MATLAB: How to record two simultaneous key responses? (using Psychtoolbox)

key responsesMATLAB

In my experiment design, a pair of participants should press different keys (one should press 'z', the other should press '/' on the same keyboard) to respond to the signal appearing on the same screen. But I want to know how to record two different key responses with very short time intevals.
Hope I can get some advice on how to fix the code below:
while true
            [~,~,keyCode]=KbCheck;
            if keyCode(KbName('z'))
                endtime1=GetSecs
            end
 end
 while true
            [~,~,keyCode]=KbCheck;
            if keyCode(KbName('/'))
                endtime2=GetSecs
            end
            i=i+1;
            break;
 end

Best Answer

  gotem = false(1,2)
  times = zeroes(1,2)
  while ~all(gotem)
     get a key
     [tf,idx] = ismember(the key, appropriate values )
    if tf 
       gotem(idx) = true
       times(idx) = GetSecs
   end
   end
Note that in this code if the same key is pressed multiple times then the last is recorded . Recording the first instead would be easy
Related Question