fbsear_fixStairInitTask.m

% fixStairInitTask.m
%
%        $Id$
%      usage: [fixTask myscreen] = fixStairInitTask(myscreen)
%         by: justin gardner
%       date: 09/07/06
%  copyright: (c) 2006 Justin Gardner (GPL see mgl/COPYING)
%    purpose: Implements a fixation task. In this task, the fixation cross
%             starts out cyan and then darkens twice. The fixation cross then
%             turns yellow to indicate the response interval, and the subject
%             is required to press 1 or 2 to indicate in which interval the cross
%             appeared darker. The cross will then turn green or red to indicate
%             correct or incorrect responses. The dimness of the target is 
%             controlled by a 2 down 1 up staircase to keep task difficulty
%             the same. 
%
%             See testExperiment.m for how this is used in a task. If you want
%             to change parameters, before you call fixStairInitTask, set 
%             appropriate fields of the global variable fixStimulus. e.g.:
%
%             global fixStimulus
%             fixStimulus.interTime = 1;
%
%             See the code, for a list of all parameters that can be changed.
%
function [task myscreen] = fbsear_fixStairInitTask(myscreen)

% check arguments
if ~any(nargin == [1])
  help fixDispStairInitTask
  return
end

% create the stimulus for the experiment, use defaults if they are
% not already set
global fixStimulus;
myscreen = initStimulus('fixStimulus',myscreen);
if ~isfield(fixStimulus,'threshold') fixStimulus.threshold = 0; end
if ~isfield(fixStimulus,'pedestal') fixStimulus.pedestal = 0.4; end
if ~isfield(fixStimulus,'stairUp') fixStimulus.stairUp = 1; end
if ~isfield(fixStimulus,'stairDown') fixStimulus.stairDown = 2; end
if ~isfield(fixStimulus,'stairStepSize') fixStimulus.stairStepSize = 0; end
if ~isfield(fixStimulus,'stairUseLevitt') fixStimulus.stairUseLevitt = 0; end
if ~isfield(fixStimulus,'stimColor') fixStimulus.stimColor = [0 1 1]; end
if ~isfield(fixStimulus,'responseColor') fixStimulus.responseColor = [1 1 0]; end
if ~isfield(fixStimulus,'interColor') fixStimulus.interColor = [0 1 1]; end
if ~isfield(fixStimulus,'correctColor') fixStimulus.correctColor = [0 0.8 0]; end
if ~isfield(fixStimulus,'incorrectColor') fixStimulus.incorrectColor = [0.8 0 0]; end
if ~isfield(fixStimulus,'responseTime') fixStimulus.responseTime = 1; end
if ~isfield(fixStimulus,'stimTime') fixStimulus.stimTime = 0.4; end
if ~isfield(fixStimulus,'interTime') fixStimulus.interTime = 0.8; end
if ~isfield(fixStimulus,'diskSize') fixStimulus.diskSize = 1; end
if ~isfield(fixStimulus,'pos') fixStimulus.pos = [0 0]; end
if ~isfield(fixStimulus,'fixWidth') fixStimulus.fixWidth = 1; end
if ~isfield(fixStimulus,'fixLineWidth') fixStimulus.fixLineWidth = 3; end
if ~isfield(fixStimulus,'trainingMode') fixStimulus.trainingMode = 0;end
if ~isfield(fixStimulus,'verbose') fixStimulus.verbose = 1;end

% for trainingMode set text
if fixStimulus.trainingMode
  mglTextSet('Helvetica',64,[1 1 1],0,0,0,0,0,0,0);
end

% create a fixation task
task{1}.seglen = [fixStimulus.interTime fixStimulus.stimTime fixStimulus.interTime fixStimulus.stimTime fixStimulus.interTime fixStimulus.responseTime];
task{1}.getResponse = [0 0 0 0 0 1];
[task{1} myscreen] = addTraces(task{1}, myscreen, 'segment', 'phase', 'response');

% init the staircase
fixStimulus.staircase = upDownStaircase(fixStimulus.stairUp,fixStimulus.stairDown,fixStimulus.threshold,fixStimulus.stairStepSize,fixStimulus.stairUseLevitt);
fixStimulus.staircase.minThreshold = 0;
fixStimulus.staircase.maxThreshold = 1;

% init the task
[task{1} myscreen] = initTask(task{1},myscreen,@fixStartSegmentCallback,@fixDrawStimulusCallback,@fixTrialResponseCallback,@fixTrialStartCallback);

[task{1} myscreen] = addTraces(task{1}, myscreen, 'fixStair');

