Gap between videos - please help! (case 11350)

Hello!
I am having a problem playing 25 trials of a music clip (8sec) while a black screen with a white fixation cross remains on screen. I have been able to get the image full screen (which I had trouble with when it was a separate .jpg file) by combining the audio clip and image in a single video file (.wmv). I also need a ttl marker to be sent at the onset of each of my 25 stimulus trials, and thus need them to be entered as separate 'lines' in the MediaLab v2012 Experiment Editor window. However, when the individual video clips (image+music) play, there is a flash of the default light purple Media Lab window in the background, which interrupts the flow of the experiment. Ideally, I would like the fixation cross to remain on the screen seamlessly the entire time, even between trials of the music clip, but every time a new file needs to be loaded, there is a visible lag and flash of the screen. Do you have any suggestions as to how I can remedy this and get my study up and running? Thank you!

Paula,


I talked with Blair Jarvis about your question. If we understand correctly, you would like to specify a non-numeric key from the keyboard and have a ttl signal send the ASCII code for those keys. However, MediaLab's use of ttl signals expect a numerical value between 0-255. Thus, you would need to find out the ASCII values for the keys you are interested in and use those numbers in your ttl parameters in MediaLab. So sending a signal for the % key on the keyboard, for example, would require you to specify a value of 37-the dec ASCII code for the % key-in your item parameter.


Jason