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matlabpsychtoolbox

Divide screen experiment in upper/lower part

I am new with Matlab and Psychtoolbox, and I have three codes :

  • One code that creates circles with a certain pattern of movement that we can call pattern 1

  • Another code that creates circles with a different pattern of movement (pattern 2)

  • A code that plays pattern 1 OR pattern 2 (like we would play a video) on a full screen.

I would like to divide the screen in two where pattern 1 will be played in the upper part, and pattern 2 played in the lower part in 50 % of the trials, and the inverse (pattern 1 in lower part/ pattern 2 in the upper part) in the rest of the trials. Both patterns have to be played at the same time. Is there a function or a set of functions that would allow me to do that?

Thank you very much for your help!

Solution

  • I think without the code it is very difficult to answer. In general, you can choose where to present stimuli by determining the rect.

    For instance, if you screen is 1280 x 1024 your rect is 

    rect = [0 0 1280 1024];

    The you can create the upper and lower rect by

    upperRect = [0 0 rect(3) rect(4)/2];
lowerRect = [0 rect(4)/2+1 rect(3) rect(4)];

    You can now use these to display things only in one half of the screen. The exact implementation depends on your code though.