I’m trying to build an experiment in SuperLab 4.0. My experiment needs to be 6 seconds of fixation on a + sign followed by a stimulus of a flashing + sign at 2Hz for 30 seconds. The subject should then be presented with a non-flashing + sign for 30 seconds, then flashing, then non-flashing for a total of three epochs. The confounding variable is that I would like auditory instructions to preceed each change in flashing/non-flashing state.
For example, I have 2 audio files, one says “start tapping your finger” and the other says “stop tapping your finger”. Each have a length of 2 seconds. So I would like the software to present the fixation + for 4 seconds silently, then begin playing the “start tapping” audio while the + is presented for another 2 seconds. I would then like the + sign to flash for 28 seconds silently followed by 2 seconds in which the “stop tapping” sound is played while a flashing cross is presented.
My solution so far has been to break each visual “state” up into 2 parts, a silent part and a part with audio. For the fixation, I have created a “Show the text below” event with a + sign for 4 seconds, followed by an audio event with a maximum length of 0 ms, but the “Allow sound to continue playing beyond trial end”. The next event is another 2 seconds of the solid + sign.
To create the flashing + sign, I’ve created 2 lists of “+” or " " text, repeated a total of 60 times. I give each event a duration of 250 ms, i.e. 2 Hz. The first list has 52 entries, I then play the sound as above (duration of 0 ms, etc) and start another 2 second trial of the flashing “+” sign. I’ve tried this with both “Reset RT Timer” checked and unchecked.
The first trial (Silent solid + sign, audio, solid + sign) works great. The second state however results in my audio file being played in a very choppy manner at the beginning of the trial, not the end. Also, the flashing + sign is very irregular. My conclusion is that all three events are playing at once. Could someone on the list help me?
I know this is fairly complicated, so let me know if I need to upload the experiment.