URGENT - keypresses for movie events not recorded


I need URGENT HELP. I have made an experiment where the subjects have to watch short video clips, and indicate change in the action by pressing a key. Each trial includes the movie event twice plus four ‘helper’ events.

For the first movie event and the ‘helper’ events either no response is required, or the subjects have to press Space to continue to the next event. The secont movie event terminates naturally, but the subjects have to press Space to indicate change in the action during the movie.

The STRANGE thing with the output file is that I can see nothing whatsoever recorded about the two movie events in each trial (or am I seeing wrong?). There are only things recorded about the helper events. And for me the crucial thing is to record the keypresses which happen during the second movie event. I have specified Space as the correct response for this event, and I’ve specified that the response is to be recorded. What have I forgotten to do?

I tried to attach both the output file and the experiment package (1021 kB) but I get ‘Database error’ each time.

yours desperate


Recording key presses that occur during the movie is a little tricky, especially since you have more than one movie in a single trial. However, it can be done.

First, you must have SuperLab 4.0.3 or later, as the solution is dependent on a feature added in 4.0.3. See here about upgrading, if necessary.

Second, your movie must play asynchronously. That is SuperLab shouldn’t wait for the movie to finish before moving on. To change this, go to the movie’s “Stimulus” tab, click “Settings…”, and then click “Presentation Options” in the dialog that appears. Uncheck “Wait for movie to finish playing before looking for input.” If you don’t do this, SuperLab will ignore input that occurs while the movie is playing, which is likely your problem.

Where we go from here depends on the precise behavior you are expecting. It doesn’t sound like you want more than one movie playing at the same time, so you probably don’t want the movie to continue playing beyond the end of the event.

If you’re expecting only one response while the movie is playing, then set the event to end and move on after any response from the participant. If you want the movie to then stop, then set it to stop at the end of the event. If you want it to play through to the end, then set it to wait for the movie at the end of the event.

If instead you want to allow multiple responses, then you want to set the event to end after a time limit. You’ll need to figure out the length of your movie and enter this as your time limit. At this point, whether SuperLab waits for the movie or stops the movie is relatively inconsequential.

I believe these two areas are what are important to how to configure your experiment. This isn’t a step-by-step, but it should get you started.

many thanks again

this one worked too!