TaskObjects

Type Syntax Remarks
Fixation point1 fix(Xdeg, Ydeg) Xdeg and Ydeg: XY positions in degrees2
Static image1 pic(filename, Xdeg, Ydeg)
pic(filename, Xdeg, Ydeg, colorkey)
pic(filename, Xdeg, Ydeg, Wpx, Hpx)
pic(filename, Xdeg, Ydeg, Wpx, Hpx, colorkey)
filename: BMP, GIF, JPG, TIF or PNG
Xdeg and Ydeg: in degrees2
colorkey: a color [R G B] which will be treated as transparent
Wpx and Hpx: optional resizing parameters (width and height in pixels)
Movie1 mov(filename, Xdeg, Ydeg)
mov(filename, Xdeg, Ydeg, looping)
filename: AVI, MPG or animated GIF
Xdeg and Ydeg: in degrees2
looping: 0 (not repeat) or 1 (repeat)
• See the remark below for compatibility with the original ML6.
Circle1 crc(radius, RGB, fill, Xdeg, Ydeg) radius: in degrees
RGB: a triplet [R G B] with values 0-1
fill: 0 (outline) or 1 (filled)
Xdeg and Ydeg: in degrees2
Square1 sqr(size, RGB, fill, Xdeg, Ydeg) size: 1 element (square) or 2 (rectangle) in degrees
RGB: a triplet [R G B] with values 0-1
fill: 0 (outline) or 1 (filled)
Xdeg and Ydeg: in degrees2
Sound snd(filename)
snd(sin, duration, frequency)
filename: WAV or MAT3
sin is to be typed literally.
duration: in seconds
frequency: in Hertz
Stimulation stm(port, datasource)
stm(port, datasource, retriggerable)
port: Stimulation # on the main menu I/O panel
datasource: WAV or MAT3
retriggerable: 0 (can be triggered only once) or 1 (multiple times)4
TTL pulse ttl(port) port: TTL # on the main menu I/O panel
User-generated Pic or Mov1 gen(function_name)
gen(function_name, Xdeg, Ydeg)
function_name: a user-provided MATLAB function5
Xdeg and Ydeg: in degrees2
  1. For visual stimuli, an object with a smaller number will layer atop those with larger numbers.  For example, when TaskObject#1 and TaskObject#2 are presented at the same location, TaskObject#1 will appear in front of TaskObject#2.

  2. The center of the screen is the origin ([0 0]). The positive direction is the right of the origin for x axis and above the origin for y axis.

  3. The MAT files must contain two variables, “y” and “fs”, for waveform and frequency, respectively.

  4. When the “retriggerable” flag of an STM object is 1, stopping the stimulation will take a slightly longer time, to reload the waveform.

  5. The GEN user function can take one of the following prototypes.

      imdata = gen_func(TrialRecord);
      imdata = gen_func(TrialRecord, MLConfig);
      [imdata, info] = gen_func(___);
      [imdata, Xdeg, Ydeg] = gen_func(___);
      [imdata, Xdeg, Ydeg, info] = gen_func(___);

    The GEN function takes the TrialRecord structure as input and can optionally take the MLConfig structure as the second argument.

    imdata can be a filename or a matrix of one of the following dimensions.

      Y-by-X: gray-scale image
      Y-by-X-by-3: RGB image
      Y-by-X-by-4: ARGB image (A: alpha channel)
      Y-by-X-by-3-by-N: RGB movie (N: # of frames)
      Y-by-X-by-4-by-N: ARGB movie (A: alpha channel, N: # of frames)

    If Xdeg and Ydeg are not given in the conditions file, they can be provided from the GEN function.  They are both 0 by default.

    Users can deliver extra information about the GEN stimulus to the timing script or other user functions by adding new fields to the info structure.  There are a few reserved field names.

      info.Colorkey (for images only): a 1-by-3 RGB color, [R G B], which should be treated as transparent
      info.Looping (for movies only): true or false; if true, the movie is repeated when the last frame is reached.
      info.TimePerFrame (for matrix-based movies only): the interval between movie frames; in milliseconds
      info.FrameByFrame (for file-based movies only): true or false; if true, the movie is played as in the original MonkeyLogic (repeatable and manipulatable frame by frame)

    The info structure can be accessed in the timing script or other user functions this way.

      StimulusInfo(TaskObject#).MoreInfo                               % in timing script
      TrialRecord.CurrentConditionStimulusInfo(TaskObject#).MoreInfo   % via TrialRecord structure

  6. The original ML processes movies frame by frame without respecting their frame rates. This makes the speed of movies dependent on the refresh rate. To play movies in the same way as the original MonkeyLogic does, use GEN, instead of MOV, and assign 1 to info.FrameByFrame.

      gen(moviefile,0,0)     % in the conditions file

      function [imdata,info] = moviefile(TrialRecord,MLConfig)  % gen script
      imdata = 'moviefile.avi';
      info.FrameByFrame = 1;
      end

The National Institute of Mental Health (NIMH) is part of the National Institutes of Health (NIH), a component of the U.S. Department of Health and Human Services.