Response triggers with accurate timing

[RB209]

Hi,

I had been working from that post but it doesn't work - at least not
when I try it. In order to initiate the inline immediately you need to
set a large prerelease time (as suggested in the thread) but this
interferes with data logging in Eprime. So I can get accurate response
triggers using this method but for at least 30% (but sometimes up to
70%) of trials no data is logged by Eprime. : (


On Dec 13, 7:03 pm, David McFarlane <mcfar... at msu.edu> wrote:
> Did you see the thread athttp://groups.google.com/group/e-prime/browse_thread/thread/cfc3d0307...?
>
> -- David McFarlane, Professional Faultfinder
>
> At 12/13/2010 08:25 AM Monday, you wrote:
>
>
>
> >I have been struggling to send triggers to Actiview at the exact time
> >a participant makes a response.
>
> >I'm running a memory experiment where images are presented in a slide
> >object and participants respond by pressing 1,2,3 or 4. I would like
> >triggers to be sent a.) at the onset of the slide and b.) at the exact
> >point a participant makes a response. I want the slide to run for
> >2500ms but responses to be collected for 3700ms in total. (Slide1 is
> >followed by a blank screen for 1200ms).
>
> >The first issue is fine. I use ...
>
> >slide1.onsetsignalenabled = true
> >slide1.onsetsignalport = &H378
> >slide1.onsetsignaldata = &H05 'send 5 so the value does not clash with
> >a possible response.
> >sleep (10)
> >writeport, &H37, 0
>
> >However, I can't get the response trigger to send accurately. I have
> >been trying to use slide1.inputmasks.Ispending to collect the
> >participant's response and writeport it while the slide is presented.
> >Unfortunaltely, this sends the trigger late (looks like it is being
> >sent after slide1 has finished running). This remains the case even if
> >I set the slide1 duration to 0 . I have also tried setting the slide
> >duration in properties to 2500 and using a large prerelease on the
> >slide object. This seems to send the response triggers on time
> >although I'm only judging this by eye at the moment. However, it
> >causes problems with data logging in eprime. I.e Eprime only logs
> >about 30% of the responses unless I reduce the prerelease. Also, no
> >matter what I try I seem to either get stimulus onset triggers OR
> >response triggers but not both. (I am sending 0s after each trigger to
> >clear everything but still having problems).
>
> >I would appreciate any help with this issue - I have honestly been
> >trying for days to sort this by myself. I have found previous
> >discussions useful and have looked at some of the sample experiments
> >but I still haven't gotten close to solving this problem. I am able to
> >achieve most of the subtasks but cannot put them together in a way
> >that works.- Hide quoted text -
>
> - Show quoted text -

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