On Wed, May 11, 2011 at 6:36 PM, Markus Bauer <[log in to unmask]> wrote:
> Dear all
> I have a question concerning the image conversion of individual virtual EEG
> channels (time-frequency data)
> The data were imported from fieldtrip with the spm_eeg_ft2spm routine
> Presumably since the labels are arbitrary (and only 4 channels) SPM did not
> assign a channel type, meaning that the image conversion routine does not
> recognize these channels.
> How can I force it to assign the type 'MEEG' / manipulate the data-structure
> in such a way that they can be treated that way?
> I also had problems converting an EEG raw data set (from BrainVision *.eeg
> file) - this gets stuck in ft_senstype (even when converting from raw
> Our cap was custom-made and therefore has arbitrary channel names (from 1 to
> 128), apparently SPM cant deal with that situation ???
ft_senstype is a Fieldtrip function so if it can't deal with this
situation, neither can SPM ;-) I suspect this might be related to the
fact that your channel labels are actually numbers. This is not what
SPM or Fieldtrip would expect. I suggest that you look at
ft_read_header and make sure that the labels are read as strings, i.e.
'1', '2'... rather than 1, 2... Then you will have to use Prepare
again to set the channel types and load sensor locations because SPM
will not be able to do it automatically.