[FieldTrip] Problem with FT_DEFINETRIAL

[Jarmo Kontinen]

Dear Stephen,
Thanks for your reply. I  have added the  missing field you sugegsted, but FT
still gives the same error-message.

Maybe I was also unclear what I want to do in the first place. The data we
have is already preprocessed ( filtered, segmented etc.) with the Analyzer.
Also, we have averaged the ERP's for each subject and each experimental
condition over all the trials. I would like to import these averaged ERP's
into FT and do some statisitics on the data. The problem is that I do not know
how to get required data-structure to use the FT-functions.

Best,
Jarmo


Stephen Politzer-Ahles schrieb am 2012-03-25:
> Hello Jarmo,

> I haven't tried importing Brain Vision files into FieldTrip myself,
> but
> based on the code you sent it looks like the problem may be that
> you're
> missing cfg.trialdef.eventvalue (which is used to tell FieldTrip
> which
> triggers to select), cfg.trialdef.prestim, and cfg.trialdef.poststim
> . See
> the example at
> http://fieldtrip.fcdonders.nl/tutorial/preprocessing#reading_and_preprocessing_the_interesting_trials.

> If what you are trying to do is import all trials from all triggers
> in the
> file, I think you have to define your own "trialfun" function to do
> that
> (although I haven't tried this myself so I'm not sure).
> http://fieldtrip.fcdonders.nl/reference/ft_definetrial has some more
> information.

> Best,
> Steve Politzer-Ahles
> University of Kansas


> Message: 1
> > Date: Thu, 22 Mar 2012 17:14:46 +0100 (CET)
> > From: Jarmo Kontinen <Jarmo.Kontinen at ruhr-uni-bochum.de>
> > To: <fieldtrip at donders.ru.nl>
> > Subject: [FieldTrip] Problem with FT_DEFINETRIAL
> > Message-ID:
> >        <
> > permail-201203221614466509e8c700002494-Jarmo.Kontinen at msgid.mail.ruhr-uni-bochum.de


> > Content-Type: text/plain; charset=us-ascii

> > Dear all,
> > I am trying to import EEG subject averages into Field Trip. The
> > files are
> > exported with the Brainvision Analyzer in binary form
> > :subject10_konPro2002.dat and subject10_konPro2002.vhdr.
> > I have a problem with turning the data into the Field Trip
> > data-structure.
> > I
> > am following instructions given on this forum on one similar post.
> > What I
> > have
> > tried is the following:

> > cfg=[];
> > cfg.trialdef.eventtype='average'
> > cfg.dataset='subject10_konPro2002.dat'

> >  cfg=ft_definetrial(cfg);

> > Warning: no trialfun was specified, using trialfun_general
> > > In ft_definetrial at 123
> > evaluating trialfunction 'trialfun_general'
> > reading the events from 'subject10_konPro2002.vhdr'
> > ??? Error using ==> ft_definetrial at 176
> > no trials were defined, see FT_DEFINETRIAL for help

> > I am grateful for all the help.
> > Thanks,
> > Jarmo Kontinen