Example Experiment

function BasicPsychtoolobox

% Clear the workspace and the screen
sca;
close all;
clearvars;

% If you are recording with EEG, enter 1
EEG = 0;

% Initializing psychtoolbox
[screens,screenNumber,grey,white,black,window] = initPsychtoolbox();

% Initializing EEG
if EEG
    [BIOSEMI,BIO_LPT_ADDRESS] = initBIO_h();
end


% Setting the triggers for EEG
stimOnsetTrigger = 100;
fixationOnsetTrigger = 150;


% Loading a blank image of the same dimension as the stimuli of the
% experiment
theImageLocation = 'C:\Users\alexander.lepauvre\Pictures\diodeTest.png';
theImage = imread(theImageLocation);

% Make the image into a texture
imageTexture = Screen('MakeTexture', window, theImage);

% Displazing the instructions, telling the experimenter what they should do
% to measure the delays
displayInstructions(window)


% If you are recording with the EEG, send a trigger informing of the start
% of the experiment
if EEG
    sendTrig(1,BIOSEMI,BIO_LPT_ADDRESS);
end

% This is the presentation loop. 100 iterations. For each iteration a white
% picture will be presented for 1.5 second, then only the fixation will be
% presented for 0.5sec. 
for i = 1 : 10
    % Draw the image to the screen, unless otherwise specified PTB will draw
    % the texture full size in the center of the screen. We first draw the
    % image in its correct orientation.
    Screen('DrawTexture', window, imageTexture, [], [], 0);
    drawFixation(window)
    % Flip to the screen
    Screen('Flip', window);
    if EEG
        sendTrig('100',biosemi,LPT_address);
    end
    
    % Getting the time of the begining of the trial. Trial begins as soon
    % as the picture is presented
    beginTrial = GetSecs;
    % The time elapsed correspond to the time we are at, minus the time we
    % started measuring
    elapsedTime = GetSecs - beginTrial;
    
    % As long as the elapsed time is inferior to 2 seconds, the trial
    % continues
    while elapsedTime < 2
        
        % Once 1.5 msec have passed, diplay the fixation only
        if elapsedTime>= 1.5
            % Fill the screen with the grey color
            Screen('FillRect', window,grey);
            % Draw the fixation
            drawFixation(window)
            % Flip to the screen
            Screen('Flip', window);
            
            % If you are using EEG, send the trigger for the end of
            % stimulus presentation
            if EEG
                sendTrig('150',biosemi,LPT_address);
            end
        end
        % Actualize the elapsed Time counter
        elapsedTime = GetSecs - beginTrial;
    end    
end
% Sending the end trigger to the EEG
if EEG 
    sendTrig(TRG_MINIBLOCK_ENDED,BIOSEMI,BIO_LPT_ADDRESS); 
    saveTrigToHD(); 
end

% Now we are done with the trials, we can save teh EEG triggers to the hard
% drive and terminate the EEG recording
if EEG 
    
end

% Clear the screen.
safeExit(EEG,BIOSEMI,BIO_LPT_ADDRESS)
% Ideally here, I would have something loading the EEG data and analyze
% them directly to get the delays. 
end


function [screens,screenNumber,grey,white,black,window] = initPsychtoolbox()

% Here we call some default settings for setting up Psychtoolbox
PsychDefaultSetup(2);

% Setting the sync tests: SkipSyncTests set to 0 because we want the sync
% tests to be performed
Screen('Preference', 'SkipSyncTests', 0);

% Setting the level of visual debug. In other word, this lets you decide
% how much of the warnings sent by Psychtoolbox you want to see. Set to 4,
% the most thorough: we want everything psychtoolbox sends to be sent. 
Screen('Preference', 'VisualDebugLevel', 4);

% Get the screen numbers. This gives us a number for each of the screens
% attached to our computer.
screens = Screen('Screens');

% To draw we select the maximum of these numbers. So in a situation where we
% have two screens attached to our monitor we will draw to the external
% screen.
screenNumber = max(screens);

% Define black and white (white will be 1 and black 0). This is because
% in general luminace values are defined between 0 and 1 with 255 steps in
% between. All values in Psychtoolbox are defined between 0 and 1
white = WhiteIndex(screenNumber);
black = BlackIndex(screenNumber);
% But here, we are setting the gray to be fitting our experiment:
grey  =   [0.5 0.5 0.5];


% Open an on screen window using PsychImaging and color it grey.
[window, windowRect] = PsychImaging('OpenWindow', screenNumber, grey);
% Getting the dimensions of the window
ScreenWidth     =  windowRect(3);
ScreenHeight    =  windowRect(4);
center          =  [ScreenWidth/2; ScreenHeight/2];
% Getting the frame rate
hz = Screen('NominalFrameRate', window);
disp(hz);
refRate = hz.^(-1);

