Hi
I'm modifying the script for the N-Back Task (letter stimuli) so that it only includes the 1, 2 and 3-back levels, i.e. I have deleted the 0-back level.
When testing the script I see this error message: "Unable to initialize <picture expinstructionslide> item number 4. Verify the item exists and is correctly defined."
Evidently I need to change something in the Instruction script, however, I can't figure out what that may be. Here is the script I have for Instruction Image Selection:
***********INSTRUCTION IMAGE SELECTION******************************************
<picture SingleNbackinstructions_start>
/ items = Nback_startinstructions
/ select = sequence
/ size = (100%, 100%)
</picture>
<picture Practice_end>
/ items = practiceend
/select = 1
/ size = (100%, 100%)
</picture>
<picture StartExp_slide>
/ items = startendslides
/ select = 1
/ size = (100%, 100%)
</picture>
<picture EndExp_slide>
/ items = startendslides
/select = 2
/ size = (100%, 100%)
</picture>
*instructions for individual experimental trials are selected depending on level of N
<picture expinstructionslide>
/items = expinstructions
/select = expressions.selectinstruct
/size = (100%, 100%)
</picture>
<picture repeatpractice_page>
/items = ("SingleNbackInstructions_practicerepeat.gif")
/size = (100%, 100%)
</picture>