Registering response times to audio stimulus 'on top of' video file (case 34358)
Registering response times to audio stimulus 'on top of' video file (case 34358)
Hi,
I just started using DirectRT (also have MediaLab newly installed) and I have a question that is maybe very easy, but I didn't find an answer yet...
For my experiment, I am presenting a 12 minute video clip with a narration at two different speeds. I want to register response times to short audio stimuli that are presented at different moments in the video and my question is if (and how) I can indicate in my .csv-file at what time the audio stimuli have to be presented. In other words, I would need a time code to indicate to the software when the audio stimulus is to be presented.
Many thanks in advance for any help!
Gert
Hello Gert,
Welcome to the world of DirectRT and MediaLab! We are happy to hear you our using our software and are here to support your use.
When using a sound file for a stimulus, you should enter a "0" in the Time column if you want DirectRT to play the sound and proceed immediately to the next stimulus, like your video. If you want a delay before the next stimulus occurs, then you should enter the length of that delay in the Time column in milliseconds. So you will want to enter the number of milliseconds that you want to pass before each clip should start to play during your video file.
Hello Jason,
I'm still not sure I know what exactly has to be done because I want a) a delay between two sound files and b) to register a response time. So I would have to enter both a delay & an RT-value in the 'time' column, no?
I sent you an email with some more explanations on the experiment. I hope you found it and can help me some more. I can also send you the beginning of the experiment file, but I gave up very quickly since I don't know how to enter both conditions (delay and response required) in the time column. I added an example of the csv-file, showing the video as a stimulus that should run continuously (hence the long duration) and then the first sound files that should appear after 31'' and 37''. Is this 'construction' correct? And if so, how do I add the requirement of a response for all those tones?
Kind regards,
Gert
Hi Jason,
I just found a way to insert the sound files in the existing video clip. So all I would need is a way to register mouseclicks or key strokes in response to those sounds. It would require some more work afterwards since I would have to calculate the difference between the onset of the sound and the moment of the response time (I guess), but if that is easier to realize in the .csv-file, I would be happy to use that option too ;-)
Kind regards,
Gert
Gert,
I'm glad to hear that you got the sound clips to work. To get a keypress for each of these soundclips, you could insert a blank stim cell (by putting just ~ in the stim cell) next to each of the soundclips and then use a fixed response window in conjuciton with the MinMax field of your styles.drt file (see here in the DirectRT manual for more information: http://empirisoft.com/directrt/help/directrt_minmax_setting_rt_limits.htm)