% Setting the text preferences: text renderer 1 is for HQ, TextEncodingLocale UTF-8
Screen('Preference', 'TextRenderer', 1); 
Screen('Preference','TextEncodingLocale','UTF-8');

% this enables us to use the alpha transparency
Screen('BlendFunction', window, 'GL_SRC_ALPHA', 'GL_ONE_MINUS_SRC_ALPHA', [grey 128]);

% Setting the priority level to maximal for the screen on which we will
% present
priorityLevel=MaxPriority(window);
Priority(priorityLevel);

%% Text parameters
fontType = 'David';
Screen('TextFont',window, fontType);
Screen('TextStyle', window, 0);
%Screen('TextSize', window, round(fontSize*screenScaler));

%% PRELIMINTY PREPATATION
% check for Opengl compatibility, abort otherwise
AssertOpenGL;

% Do dummy calls to GetSecs, WaitSecs, KbCheck
KbCheck;
WaitSecs(0.1);
GetSecs;

end

% Setting the fixation
function [ ] = drawFixation(w)

Screen('TextSize', w);
FIXATION_COLOR = [0 0 0];

DrawFormattedText(w, double('o'), 'center', 'center', FIXATION_COLOR);

Screen('TextSize', w);

end


function displayInstructions(w)

Screen('TextSize', w);
FIXATION_COLOR = [0 0 0];

DrawFormattedText(w, double('You are about to start. Make sure the diode is sticked to the screen the right way'), 'center', 'center', FIXATION_COLOR);

Screen('TextSize', w);

Screen('Flip', w);
KbWait;
end

%% EEG System


function [BIOSEMI, BIO_LPT_ADDRESS] = initBIO_h()

global trigMatName triggers triggsCounter triggsStart

prf1 = sprintf('%s', date);
trigMatName  = sprintf('%s%c%s%c%s_S%d_%s_triggers.mat',pwd,filesep,'data',filesep,'DiodeTest', prf1);

% Doing some preallocation for the triggers
TRIGGER_ARRAY_SIZE = 1000;
% The triggers matrix will contain the different triggers onsets
triggers = nan(TRIGGER_ARRAY_SIZE,2);
% Setting a counter for the triggers
triggsCounter= 0;
% Finding out the moment where we start to record to get the time of the
% other triggers relative to the beining
triggsStart = GetSecs;

% Starting the hardware
try
    [BIOSEMI, BIO_LPT_ADDRESS]=init_bio;
catch e
    warning('BioSemi connection initiation failed! Triggers will not be sent!');
    if ~DEBUG throw(e); end
end

end
%INIT_BIO
% EEG trigger function trigger hardware intilization
function [ biosemi,LPT_address ] = init_bio()


% config_io;
% RB_address = hex2dec('D010');
% LPT_address = hex2dec('0378');
LPT_address = hex2dec('c010');

biosemi=io64;
status=io64(biosemi);
if status
    disp ('fail')
    biosemi = [];
end

end

% Sending the triggers: this function is sending the triggers
% Input: BIOSEMI and BIO_LPT_ADDRESS are required fpr the program to know
% where  to send the triggers, and the trigger code is the code of the
% current trigger
function [] = sendTrig(trigCode,BIOSEMI,BIO_LPT_ADDRESS)

% Setting the global variables: triggsCounter counts how many triggers were
% sent in total, triggsStart gets when the trigger was sent
global triggsCounter triggsStart triggers
try
    % This command is sending the  trigger through the parallel port
    io64(BIOSEMI,BIO_LPT_ADDRESS,trigCode);
    % Setting the triggers counter
    triggsCounter = triggsCounter + 1;
    % Saving the time of the trigger in the triggers matrix
    triggers(triggsCounter,2) = GetSecs - triggsStart;
    % Waiting a little and then resetting the trigger (setting it back to
    % 0) through the parallel port
    WaitSecs(0.001);
    io64(BIOSEMI,BIO_LPT_ADDRESS,0);
    WaitSecs(0.001);
    % Adding the trigger code to the triggers matrix.
    triggers(triggsCounter,1) = trigCode;
catch %e
    warning ('Trigger not sent correctly!');
end
end

% This function saves the triggers to the hard drive
function saveTrigToHD()

global trigMatName triggers

try
    save(trigMatName,'triggers');
catch
    try
        save(trigMatName,'triggers');
    catch
    end
end
end


%% Safe exit
% This function closes everything that eneds to be closed and so on
function [] = safeExit(EEG,BIOSEMI,BIO_LPT_ADDRESS)

Priority(0);
sca;
ShowCursor;
ListenChar(0);
try
    if EEG 
        saveTrigToHD(); 
        sendTrig(255,BIOSEMI,BIO_LPT_ADDRESS);
    end
catch
end
end