maybe you you'd want to sleep for 10 ms before sending the "WritePort &H378, 0"... just a suggestion, won't necessarily fix it.<div><br></div><div>ben<br><br><div class="gmail_quote">On Tue, Aug 18, 2009 at 9:42 AM, vinz <span dir="ltr"><<a href="mailto:godotworkaround@googlemail.com">godotworkaround@googlemail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><br>
Hello group,<br>
<br>
I am current running a subliminal ERP study. Everything is fine as far<br>
as the implementation of subliminal stimuli is concerned but we are<br>
experiencing problems with the triggers from E-Prime to the Neuroscan<br>
station.<br>
<br>
Specifically, we have noticed that any time E-Prime sends a trigger<br>
relative to a slide presented for a time between 100ms and 20ms (we<br>
don't have anything in between this two values, so I cannot be more<br>
specific) the trigger is sent twice, also affecting the following<br>
slide (presented for about 500ms).<br>
<br>
For the sake of clearness, the event table in Neuroscan looks like<br>
this:<br>
<br>
1 3 3 7 7 1 |1| 3 |3| 3 7 7 3 3 1<br>
<br>
instead of:<br>
<br>
1 3 3 7 7 1 3 3 7 7 1 3 3 7 7 1<br>
<br>
where '1' is the trigger code for the subliminal stimulus, and |1|,|3|<br>
are actually doubled. In fact the latencies for the first 1 and the<br>
second |1| are equal. The same happens for 3 and |3|.<br>
<br>
Being most likely a problem caused by incorrect trigger settings in<br>
the InLine procedures, here it is what we are using:<br>
<br>
WritePort &H378,1<br>
WritePort &H378,0<br>
<br>
WritePort &H378,3<br>
WritePort &H378,0<br>
<br>
WritePort &H378,7<br>
WritePort &H378,0<br>
<br>
If anyone is familiar with E-Prime triggers and has a suggestion to<br>
give, I would greatly appreciate.<br>
<br>
Thank you,<br>
vinz.<br>
<div class="im"><br>
<br>
<br>
<br>
On Aug 17, 9:19 am, liwenna <<a href="mailto:liwe...@gmail.com">liwe...@gmail.com</a>> wrote:<br>
> Hey,<br>
><br>
> I looked around a bit and I think the link in this page downloads a<br>
</div>> estudio file with subliminal exposure in it:<a href="http://www.docstoc.com/docs/5417962/Instructions-for-running-the-E-Pr.." target="_blank">http://www.docstoc.com/docs/5417962/Instructions-for-running-the-E-Pr..</a>..<br>
<div><div></div><div class="h5">> It's part of some book... and it also mentions some other usefull<br>
> things. I think there really isn't all that much special to the design<br>
> of a subliminal task... simply make the exposureduration on the<br>
> primeslide really short (dependent on the exact nature of your task)<br>
> and ussually you'll want to show a mask right after your prime but<br>
> this is, again, dependent on the nature of your task. Then consider<br>
> options like enabling preloading and disabling showafter (all should<br>
> be explained in the mentioned chapter in the user-guide), and make<br>
> sure that your hardware is actually capable of subliminal<br>
> presentation.<br>
><br>
> Greetz,<br>
><br>
> liwenna<br>
><br>
> On Aug 17, 8:25 am, Kim Janssens <<a href="mailto:kim.jansse...@gmail.com">kim.jansse...@gmail.com</a>> wrote:<br>
><br>
> > Hello liwenna,<br>
><br>
> > Thank you for your fast reply: the advice on the refresh rate is really<br>
> > helpful! If I come across any specific problems when building, I will post<br>
> > my question again.<br>
><br>
> > greetz,<br>
> > Kim<br>
> > ps: do you know where i could find an example of experiments designed for<br>
> > subliminal priming? they could help me on the way..<br>
><br>
> > 2009/8/15 liwenna <<a href="mailto:liwe...@gmail.com">liwe...@gmail.com</a>><br>
><br>
> > > Hello Kim,<br>
><br>
> > > Perhaps you could elaborate a bit on what part of designing the<br>
> > > experiment you need help with.<br>
> > > In general I think you should start with reading chapter 3 and<br>
> > > appendix A of the user guide (top of my head), which deal with timing<br>
> > > issues, obviously important for subliminal priming. Only other thing<br>
> > > that I can think of now is the monitor issue... make sure that you use<br>
> > > a monitor (when doing the experiment) that is actually capable of<br>
> > > subliminal-range exposure time i.e. has a sufficiently high enough<br>
> > > refresh rate.<br>
><br>
> > > I'm guessing that you're relatively new to e-prime (forgive me if I'm<br>
> > > wrong there). I think it's the most easiest if you simply start<br>
> > > building and post back here with problems that you encounter along the<br>
> > > way.<br>
><br>
> > > Good luck with it!<br>
><br>
> > > liwenna<br>
><br>
> > > On Aug 14, 2:20 pm, kimio <<a href="mailto:kim.jansse...@gmail.com">kim.jansse...@gmail.com</a>> wrote:<br>
> > > > Hello group,<br>
><br>
> > > > I want to design an experiment in eprime in which I want to show the<br>
> > > > participants a set of pictures and subliminally prime them with a word<br>
> > > > in between the pictures.. Does anyone have any experience with this?<br>
> > > > All help is welcome...<br>
><br>
> > > > thanks,<br>
> > > > Kim<br>
<br>
</div></div></blockquote></div><br></div>
<br>
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