Millisecond Forums

Nback Practice Trial Target Amount

https://forums.millisecond.com/Topic34977.aspx

By charsiubhau - 11/22/2022

Hi Dave,

I'm running the 2key nback with 10 practice trials. I was wondering how many target trials there are for the practice/how to find this out? Thanks!

Belle
By Dave - 11/22/2022

charsiubhau - 11/22/2022
Hi Dave,

I'm running the 2key nback with 10 practice trials. I was wondering how many target trials there are for the practice/how to find this out? Thanks!

Belle

<block Practice>
/ preinstructions = (nback_levelInstructions)
/ trials = [
  1 = start;
  2 - 10 = noreplace(nontarget, nontarget, target); 

/ screencolor = (0, 0, 0)
/ recorddata = true
/ errormessage = true(text.ErrorFeedback, 500)
/ correctmessage = true(text.CorrectFeedback, 500)
/ branch = [
  block.PracticeEnd;
]
/ errormessage = true(ErrorFeedback, 500)
/ correctmessage = true(CorrectFeedback, 500)
</block>

There are 9 practice trials, with a 2:1 non-target to target ratio (i.e. 6 non-target trials, 3 target trials). Start trials don't count. Amount of start trials varies with N-level, i.e. there'll be 1 start trial when N=1, there'll be 2 when N=2, and so forth.