% keep the correct and incorrect counts
task{1}.correct = 0;
task{1}.incorrect = 0;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% function that gets called at the start of each segment
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [task myscreen] = fixTrialStartCallback(task, myscreen)

global fixStimulus;
% choose stimulus interval
task.thistrial.sigInterval = 1+(rand > 0.5);
if fixStimulus.verbose
  disp(sprintf('sigint = %i threshold = %0.2f',task.thistrial.sigInterval,fixStimulus.threshold));
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% function that gets called at the start of each segment
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [task myscreen] = fixStartSegmentCallback(task, myscreen)

global fixStimulus;

if isfield(fixStimulus,'displayText')
  % delete the texture
  if ~isempty(fixStimulus.displayText)
    mglDeleteTexture(fixStimulus.displayText);
  end
end
fixStimulus.displayText = [];

% choose what color the fixation cross will be
whichInterval = find(task.thistrial.thisseg == [2 4]);
% if this is the signal interval
if ~isempty(whichInterval)
  if task.thistrial.sigInterval == whichInterval
    fixStimulus.thisStrength = (1-(fixStimulus.pedestal+fixStimulus.threshold));
  else
    fixStimulus.thisStrength = (1-fixStimulus.pedestal);
  end
  fixStimulus.thisColor = fixStimulus.stimColor*fixStimulus.thisStrength;
  % write out what the strength is
  myscreen = writeTrace(fixStimulus.thisStrength,task.fixStairTrace,myscreen);
  % training mode text
  if fixStimulus.trainingMode
    if whichInterval == 1
      fixStimulus.displayText = mglText('Interval 1');
      fixStimulus.displayTextLoc = [fixStimulus.pos(1) fixStimulus.pos(2)+fixStimulus.diskSize*2];
    else
      fixStimulus.displayText = mglText('Interval 2');
      fixStimulus.displayTextLoc = [fixStimulus.pos(1) fixStimulus.pos(2)+fixStimulus.diskSize*2];
    end
  end
% if this is the response interval
elseif task.thistrial.thisseg == 6
  fixStimulus.thisColor = fixStimulus.responseColor;
  if fixStimulus.trainingMode
    fixStimulus.displayText = mglText('Which interval was darker (1 or 2)?');
    fixStimulus.displayTextLoc = [fixStimulus.pos(1) fixStimulus.pos(2)+fixStimulus.diskSize*2];
  end
% if this is the inter stimulus interval
else
  % training mode, clear sceen here
  if fixStimulus.trainingMode,mglClearScreen;end
  fixStimulus.thisColor = fixStimulus.interColor;
  myscreen = writeTrace(0,task.fixStairTrace,myscreen);
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% function that gets called every frame udpate to draw the fixation 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [task myscreen] = fixDrawStimulusCallback(task, myscreen)

global fixStimulus;

if fixStimulus.trainingMode,mglClearScreen;end

if ~isempty(fixStimulus.displayText)
  mglBltTexture(fixStimulus.displayText,fixStimulus.displayTextLoc);
end
mglGluDisk(fixStimulus.pos(1),fixStimulus.pos(2),fixStimulus.diskSize*[1 1],myscreen.background,60);

mglFixationCross(fixStimulus.fixWidth,fixStimulus.fixLineWidth,fixStimulus.thisColor,fixStimulus.pos);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% function that gets called when subject responds
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [task myscreen] = fixTrialResponseCallback(task, myscreen)

global fixStimulus;
global stimulus;

response = find(task.thistrial.buttonState) == stimulus.live.correctButton;
response = response(1);

if response
    fixStimulus.thisColor = fixStimulus.correctColor;
else
    fixStimulus.thisColor = fixStimulus.incorrectColor;
end

% if response
%   % for training mode
%   if fixStimulus.trainingMode
%     mglDeleteTexture(fixStimulus.displayText);
%     fixStimulus.displayText = mglText('Correct!');
%     fixStimulus.displayTextLoc = [fixStimulus.pos(1) fixStimulus.pos(2)+fixStimulus.diskSize*2];
%   end
%   % set to correct fixation color
%   fixStimulus.thisColor = fixStimulus.correctColor;
%   % set trace to 2 to indicate correct response
%   myscreen = writeTrace(2,task.fixStairTrace,myscreen);
%   % and update correct count
%   task.correct = task.correct+1;
% else
%   if fixStimulus.trainingMode
%     mglDeleteTexture(fixStimulus.displayText);
%     fixStimulus.displayText = mglText('Incorrect.');
%     fixStimulus.displayTextLoc = [fixStimulus.pos(1) fixStimulus.pos(2)+fixStimulus.diskSize*2];
%   end
%   % set to incorrect fixation color
%   fixStimulus.thisColor = fixStimulus.incorrectColor;
%   % set trace to -2 to indicate incorrect response
%   myscreen = writeTrace(-2,task.fixStairTrace,myscreen);
%   % and update incorrect count
%   task.incorrect = task.incorrect+1;
% end
% 
% % update staircase
% fixStimulus.staircase = upDownStaircase(fixStimulus.staircase,response);
% fixStimulus.threshold = fixStimulus.staircase.threshold;