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Hi Rik, Both things are available in Fieldtrip which is included in SPM8. On Wed, Nov 18, 2009 at 1:53 PM, Rik Henson <[log in to unmask]> wrote: > > Do you know of any functions/toolboxes in > SPM8 to: > > 1. Do a straight Fourier transform (ideally with tapers) for each channel > across an epoch (ie, without using wavelets, ie if one does not want a time > dimension)? > This can be done using the function freqanalysis (ft_freqanalysis from SPM) with cfg.method = 'mtmfft' . If you do: D = spm_eeg_load; data = D.ftraw; you'll get data in Fieldtrip format that you can use as an input to that function. For other settings see the headers of freqanalysis and freqanalysis_mtmfft that you can find in /external/fieldtrip/private. Since in SPM there is little support for data without time dimension (I'm not sure how well @meeg will handle a TF dataset with a single time point, but you can try) if you want to generate scalp x frequency images you might need to write your own code for that. > 2. Calculate a Current Source Density for EEG - ie a topography of the > spatial derivative of the potential? > This can be done with the function scalpcurrentdensity (ft_scalpcurrentdensity). The same idea as above. You can then convert the output back to SPM dataset using spm_eeg_ft2spm. Best, Vladimir > R > > > -- > > ------------------------------------------------------- > Dr Richard Henson > MRC Cognition & Brain Sciences Unit > 15 Chaucer Road > Cambridge > CB2 7EF, UK > > Office: +44 (0)1223 355 294 x522 > Mob: +44 (0)794 1377 345 > Fax: +44 (0)1223 359 062 > > http://www.mrc-cbu.cam.ac.uk/people/rik.henson/personal > ------------------------------------------------------- > > >