Using InLine feature to manipulate timing of an auditory stimulus
 
 
 
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Posted 3/21/2007 9:06:56 AM
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Hello

I am programming an auditory experiment. My SoundOut file objects are all set to 4000 msec. However, most of my stimuli are shorter than 4000 msec. I need to tell EPrime to play an equal amount of silence before and after each stimulus to ensure that each presentation is actually 4000 msec long.

For example, if Stimulus 1 is 3000 msec long, I need to have the computer play 500 msec of silence before and after the stimulus is presented. If Stimulus 2 is 2500 msec long, I need to play 750 msec of silence before and after the stimulus is presented.

Is there a way to set this using an InLine object?

Thanks!
Post #249
Posted 3/22/2007 9:25:45 AM
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1) Setup a wait object before your sound and one after your sound.
2) Make sure the Sync tab has (none) from onset/offset as you don't want to sync with the vertical blank
3) In the Duration field of each, enter [DurationBefore] and [DurationAfter] (or choose your names)
4) In the List object that holds the filename of the Stimuli, add the DurationBefore and DurationAfter values.

If you are presenting visual stimuli at the same effective time, you will need to use something like CoolEdit to put actual silence values at the start and stop of your .wav files.

-Brandon

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