[Mne_analysis] source localizing frequency bands

[Kanal Eliezer]

Just a few thoughts...

I'm not familiar enough to comment on the DICS method, but the MNE method returns a distribution based on the provided sensor waveforms. It would seem intuitive to me that performing a restrictive (say, only alpha activity) bandpass on the sensor waveform prior to performing MNE would significantly change the topology of the waveform, and thus significantly affect how the sources are localized.

The real question being asked is whether the steps are commutative; i.e., do the following two analysis streams produce identical results:
1) bandpass, MNE
2) MNE, bandpass
My gut intuition is that they are NOT, since the first method performs the bandpass on the raw MEG data, so to speak, while the second one performs the bandpass on reconstructed data. However, I can't prove this, and it bears further investigation. Anyone else have any thoughts?

Elli Kanal



On Nov 30, 2009, at 5:20 PM, Gustavo Sudre wrote:

> Hello,
> 
> I have a generic question about source localization. From what I've  
> seen so far, when the goal is to localize the activity in certain  
> frequency bands, it's common to use methods such as DICS or the  
> variant of MCE for frequency bands. I was wondering if it is also  
> correct to do source localization using a different method (e.g. MNE)  
> with the whole signal (i.e. prior to band-pass filtering to specific  
> bands) and then convert the signal in the localized sources to  
> frequency domain. Another alternative would be to band-pass the signal  
> to a certain frequency band in source space, and then run a different  
> source localization method on it (e.g. MNE).
> 
> Could anyone elaborate on the advantages / disadvantages ( / validity)  
> of these two methods?
> 
> Thank you,
> 
> Gus
> 
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