Add tricky stimulus and better number selection to RapidMemory Dual n-back

New Features

Add tricky stimulus (Interference), trying to emulate n +-1/(n-back+1) instead of novel/ totally random stimuli

Why?

Increased parietal activity after training of interference control
High interference led to partial improvements in the Attention Network Test (ANT
This suggest that training on an interference control task leads to higher electrophysiological activity in the parietal cortex, which may be related to improvements in processing speed, attentional control, or both.

https://www.ncbi.nlm.nih.gov/pubmed/23982078

Other study: https://www.ncbi.nlm.nih.gov/pubmed/21787103

Video

 //tricky
          if(_.random(1,100)<=tricky  && nBack!=1 && currentPass-nBack+1>=0){
           //selecting previous last elements in the stimulus array 
            __x=salidas[_.random(currentPass-nBack+1,currentPass-1)][0];
            __y=salidas[_.random(currentPass-nBack+1,currentPass-1)][1];
            console.log("tricky n-back A");
          }

Add new form of select the numbers

for(i=0;i<8;i++){

      for(;;){

       if(myDigits==1) //number of digits of the span-task
          _myImagen1=arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]; 
        if(myDigits==2)
           _myImagen1=arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]; 
        if(myDigits==3)
           _myImagen1=arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]+""+arrayImages1[_.random(0,9)]; 
        if(myDigits==4){ // All digits go to span task
          _myImagen1="";
          for(_i=0;_i<max;_i++){
            _myImagen1+=""+arrayImages1[_.random(0,9)];

          }//for
        }//if

          if(txt.indexOf(_myImagen1)==-1) break; // the combination is new

      }//for(;;)

      txt+=_myImagen1; arrayResults[i]=_myImagen1; // add the combination to the array stimulus

     }//for i

Thanks!