# source localizing frequency bands **URL:** \ **Category:** Mailing List Archive (read-only)\ **Tags:** list-archive\ **Created:** [November 30, 2009, 10:20pm UTC](https://mne.discourse.group/t/source-localizing-frequency-bands/183 "2009-11-30T22:20:06Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\ **Post date:** [December 2, 2009, 7:36pm UTC](https://mne.discourse.group/t/source-localizing-frequency-bands/183/4 "2009-12-02T19:36:32Z")
Hi Kanal,    You are right, they are are not the same. The reason they are not the same practically is that the noise covariance when generated after bandpass filtering the signal first can be very very different (in scale and possibly also in the spatial structure) and hence the inverse operator is different. I would vouch for computing one inverse operator with the entire band of interest (0-100Hz for example) and then looking at narrower bands once the data is in source space. My reason for that would be to not impose too much temporal correlation in the noise by band-pass filtering in sensor space. MNE as such is equivalent to a maximum aposteriori probability (MAP) estimate of the source space activity only under the assumption that the noise is uncorrelated in time. It is robust to violations of the assumption to a large extent (correct me if I'm wrong here) but filtering around 7Hz, for instance to look at alpha makes the noise heavily different from its assumed no temporal correlation behaviour. Having said that, if its an event related paradigm and you have enough trials and excellent SNR, doing it either way should not make a difference. Regards, Hari --- _[View the full topic](https://mne.discourse.group/t/source-localizing-frequency-bands/183)._