thanks so much for the answer. i try to explain the best that i can
I try to program a antisaccade task
this task consist in a fixation point in the screen, follow of a signal to indicate to the subject to make a response.
this signal indicates if the trial is a saccade or antisaccade trial.
And finally a point in the screen (left or rigth) to make the response.
all the stilumus are presented in time order (few seconds)
The motor response is to look in direction of the last point, in other words a saccade (look in direction of the stimulus) or a antisacade (look in the oposite direction of the stimulus). We have only 2 responses.
we gonna use a eye tracker to measure the motor response.
i succes in the program the 7 conditions.
1: sacade to the rigth
2: saccade to the left
3: antisaccade to the rigth
4: antisaccade to the left
5: Preparatory saccade (is just the signal that indicate that the trial is a saccade trial without response)
6: preparatory antisaccade (just the signal that indicate that the trial is a antisaccade trial)
7: is just a central fixation point in the screen like a control
i put the 7 conditions in the flow like the image.
each condition (1,2,3,4,5,6,7) need the correct order of the presentation (first a fixation point, the signal, and the stimulus target, all dots in the screen)
then i put a loop to repeat each condition 5 times.
until this point i dont have problem
however i need to randomize the loop, in other words, randomize the conditions (1,2,3,4,5,6,7)
to make appear sometimes first the saccade rigth condition and follow antisaccade left, etc, and sometimes firts the antisaccade rigth and then preparatory saccade, etc.
my trouble is that i dont know how i can randomize the 7 conditions without change the internal order of the stimulus.
thanks so much. i really appreciaty the help