[solved] Simultaneous presentation of sound and sketchpad item

Hanna

Hi all,

I am working on a cross-modal oddball task, where I want to present a sound and a fixation cross simultaneously for the duration of 400 ms at the beginning of each trial. Following this, an image will be presented for 200 ms. There will then be a response window for 1000 ms, during which the fixation cross is presented again.

My main problem is the timing of the sound and fixation cross in the beginning of the trial. Since the sampler function does not support the coroutines plugin, I'm not sure how to present the sound and fixation cross simultaneously for the duration of the sound. More precisely, I don’t know how to make the fixation cross disappear at the offset of the sound.
I took the answer posted in the link below to mean that setting the fixation to a very short duration, say 5 ms, and the sound to 395 ms, would make the fixation stay on the screen for the duration of the sound and then disappear immediately. However, it stays on the screen for a while after the sound has finished, before displaying the subsequent 200-ms image.

http://www.cogsci.nl/forum/index.php?p=/discussion/189/open-simultaneous-presentation-of-stimuli/p1

I’m guessing I will need an inline script to get my timing right(?), but my programming skills are too limited to figure this out on my own. Any advice? Many thanks in advance!

Kind regards,
Hanna

eduard

Hi Hanna,

This sounds odd. I just tried the set up you are describing and it works as it should.
How much longer does the image stay on screen after the sound stopped?

Btw. you don't even have to specify the duration of the image to 5ms. If you set it to 0, the image will be shown, but the experiment proceeds with the sampler right away.

Eduard

Hanna

Hi Eduard,

Thanks for your reply! I set the duration for both the image and sampler to 0, and it seems to work as it should! Previously, I had only tried setting the sampler to 395 or "sound".

Many thanks!
Hanna

eduard

That was actually not what I suggested, but if it works, it works.

Eduard