importing CTF data

[Robert Oostenveld]

Hi Thomas,

Your data is pretty standard, the following snippet of code should get
you started.

cfg = [];
cfg.dataset = 'sub12_SAM_a_C1_A1.ds';
cfg.trialdef.eventtype = '?'

% see which eventtypes and values are present in the dataset
% dum = definetrial(cfg);

cfg.trialdef.eventtype = 'C1_A1'
cfg.trialdef.prestim   = 0;    % trial starts at time t=0 at the marker
cfg.trialdef.poststim  = 0.5;  % trial ends at t=0.5 sec
cfg = definetrial(cfg);

raw = preprocessing(cfg);

cfg = [];
avg = timelockanalysis(cfg, raw);
plot(avg.time, avg.avg(31:180,:))

If you want to do conditional definition of trials (e.g. exclude bad
trials), you should have a look at the example that Ole mentioned.

best,
Robert


On 4 May 2005, at 1:01, Ole Jensen wrote:

> Dear Thomas,
>
> First try to have a look at the appendix in of the tutorial 'Event
> Related Fields'. There is an example on reading 'continues' data (this
> includes AUX files). There is also a definetrial.m example function -
> you can use this to check the stimulus channel etc - hopefully this
> will help you get going.
>
> Good luck,
>
> Ole
>
> Thomas Thesen wrote:
>
>> Dear Robert and Ole,
>>
>> I am trying to import data from a 151 channel CTF system into
>> FieldTrip
>> format. I tried following the instructions in preprocessing.m and
>> definetrial.m but got the error message that the markerfile can't be
>> read. I
>> think that importing raw data wasn't covered during the last workshop
>> (which
>> was extremely helpful by the way!), so I am not sure if I did the
>> right
>> thing at all and probably have overlooked something.
>>
>> I have put an example dataset here:
>> http://www.physiol.ox.ac.uk/~tnt/fieldtrip/
>> There is one trigger in this dataset (C1_A1). Would it be possible
>> for you
>> to have a look and suggest some Matlab code that will allow me to
>> import the
>> data so that I can use it with preprocessing.m, etc?
>>
>> Thank you very much for your help.
>>
>> Best wishes,
>>
>> Thomas
>>
>> ---------------------------------------------------
>> Thomas Thesen
>> University Laboratory of Physiology
>> & Centre for Functional MRI of the Brain
>> University of Oxford
>> Oxford, OX1 3PT
>> United Kingdom
>>
>> Phone: +44(0)1865-272 434
>> Mobile: +44(0)781-355 6528
>> Fax:     +44(0)1865-272 469
>> e-mail:  thomas.thesen at physiol.oxford.ac.uk
>> http://www.fmrib.ox.ac.uk/~tnt/
>>
>> ---------------------------------------------------
>>
>>
>
>
> --
> Ole Jensen
> Principal Investigator
> F.C. Donders Centre for Cognitive Neuroimaging
> P.O. Box 9101
> NL-6500 HB Nijmegen
> The Netherlands
>
> Office  : +31 24 36 10884
> MEG lab : +31 24 36 10988
>
> Fax     : +31 24 36 10989
>
> e-mail : ole.jensen at fcdonders.ru.nl
> URL    : http://oase.uci.ru.nl/~olejen
>
----------------------------------------------------------------------
Robert Oostenveld, PhD
F.C. Donders Centre for Cognitive Neuroimaging
Radboud University Nijmegen
phone: +31-24-3619695
http://www.ru.nl/fcdonders/
----------------------------------------------------------------------
N.B. Starting from 1 September 2004, the University of Nijmegen has
changed its name to Radboud University Nijmegen. All web- and
email-addresses ending in ".kun.nl" should therefore be changed into
".ru.nl". Please update your address book and links.