Hello,
I've been running an edited version of Motter's Visual Search task using words instead of letters.
I'm having problems getting the 'values.target.present' column to show data for all trials. It is showing 0 (not present) and 1 (present) for all the practice trials, as it should, but only some of the task trials. This is seemingly at random, throughout all of the conditions and in a variety of word positions. 
I have no idea which bit of code needs altering, or if there is a way to recover any of this data from trials already undertaken.
I've copied some of the code below, but as I don't know which bit of code the problem relates to, please let me know what it would be helpful for me to post here (e.g. values/ lists).

Any advice gratefully received
Many thanks.

-<list Threat3T_targetPresent>
/items =  (0, 0, 1, 1, 1, 1, 1, 1, 1, 1)
/ selectionmode = list.arraysize_Threat.currentindex
</list>
also
-<trial Threat3T>
/ ontrialbegin = [
values.arraysize = list.arraysize_Threat.nextvalue;
values.selectTarget = list.Threat_targetStimItemNumber.nextvalue;
values.currentTarget = values.selectTarget;
values.targetPresent = list.Threat3T_targetPresent.nextvalue;
etc.

For someone to assess this, please provide:
(1) The full modified script and any external files that script requires to run. Please don't paste the code into a post's body, but attach the files to your post via +Insert -> Add File.
(2) A description of the various changes to the code you made and why each change was made.
(3) One or two data files illustrating the problem.

Thank you. 
I adapted the 'Visual Search Task (Divided Attention)'. I've changed the letters to words (threat, neutral and positive - 3x8 rather than 4x6) in line with Rinck (2003) and created additional conditions, threat in a positive, neutral and threat matrix, neutral in a threat, positive and neutral matrix and positive in a threat, neutral and positive matrix. I've changed the array size to always be 24, and I've also prevented the target from being added as a distractor.

Many thanks for your help.

<list arraySize_Threat>
/items = (
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24)
/ replace = false
/ resetinterval = 0
</list>

has 32 items, i.e. the index runs from 1 to 32.

Your various targetPresent lists are linked to the above per its index:

// 11 items
<list Threat1N_targetPresent>
/items = (
0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1)
/ selectionmode = list.arraySize_Threat.currentindex
</list>

// 11 items
<list Threat2P_targetPresent>
/items = (
0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1)
/ selectionmode = list.arraySize_Threat.currentindex
</list>

// 10 items
<list Threat3T_targetPresent>
/items = (
0, 0, 1, 1, 1, 1, 1, 1, 1, 1)
/ selectionmode = list.arraySize_Threat.currentindex
</list>

Those lists have 11 and 10 items respectively, i.e. the index runs from 1 to 11 and 1 to 10 respectively.

Whenever you have an index number sampled in list.arraySize_Threat that does not exist in the target present lists linked to it, say for example index 18, the list will return nothing.

The exact same flaw exists for the neutral and positive conditions as well.

Thank you for your response, I created separate lists for each condition and this fixed the problem. Also, just to be clear, I'm assuming there is nothing I can do to work out whether the target was absent or present in the trials that have already been recorded where there was no indication of target presence/absence? I'm purely asking out of desperation...
Many thanks

Given the logic

if (!values.targetPresent){
values.selectTarget = list.Threat.nextvalue;
};

I think the target would have been present in all instances where the value was empty.

<values>
/ targetPresent = ""
/ index = 3
/ textitem = 1
</values>

<list targetpresent>
/ items = (0,1)
/ selectionmode = values.index
</list>


<trial example>
/ ontrialbegin = [
values.targetPresent = list.targetpresent.nextvalue;
]
/ ontrialbegin = [
if (!values.targetPresent){
values.textitem = 2;
};
]
/ stimulusframes = [1=target]
/ validresponse = (57)
</trial>

<text target>
/ items = ("Present? YES", "Present? NO")
/ select = values.textitem
</text>