[solved] RT collection for simultaneously presented visual and auditory stimuli

Yulia

Hi all,

I'm having a hard time trying to collect the RT for simultaneously presented visual and auditory stimuli.
I display visual stimulus (colored rectangle) using a sketchpad and auditory stimulus (spoken color word) using a sampler. In the trial sequence, the sketchpad (duration set to 0) is followed by the sampler (duration ="sound"), which is in turn followed by a keyboard_response (timeout = 2500 ms).
Here is my problem:
I want the RT to be measured from the moment both stimuli appear, and not after the word presentation is completed, which is exactly what I have now (apparently because the duration of the sampler cannot be 0, it has to be "sound", that is the keyboard_response can be initiated only after the sampler proceeds to the end).
One more thing, just to clarify, I also want the visual stimulus to stay on the screen until the response is made or until 2500 ms.

I tried to use parallel plug-in with sampler and keyboard_response but it didn't seem to work...
Do you have any ideas how can I solve this issue?

Thanks!
Yulia

sebastiaan

Hi Yulia,

(apparently because the duration of the sampler cannot be 0, it has to be "sound", that is the keyboard_response can be initiated only after the sampler proceeds to the end).

There is a misunderstanding here, I think. You can set the duration of the sampler to 0. If you do this, the experiment will advance right away and the sound will play in the background. So that basically gives you what you want, right?

One more thing, just to clarify, I also want the visual stimulus to stay on the screen until the response is made or until 2500 ms

Simply setting the timeout of the keyboard_response to 2500 and having it followed by a blank sketchpad should do the trick!

Cheers,
Sebastiaan

Yulia

Thank you very much, Sebastiaan! It works now. My mistake was to put 0ms in the duration field of the sampler instead of just 0..:)
Thanks again!
Yulia