[open] Collecting accumulative RT across two sketchpad frames

Comments

• sebastiaan

  August 2013 edited February 2014

  Hi Tilly,

  The script below shows how you can collect responses while two sketchpads are being presented. In general, the trick is to alternate between showing a display and polling the keyboard. The responses are stored as response1, response_time1, etc. For more details and instructions on how to use this script in your experiment, see the code comments.

  Similar questions have been asked a few times before, and these discussions may be useful as well:

  • http://forum.cogsci.nl/index.php?p=/discussion/232/open-recording-responses-during-and-after-a-displayed-object/p1
  • http://forum.cogsci.nl/index.php?p=/discussion/143/open-how-do-i-collect-the-keyboard_response-after-a-stimulus-disappears/p1

  The script may seem a bit complicated. To get some feel about how this works, I would recommend walking through one of the Python tutorials. You won't need any extreme coding skills, just a basic understanding of the syntax:

  • http://osdoc.cogsci.nl/python-inline-code/about-python-inline-code/#learning

  Cheers!
  Sebastiaan

  Update: Fixed typo

  from openexp.keyboard import keyboard
  
  # Durations for the two displays
  duration1 = 1000
  duration2 = 1000
  
  # Displays are copied from sketchpads. To avoid these
  # sketchpads from being shown twice (i.e. once in the 
  # normal way, and once in this inline_script), you can set
  # their 'Run-if' statement to 'never'.
  canvas1 = self.copy_sketchpad('sketchpad1')
  canvas2 = self.copy_sketchpad('sketchpad2')
  
  # Create a keyboard object with a zero timeout to allow
  # for continuous polling.
  my_keyboard = keyboard(exp, timeout=0)
  
  # Keep track of which response we are collecting, in case
  # the participant responds multiple times.
  response_nr = 1
  
  # We collect at most 10 responses, and reset these 10 responses
  # to 'NA' before we start collecting new responses.
  max_response_nr = 10
  for i in range(1, max_response_nr+1):
      exp.set('response%d' % i, 'NA')
      exp.set('response_time%d' % i, 'NA')
  
  # Show the first canvas, and poll the keyboard for the
  # specified duration.
  show_time1 = canvas1.show()
  while self.time() - show_time1 < duration1:
      key, time = my_keyboard.get_key()
      # If a key is pressed, store the key and the response time.
      # The response time is the time after the presentation of the
      # first display.
      if key != None and response_nr <= max_response_nr:      
          exp.set('response%d' % response_nr, key)
          exp.set('response_time%d' % response_nr, time-show_time1)
          response_nr += 1
  
  # Show the second canvas, and poll the keyboard for the
  # specified duration.       
  show_time2 = canvas2.show()
  while self.time() - show_time2 < duration2:
      key, time = my_keyboard.get_key()
      # If a key is pressed, store the key and the response time.
      # The response time is the time after the presentation of the
      # first display.
      if key != None and response_nr <= max_response_nr:      
          exp.set('response%d' % response_nr, key)
          exp.set('response_time%d' % response_nr, time-show_time1)
          response_nr += 1        
  

  
  
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• Tilly

  August 2013 edited 2:42AM

  Hi Sebastiaan,
  Thank you so much for all your help with this - will give it a go!
  BW, Tilly
• filo

  February 2014 edited 2:42AM

  I think there is a typo in this script. second while loop should compare with "duration2" not "duration1".
• sebastiaan

  February 2014 edited 2:42AM

  Good spot @filo!

  
  
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