Dear Christian,
the reason for "missing TTL-pulses" from the scanner might be
caused by the lenght of the pulses. We had a similar problem with
ERTS. I checked the scanner (Philips Gyroscan NT ) defaults for
the TTL puls and found it was set to 50 nsec! After increasing it to 1
msec I never had problems again.
All the best,
Lukas
> Dear Robert,
>
> we use Presentation and are quite happy with it. The only problem we
> have encountered is that in complicated paradigms some pulses from the
> scanner are missed. On another computer we saw some other timing
> irregularity, which seems to be computer related. Peter Pebler the main
> developper plans an interrupt driven MRI pulse module (instead of
> polling the port) which would definitely overcome this problem. Check
> out the latest version (0.40) which has a nice extension through a
> control language
> (PCL).
>
> "Robert M. Roth" wrote:
> >
> > Dear Colleagues:
> >
> > I have been considering using Presentation from
> > Neurobehavioral Systems for event-related fMRI research. I
> > would greatly appreciate information on others' experience
> > with this program, particularly timing accuracy and
> > provision of feedback.
> >
> > Thank you
> >
> > Robert Roth, Ph.D.
> > Neuropsychology and NeuroImaging Program
> > Department of Psychiatry
> > Dartmouth Medical School
> > Lebanon, NH
>
> --
>
> -Christian Buechel
>
> --
> Dr. Christian Buechel
> Neurologische Universitaetsklinik, Haus B
> Universitaets-Krankenhaus Eppendorf
> Martinistr. 52
> D-20246 Hamburg
> Germany
> Tel.: +49-40-42803-4726
> Fax.: +49-40-42803-5086
> email:[log in to unmask]
> www.uke.uni-hamburg.de/kliniken/neurologie/pages/mitarbeiter/buechel_c.htm
> www.uke.uni-hamburg.de/kliniken/neurologie/pages/forschung/cnl_index.htm
Lukas Scheef, MD, MSc
MR-Tomography
Department of Radiology
University of Bonn
Sigmund-Freud-Straße 25
D-53105 Bonn
Fax: +49-228-287-5598
Phone:+49-228-287-5960
E-mail: [log in to unmask]
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