Pausing experiment execution

Interactive elements and commands can pause experiment script execution, in order to give participants time to interact with the screen.

Some h2

• audio.wait: Pauses experiment script execution until audio playback finishes.
• key.wait: Pauses experiment script execution until a valid keypress.
• Also: button.wait, controller.wait, dropdown.wait, and more.

 
@// Type code below this line.
@
@// Remove command prefix
@PennController.ResetPrefix(null)
@
@newTrial("experimental-trial",
@    newAudio("fish-audio", "2fishRoundTank.mp3")
@        .play()
@    ,
@    newText("fish-sentence", "The fish swim in a tank which is perfectly round.")
@        .print()
@    ,
@    newImage("fish-plural", "2fishRoundTank.png")    
@        .print()
+    ,
+    newKey("keypress", "FJ")
+        .wait()
@)

If the participant presses the F or J key while the audio file is still playing, the trial ends and the experiment sends its results while the audio file continues playing.

However, you might want a different sequence of events:

• Option 1: End trial and stop audio playback after a valid keypress.
• Option 2: End trial after audio playback finishes, instead of after a valid keypress.
• Option 3: End trial after audio playback finishes or after a valid keypress, whichever comes second.

In this experiment we’ll use Option 3, but provide all options for reference.

 
@// Type code below this line.
@
@// Remove command prefix
@PennController.ResetPrefix(null)
@
@// Experimental trial
@newTrial("experimental-trial",
@    newAudio("fish-audio", "2fishRoundTank.mp3")
@        .play()
@    ,
@    newText("fish-sentence", "The fish swim in a tank which is perfectly round.")
@        .print()
@    ,
@    newImage("fish-plural", "2fishRoundTank.png")    
@        .print()
@    ,
@    newKey("keypress", "FJ")
@        .wait()
+    ,
+    getAudio("fish-audio")
+        .stop()
@)

 
@// Type code below this line.
@
@// Remove command prefix
@PennController.ResetPrefix(null)
@
@// Experimental trial
@newTrial("experimental-trial",
@    newAudio("fish-audio", "2fishRoundTank.mp3")
@        .play()
@    ,
@    newText("fish-sentence", "The fish swim in a tank which is perfectly round.")
@        .print()
@    ,
@    newImage("fish-plural", "2fishRoundTank.png")    
@        .print()
@    ,
@    newKey("keypress", "FJ")
-        .wait()
+    ,
+    getAudio("fish-audio")
+        .wait()
@)

End trial after audio playback finishes or valid keypress

To end the trial after audio playback finishes or after a valid keypress, whichever comes second, pause the experiment script execution at the "keypress" Key and at the "fish-audio" Audio.

 
@// Type code below this line.
@
@// Remove command prefix
@PennController.ResetPrefix(null)
@
@// Experimental trial
@newTrial("experimental-trial",
@    newAudio("fish-audio", "2fishRoundTank.mp3")
@        .play()
@    ,
@    newText("fish-sentence", "The fish swim in a tank which is perfectly round.")
@        .print()
@    ,
@    newImage("fish-plural", "2fishRoundTank.png")    
@        .print()
@    ,
@    newKey("keypress", "FJ")
@        .wait()
+    ,
+    getAudio("fish-audio")
+        .wait("first")
@)

Some h3

When called on an Audio element, the wait("first") command and the plain wait command differ in an important way:

• wait("first"): tells PennController to wait for any end-of-audio-playback event.
• wait: tells PennController to start waiting for an end-of-audio-playback event.

This difference is important in the situation where audio playback finishes before the participant presses a valid key:

• Using the wait("first") command:
  1. Audio playback finishes.
  2. The wait command on the "keypress" Key pauses experiment script execution. The participant presses a valid key.
  3. The wait("first") command on the "fish-audio" Audio pauses experiment script execution. PennController waits for any end-of-audio-playback event.
  4. Audio playback has already finished, which satisfies the wait("first") command. Experiment script execution continues immediately and the trial ends.
• Using the plain wait command:
  1. Audio playback finishes.
  2. The wait command on the "keypress" Key pauses experiment script execution. The participant presses a valid key.
  3. The basic wait command on the "fish-audio" Audio pauses experiment script execution. PennController starts waiting for an end-of-audio-playback event.
  4. However, audio playback has already finished, and PennController will never detect an end-of-audio-playback event. The basic wait command cannot be satisfied, and experiment script execution pauses indefinitely.