Press and hold key for set duration before continuing sequence

Comments

• sebastiaan

  December 2017

  Hi,

  The problem with your script is the indentation, i.e. the number of tabs that precede each line. The break statement should be intended one step down, so that it's not in the else block. Does that make sense? Like this:

  import pygame
  
  while True:
      for event in pygame.event.get():
          if event.type == pygame.KEYDOWN:
              break
      else:
          continue
      break
  

  An equivalent code that is perhaps easier to read would be:

  import pygame
  
  while not any(event.type == pygame.KEYDOWN for event in pygame.event.get()):
      pass
  

  To learn a bit more about loops, check out this video:

  

  Cheers!
  Sebastiaan

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

  December 2017

  That makes perfect sense, Sebastiaan. The video was quite helpful but I am still struggling to implement the hold component for this task.

  I can get an approximation by setting the duration of a sketchpad for 3995ms (we've increased the length of the press). However, I need to be able to reset the trial if the key is released early. I need the key release time before a reaching response is performed to the target on a touchscreen.

  I have been trying to adapt some of your code from an earlier post for measuring key press durations within a while loop plus an else loop, combined with another post that used items.execute() command to break from a component if response incorrect. I can't quite get it to work and I think I may have the logic/structure of the loop confused or maybe I need a coroutine?

  I have included a screenshot of the structure of the experiment and the code element I have been working on.

  My intention was something along these lines:
  While a key is held down for less than 4 seconds, draw a canvas with some text and a prompt image. Get the time and update key_down_time. Then break/continue with the next component.

  Else: if the key is released before the 4s time limit then reduce the trial_loop count by 1 and execute the reset_loop.

  Begin trial again

  

  Apologies for the long-winded nature of my query. Any help is much appreciated.

  Josh
• jspayne

  January 2018 edited January 2018

  Hi there,

  I have got the task working in terms of basic functionality. Ideally, it would be good if I could implement a coroutine that exits if a key release is made during the presentation of two sequential sketchpads to catch early releases.

  I have tried to adapt the information about creating custom coroutines that terminate with a response but it does not register for the key release - I suppose because the return does not include a 'key release response' component. I am not sure how to implement that.

  At the minute I have the following in place:

  1. inline: defining the key release generator
  2. coroutines: sketchpad hold (3995ms)
  3. coroutines: sketchpad: show three stimulus positions (variable delay; ~750 - 2500ms)

  If there's no key release by the end of coroutine, coroutine should exit to continue sequence. If there is a key release during coroutine then it should exit to a 'Too early' feedback screen and reset or repeat that trial.

  An example, or suggestions for how to proceed would be greatly appreciated.

  Josh