[solved] (EEG) Sending trigger after trigger

Comments

• sebastiaan

  August 2014 edited 9:55AM

  Hi Joshua,

  If understand correctly, you want to continuously monitor the keyboard, and send a trigger whenever a certain key is pressed, at any time during the trial?

  Basically, you cannot do this with keyboard_responses, at least not, as you say, without having loads of them and having a very complicated experimental structure. You will probably be better off implementing your trial through an inline_script that continuously polls for key presses.

  If you have specific questions about how to do this, don't hesitate to ask. There are quite a few related discussions on the forum (but not exactly the same), for example this one:

  • http://www.cogsci.nl/forum/index.php?p=/discussion/228/

  Good luck!

  Cheers,
  Sebastiaan

  
  
  Check out SigmundAI.eu for our OpenSesame AI assistant!
  
• JoshuaBaker

  August 2014 edited 9:55AM

  Hi Sebastiaan,

  That's exactly right. I will have a gander at the code you suggested in the link
• JoshuaBaker

  August 2014 edited August 2014

  Hi Sebastian, ive had a look at the link and im starting to make sense of it. Im wanting to drive my stimuli with a normal item structure, but just continuously monitor the keyboard in an inline script. Could you please comment on the below code? many thanks. Also would i insert this inline script before a loop or would it have to be in the loop of my trial sequence?

  from openexp.keyboard import keyboard
  
  my_keyboard = keyboard(self.experiment, keylist=["1","2","3","4"], timeout=0)
  
  
  l=[]
  
  while True:
      resp, time = my_keyboard.get_key()
      if resp =='1':
          global io
          trigger = 201
          port = 0x1030
          try:
              io.DlPortWritePortUchar(port, trigger)
          except:
              print 'Failed to send trigger!'
  
      if resp =='2':
          global io
          trigger = 202
          port = 0x1030
          try:
              io.DlPortWritePortUchar(port, trigger)
          except:
              print 'Failed to send trigger!'
  
      if resp =='3':
          global io
          trigger = 203
          port = 0x1030
          try:
              io.DlPortWritePortUchar(port, trigger)
          except:
              print 'Failed to send trigger!'
  
      if resp =='4':
          global io
          trigger = 204
          port = 0x1030
          try:
              io.DlPortWritePortUchar(port, trigger)
          except:
              print 'Failed to send trigger!'
  
      if resp =='':
          print 'shouldnt do this'
  
  
  l = l[-100:]
  
• JoshuaBaker

  August 2014 edited 9:55AM

  ignore the last conditional statement. Any thoughts on this? Many thanks
• sebastiaan

  August 2014 edited 9:55AM

  Hi Joshua,

  Well, one thing that is clearly wrong with this script is that the while loop will never ever break. So once the while loop starts, OpenSesame will freeze until you forcefully close the program, which is probably not what you want. Instead, you will probably want to break the loop after a given duration. For example, something like this:

  # Loop for 1000 ms
  start_time = self.time()
  duration = 1000
  while self.time() - start_time < duration
      # Do something
      pass
  

  Do you see the logic here?

  Secondly, there's a lot of redundancy in the code that--while not strictly incorrect--kind of suggests that you don't fully understand what is going on. For example, this ...

  if resp =='1':
      global io
      trigger = 201
      port = 0x1030
      try:
          io.DlPortWritePortUchar(port, trigger)
      except:
          print 'Failed to send trigger!'
  
  if resp =='2':
      global io
      trigger = 202
      port = 0x1030
      try:
          io.DlPortWritePortUchar(port, trigger)
      except:
          print 'Failed to send trigger!'
  

  ... is equivalent to this ...

  global io
  port = 0x1030
  if resp =='1':  
      trigger = 201
  elif resp =='2':
      trigger = 202
  try:
      io.DlPortWritePortUchar(port, trigger)
  except:
      print 'Failed to send trigger!'
  

  See? Only the trigger depends on the response, so there's no need to duplicate whole chunks of code.

  So I would first make sure that the while loop stops when you want it to stop (for example after a specific duration), and then clean up the code so that there's no unnecessary duplication. After that you will have a nice runnable script that you can test and debug further.

  And don't forget:

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

  Cheers!
  Sebastiaan

  
  
  Check out SigmundAI.eu for our OpenSesame AI assistant!
  
• JoshuaBaker

  August 2014 edited 9:55AM

  Thanks for this Sebastiaan! I've managed to get it working before your response. I ended up closing the while loop and basically ended up driving the stimuli through the same inline script. Thanks for your advice