Millisecond Forums

Hi Luke, 

Don't know if this will help, but I programmed an affective priming expt myself a few months ago, and counterbalancing for all the manipulated variables worked properly only when all trial numbers were specified in the lists. I noticed your lists don't have /itemprobabilities = uniform and /poolsize = XX (number). 

Also, for each type of trial you might need to create separate lists just to be safe.

Hope this helps- poolsize and itemprobabilities are life savers; it just takes some time to break down all trial combinations and numbers. 

Best, 
Loukia

What you need to do is define the prime-target pairs e.g. using paired <list> elements and then have you trials sample randomly from those pairs.

//PP
<list PP_primes>
/ items = (1,1,1,1,1,1,1,1,1,1,
    2,2,2,2,2,2,2,2,2,2)
</list>

<list PP_targets>
/ items = (1,2,3,4,5,6,7,8,9,10,
    1,2,3,4,5,6,7,8,9,10)
/ selectionmode = list.pp_primes.currentindex
</list>

//PU
<list PU_primes>
/ items = (1,1,1,1,1,1,1,1,1,1,
    2,2,2,2,2,2,2,2,2,2)
</list>

<list PU_targets>
/ items = (1,2,3,4,5,6,7,8,9,10,
    1,2,3,4,5,6,7,8,9,10)
/ selectionmode = list.pu_primes.currentindex
</list>

//UP
<list UP_primes>
/ items = (1,1,1,1,1,1,1,1,1,1,
    2,2,2,2,2,2,2,2,2,2)
</list>

<list UP_targets>
/ items = (1,2,3,4,5,6,7,8,9,10,
    1,2,3,4,5,6,7,8,9,10)
/ selectionmode = list.up_primes.currentindex
</list>

//UU
<list UU_primes>
/ items = (1,1,1,1,1,1,1,1,1,1,
    2,2,2,2,2,2,2,2,2,2)
</list>

<list UU_targets>
/ items = (1,2,3,4,5,6,7,8,9,10,
    1,2,3,4,5,6,7,8,9,10)
/ selectionmode = list.uu_primes.currentindex
</list>

Then sample the respective prime and target item numbers from the appropriate <list>s in your <trial>s:

<trial PP_test>
/ ontrialbegin = [values.counttrials_test += 1; values.PP_test += 1]
/ ontrialbegin = [values.primecategory="Pleasant"; values.targetcategory="Pleasant"]
/ ontrialbegin = [
    values.primeitemnumber = list.PP_primes.nextvalue;
    values.targetitemnumber = list.PP_targets.nextvalue;
]
...
</trial>

<trial PU_test>
/ ontrialbegin = [values.counttrials_test += 1; values.PU_test += 1]
/ ontrialbegin = [values.primecategory="Pleasant"; values.targetcategory="Unpleasant"]
/ ontrialbegin = [
    values.primeitemnumber = list.UP_primes.nextvalue;
    values.targetitemnumber = list.UP_targets.nextvalue;
]
...
</trial>

and so forth.

Thank you both for your replies.

I tried running the script you attached and it worked a lot closer to what I'm wanting - but there were still cases where one word was presented more than once with a prime, and where a prime wasn't presented with a word (attached data set shows this). I also tried playing with the pool size and itemprobabilities to no avail. Is there any other way around this you can think of?

Thanks,
Luke

Gah, there is a copy & paste mistake in the script. That was my oversight.

<trial PU_test>
/ ontrialbegin = [values.counttrials_test += 1; values.PU_test += 1]
/ ontrialbegin = [values.primecategory="Pleasant"; values.targetcategory="Unpleasant"]
/ ontrialbegin = [
    values.primeitemnumber = list.UP_primes.nextvalue;
    values.targetitemnumber = list.UP_targets.nextvalue;
]
...
</trial>

obviously ought to be

<trial PU_test>
/ ontrialbegin = [values.counttrials_test += 1; values.PU_test += 1]
/ ontrialbegin = [values.primecategory="Pleasant"; values.targetcategory="Unpleasant"]
/ ontrialbegin = [
    values.primeitemnumber = list.PU_primes.nextvalue;
    values.targetitemnumber = list.PU_targets.nextvalue;
]
...
</trial>

Awesome - thanks Dave. Works a treat now!

Hi Dave,

I am running another experiment and want to tweak the lists I created above. I still have the same 2 lists of target words with 10 words each and want to run 80 trials, but instead of presenting each word with only one prime stimulus, I want to rotate through 4 different prime stimuli: so I would show word 1 with prime stimulus 1, word 2 with prime stimulus 2, word 3 with prime stimulus 3, word 4 with prime stimulus 4, word 5 with prime stimulus 1, word 6 with prime stimulus 2.... etc.. until the 10 words have been shown with those 4 prime stimuli - so each prime will be shown twice, and 2 will be shown 3 times, but no prime will be shown with the same word more than once. And I want to do this with 4 lots of 4 prime stimuli each being presented with the 2 lists of 10 target words. I tried playing around with Loukia's suggestions above and some other ideas but I couldn't get it to work how I want it to - how do I define the lists to make this happen?

Thanks,
Luke

Not sure I understand the question. Sounds like you'll simply want to define your prime-target pairs using <list>s and then sample from those pairs. So, I don't quite understand how this is different from what's been discussed before.

You are correct - I had an error in my picture element that was returning the wrong pairings leading me to believe I had to do something differently with the lists. All sorted now - Thanks Dave.

Luke

I have the same question.thanks for sharing