[open] Response time collection during video playback
Hi Sebastiaan, Daniel, et al.,
A student of mine is currently working on an experiment that involves video playback using the media_player_vlc plug in. According to the documentation, is you set duration of the playback to keypress, the video playback should stop when you hit a key, while response times, accuracy etc, are logged. We can't get this to work however.
It's a recognition task; the movie plays for a few seconds, and participants should respond as soon as they recognize what's in the movie. The movie should then stop playing.
I notice a couple of things:
- In the media_player_vlc object, there is no way to specify what the correct response should be.
- A keypress does not stop the movie
- Also, I tried adding custom python code; but this code also only seems to be triggered when you hit a key right at the end of the video.
Is there a solution to determine a reaction time while playing the video? It's an audiovisual experiment, so breaking down the video and doing it manually by presenting is frame by frame is not really possible unfortunately.
Thanks in advance,
Durk
Comments
Quick update: It does look like response information is collected as advertised; however the keyboard event are not passed to opensesame when the experiment is run in "windowed" or "quick run" mode. Mouse events are handled as expected.
I'm still not seeing any reaction times in the log file though. After some tinkering and tweaking with the media_player_vlc.py code, I did manage to log the key code, and I've added a couple of custom lines of code to get the reaction time, so my student can start her experiment without delay (I hope; we still need to test this on a windows machine). Still, I would be interested to hear some further thoughts on this.
Cheers,
Durk
Hi durk,
did you try putting a key logger after the vlc player plugin ?
So far I myself did only collect response times after the video which is a more straightforward approach.
Did you try setting the video duration to mouseclick and adding a key_response item afterwards ?
Sorry I don't have a testing possibility atm.
--
edit:
I guess there is no out of the box solution for this.
An idea would be to call custom pycode on the keypress event, check if the pressed key is the correct one, stop playing and take this key as response. response time for this should be logged.
e.g., edit this idea from the help
Custom event handling
If you want, you use your own code to handle keypress and mouseclick events, which should be entered in the edit field. The PyGame event is passed as 'event'. For example, in order to register if the spacebar is pressed or if a mousebutton is clicked, you enter:
if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
best,
daniel