Measuring how much time a button was pressed

Comments

• Pascal

  June 2016 edited 11:40PM

  Hi Amihai,

  I am not completely sure what your exact problem is. Are you using a button in a form base plugin and do you want to know the total response time for the form?

  If so, I don't think that it calculates response times.

  However, you could calculate them using Python code in inline scripts. You first get the time (t0) in the run phase of an inline script directly before the form is presented. Then you present the form. Then you get the time (t1) in the run phase after the inline script. The difference (t1-t0) is your response time. This is similar to the general example in the clock functions (http://osdoc.cogsci.nl/python/clock/).

  Alternatively, you could install and use the mousetrap form plugin (general information about mousetrap: http://osdoc.cogsci.nl/devices/mouse-tracking/ , specific information about mousetrap_form https://github.com/PascalKieslich/mousetrap-os/blob/master/plugins/mousetrap_form/mousetrap_form.md). It is a modified version of the form base plugin and it calculates response times automatically. If you are not interested in the mouse-tracking data (which is the actual purpose of the plugin), you can simply uncheck the option "Save mouse-tracking data".

  Hope this answers your question - feel free to ask if not!

  Best
  Pascal
• amihai_gottlieb

  February 2017

  Dear Pascal,

  I just saw your answer to my questions (after quite a delay, sorry..).

  In my exp I am asking participants to reproduce duration times of stimuli by pressing the space button.
  Is there a way to measure the time this button was pressed? I use the logger to record response time of the keyboard response but it does not seem to measure the pressing time.

  Thanks
  Amihai
• amihai_gottlieb

  February 2017

  Or maybe anyone else has an idea how to measure how much time a button was pressed using a keyboard response?

  Amihai
• Pascal

  February 2017

  Hi Amihai,

  I assume you are using a keyboard_response item to record the key press. This will give you the duration after which the key was pressed (in the variable response_time). However, as far as I know it will not tell you for how long the key was pressed.

  Unfortunately, I don't know much about the technical details of the keyboard Python functions - so I cannot tell you whether it is possible to determine that at all - If this is what you want to know. I think that it is not possible using OpenSesame's keyboard class. One idea I have is that you maybe could directly use a Python function from one of the backends.

  Best,

  Pascal
• amihai_gottlieb

  February 2017

  Hi Pascal,

  Thanks for the help.
  I found this thread:

  http://forum.cogsci.nl/index.php?p=/discussion/2271/measure-duration-of-key-press

  But unfortunately, I do not know python very well and cannot understand which part of the code I can use just to measure the keypress and create a variable out of it. Can you help?

  Amihai
• Jarik

  February 2017

  Hi Amihai,

  Maybe searching the forum for "keyup" helps.

  Best,
  Jarik
• amihai_gottlieb

  February 2017

  Jarik,

  Thanks for the tip! I found this thread:

  http://forum.cogsci.nl/index.php?p=/discussion/37/solved-how-to-log-the-duration-of-a-key-press

  which looks very relevant, but I can not figure out where to put this script and how to define the key which I need to measure. Do you know?

  Amihai
• Jarik

  February 2017

  You can copy the code in an inline item that follows a sketchpad item for example. This sketchpad item can have a duration of 0 milliseconds so it advances to your inline code immediately. You can use the sketchpad item to present instructions like "press space for 2 seconds" to the subject.

  The code logs all keys now.

  Best,
  Jarik
• amihai_gottlieb

  March 2017

  Dear Jarik,

  I did what you wrote and it workes!

  Thank you very much.

  Amihai
• amihai_gottlieb

  March 2017

  Jarik, or anyone else how can help,

  Is there a way to record which button was pressed using the inline script item?

  Amihai
• eduard

  March 2017

  Hi,

  Maybe you can summarize what you already accomplished and what is the code that you use? Then, it will be easier to find out what else is missing.

  Eduard

  
• amihai_gottlieb

  November 2017

  Eduard,

  I just noticed that I never answered your message. Sorry about that.
  I ended up using the following code in the run part of the inline script:

  import pygame
  from pygame.locals import *

  key_down_time = None
  while key_down_time == None:
  for event in pygame.event.get():
  if event.type == KEYDOWN:
  key_down_time = self.time()
  key_pressed = event.key
  break

  key_up_time = None
  while key_up_time == None:
  for event in pygame.event.get():
  if event.type == KEYUP:
  key_up_time = self.time()
  break

  key_duration = key_up_time - key_down_time
  self.experiment.set("key_duration", key_duration)
  self.experiment.set("key_pressed" , key_pressed)

  With this, I manage to log the pressing time of the key that was pressed but the actual key name is logged as a number which I need to "translate" using an ASCII table. I was wondering whether it is possible to just log the name of the key.

  Thanks
  Amihai
• eduard

  November 2017

  Hi Amihai,

  Good to know it works.

  I was wondering whether it is possible to just log the name of the key.

  Maybe this discussion helps: https://stackoverflow.com/questions/227459/ascii-value-of-a-character-in-python

  
• amihai_gottlieb

  November 2017

  Eduard,

  Thanks for the link. I understand that I can use the chr() function to return the key but I do not know how to implement it in the code.
  Do you think this will this work (I do not know how to code in python):

  self.experiment.set("key_pressed" , chr(key_pressed))

  Amihai
• eduard

  November 2017

  That is exactly how it works.

  Eduard