How to use

This is the main source code for the experiment. If you want to use it, you should copy the actual zip file to your own PsyToolkit account, because often there are other files included for stimuli.

The source code for fitts

options
  mouse on
  bitmapdir stimuli
  origin topleft

bitmaps
  afterwords
  instruction

fonts
  arial 20
  
task fitts
  set $x random 50 750                 # choose a random x position
  set $y random 50 550                 # choose a random y position
  set $w random 5 100                  # choose a random size
  show rectangle 10 10 20 20 255 255 0 # show top left yellow rectangle
  readmouse l 1 10000 range 1 1        # wait until user clicks yellow rectangle
  clear 1                              # and erase the yellow rectangle
  delay 300                            # wait a little bit
  show rectangle $x $y $w $w 255 0 0   # show red target
  readmouse 2 2000                     # measure how long it takes to move there
  clear 2                              # erase the red target rectangle
  delay 1000                           # intertrial interval of 1 second
  set $distance expression sqrt ( $x * $x + $y * $y )
  set $fittslaw expression log2 ( 2 * $distance / $w ) * 100.0
  save $x $y $w $distance $fittslaw RT STATUS # save everything to data file

block test
  message instruction
  tasklist
    fitts 20
  end
  feedback
    text 400 150 "Press space bar to continue"
    xyplot c5 c6 ; select c7 == 1
  end
  message afterwords