and I cannot figure out why. I have tried to set it to reset by block and that didnt help.

Here is the relevant code:


<values>
/ t2position = 0

/ targetcolorr = " "
/ targetcolors = " "

/ currentd = ""
/ target = ""

/ t1correct = 0
/ t2correct = 0
/ xpresent = 0

/ condition = 0

/ ttot = 0
/ adjusted = 0

/ order = 0

</values>

<list targetlist>
/ items = ("A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" "U" "V" "W" "Y" "Z")
/ selectionmode = random
</list>



<data>
/file = "rsvpuw.iqdat"
/ columns = [subject, trialcode, latency, values.t2position, values.currentd, values.target, values.xpresent, values.t1correct, values.t2correct, values.condition, values.ttot, values.adjusted]
</data>

<text introc>
/ items = ("In this task you will see rapidly flashing streams of 23 letters that will appear at the center of the screen following the presentation of a fixation dot (a dot at the center of the screen you should look at). Each letter will flash for 15ms and be seperated by a 75ms blank space. You will encounter 1000 of these streams. For each stream will have two tasks:

First, one letter will be colored either <%values.targetcolorr%> or <%values.targetcolors%> and you will need to remember and enter this letter at the end of the stream. Importantly, if the letter is <%values.targetcolors%> and you get it correct you will earn 1 point, while if the letter is <%values.targetcolorr%> you will earn 9 points.

Second, in half of the streams an X will flash. At the end of the stream you will be asked if an X was present. If you answer correctly you will earn .9 pts.

You will now have some practice trials to familiarize you with the tasks.

Please press ~Continue~ when you are ready to begin.")
/ size = (80%, 20%)
/ position = (50%, 20%)
/ txbgcolor = transparent
/ txcolor = lightgrey
</text>

<text presenter>
/ items = ("<%list.targetlist.nextvalue%>")
/ position = (50%, 50%)
/ txbgcolor = transparent
/ txcolor = black
/ fontstyle = ("Arial", 10%, false, false, false, false, 5, 0)
</text>

<text targets>
/ items = ("<%list.targetlist.nextvalue%>")
/ position = (50%, 50%)
/ txbgcolor = transparent
/ fontstyle = ("Arial", 10%, false, false, false, false, 5, 0)
</text>

<text targetr>
/ items = ("<%list.targetlist.nextvalue%>")
/ position = (50%, 50%)
/ txbgcolor = transparent
/ fontstyle = ("Arial", 10%, false, false, false, false, 5, 0)
</text>

<text targett2>
/ items = ("X")
/ position = (50%, 50%)
/ txbgcolor = transparent
/ txcolor = black
/ fontstyle = ("Arial", 10%, false, false, false, false, 5, 0)
</text>


<shape dot>
/ shape = circle
/ position = (50%, 50%)
/ size = (1%, 1%)
</shape>

<trial dot>
/ stimulusframes = [1 = dot;]
/ trialduration = 500
/ recorddata = false
/ ontrialbegin = [values.t1correct = 0; values.t2correct = 0;]
</trial>

<trial blank>
/ trialduration = 250
/ recorddata = false
</trial>

<trial distractor>
/ stimulusframes = [1 = presenter;]
/ trialduration = 15
/ ontrialbegin = [values.currentd = text.presenter.item.1;]
</trial>

<trial filler>
/ stimulusframes = [1 = presenter;]
/ trialduration = 75
/ recorddata = false
</trial>

<trial targeterr>
/ stimulusframes = [1 = targetr;]
/ trialduration = 15
/ ontrialbegin = [values.target = text.targetr.item.1;]
</trial>

<trial targeters>
/ stimulusframes = [1 = targets;]
/ trialduration = 15
/ ontrialbegin = [values.target = text.targets.item.1;]
</trial>

<trial targetx>
/ stimulusframes = [1 = targett2;]
/ trialduration = 15
</trial>

<textbox targetthere>
/ caption = "Please enter the letter you saw that flashed in red or yellow."
/ mask = alphabetic
/ maxchars = 1
/ required = true
</textbox>

<dropdown xthere>
/ caption = "Was there an X presented in the stream?"
/ required = true
/ options = ("Yes", "No")
/ optionvalues = ("1", "2")
</dropdown>


<surveypage questions>
/ questions = [1 = targetthere; 2 = xthere;]
/ showquestionnumbers = false
/ showpagenumbers = false
/ ontrialend = [if(values.target == textbox.targetthere.response && values.condition == 1) {values.t1correct = 1; values.ttot += 9;}]
/ ontrialend = [if(values.target == textbox.targetthere.response && values.condition == 0) {values.t1correct = 1; values.ttot += 1;}]
/ ontrialend = [if(values.xpresent == 1 && dropdown.xthere.selectedvalue == "1") {values.t2correct = 1; values.ttot += .9;}]
/ ontrialend = [if(values.xpresent == 0 && dropdown.xthere.selectedvalue == "2") {values.t2correct = 1; values.ttot += .9;}]
</surveypage>


<block typep2>
/ trials = [1 = dot; 2 = blank; 3,5,7,9,11,13,15,17 = distractor; 4,6,8,10,12,14,16,18 = filler; 19 = targeterr; 20 = filler; 21 = distractor; 22 = filler; 23 = targetx; 24 = filler; 25,27,29,31,33,35,37,39,41,43,45 = distractor; 26,28,30,32,34,36,38,40,42,44,46 = filler; 47 = questions;]
/ onblockbegin = [values.t2position = 2; values.condition = 1; values.xpresent = 1; values.order += 1;]
</block>


<expt main1>
/ blocks = [1 = typep2;]]
/ onexptbegin = [values.targetcolorr = "red"; values.targetcolors = "yellow"; text.targetr.textcolor = red; text.targets.textcolor = yellow;]
</expt>