Our standard protocol is to trigger Presentation
(www.neurobehavioralsystems.com) software from our GE 1.5T scanner.
On our system there is a jack in the computer room called J7 rf-unblank that
sends out a ttl pulse for each and every slice. Customization for our site
was trivial--We had to put a parallel port connector on the end of a BNC
cable. Its worked great--very reliable. Your GE service guy can help you
find the appropriate port on the scanner. With this type of configuration
you can trigger events with a great deal of flexibility and precision.
Best wishes,
Sterling
Sterling C. Johnson, PhD
Director, Neuropsychology and Neuroimaging Lab
Barrow Neurological Institute
222 W. Thomas Rd. Ste 315
Phoenix AZ 85013
ph: 602-406-6704
fx: 602-406-6115
email: [log in to unmask]
-----Original Message-----
From: Peter Erhard [mailto:[log in to unmask]]
Sent: Thursday, June 13, 2002 9:28 AM
To: [log in to unmask]
Subject: Re: synchronization betwwen scanner and visual stimuli presentation
Harold,
we sometimes use a very simple and (IMO) straightforward way:
we use the mr scanner's digital signal, which either appears before each
slice or each multislice volume, we run this signal into a digital
counter/divider and
then into a mouse which simply forwards a powerpoint (or whatever)
presentation.
It is usualy not advisable to trigger the scanner, unless you have very
accurate timing in your stimulus-presentation software. Otherwise you
modulate the train of TR's and get signal fluctuations which might reduce
your functional contrast.
Best,
Peter
On Thu, 13 Jun 2002, Harold Mouras wrote:
> Dear SPMers,
>
> we would like to synchronize the beginning of fMRI acquisitions performed
on
> a 1,5 GE and the beginning of functional runs where we show visual
stimuli
> (bmp pictures).
> Please could you let me know if someone found a solution for such a
> synchronization between GE scanners and presentation softwares. Are
specific
> softwares more specific for such a synchronization?
>
> Thank your very much in advance for your help,
> H. Mouras
> ----------------------------------------
> Harold Mouras
> Inserm U483 - Université Pierre et Marie Curie
> 9, quai Saint Bernard
> 75005 Paris
> Téléphone : 33 1 44272624
> Fax : 33 1 44273438
> [log in to unmask]
> ------------------------------------------
>
-----------------------------------------
Peter Erhard, Ph.D.
Neurologische Klinik und Poliklinik
Klinikum rechts der Isar
Technische Universitaet Muenchen
Moehlstrasse 28
81675 Muenchen
Germany
Phone: 49-89-4140 4686
Mobil: (49) 179-2308931
Fax : 49-89-4140 4867
[log in to unmask]
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Theresa, Laura, Marie & Peter Erhard
Am Weiher 39
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Germany
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