[open] simultaneous presentation of stimuli

Christiane

Dear All, we are trying to present stimuli simultaneously which in itself does not seem to be problematic at all. However, we would like to present a visual stimulus first and have it running for say 3000ms, but after 2000ms we would like to present simultaneously an auditory stimulus. Right now we are presenting the picture for 2000 ms and then have the same picture selected again together with the auditory stimulus. We are a little worried that depending on the computer the new selection of the picture might cause jitter in the presentation.
Is there a way that we can present the picture for the entire duration (3000ms) and present the auditory stimulus simultaneously for the last 1000ms of this duration.
I hope I was able to make my query clear enough!
Thanks in advance!
Christiane

lvanderlinden

Hi Christiane,

I would recommend to structure your trial sequence as follows:

• Present the visual stimulus with a duration of 2000 ms.
• Present the auditory stimulus with a duration of 1000 ms.

This will give the desired result because a sampler item does not change what's presented on screen; it just pauses the experiment for a given period of time. Note that unless you set the duration of a sampler item to [sound], the length of this pause is irrespective of the duration of the sound. This enables you to have equal trial durations across trials with sounds of unequal duration.

Does this answer your question?

Please let us know if we could be of any further help!

Lotje