Responding during and only during a short movie clip and moving to the next clip even if you don't

alerou

Hello everyone.
I tried making the title as self explanatory as possible.
I am building a 2AFC facial expression identification task.
On each trial, following a fixation point, an avatar face will be presented with a neutral expression for a few seconds. Then, it will produce one of two different facial expressions. Participants will be asked to fixate on the avatar’s eyes and make speeded judgments about said expressions using a two-choice keypress response.
The stimuli are movie clips done in Poser containing the whole sequence.
How do I get them to respond only during the clip and have the clip not freeze, not stay longer, not end prematurely, but simply end when it is supposed to and move to the next one even if they don't respond at all?
Codeless solutions will be much appreciated.
Thank you.
Alexandros

eduard

Hi Alexandros,

Sorry, I am not familiar with video presentation. If the video behaves similarly to the sampler, you can set its duration to 0 and let it follow by a keyboard_response, whose duration is set to the length of the video. Like this the video shouldn't hang and the response is only allowed during the video. However, I have no idea whether these options are available for videos, and in case it works, you have to make sure that the video is not aborted once the key is pressed, but this is certainly possible.

Alternatively, you might look into co-routines. But also here, I don;t know whether they will work with video.

http://osdoc.cogsci.nl/3.2/manual/structure/coroutines/

Good luck,

Eduard