% Clear the workspace and the screen sca; close all; clear; % Here we call some default settings for setting up Psychtoolbox PsychDefaultSetup(2); % Get the screen numbers screens = Screen('Screens'); % Draw to the external screen if avaliable screenNumber = max(screens); % Define black and white white = WhiteIndex(screenNumber); black = BlackIndex(screenNumber); % Open an on screen window [window, windowRect] = PsychImaging('OpenWindow', screenNumber, black); % Get the size of the on screen window [screenXpixels, screenYpixels] = Screen('WindowSize', window); % Query the frame duration ifi = Screen('GetFlipInterval', window); % Set up alpha-blending for smooth (anti-aliased) lines Screen('BlendFunction', window, 'GL_SRC_ALPHA', 'GL_ONE_MINUS_SRC_ALPHA'); % Setup the text type for the window Screen('TextFont', window, 'Ariel'); Screen('TextSize', window, 36); % Get the centre coordinate of the window [xCenter, yCenter] = RectCenter(windowRect); % Here we set the size of the arms of our fixation cross fixCrossDimPix = 40; % Now we set the coordinates (these are all relative to zero we will let % the drawing routine center the cross in the center of our monitor for us) xCoords = [-fixCrossDimPix fixCrossDimPix 0 0]; yCoords = [0 0 -fixCrossDimPix fixCrossDimPix]; allCoords = [xCoords; yCoords]; % Set the line width for our fixation cross lineWidthPix = 4; % Draw the fixation cross in white, set it to the center of our screen and % set good quality antialiasing Screen('DrawLines', window, allCoords,... lineWidthPix, white, [xCenter yCenter], 2); % Flip to the screen Screen('Flip', window); % Wait for a key press KbStrokeWait; % Clear the screen sca;