SpmAnalysis - Meg Wiki

Revision 13 as of 2007-05-21 08:32:59

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Analysis of MEG Data in SPM5

  1. First you will probably need to run your raw data through Max Filter, particularly if you 1) used Active Shielding during acquisition, 2) if you want to apply SSS to remove noise, 3) if you used continuous HPI. Max Filter can also downsample and convert the data into different datatypes.
  2. Next you will need to convert your *.FIF files into Matlab and SPM format. For those using SPM5 at the CBU, this is now an option on the SPM5 GUI "convert" button (when in "EEG" mode) (utilising the function spm_eeg_rdata_FIF306.m in /cbu_updates). Then you can perform averaging, filtering and other preprocessing in SPM, as well as distributed source localisation.

Here is a batch script for doing steps 1+2 for FIF data on our machine: attacht:spm5_meg_batch_preproc.m

(Note that Matlab will have memory problems if you try to read in data of more than approx 10mins (at 1kHz), so downsampling to ~200-300Hz during Max Filter may be necessary.)

  • For a more detailed example of EEG/MEG analysis in SPm5, with proper step-by-step instructions via the GUI (though not on FIF data from our machine), see: http://www.mrc-cbu.cam.ac.uk/~rh01/analysis.html

  • For a more theoretical introduction to source localisation in SPM5, see these slides: attachment:spm5_meg_wiki.ppt

To be continued...