Moving Stimuli in E-prime

[David McFarlane]

Alice,

Two brief thoughts...

1) You can use List.Terminate to exit out of a running List before it 
reaches its own end -- see that topic in the E-Basic Help facility. 
(With a bit of programming knowhow you don't even have to know the name 
of the running List, but I am not near my FAQ now to point you to the 
thread where I show that.)

2) Yes, adding up times is fraught with difficulty, you will almost 
certainly fail to include some interim times and get wrong values.  But 
the E-Prime input mask facility really is beautiful once you fully 
understand it.  Put a Wait object just before the start of your 
stimulus/response loop, outside the loop.  Give that Wait a Duration of 
0 (and think about the proper Onset Sync), and add your desired input 
mask to this Wait instead of within the loop.  Give this input mask a 
Time Limit of (infinite).  Now that Wait will look for a response any 
time during your stimulus/response loop, and Wait.RT will be the RT from 
the start of the loop until the response, without you having to compute 
anything!  My online E-Prime course actually includes an exercise where 
we do this, might be worth looking into.

-----
David McFarlane
E-Prime training online: 
http://psychology.msu.edu/Workshops_Courses/eprime.aspx
Twitter:  @EPrimeMaster (twitter.com/EPrimeMaster)


Alice Cai wrote:
> Dear David,
>  
> Thank you so much, that was very helpful! Right now I have only one 
> slide, and have many levels in the list to code for the location of the 
> square (e.g., left, middle, right). I would like the slides to repeat 
> itself until participants give a response. Once participants give a 
> response, I want to give a 'feedback display'. I thought of using the 
> jump function with labels, but the label can only jump within a 
> procedure. This is a bit problematic because right now, even when 
> participants give a response, it will only exit the procedure once all 
> lists have been displayed (or when it reaches a time limit that I set, 
> e.g., 4000 ms).
>  
>  
> Also, I need to record reaction time to the moving stimuli. However, 
> right now e-prime doesn't record RT from the very first slide that 
> participants see, but only for the slide that the responded to. So in 
> order to know how long participants took to respond, I will need to add 
> up the number of slides that was presented before hand and multiply it 
> by how long the slides were displayed for (50 ms). Is there an easier 
> way to record reaction time?
>  
> Thank you very much for your help, please take your time to reply and 
> any comments will be greatly appreciated!
>  
> Thank you again!
> Alice
>  
>  
> 
> On Wednesday, December 5, 2012 4:39:07 PM UTC, Alice Cai wrote:
> 
>     Hi,
> 
>     I have a question regarding my experiment design. I would like to
>     create a moving stimuli where participants decide whether the box is
>     moving vertically or horizontally. I know that I can use different
>     slides changing at 50 ms. per slide with different locations for the
>     box (left, middle, right) but the problem is I will need to create a
>     lot of slides and the E-prime program runs out of memory space.
> 
>     Is there any way to create just three slides, and have E-prime
>     repeat these three slides until participants give a response? And
>     then the experiment will jump to the next trial with three more slides?
> 
>     Any help will be greatly appreciated! Thank you!

-- 
You received this message because you are subscribed to the Google Groups "E-Prime" group.
To post to this group, send email to e-prime at googlegroups.com.
To unsubscribe from this group, send email to e-prime+unsubscribe at googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.