Millisecond Forums

Dear experts,

I am trying to modify the adaptive n-back task (from Jaeggi et al 2010).
In this task, stimuli are selected from a list of items. The version that I am programming includes three conditions:
1-back, where correct response is to press a button if the current stimulus is the same than the previous one
2-back, where correct response is to press a button if the current stimulus is the same than the stimulus presented two positions before
3-back, where correct response is to press a button if the current stimulus is the same than the stimulus presented three positions before
In the original script the stimuli selection is made using the "replace" option. However, I need a version with no lures. It means that, for example, if the participant is performing the 3-back condition, 1-back and 2-back conditions cannot appear.
I am not familiarized with Inquisit programming options, and I wonder if I could somehow specify the following conditions for stimulus selection:

//Assuming that N is the n-back condition
// Declare the following variables:
values.n1 = 0;
values.n2 = 0;
values.n3 = 0;
// Conditions for stimulus selection
if ( values.N = 1) {
    do {
    values.currenttarget = list.items.item(values.N);
    } while (values.currenttarget = values.n2 or values.currenttarget.n3)
    
else if ( values.N = 2) {
    do {
    values.currenttarget = list.items.item(values.N);
    } while (values.currenttarget = values.n1 or values.currenttarget.n2)    
else if ( values.N = 3) {
    do {
    values.currenttarget = list.items.item(values.N);
    } while (values.currenttarget = values.n1 or values.currenttarget.n2)
// Update the variables after each trial        
values.n1 = currenttarget;
values.n2 = values.n1;
values.n3 = values.n3

I hope you understand this issue.
Thank you very much!

Best regards,
Naiara