Millisecond Forums

conditional stimulus selection

https://forums.millisecond.com/Topic10318.aspx

By juliane_d - 4/22/2013

Hi there,


I have two lists of stimuli which a variants of each other (e.g., list A contains faces, list B contains the same faces inverted, etc). During one block, I want to make sure that if stimulus 1 has been randomly selected from list A, it will not be selected from list B at any time during this block.
Counters and different select options seem to allow only to make sure that the same stimulus is not selected in the consecutive trial but not throughout the whole block, right? Any clever way to implement such conditional stimulus selections?


Many thanks for any insight,


Juliane


By Dave - 4/22/2013

Counters and different select options seem to allow only to make sure that the same stimulus is not selected in the consecutive trial but not throughout the whole block, right


No. All you need to do is use the same <counter> or <list> for both <picture> elements. Here's a quick example:


<text atext>
/ items = ("A1", "A2", "A3", "A4")
/ select = mycounter
</text>

<text btext>
/ items = ("B1", "B2", "B3", "B4")
/ select = mycounter
</text>

<counter mycounter>
/ select = noreplace(1-4)
</counter>

<trial atrial>
/ stimulusframes = [1=atext]
/ validresponse = (57)
</trial>

<trial btrial>
/ stimulusframes = [1=btext]
/ validresponse = (57)
</trial>

<block myblock>
/ trials = [1-4=noreplace(atrial, btrial)]
</block>

By juliane_d - 4/22/2013

sooo simple - i am embarrassed...


many thanks!