Presenting stimuli only while a button is pressed

Comments

• sebastiaan

  September 2018

  Hi Amihai,

  There are multiple ways to do this, either with a script or coroutines item, but the easiest way depends on what you want to do exactly, and what you have programmed already. Could you upload the experiment here?

  Cheers!
  Sebastiaan

  
  
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• DahmSF

  September 2018

  Hi Amihai,
  If you use an inline_script it may help to write a while loop, and ask for keylifts.
  You can find an example here: http://forum.cogsci.nl/index.php?p=/discussion/comment/14335#Comment_14335
  Good luck
  Stephan
• amihai_gottlieb

  September 2018

  Hi Sebastiaan, DahmSF,

  Thanks for the answers.

  Sebastiaan - I am attaching my experiment. Notice it is a bit "dirty" and has some scripts used for other purposes that I got from people in this forum (and for that I am grateful, I do not know how to code ). I want to add a script that will present the stimuli loop as long as the participant presses the space key. I would also appreciate advice on where to plant the script.

  DahmSF - I could not understand where is the example that you mentioned in the link you sent.

  Thanks again
  Amihai
• amihai_gottlieb

  September 2018

  Bump.
  Help anyone?
• DahmSF

  September 2018

  The example is in the experiment which is uploaded in the linked discussion. If you lift the button too early you get back to the beginning.
  --> There you need to keep the mouse button pressed, but you can easily change it to the space key on the keyboard.
• amihai_gottlieb

  September 2018

  DahmSF,

  I do not really know how to code so I cannot identify the specific part of the code that enables to present stimuli while a button is pressed. Can you point me to this part?
  Also, in my experiment, I measure the duration of the pressed button so it is a dependent variable. I do not want the experiment to go back to the beginning at any point. is the code in your example appropriate for this?

  Thanks
  Amihai
• DahmSF

  September 2018

  Hi Amihai,

  did you try the experiment i attached in the link?
  It contains not much more than pressing a button and keeping it pressed while some stimuli are presented.
  The duration you are asking for is easy to code. Just create a new variable: time of keylift - time of keypress.
  You can also look into the handbook for the keylift function Keyboard.get_key_release: https://osdoc.cogsci.nl/3.2/manual/python/keyboard/#function-keyboard46get95key95release404242resp95args41

  Even if you do not want the experiment to go back to some point you need to specify what shall happen if a participant lifts the key too early. (I thought the best thing is to go back and start the trial again)

  You re welcome
  Stephan
• amihai_gottlieb

  September 2018

  Hi Stephan,

  I tried to take a look at the experiment but it did not work for me for some reason.
  I did look at the code in it though and saw that it is way above my level of understading.
  At this point, I think I will seek paid assistance.
  Do you know if there someone in this forum that offers such services?

  Amihai