[FieldTrip] non-parametric methods for comparison of power spectra

[Sangita Dandekar]

Dear Fieldtrippers,

Forgive me if I have overlooked something in the FT documentation, but
I was wondering if there are any non-parametric methods for comparison
of power spectra in Fieldtrip?  When I say 'power spectra' I mean
frequency vs power spectrum data without a time component (i.e. not
the TFR data structures in Fieldtrip, but what one would get by
applying an FFT to a time series and finding the magnitude of the
power spectrum as a function of frequency).

One (clumsy) way to do this would be to use the framework of FT's
timelockstatistics function, but instead of entering channel x time x
voltage data for each trial, use channel x  frequency x power data for
each trial.

I think the above should work, but am guessing it will probably be
fine for detecting low frequency differences but not as sensitive for
differences in the higher frequencies due to the 1/f power spectrum.

Is there an alternative method that anyone can suggest? Does the
suggested method above sound ok?  Maybe log transforming prior to
application of the existing timelockstatistics framework?

Thanks in advance for any help!
Sangi