Neuromag 306 channel data import

Robert Oostenveld r.oostenveld at FCDONDERS.RU.NL
Thu Apr 27 11:04:16 CEST 2006


Hi Yisheng

Some additional comments:

>> Any one can provide a "cookbook" reference for how to import the
>> raw and averaged fif files into FieldTrip?
> Neuromag fif files should be directly accessible by the standard
> FieldTrip functions for opening/reading MEG/EEG data files. Try
> first with read_fcdc_header() to get the "meta information" and
> then with read_fcdc_data() to actually read some data from the
> file. These functions should work both with raw/continuous and
> averaged data.

The functions from the meg-pd are not included in Fieldtrip, you have
to add them seperately to your matlab path.

> NB: I just downloaded the newest daily FieldTrip release and
> noticed that read_fcdc_data is unable to retrieve data when the
> requested span extends over a buffer boundary. I will look into
> this and try to fix it.

I did not know whether the blocks in the data are trials (with a
potential gap in between) or buffers. In case of continuous blocked
data, you would set the last argment of
   dat = read_fcdc_data(datfile, hdr, begsample, endsample, chanindx,
continuous)
i.e. the continuous to 1. Then it will not perform the boundary
check. To get this behaviour in fieldtrip prepropcessing, you should
specify cfg.datatype='continuous'.

best regards,
Robert



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