Question about how to set a paradigm of different onset primes?

[Tony Zuccolotto]

Hi Stephen,

I think you still want to stick with a Slide, e.g. at least to implement
a simultaneous onset of multiple modality stimuli.

The trick here is to adjust the Duration on the Slide to the smallest
Duration of any of the stimuli on the slide.   While you can't adjust
the Duration of any single subobject on the Slide, you can specify it
for the entire Slide.

At the end of the Slide.Duration you can then either clear the visual
stimulus via script or alternatively run another slide that is similarly
arranged so it clears the stimulus.   You may have to control the
StopAfter setting on the SoundOut subobject to make sure sound continues
to play after the Slide's duration is over.

If you just want to clear the entire screen you could run a TextDisplay
with nothing on it, or in script you could...
	Sleep 500	' however long you want to wait until after the
Slide ends.
	Display.WaitForVerticalBlank
	Display.Canvas.Clear

If you just want to clear individual visual stimuli out of N stimuli
that were presented on a Slide you can do something like the following

' Assuming you have a Slide named MySlide with 2 Text objects on it
(Text1 and Text2).  
' Assume this script is in an Inline after the Slide runs.
Set MySlide_SlideText =
CSlideText(MySlide.States.Item("Default").Objects("Text1"))
Sleep 500
Display.WaitForVerticalBlank
MySlide_SlideText.Clear

Set MySlide_SlideText =
CSlideText(MySlide.States.Item("Default").Objects("Text2"))
Sleep 500
Display.WaitForVerticalBlank
MySlide_SlideText.Clear

The above script will clear Text1 500ms after the Slide ends and then
Text2 will clear 500 msec after Text1 is cleared.

If you have the TimeLimit property set correctly and the StopAfter
property on any SoundOut object then inputs and auditory stimuli that
were initiated by the Slide will continue over this inline.

Depending on how precise you need to be you may want to change the Sleep
commands to use Clock.Read instead, e.g. if you set the Slide.Duration
to 300 but you want something to happen 500msec after its onset you can
do the timing like...

	Dim nEndTime As Long

	' Calculate end time
	nEndTime = Slide.OnsetTime + 500

	Do
		DoEvents
	Loop Until Clock.Read >= nEndTime

If you need to see how to manipulate objects on a Slide via script I
would recommend you write a small paradigm with just 1 slide on it, vary
the properties you are interested in, generate the script, and then
examine the Full Script, e.g. if your slide is named MySlide then search
for MySlide.Run and the script right before the call to the Run method
should show you how to access the property you are interested in.

Hope that helps,
Tony

*** DISCLAIMER: VIEWS EXPRESSED ARE MY OWN AND DO NOT NECESSARILY
REFLECT THOSE OF MY EMPLOYER ***
Anthony P. Zuccolotto
Vice President of Operations
Psychology Software Tools, Inc.
2050 Ardmore Boulevard
Suite 200
Pittsburgh, PA 15221-4610
Phone     412-271-5040
FAX       412-271-7077
Email     anthony.zuccolotto at pstnet.com
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> -----Original Message-----
> From: Stephen Lai [mailto:g8915013 at ccunix.ccu.edu.tw]
> Sent: Sunday, June 16, 2002 9:56 AM
> To: eprime at mail.talkbank.org
> Subject: Question about how to set a paradigm of different 
> onset primes?
> 
> 
> Hi,
> I am currently now developing a cross-modal priming paradigm ( image
> (prime) -- autitory (target)).
> I want to set up two conditions:
> (1). Stimulus onset= 0msec; that is, the prime and the target appear
> simultaneously, but I just want the prime to appear for 300 msec...
> This cannot be done in a "Slide" since I cannot control the 
> duration of the
> image.  So, how can I do this without using a "Slide"?
> 
> Actually, I have no idea about how to set different onset 
> conditions. For
> example, I want the prime to appear simultaneously with the target..
> or let the prime to appear around the middle or the late part of the
> target.....
> 
> Can anyohe help me ?
> 
> Stephen Lai
>  Stephen Y.D. Lai
>  Graduate Institute of Linguistics
>  National Chung Cheng University
>  Min-Hsiung, Chia-Yi  621
>  TAIWAN, ROC
>  Email:  g8915013 at ccunix.ccu.edu.tw
> 
> 
> 
> 
> 
>