% discs setting
frame = CenterRect([0, 0, 300, 300], rect);
disc1 = AlignRect([0, 0, 20, 20], frame, 'center', 'left');
disc2 = AlignRect([0, 0, 20, 20], frame, 'center', 'right');

if VideoStimulusToPlay == 1
    Screen('Flip', w);
    for i = 0:2:280
        Screen('FillRect', w, 255, frame);
        Screen('FillOval',w,0,[disc1(1)+i,disc1(2),disc1(3)+i,disc1(4)]);
        Screen('FillOval',w,0,[disc2(1)-i,disc2(2),disc2(3)-i,disc2(4)]);
        Screen('Flip', w);
    end
elseif VideoStimulusToPlay == 2
    Screen('Flip', w);
    for i = [0:2:140, 140, 140:2:280]
        Screen('FillRect', w, 255, frame);
        Screen('FillOval', w,0,[disc1(1)+i,disc1(2),disc1(3)+i,disc1(4)]);
        Screen('FillOval', w,0,[disc2(1)-i,disc2(2),disc2(3)-i,disc2(4)]);
        Screen('Flip', w);
    end
end
Screen('FillRect', w, 255, frame);
Screen('Flip', w);